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Zhang M, Meng H, Zhou Q, Chunyu H, He L, Meng H, Wang H, Wang Y, Sun C, Xi Y, Hai W, Huang Q, Li B, Chen S. Microglial Activation Imaging Using 18F-DPA-714 PET/MRI for Detecting Autoimmune Encephalitis. Radiology 2024; 310:e230397. [PMID: 38441089 DOI: 10.1148/radiol.230397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2024]
Abstract
Background Translocator protein (TSPO) PET has been used to visualize microglial activation in neuroinflammation and is a potential imaging tool for detecting autoimmune encephalitis (AIE). Purpose To compare the detection rate between TSPO radioligand fluorine 18 (18F) DPA-714 PET and conventional MRI and assess the relationship between 18F-DPA-714 uptake and clinical features in participants with AIE. Materials and Methods Healthy volunteers and patients with AIE were enrolled in this prospective study between December 2021 and April 2023. All participants underwent hybrid brain 18F-DPA-714 PET/MRI and antibody testing. Modified Rankin scale scoring and AIE-related symptoms were assessed in participants with AIE. Positive findings were defined as intensity of 18F-DPA-714 uptake above a threshold of the mean standardized uptake value ratio (SUVR) plus 2 SD inside the corresponding brain regions of healthy controls. The McNemar test was used to compare the positive detection rate between the two imaging modalities; the independent samples t test was used to compare continuous variables; and correlation with Bonferroni correction was used to assess the relationship between 18F-DPA-714 uptake and clinical features. Results A total of 25 participants with AIE (mean age, 39.24 years ± 19.03 [SD]) and 10 healthy controls (mean age, 28.70 years ± 5.14) were included. The positive detection rate of AIE was 72% (18 of 25) using 18F-DPA-714 PET compared to 44% (11 of 25) using conventional MRI, but the difference was not statistically significant (P = .065). Participants experiencing seizures exhibited significantly higher mean SUVR in the entire cortical region than those without seizures (1.23 ± 0.21 vs 1.15 ± 0.18; P = .003). Of the 13 participants with AIE who underwent follow-up PET/MRI, 11 (85%) demonstrated reduced uptake of 18F-DPA-714 accompanied by relief of symptoms after immunosuppressive treatment. Conclusion 18F-DPA-714 PET has potential value in supplementing MRI for AIE detection. Clinical trial registration no. NCT05293405 © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Zaharchuk in this issue.
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Affiliation(s)
- Min Zhang
- From the Departments of Nuclear Medicine (M.Z., H.C., Hongping Meng, Y.W., C.S., Y.X., W.H., B.L.) and Neurology (Huanyu Meng, Q.Z., L.H., S.C.), Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, 197 Ruijin 2nd Rd, Shanghai, China; Shanxi Medical University-Collaborative Innovation Center for Molecular Imaging of Precision Medicine, Taiyuan, China (M.Z., B.L.); School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China (H.W., Q.H.); and Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China (S.C.)
| | - Huanyu Meng
- From the Departments of Nuclear Medicine (M.Z., H.C., Hongping Meng, Y.W., C.S., Y.X., W.H., B.L.) and Neurology (Huanyu Meng, Q.Z., L.H., S.C.), Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, 197 Ruijin 2nd Rd, Shanghai, China; Shanxi Medical University-Collaborative Innovation Center for Molecular Imaging of Precision Medicine, Taiyuan, China (M.Z., B.L.); School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China (H.W., Q.H.); and Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China (S.C.)
| | - Qinming Zhou
- From the Departments of Nuclear Medicine (M.Z., H.C., Hongping Meng, Y.W., C.S., Y.X., W.H., B.L.) and Neurology (Huanyu Meng, Q.Z., L.H., S.C.), Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, 197 Ruijin 2nd Rd, Shanghai, China; Shanxi Medical University-Collaborative Innovation Center for Molecular Imaging of Precision Medicine, Taiyuan, China (M.Z., B.L.); School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China (H.W., Q.H.); and Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China (S.C.)
| | - Hangxing Chunyu
- From the Departments of Nuclear Medicine (M.Z., H.C., Hongping Meng, Y.W., C.S., Y.X., W.H., B.L.) and Neurology (Huanyu Meng, Q.Z., L.H., S.C.), Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, 197 Ruijin 2nd Rd, Shanghai, China; Shanxi Medical University-Collaborative Innovation Center for Molecular Imaging of Precision Medicine, Taiyuan, China (M.Z., B.L.); School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China (H.W., Q.H.); and Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China (S.C.)
| | - Lu He
- From the Departments of Nuclear Medicine (M.Z., H.C., Hongping Meng, Y.W., C.S., Y.X., W.H., B.L.) and Neurology (Huanyu Meng, Q.Z., L.H., S.C.), Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, 197 Ruijin 2nd Rd, Shanghai, China; Shanxi Medical University-Collaborative Innovation Center for Molecular Imaging of Precision Medicine, Taiyuan, China (M.Z., B.L.); School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China (H.W., Q.H.); and Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China (S.C.)
| | - Hongping Meng
- From the Departments of Nuclear Medicine (M.Z., H.C., Hongping Meng, Y.W., C.S., Y.X., W.H., B.L.) and Neurology (Huanyu Meng, Q.Z., L.H., S.C.), Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, 197 Ruijin 2nd Rd, Shanghai, China; Shanxi Medical University-Collaborative Innovation Center for Molecular Imaging of Precision Medicine, Taiyuan, China (M.Z., B.L.); School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China (H.W., Q.H.); and Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China (S.C.)
| | - Hanzhong Wang
- From the Departments of Nuclear Medicine (M.Z., H.C., Hongping Meng, Y.W., C.S., Y.X., W.H., B.L.) and Neurology (Huanyu Meng, Q.Z., L.H., S.C.), Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, 197 Ruijin 2nd Rd, Shanghai, China; Shanxi Medical University-Collaborative Innovation Center for Molecular Imaging of Precision Medicine, Taiyuan, China (M.Z., B.L.); School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China (H.W., Q.H.); and Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China (S.C.)
| | - Yue Wang
- From the Departments of Nuclear Medicine (M.Z., H.C., Hongping Meng, Y.W., C.S., Y.X., W.H., B.L.) and Neurology (Huanyu Meng, Q.Z., L.H., S.C.), Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, 197 Ruijin 2nd Rd, Shanghai, China; Shanxi Medical University-Collaborative Innovation Center for Molecular Imaging of Precision Medicine, Taiyuan, China (M.Z., B.L.); School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China (H.W., Q.H.); and Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China (S.C.)
| | - Chenwei Sun
- From the Departments of Nuclear Medicine (M.Z., H.C., Hongping Meng, Y.W., C.S., Y.X., W.H., B.L.) and Neurology (Huanyu Meng, Q.Z., L.H., S.C.), Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, 197 Ruijin 2nd Rd, Shanghai, China; Shanxi Medical University-Collaborative Innovation Center for Molecular Imaging of Precision Medicine, Taiyuan, China (M.Z., B.L.); School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China (H.W., Q.H.); and Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China (S.C.)
| | - Yun Xi
- From the Departments of Nuclear Medicine (M.Z., H.C., Hongping Meng, Y.W., C.S., Y.X., W.H., B.L.) and Neurology (Huanyu Meng, Q.Z., L.H., S.C.), Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, 197 Ruijin 2nd Rd, Shanghai, China; Shanxi Medical University-Collaborative Innovation Center for Molecular Imaging of Precision Medicine, Taiyuan, China (M.Z., B.L.); School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China (H.W., Q.H.); and Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China (S.C.)
| | - Wangxi Hai
- From the Departments of Nuclear Medicine (M.Z., H.C., Hongping Meng, Y.W., C.S., Y.X., W.H., B.L.) and Neurology (Huanyu Meng, Q.Z., L.H., S.C.), Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, 197 Ruijin 2nd Rd, Shanghai, China; Shanxi Medical University-Collaborative Innovation Center for Molecular Imaging of Precision Medicine, Taiyuan, China (M.Z., B.L.); School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China (H.W., Q.H.); and Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China (S.C.)
| | - Qiu Huang
- From the Departments of Nuclear Medicine (M.Z., H.C., Hongping Meng, Y.W., C.S., Y.X., W.H., B.L.) and Neurology (Huanyu Meng, Q.Z., L.H., S.C.), Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, 197 Ruijin 2nd Rd, Shanghai, China; Shanxi Medical University-Collaborative Innovation Center for Molecular Imaging of Precision Medicine, Taiyuan, China (M.Z., B.L.); School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China (H.W., Q.H.); and Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China (S.C.)
| | - Biao Li
- From the Departments of Nuclear Medicine (M.Z., H.C., Hongping Meng, Y.W., C.S., Y.X., W.H., B.L.) and Neurology (Huanyu Meng, Q.Z., L.H., S.C.), Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, 197 Ruijin 2nd Rd, Shanghai, China; Shanxi Medical University-Collaborative Innovation Center for Molecular Imaging of Precision Medicine, Taiyuan, China (M.Z., B.L.); School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China (H.W., Q.H.); and Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China (S.C.)
| | - Sheng Chen
- From the Departments of Nuclear Medicine (M.Z., H.C., Hongping Meng, Y.W., C.S., Y.X., W.H., B.L.) and Neurology (Huanyu Meng, Q.Z., L.H., S.C.), Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, 197 Ruijin 2nd Rd, Shanghai, China; Shanxi Medical University-Collaborative Innovation Center for Molecular Imaging of Precision Medicine, Taiyuan, China (M.Z., B.L.); School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China (H.W., Q.H.); and Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China (S.C.)
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Petropoulos IN, John K, Al-Shibani F, Ponirakis G, Khan A, Gad H, Mahfoud ZR, Altarawneh H, Rehman MH, Al-Merekhi D, George P, Ibrahim F, Francis R, Canibano B, Deleu D, El-Sotouhy A, Vattoth S, Stettner M, Own A, Shuaib A, Akhtar N, Kamran S, Malik RA. Corneal immune cells as a biomarker of inflammation in multiple sclerosis: a longitudinal study. Ther Adv Neurol Disord 2023; 16:17562864231204974. [PMID: 37915502 PMCID: PMC10617262 DOI: 10.1177/17562864231204974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 09/12/2023] [Indexed: 11/03/2023] Open
Abstract
Background Corneal immune cells (ICs) are antigen-presenting cells that are known to increase ocular and systemic inflammatory conditions. Objective We aimed to assess longitudinal changes in corneal IC in patients with multiple sclerosis (MS) and relation to disability and ongoing treatment. Design Prospective observational study conducted between September 2016 and February 2020. Methods Patients with relapsing-remitting MS (RRMS) (n = 45) or secondary progressive MS (SPMS) (n = 15) underwent corneal confocal microscopy (CCM) at baseline and 2-year follow-up for estimation of corneal IC density [dendritic cells with (DCF) (cells/mm2) or without nerve fiber contact (DCP); and non-dendritic cells with (NCF) or without nerve fiber contact (NCP)]. Optical coherence tomography, neuroimaging, and disability assessments were additionally performed. Healthy controls (n = 20) were assessed at baseline. Results In both RRMS and SPMS compared to controls, DCP (p < 0.001 and p < 0.001, respectively) and DCF (p < 0.001 and p = 0.005) were higher and NCF (p = 0.007 and p = 0.02) was lower at baseline. DCP showed excellent performance in identifying patients with MS (sensitivity/specificity = 0.88/0.90) followed by DCF (0.80/0.75) and NCF (0.80/0.85). At follow-up compared to baseline, DCP (p = 0.01) was significantly reduced, and NCP (p = 0.004) and NCF (p = 0.04) were increased. Subgroup analysis showed that baseline NCP and NCF were significantly higher (p = 0.04-0.05) in patients who switched disease-modifying treatment, and baseline NCP (p = 0.05) was higher in patients on interferon. Conclusion Baseline and change in corneal IC were related to axonal degeneration and treatment status. Evaluation of corneal IC using CCM may allow an assessment of ongoing inflammation, disease progression, and the effect of treatment in MS.
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Affiliation(s)
| | - Karen John
- Division of Research, Weill Cornell Medicine, Doha, Qatar
| | | | | | - Adnan Khan
- Division of Research, Weill Cornell Medicine, Doha, Qatar
| | - Hoda Gad
- Division of Research, Weill Cornell Medicine, Doha, Qatar
| | - Ziyad R. Mahfoud
- Division of Medical Education, Weill Cornell Medicine, Doha, Qatar
- Division of Epidemiology, Department of Population Health Sciences, Weill Cornell Medicine, New York, NY, USA
| | | | | | | | - Pooja George
- Neuroscience Institute, Hamad Medical Corporation, Doha, Qatar
| | - Faiza Ibrahim
- Neuroscience Institute, Hamad Medical Corporation, Doha, Qatar
| | - Reny Francis
- Neuroscience Institute, Hamad Medical Corporation, Doha, Qatar
| | | | - Dirk Deleu
- Neuroscience Institute, Hamad Medical Corporation, Doha, Qatar
| | | | - Surjith Vattoth
- Neuroscience Institute, Hamad Medical Corporation, Doha, Qatar
- Department of Radiology, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Mark Stettner
- Department of Neurology and Center for Translational Neuro- and Behavioral Sciences (C-TNBS), University Hospital Essen, Essen, Germany
| | - Ahmed Own
- Neuroscience Institute, Hamad Medical Corporation, Doha, Qatar
| | - Ashfaq Shuaib
- Neuroscience Institute, Hamad Medical Corporation, Doha, Qatar
- Department of Medicine, University of Alberta, Edmonton, Qatar
| | - Naveed Akhtar
- Neuroscience Institute, Hamad Medical Corporation, Doha, Qatar
| | - Saadat Kamran
- Neuroscience Institute, Hamad Medical Corporation, Doha, Qatar
| | - Rayaz A. Malik
- Weill Cornell Medicine-Qatar of Cornell University, Research Division, Qatar Foundation, Education City, Al-Luqta street, Doha 24144, Qatar
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Jiang A, Handley RR, Lehnert K, Snell RG. From Pathogenesis to Therapeutics: A Review of 150 Years of Huntington's Disease Research. Int J Mol Sci 2023; 24:13021. [PMID: 37629202 PMCID: PMC10455900 DOI: 10.3390/ijms241613021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 08/15/2023] [Accepted: 08/18/2023] [Indexed: 08/27/2023] Open
Abstract
Huntington's disease (HD) is a debilitating neurodegenerative genetic disorder caused by an expanded polyglutamine-coding (CAG) trinucleotide repeat in the huntingtin (HTT) gene. HD behaves as a highly penetrant dominant disorder likely acting through a toxic gain of function by the mutant huntingtin protein. Widespread cellular degeneration of the medium spiny neurons of the caudate nucleus and putamen are responsible for the onset of symptomology that encompasses motor, cognitive, and behavioural abnormalities. Over the past 150 years of HD research since George Huntington published his description, a plethora of pathogenic mechanisms have been proposed with key themes including excitotoxicity, dopaminergic imbalance, mitochondrial dysfunction, metabolic defects, disruption of proteostasis, transcriptional dysregulation, and neuroinflammation. Despite the identification and characterisation of the causative gene and mutation and significant advances in our understanding of the cellular pathology in recent years, a disease-modifying intervention has not yet been clinically approved. This review includes an overview of Huntington's disease, from its genetic aetiology to clinical presentation and its pathogenic manifestation. An updated view of molecular mechanisms and the latest therapeutic developments will also be discussed.
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Affiliation(s)
- Andrew Jiang
- Applied Translational Genetics Group, Centre for Brain Research, School of Biological Sciences, The University of Auckland, Auckland 1010, New Zealand; (R.R.H.); (K.L.); (R.G.S.)
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Ellen O, Ye S, Nheu D, Dass M, Pagnin M, Ozturk E, Theotokis P, Grigoriadis N, Petratos S. The Heterogeneous Multiple Sclerosis Lesion: How Can We Assess and Modify a Degenerating Lesion? Int J Mol Sci 2023; 24:11112. [PMID: 37446290 DOI: 10.3390/ijms241311112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 06/21/2023] [Accepted: 06/30/2023] [Indexed: 07/15/2023] Open
Abstract
Multiple sclerosis (MS) is a heterogeneous disease of the central nervous system that is governed by neural tissue loss and dystrophy during its progressive phase, with complex reactive pathological cellular changes. The immune-mediated mechanisms that promulgate the demyelinating lesions during relapses of acute episodes are not characteristic of chronic lesions during progressive MS. This has limited our capacity to target the disease effectively as it evolves within the central nervous system white and gray matter, thereby leaving neurologists without effective options to manage individuals as they transition to a secondary progressive phase. The current review highlights the molecular and cellular sequelae that have been identified as cooperating with and/or contributing to neurodegeneration that characterizes individuals with progressive forms of MS. We emphasize the need for appropriate monitoring via known and novel molecular and imaging biomarkers that can accurately detect and predict progression for the purposes of newly designed clinical trials that can demonstrate the efficacy of neuroprotection and potentially neurorepair. To achieve neurorepair, we focus on the modifications required in the reactive cellular and extracellular milieu in order to enable endogenous cell growth as well as transplanted cells that can integrate and/or renew the degenerative MS plaque.
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Affiliation(s)
- Olivia Ellen
- Department of Neuroscience, Central Clinical School, Monash University, Melborune, VIC 3004, Australia
| | - Sining Ye
- Department of Neuroscience, Central Clinical School, Monash University, Melborune, VIC 3004, Australia
| | - Danica Nheu
- Department of Neuroscience, Central Clinical School, Monash University, Melborune, VIC 3004, Australia
| | - Mary Dass
- Department of Neuroscience, Central Clinical School, Monash University, Melborune, VIC 3004, Australia
| | - Maurice Pagnin
- Department of Neuroscience, Central Clinical School, Monash University, Melborune, VIC 3004, Australia
| | - Ezgi Ozturk
- Department of Neuroscience, Central Clinical School, Monash University, Melborune, VIC 3004, Australia
| | - Paschalis Theotokis
- Laboratory of Experimental Neurology and Neuroimmunology, Department of Neurology, AHEPA University Hospital, Stilponos Kiriakides Str. 1, 54636 Thessaloniki, Greece
| | - Nikolaos Grigoriadis
- Laboratory of Experimental Neurology and Neuroimmunology, Department of Neurology, AHEPA University Hospital, Stilponos Kiriakides Str. 1, 54636 Thessaloniki, Greece
| | - Steven Petratos
- Department of Neuroscience, Central Clinical School, Monash University, Melborune, VIC 3004, Australia
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Roussakis AA, Gennaro M, Gordon MF, Reilmann R, Borowsky B, Rynkowski G, Lao-Kaim NP, Papoutsou Z, Savola JM, Hayden MR, Owen DR, Kalk N, Lingford-Hughes A, Gunn RN, Searle G, Tabrizi SJ, Piccini P. A PET-CT study on neuroinflammation in Huntington's disease patients participating in a randomized trial with laquinimod. Brain Commun 2023; 5:fcad084. [PMID: 37020532 PMCID: PMC10069663 DOI: 10.1093/braincomms/fcad084] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 12/19/2022] [Accepted: 03/17/2023] [Indexed: 04/05/2023] Open
Abstract
Microglia activation, an indicator of central nervous system inflammation, is believed to contribute to the pathology of Huntington's disease. Laquinimod is capable of regulating microglia. By targeting the translocator protein, 11C-PBR28 PET-CT imaging can be used to assess the state of regional gliosis in vivo and explore the effects of laquinimod treatment. This study relates to the LEGATO-HD, multi-centre, double-blinded, Phase 2 clinical trial with laquinimod (US National Registration: NCT02215616). Fifteen patients of the UK LEGATO-HD cohort (mean age: 45.2 ± 7.4 years; disease duration: 5.6 ± 3.0 years) were treated with laquinimod (0.5 mg, N = 4; 1.0 mg, N = 6) or placebo (N = 5) daily. All participants had one 11C-PBR28 PET-CT and one brain MRI scan before laquinimod (or placebo) and at the end of treatment (12 months apart). PET imaging data were quantified to produce 11C-PBR28 distribution volume ratios. These ratios were calculated for the caudate and putamen using the reference Logan plot with the corpus callosum as the reference region. Partial volume effect corrections (Müller-Gartner algorithm) were applied. Differences were sought in Unified Huntington's Disease Rating Scale scores and regional distribution volume ratios between baseline and follow-up and between the two treatment groups (laquinimod versus placebo). No significant change in 11C-PBR28 distribution volume ratios was found post treatment in the caudate and putamen for both those treated with laquinimod (N = 10) and those treated with placebo (N = 5). Over time, the patients treated with laquinimod did not show a significant clinical improvement. Data from the 11C-PBR28 PET-CT study indicate that laquinimod may not have affected regional translocator protein expression and clinical performance over the studied period.
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Affiliation(s)
| | - Marta Gennaro
- Brain Sciences, Imperial College London, Hammersmith Hospital, London W12 0NN, UK
| | | | | | | | | | - Nicholas P Lao-Kaim
- Brain Sciences, Imperial College London, Hammersmith Hospital, London W12 0NN, UK
| | - Zoe Papoutsou
- Brain Sciences, Imperial College London, Hammersmith Hospital, London W12 0NN, UK
| | | | - Michael R Hayden
- Centre for Molecular Medicine and Therapeutics, BC Children’s Hospital and Research Institute, University of British Columbia, Vancouver V5Z 4H4, Canada
| | - David R Owen
- Brain Sciences, Imperial College London, Hammersmith Hospital, London W12 0NN, UK
| | - Nicola Kalk
- Brain Sciences, Imperial College London, Hammersmith Hospital, London W12 0NN, UK
| | - Anne Lingford-Hughes
- Brain Sciences, Imperial College London, Hammersmith Hospital, London W12 0NN, UK
| | - Roger N Gunn
- Brain Sciences, Imperial College London, Hammersmith Hospital, London W12 0NN, UK
- Invicro, Hammersmith Hospital,, London W12 0NN, UK
| | | | - Sarah J Tabrizi
- Huntington’s Disease Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London WC1N 3BG, UK
| | - Paola Piccini
- Brain Sciences, Imperial College London, Hammersmith Hospital, London W12 0NN, UK
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In vivo characterization of microglia and myelin relation in multiple sclerosis by combined 11C-PBR28 PET and synthetic MRI. J Neurol 2023; 270:3091-3102. [PMID: 36859627 DOI: 10.1007/s00415-023-11621-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 02/07/2023] [Accepted: 02/08/2023] [Indexed: 03/03/2023]
Abstract
BACKGROUND The in vivo relation between microglia activation and demyelination in multiple sclerosis is still unclear. OBJECTIVE We combined 11C-PBR28 positron emission tomography and rapid estimation of myelin for diagnostic imaging (REMyDI) to characterize the relation between these pathological processes in a heterogeneous MS cohort. METHODS 11C-PBR28 standardized uptake values normalized by a pseudo-reference region (SUVR) were used to measure activated microglia. A voxelwise analysis compared 11C-PBR28 SUVR in the white matter of 38 MS patients and 16 matched healthy controls. The relative difference in SUVR served as a threshold to classify patients' lesioned, perilesional and normal-appearing white matter as active or inactive. REMyDI was acquired in 27 MS patients for assessing myelin content in active and inactive white matter and its relationship with SUVR. Finally, we investigated the contribution of radiological metrics to clinical outcomes. RESULTS 11C-PBR28 SUVR were abnormally higher in several white matter areas in MS. Myelin content was lower in active compared to inactive corresponding white matter regions. An inverse correlation between SUVR and myelin content was found. Radiological metrics correlated with both neurological and cognitive impairment. CONCLUSION our data suggest an inverse relation of microglia activation and myelination, particularly in perilesional white matter tissue.
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Boyko AN, Dolgushin MB, Karalkina MA. [New neuroimaging methods in assessing the activity of neuroinflammation in multiple sclerosis]. Zh Nevrol Psikhiatr Im S S Korsakova 2023; 123:8-14. [PMID: 37560828 DOI: 10.17116/jnevro20231230728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/11/2023]
Abstract
The review presents current data on the use of positron emission tomography and single-photon emission computed tomography in multiple sclerosis (MS) to assess the activity of the pathological process, including neuroinflammation, demyelination, activation of microglia, neurodegeneration and local blood flow disorders. These methodologies are a new approach for studying the mechanisms of action and evaluating the clinical effect of disease modifying therapy of MS, especially those capable of penetrating into brain tissue. Among them, the most attention is attracted by cladribine tablets acting on the mechanism of immune reconstitution therapy, most likely with the modulation of immune reactions directly in the brain tissue.
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Affiliation(s)
- A N Boyko
- Federal Center of Brain and Neurotechnologies of the Federal Medical Biological Agency, Moscow, Russia
- Pirogov Russian National Research Medical University, Moscow, Russia
| | - M B Dolgushin
- Federal Center of Brain and Neurotechnologies of the Federal Medical Biological Agency, Moscow, Russia
| | - M A Karalkina
- Federal Center of Brain and Neurotechnologies of the Federal Medical Biological Agency, Moscow, Russia
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18F-Radiolabeled Translocator Protein (TSPO) PET Tracers: Recent Development of TSPO Radioligands and Their Application to PET Study. Pharmaceutics 2022; 14:pharmaceutics14112545. [PMID: 36432736 PMCID: PMC9697781 DOI: 10.3390/pharmaceutics14112545] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 11/16/2022] [Accepted: 11/17/2022] [Indexed: 11/23/2022] Open
Abstract
Translocator protein 18 kDa (TSPO) is a transmembrane protein in the mitochondrial membrane, which has been identified as a peripheral benzodiazepine receptor. TSPO is generally present at high concentrations in steroid-producing cells and plays an important role in steroid synthesis, apoptosis, and cell proliferation. In the central nervous system, TSPO expression is relatively modest under normal physiological circumstances. However, some pathological disorders can lead to changes in TSPO expression. Overexpression of TSPO is associated with several diseases, such as neurodegenerative diseases, neuroinflammation, brain injury, and cancers. TSPO has therefore become an effective biomarker of related diseases. Positron emission tomography (PET), a non-invasive molecular imaging technique used for the clinical diagnosis of numerous diseases, can detect diseases related to TSPO expression. Several radiolabeled TSPO ligands have been developed for PET. In this review, we describe recent advances in the development of TSPO ligands, and 18F-radiolabeled TSPO in particular, as PET tracers. This review covers pharmacokinetic studies, preclinical and clinical trials of 18F-labeled TSPO PET ligands, and the synthesis of TSPO ligands.
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Misin O, Matilainen M, Nylund M, Honkonen E, Rissanen E, Sucksdorff M, Airas L. Innate Immune Cell–Related Pathology in the Thalamus Signals a Risk for Disability Progression in Multiple Sclerosis. NEUROLOGY - NEUROIMMUNOLOGY NEUROINFLAMMATION 2022; 9:9/4/e1182. [PMID: 35581004 PMCID: PMC9128041 DOI: 10.1212/nxi.0000000000001182] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 03/17/2022] [Indexed: 11/16/2022]
Abstract
Background and Objectives Our aim was to investigate whether 18-kDa translocator protein (TSPO) radioligand binding in gray matter (GM) predicts later disability progression in multiple sclerosis (MS). Methods In this prospective imaging study, innate immune cells were investigated in the MS patient brain using PET imaging. The distribution volume ratio (DVR) of the TSPO-binding radioligand [11C]PK11195 was determined in 5 GM regions: thalamus, caudate, putamen, pallidum, and cortical GM. Volumetric brain MRI parameters were obtained for comparison. The Expanded Disability Status Scale (EDSS) score was assessed at baseline and after follow-up of 3.0 ± 0.3 (mean ± SD) years. Disability progression was defined as an EDSS score increase of 1.0 point or 0.5 point if the baseline EDSS score was ≥6.0. A forward-type stepwise logistic regression model was constructed to compare multiple imaging and clinical variables in their ability to predict later disability progression. Results The cohort consisted of 66 patients with MS and 18 healthy controls. Patients with later disability progression (n = 17) had more advanced atrophy in the thalamus, caudate, and putamen at baseline compared with patients with no subsequent worsening. TSPO binding was significantly higher in the thalamus among the patients with later worsening. The thalamic DVR was the only measured imaging variable that remained a significant predictor of disability progression in the regression model. The final model predicted disability progression with 52.9% sensitivity and 93.9% specificity with an area under the curve value of 0.82 (receiver operating characteristic curve). Discussion Increased TSPO radioligand binding in the thalamus has potential in predicting short-term disability progression in MS and seems to be more sensitive for this than GM atrophy measures.
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van der Geest KSM, Sandovici M, Nienhuis PH, Slart RHJA, Heeringa P, Brouwer E, Jiemy WF. Novel PET Imaging of Inflammatory Targets and Cells for the Diagnosis and Monitoring of Giant Cell Arteritis and Polymyalgia Rheumatica. Front Med (Lausanne) 2022; 9:902155. [PMID: 35733858 PMCID: PMC9207253 DOI: 10.3389/fmed.2022.902155] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 05/13/2022] [Indexed: 12/26/2022] Open
Abstract
Giant cell arteritis (GCA) and polymyalgia rheumatica (PMR) are two interrelated inflammatory diseases affecting patients above 50 years of age. Patients with GCA suffer from granulomatous inflammation of medium- to large-sized arteries. This inflammation can lead to severe ischemic complications (e.g., irreversible vision loss and stroke) and aneurysm-related complications (such as aortic dissection). On the other hand, patients suffering from PMR present with proximal stiffness and pain due to inflammation of the shoulder and pelvic girdles. PMR is observed in 40-60% of patients with GCA, while up to 21% of patients suffering from PMR are also affected by GCA. Due to the risk of ischemic complications, GCA has to be promptly treated upon clinical suspicion. The treatment of both GCA and PMR still heavily relies on glucocorticoids (GCs), although novel targeted therapies are emerging. Imaging has a central position in the diagnosis of GCA and PMR. While [18F]fluorodeoxyglucose (FDG)-positron emission tomography (PET) has proven to be a valuable tool for diagnosis of GCA and PMR, it possesses major drawbacks such as unspecific uptake in cells with high glucose metabolism, high background activity in several non-target organs and a decrease of diagnostic accuracy already after a short course of GC treatment. In recent years, our understanding of the immunopathogenesis of GCA and, to some extent, PMR has advanced. In this review, we summarize the current knowledge on the cellular heterogeneity in the immunopathology of GCA/PMR and discuss how recent advances in specific tissue infiltrating leukocyte and stromal cell profiles may be exploited as a source of novel targets for imaging. Finally, we discuss prospective novel PET radiotracers that may be useful for the diagnosis and treatment monitoring in GCA and PMR.
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Affiliation(s)
- Kornelis S. M. van der Geest
- Department of Rheumatology and Clinical Immunology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Maria Sandovici
- Department of Rheumatology and Clinical Immunology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Pieter H. Nienhuis
- Department of Nuclear Medicine and Molecular Imaging, Medical Imaging Center, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Riemer H. J. A. Slart
- Department of Nuclear Medicine and Molecular Imaging, Medical Imaging Center, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
- Department of Biomedical Photonic Imaging Group, University of Twente, Enschede, Netherlands
| | - Peter Heeringa
- Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Elisabeth Brouwer
- Department of Rheumatology and Clinical Immunology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - William F. Jiemy
- Department of Rheumatology and Clinical Immunology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
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Abstract
PURPOSE OF REVIEW Microglia normally protects the central nervous system (CNS) against insults. However, their persistent activation in multiple sclerosis (MS) contributes to injury. Here, we review microglia activation in MS and their detection using positron emission tomography (PET). RECENT FINDINGS During lesion evolution and the progression of MS, microglia activity may contribute to neurotoxicity through the release of pro-inflammatory cytokines, reactive oxidative species, proteases and glutamate. A means to detect and monitor microglia activation in individuals living with MS is provided by positron emission tomography (PET) imaging using the mitochondrial 18-kDa translocator protein (TSPO) ligand. TSPO PET imaging shows increased microglial activation within the normal appearing white matter that precedes radiological signs of neurodegeneration measured by T2 lesion enlargement. PET-detected microglia activation increases with progression of MS. These findings demand the use of CNS penetrant inhibitors that affect microglia. Such therapies may include hydroxychloroquine that is recently reported in a small study to reduce the expected progression in primary progressive MS, and Bruton's tyrosine kinase inhibitors for which there are now eleven Phase 3 registered trials in MS. SUMMARY Microglial activation drives injury in MS. PET imaging with microglia-specific ligands offer new insights into progression of MS and as a monitor for treatment responses.
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Crișan G, Moldovean-Cioroianu NS, Timaru DG, Andrieș G, Căinap C, Chiș V. Radiopharmaceuticals for PET and SPECT Imaging: A Literature Review over the Last Decade. Int J Mol Sci 2022; 23:ijms23095023. [PMID: 35563414 PMCID: PMC9103893 DOI: 10.3390/ijms23095023] [Citation(s) in RCA: 60] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Revised: 04/23/2022] [Accepted: 04/28/2022] [Indexed: 02/04/2023] Open
Abstract
Positron emission tomography (PET) uses radioactive tracers and enables the functional imaging of several metabolic processes, blood flow measurements, regional chemical composition, and/or chemical absorption. Depending on the targeted processes within the living organism, different tracers are used for various medical conditions, such as cancer, particular brain pathologies, cardiac events, and bone lesions, where the most commonly used tracers are radiolabeled with 18F (e.g., [18F]-FDG and NA [18F]). Oxygen-15 isotope is mostly involved in blood flow measurements, whereas a wide array of 11C-based compounds have also been developed for neuronal disorders according to the affected neuroreceptors, prostate cancer, and lung carcinomas. In contrast, the single-photon emission computed tomography (SPECT) technique uses gamma-emitting radioisotopes and can be used to diagnose strokes, seizures, bone illnesses, and infections by gauging the blood flow and radio distribution within tissues and organs. The radioisotopes typically used in SPECT imaging are iodine-123, technetium-99m, xenon-133, thallium-201, and indium-111. This systematic review article aims to clarify and disseminate the available scientific literature focused on PET/SPECT radiotracers and to provide an overview of the conducted research within the past decade, with an additional focus on the novel radiopharmaceuticals developed for medical imaging.
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Affiliation(s)
- George Crișan
- Faculty of Physics, Babeş-Bolyai University, Str. M. Kogălniceanu 1, 400084 Cluj-Napoca, Romania; (G.C.); (N.S.M.-C.); (D.-G.T.)
- Department of Nuclear Medicine, County Clinical Hospital, Clinicilor 3-5, 400006 Cluj-Napoca, Romania;
| | | | - Diana-Gabriela Timaru
- Faculty of Physics, Babeş-Bolyai University, Str. M. Kogălniceanu 1, 400084 Cluj-Napoca, Romania; (G.C.); (N.S.M.-C.); (D.-G.T.)
| | - Gabriel Andrieș
- Department of Nuclear Medicine, County Clinical Hospital, Clinicilor 3-5, 400006 Cluj-Napoca, Romania;
| | - Călin Căinap
- The Oncology Institute “Prof. Dr. Ion Chiricuţă”, Republicii 34-36, 400015 Cluj-Napoca, Romania;
| | - Vasile Chiș
- Faculty of Physics, Babeş-Bolyai University, Str. M. Kogălniceanu 1, 400084 Cluj-Napoca, Romania; (G.C.); (N.S.M.-C.); (D.-G.T.)
- Institute for Research, Development and Innovation in Applied Natural Sciences, Babeș-Bolyai University, Str. Fântânele 30, 400327 Cluj-Napoca, Romania
- Correspondence:
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Nylund M, Sucksdorff M, Matilainen M, Polvinen E, Tuisku J, Airas L. Phenotyping of multiple sclerosis lesions according to innate immune cell activation using 18 kDa translocator protein-PET. Brain Commun 2022; 4:fcab301. [PMID: 34993478 PMCID: PMC8727984 DOI: 10.1093/braincomms/fcab301] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 10/22/2021] [Accepted: 10/29/2021] [Indexed: 12/27/2022] Open
Abstract
Chronic active lesions are promotors of neurodegeneration and disease progression in multiple sclerosis. They harbour a dense rim of activated innate immune cells at the lesion edge, which promotes lesion growth and thereby induces damage. Conventional MRI is of limited help in identifying the chronic active lesions, so alternative imaging modalities are needed. Objectives were to develop a PET-based automated analysis method for phenotyping of chronic lesions based on lesion-associated innate immune cell activation and to comprehensively evaluate the prevalence of these lesions in the various clinical subtypes of multiple sclerosis, and their association with disability. In this work, we use 18 kDa translocator protein-PET imaging for phenotyping chronic multiple sclerosis lesions at a large scale. For this, we identified 1510 white matter T1-hypointense lesions from 91 multiple sclerosis patients (67 relapsing–remitting patients and 24 secondary progressive patients). Innate immune cell activation at the lesion rim was measured using PET imaging and the 18 kDa translocator protein-binding radioligand 11C-PK11195. A T1-hypointense lesion was classified as rim-active if the distribution volume ratio of 11C-PK11195-binding was low in the plaque core and considerably higher at the plaque edge. If no significant ligand binding was observed, the lesion was classified as inactive. Plaques that had considerable ligand binding both in the core and at the rim were classified as overall-active. Conventional MRI and disability assessment using the Expanded Disability Status Scale were performed at the time of PET imaging. In the secondary progressive cohort, an average of 19% (median, interquartile range: 11–26) of T1 lesions were rim-active in each individual patient, compared to 10% (interquartile range: 0–20) among relapsing–remitting patients (P = 0.009). Secondary progressive patients had a median of 3 (range: 0–11) rim-active lesions, versus 1 (range: 0–18) among relapsing–remitting patients (P = 0.029). Among those patients who had rim-active lesions (n = 63), the average number of active voxels at the rim was higher among secondary progressive compared to relapsing–remitting patients (median 158 versus 74; P = 0.022). The number of active voxels at the rim correlated significantly with the Expanded Disability Status Scale (R = 0.43, P < 0.001), and the volume of the rim-active lesions similarly correlated with the Expanded Disability Status Scale (R = 0.45, P < 0.001). Our study is the first to report in vivo phenotyping of chronic lesions at large scale, based on 18 kDa translocator protein-PET. Patients with higher disability displayed a higher proportion of rim-active lesions. The in vivo lesion phenotyping methodology offers a new tool for individual assessment of smouldering (rim-active) lesion burden.
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Affiliation(s)
- Marjo Nylund
- Turku PET Centre, Turku, Finland.,Clinical Neurosciences, University of Turku, Turku, Finland.,Neurocenter, Turku University Hospital, Turku, Finland
| | - Marcus Sucksdorff
- Turku PET Centre, Turku, Finland.,Clinical Neurosciences, University of Turku, Turku, Finland.,Neurocenter, Turku University Hospital, Turku, Finland
| | - Markus Matilainen
- Turku PET Centre, Turku, Finland.,Faculty of Science and Engineering, Åbo Akademi University, Turku, Finland
| | - Eero Polvinen
- Turku PET Centre, Turku, Finland.,Clinical Neurosciences, University of Turku, Turku, Finland.,Neurocenter, Turku University Hospital, Turku, Finland
| | | | - Laura Airas
- Turku PET Centre, Turku, Finland.,Clinical Neurosciences, University of Turku, Turku, Finland.,Neurocenter, Turku University Hospital, Turku, Finland
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14
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The Role of Molecular Imaging as a Marker of Remyelination and Repair in Multiple Sclerosis. Int J Mol Sci 2021; 23:ijms23010474. [PMID: 35008899 PMCID: PMC8745199 DOI: 10.3390/ijms23010474] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 12/26/2021] [Accepted: 12/29/2021] [Indexed: 12/14/2022] Open
Abstract
The appearance of new disease-modifying therapies in multiple sclerosis (MS) has revolutionized our ability to fight inflammatory relapses and has immensely improved patients’ quality of life. Although remarkable, this achievement has not carried over into reducing long-term disability. In MS, clinical disability progression can continue relentlessly irrespective of acute inflammation. This “silent” disease progression is the main contributor to long-term clinical disability in MS and results from chronic inflammation, neurodegeneration, and repair failure. Investigating silent disease progression and its underlying mechanisms is a challenge. Standard MRI excels in depicting acute inflammation but lacks the pathophysiological lens required for a more targeted exploration of molecular-based processes. Novel modalities that utilize nuclear magnetic resonance’s ability to display in vivo information on imaging look to bridge this gap. Displaying the CNS through a molecular prism is becoming an undeniable reality. This review will focus on “molecular imaging biomarkers” of disease progression, modalities that can harmoniously depict anatomy and pathophysiology, making them attractive candidates to become the first valid biomarkers of neuroprotection and remyelination.
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15
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Positron emission tomography in multiple sclerosis - straight to the target. Nat Rev Neurol 2021; 17:663-675. [PMID: 34545219 DOI: 10.1038/s41582-021-00537-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/30/2021] [Indexed: 02/08/2023]
Abstract
Following the impressive progress in the treatment of relapsing-remitting multiple sclerosis (MS), the major challenge ahead is the development of treatments to prevent or delay the irreversible accumulation of clinical disability in progressive forms of the disease. The substrate of clinical progression is neuro-axonal degeneration, and a deep understanding of the mechanisms that underlie this process is a precondition for the development of therapies for progressive MS. PET imaging involves the use of radiolabelled compounds that bind to specific cellular and metabolic targets, thereby enabling direct in vivo measurement of several pathological processes. This approach can provide key insights into the clinical relevance of these processes and their chronological sequence during the disease course. In this Review, we focus on the contribution that PET is making to our understanding of extraneuronal and intraneuronal mechanisms that are involved in the pathogenesis of irreversible neuro-axonal damage in MS. We consider the major challenges with the use of PET in MS and the steps necessary to realize clinical benefits of the technique. In addition, we discuss the potential of emerging PET tracers and future applications of existing compounds to facilitate the identification of effective neuroprotective treatments for patients with MS.
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16
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Abstract
The use of PET imaging agents in oncology, cardiovascular disease, and neurodegenerative disease shows the power of this technique in evaluating the molecular and biological characteristics of numerous diseases. These agents provide crucial information for designing therapeutic strategies for individual patients. Novel PET tracers are in continual development and many have potential use in clinical and research settings. This article discusses the potential applications of tracers in diagnostics, the biological characteristics of diseases, the ability to provide prognostic indicators, and using this information to guide treatment strategies including monitoring treatment efficacy in real time to improve outcomes and survival.
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17
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Nutma E, Gebro E, Marzin MC, van der Valk P, Matthews PM, Owen DR, Amor S. Activated microglia do not increase 18 kDa translocator protein (TSPO) expression in the multiple sclerosis brain. Glia 2021; 69:2447-2458. [PMID: 34145928 PMCID: PMC8453709 DOI: 10.1002/glia.24052] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 06/08/2021] [Accepted: 06/09/2021] [Indexed: 12/20/2022]
Abstract
To monitor innate immune responses in the CNS, the 18 kDa Translocator protein (TSPO) is a frequently used target for PET imaging. The frequent assumption that increased TSPO expression in the human CNS reflects pro-inflammatory activation of microglia has been extrapolated from rodent studies. However, TSPO expression does not increase in activated human microglia in vitro. Studies of multiple sclerosis (MS) lesions reveal that TSPO is not restricted to pro-inflammatory microglia/macrophages, but also present in homeostatic or reparative microglia. Here, we investigated quantitative relationships between TSPO expression and microglia/macrophage phenotypes in white matter and lesions of brains with MS pathology. In white matter from brains with no disease pathology, normal appearing white matter (NAWM), active MS lesions and chronic active lesion rims, over 95% of TSPO+ cells are microglia/macrophages. Homeostatic microglial markers in NAWM and control tissue are lost/reduced in active lesions and chronic active lesion rims, reflecting cell activation. Nevertheless, pixel analysis of TSPO+ cells (n = 12,225) revealed that TSPO expression per cell is no higher in active lesions and chronic active lesion rims (where myeloid cells are activated) relative to NAWM and control. This data suggests that whilst almost all the TSPO signal in active lesions, chronic active lesion rims, NAWM and control is associated with microglia/macrophages, their TSPO expression predominantly reflects cell density and not activation phenotype. This finding has implications for the interpretation of TSPO PET signal in MS and other CNS diseases, and further demonstrates the limitation of extrapolating TSPO biology from rodents to humans.
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Affiliation(s)
- Erik Nutma
- Department of Pathology, Amsterdam UMC - Location VUmc, Amsterdam, HV, Netherlands
| | - Emeline Gebro
- Department of Pathology, Amsterdam UMC - Location VUmc, Amsterdam, HV, Netherlands
| | - Manuel C Marzin
- Department of Pathology, Amsterdam UMC - Location VUmc, Amsterdam, HV, Netherlands
| | - Paul van der Valk
- Department of Pathology, Amsterdam UMC - Location VUmc, Amsterdam, HV, Netherlands
| | - Paul M Matthews
- Department of Brain Sciences, Imperial College London, London, UK.,UK Dementia Research Institute, Imperial College London, London, UK
| | - David R Owen
- Department of Brain Sciences, Imperial College London, London, UK
| | - Sandra Amor
- Department of Pathology, Amsterdam UMC - Location VUmc, Amsterdam, HV, Netherlands.,Department of Neuroscience and Trauma, Blizard Institute, Barts and the London School of Medicine & Dentistry, Queen Mary University of London, London, UK
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18
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Poirion E, Tonietto M, Lejeune FX, Ricigliano VAG, Boudot de la Motte M, Benoit C, Bera G, Kuhnast B, Bottlaender M, Bodini B, Stankoff B. Structural and Clinical Correlates of a Periventricular Gradient of Neuroinflammation in Multiple Sclerosis. Neurology 2021; 96:e1865-e1875. [PMID: 33737372 PMCID: PMC8105971 DOI: 10.1212/wnl.0000000000011700] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 01/04/2021] [Indexed: 11/27/2022] Open
Abstract
Objectives To explore in vivo innate immune cell activation as a function of the distance from ventricular CSF in patients with multiple sclerosis (MS) using [18F]-DPA714 PET and to investigate its relationship with periventricular microstructural damage, evaluated by magnetization transfer ratio (MTR), and with trajectories of disability worsening. Methods Thirty-seven patients with MS and 19 healthy controls underwent MRI and [18F]-DPA714 TSPO dynamic PET, from which individual maps of voxels characterized by innate immune cell activation (DPA+) were generated. White matter (WM) was divided in 3-mm-thick concentric rings radiating from the ventricular surface toward the cortex, and the percentage of DPA+ voxels and mean MTR were extracted from each ring. Two-year trajectories of disability worsening were collected to identify patients with and without recent disability worsening. Results The percentage of DPA+ voxels was higher in patients compared to controls in the periventricular WM (p = 6.10e-6) and declined with increasing distance from ventricular surface, with a steeper gradient in patients compared to controls (p = 0.001). This gradient was found in both periventricular lesions and normal-appearing WM. In the total WM, it correlated with a gradient of microstructural tissue damage measured by MTR (rs = −0.65, p = 1.0e-3). Compared to clinically stable patients, patients with disability worsening were characterized by a higher percentage of DPA+ voxels in the periventricular normal-appearing WM (p = 0.025). Conclusions Our results demonstrate that in MS the innate immune cell activation predominates in periventricular regions and is associated with microstructural damage and disability worsening. This could result from the diffusion of proinflammatory CSF-derived factors into surrounding tissues.
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Affiliation(s)
- Emilie Poirion
- From the Sorbonne University (E.P., M.T., F.-X.L., V.A.G.R., M.B.d.l.M., C.B., G.B., B.B., B.S.), Paris Brain Institute; Imaging Department (E.P.), Foundation A. de Rothschild Hospital, Paris; Paris-Saclay University (M.T., B.K., M.B.), CEA, Orsay; and Assistance Publique des Hôpitaux de Paris (B.B., B.S.), France
| | - Matteo Tonietto
- From the Sorbonne University (E.P., M.T., F.-X.L., V.A.G.R., M.B.d.l.M., C.B., G.B., B.B., B.S.), Paris Brain Institute; Imaging Department (E.P.), Foundation A. de Rothschild Hospital, Paris; Paris-Saclay University (M.T., B.K., M.B.), CEA, Orsay; and Assistance Publique des Hôpitaux de Paris (B.B., B.S.), France
| | - François-Xavier Lejeune
- From the Sorbonne University (E.P., M.T., F.-X.L., V.A.G.R., M.B.d.l.M., C.B., G.B., B.B., B.S.), Paris Brain Institute; Imaging Department (E.P.), Foundation A. de Rothschild Hospital, Paris; Paris-Saclay University (M.T., B.K., M.B.), CEA, Orsay; and Assistance Publique des Hôpitaux de Paris (B.B., B.S.), France
| | - Vito A G Ricigliano
- From the Sorbonne University (E.P., M.T., F.-X.L., V.A.G.R., M.B.d.l.M., C.B., G.B., B.B., B.S.), Paris Brain Institute; Imaging Department (E.P.), Foundation A. de Rothschild Hospital, Paris; Paris-Saclay University (M.T., B.K., M.B.), CEA, Orsay; and Assistance Publique des Hôpitaux de Paris (B.B., B.S.), France
| | - Marine Boudot de la Motte
- From the Sorbonne University (E.P., M.T., F.-X.L., V.A.G.R., M.B.d.l.M., C.B., G.B., B.B., B.S.), Paris Brain Institute; Imaging Department (E.P.), Foundation A. de Rothschild Hospital, Paris; Paris-Saclay University (M.T., B.K., M.B.), CEA, Orsay; and Assistance Publique des Hôpitaux de Paris (B.B., B.S.), France
| | - Charline Benoit
- From the Sorbonne University (E.P., M.T., F.-X.L., V.A.G.R., M.B.d.l.M., C.B., G.B., B.B., B.S.), Paris Brain Institute; Imaging Department (E.P.), Foundation A. de Rothschild Hospital, Paris; Paris-Saclay University (M.T., B.K., M.B.), CEA, Orsay; and Assistance Publique des Hôpitaux de Paris (B.B., B.S.), France
| | - Géraldine Bera
- From the Sorbonne University (E.P., M.T., F.-X.L., V.A.G.R., M.B.d.l.M., C.B., G.B., B.B., B.S.), Paris Brain Institute; Imaging Department (E.P.), Foundation A. de Rothschild Hospital, Paris; Paris-Saclay University (M.T., B.K., M.B.), CEA, Orsay; and Assistance Publique des Hôpitaux de Paris (B.B., B.S.), France
| | - Bertrand Kuhnast
- From the Sorbonne University (E.P., M.T., F.-X.L., V.A.G.R., M.B.d.l.M., C.B., G.B., B.B., B.S.), Paris Brain Institute; Imaging Department (E.P.), Foundation A. de Rothschild Hospital, Paris; Paris-Saclay University (M.T., B.K., M.B.), CEA, Orsay; and Assistance Publique des Hôpitaux de Paris (B.B., B.S.), France
| | - Michel Bottlaender
- From the Sorbonne University (E.P., M.T., F.-X.L., V.A.G.R., M.B.d.l.M., C.B., G.B., B.B., B.S.), Paris Brain Institute; Imaging Department (E.P.), Foundation A. de Rothschild Hospital, Paris; Paris-Saclay University (M.T., B.K., M.B.), CEA, Orsay; and Assistance Publique des Hôpitaux de Paris (B.B., B.S.), France
| | - Benedetta Bodini
- From the Sorbonne University (E.P., M.T., F.-X.L., V.A.G.R., M.B.d.l.M., C.B., G.B., B.B., B.S.), Paris Brain Institute; Imaging Department (E.P.), Foundation A. de Rothschild Hospital, Paris; Paris-Saclay University (M.T., B.K., M.B.), CEA, Orsay; and Assistance Publique des Hôpitaux de Paris (B.B., B.S.), France
| | - Bruno Stankoff
- From the Sorbonne University (E.P., M.T., F.-X.L., V.A.G.R., M.B.d.l.M., C.B., G.B., B.B., B.S.), Paris Brain Institute; Imaging Department (E.P.), Foundation A. de Rothschild Hospital, Paris; Paris-Saclay University (M.T., B.K., M.B.), CEA, Orsay; and Assistance Publique des Hôpitaux de Paris (B.B., B.S.), France.
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Zhang L, Hu K, Shao T, Hou L, Zhang S, Ye W, Josephson L, Meyer JH, Zhang MR, Vasdev N, Wang J, Xu H, Wang L, Liang SH. Recent developments on PET radiotracers for TSPO and their applications in neuroimaging. Acta Pharm Sin B 2021; 11:373-393. [PMID: 33643818 PMCID: PMC7893127 DOI: 10.1016/j.apsb.2020.08.006] [Citation(s) in RCA: 70] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 07/15/2020] [Accepted: 07/29/2020] [Indexed: 12/12/2022] Open
Abstract
The 18 kDa translocator protein (TSPO), previously known as the peripheral benzodiazepine receptor, is predominately localized to the outer mitochondrial membrane in steroidogenic cells. Brain TSPO expression is relatively low under physiological conditions, but is upregulated in response to glial cell activation. As the primary index of neuroinflammation, TSPO is implicated in the pathogenesis and progression of numerous neuropsychiatric disorders and neurodegenerative diseases, including Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), Parkinson's disease (PD), multiple sclerosis (MS), major depressive disorder (MDD) and obsessive compulsive disorder (OCD). In this context, numerous TSPO-targeted positron emission tomography (PET) tracers have been developed. Among them, several radioligands have advanced to clinical research studies. In this review, we will overview the recent development of TSPO PET tracers, focusing on the radioligand design, radioisotope labeling, pharmacokinetics, and PET imaging evaluation. Additionally, we will consider current limitations, as well as translational potential for future application of TSPO radiopharmaceuticals. This review aims to not only present the challenges in current TSPO PET imaging, but to also provide a new perspective on TSPO targeted PET tracer discovery efforts. Addressing these challenges will facilitate the translation of TSPO in clinical studies of neuroinflammation associated with central nervous system diseases.
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Key Words
- AD, Alzheimer's disease
- ALS, amyotrophic lateral sclerosis
- AMPA, α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid
- ANT, adenine nucleotide transporter
- Am, molar activities
- BBB, blood‒brain barrier
- BMSC, bone marrow stromal cells
- BP, binding potential
- BPND, non-displaceable binding potential
- BcTSPO, Bacillus cereus TSPO
- CBD, corticobasal degeneration
- CNS disorders
- CNS, central nervous system
- CRAC, cholesterol recognition amino acid consensus sequence
- DLB, Lewy body dementias
- EP, epilepsy
- FTD, frontotemporal dementia
- HAB, high-affinity binding
- HD, Huntington's disease
- HSE, herpes simplex encephalitis
- IMM, inner mitochondrial membrane
- KA, kainic acid
- LAB, low-affinity binding
- LPS, lipopolysaccharide
- MAB, mixed-affinity binding
- MAO-B, monoamine oxidase B
- MCI, mild cognitive impairment
- MDD, major depressive disorder
- MMSE, mini-mental state examination
- MRI, magnetic resonance imaging
- MS, multiple sclerosis
- MSA, multiple system atrophy
- Microglial activation
- NAA/Cr, N-acetylaspartate/creatine
- Neuroinflammation
- OCD, obsessive compulsive disorder
- OMM, outer mitochondrial membrane
- P2X7R, purinergic receptor P2X7
- PAP7, RIa-associated protein
- PBR, peripheral benzodiazepine receptor
- PCA, posterior cortical atrophy
- PD, Parkinson's disease
- PDD, PD dementia
- PET, positron emission tomography
- PKA, protein kinase A
- PRAX-1, PBR-associated protein 1
- PSP, progressive supranuclear palsy
- Positron emission tomography (PET)
- PpIX, protoporphyrin IX
- QA, quinolinic acid
- RCYs, radiochemical yields
- ROS, reactive oxygen species
- RRMS, relapsing remitting multiple sclerosis
- SA, specific activity
- SAH, subarachnoid hemorrhage
- SAR, structure–activity relationship
- SCIDY, spirocyclic iodonium ylide
- SNL, selective neuronal loss
- SNR, signal to noise ratio
- SUV, standard uptake volume
- SUVR, standard uptake volume ratio
- TBAH, tetrabutyl ammonium hydroxide
- TBI, traumatic brain injury
- TLE, temporal lobe epilepsy
- TSPO
- TSPO, translocator protein
- VDAC, voltage-dependent anion channel
- VT, distribution volume
- d.c. RCYs, decay-corrected radiochemical yields
- dMCAO, distal middle cerebral artery occlusion
- fP, plasma free fraction
- n.d.c. RCYs, non-decay-corrected radiochemical yields
- p.i., post-injection
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Kreisl WC, Kim MJ, Coughlin JM, Henter ID, Owen DR, Innis RB. PET imaging of neuroinflammation in neurological disorders. Lancet Neurol 2020; 19:940-950. [PMID: 33098803 PMCID: PMC7912433 DOI: 10.1016/s1474-4422(20)30346-x] [Citation(s) in RCA: 96] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 08/06/2020] [Accepted: 08/21/2020] [Indexed: 12/11/2022]
Abstract
A growing need exists for reliable in-vivo measurement of neuroinflammation to better characterise the inflammatory processes underlying various diseases and to inform the development of novel therapeutics that target deleterious glial activity. PET is well suited to quantify neuroinflammation and has the potential to discriminate components of the neuroimmune response. However, there are several obstacles to the reliable quantification of neuroinflammation by PET imaging. Despite these challenges, PET studies have consistently identified associations between neuroimmune responses and pathophysiology in brain disorders such as Alzheimer's disease. Tissue studies have also begun to clarify the meaning of changes in PET signal in some diseases. Furthermore, although PET imaging of neuroinflammation does not have an established clinical application, novel targets are under investigation and a small but growing number of studies have suggested that this imaging modality could have a role in drug development. Future studies are needed to further improve our knowledge of the cellular mechanisms that underlie changes in PET signal, how immune response contributes to neurological disease, and how it might be therapeutically modified.
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Affiliation(s)
- William C Kreisl
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, NY, USA
| | - Min-Jeong Kim
- Molecular Imaging Branch, National Institute of Mental Health, Bethesda, MD, USA
| | - Jennifer M Coughlin
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Ioline D Henter
- Molecular Imaging Branch, National Institute of Mental Health, Bethesda, MD, USA
| | - David R Owen
- Department of Brain Sciences, Imperial College London, London, UK
| | - Robert B Innis
- Molecular Imaging Branch, National Institute of Mental Health, Bethesda, MD, USA.
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21
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Miedema A, Wijering MHC, Eggen BJL, Kooistra SM. High-Resolution Transcriptomic and Proteomic Profiling of Heterogeneity of Brain-Derived Microglia in Multiple Sclerosis. Front Mol Neurosci 2020; 13:583811. [PMID: 33192299 PMCID: PMC7654237 DOI: 10.3389/fnmol.2020.583811] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 09/23/2020] [Indexed: 12/12/2022] Open
Abstract
Microglia are important for central nervous system (CNS) homeostasis and first to respond to tissue damage and perturbations. Microglia are heterogeneous cells; in case of pathology, microglia adopt a range of phenotypes with altered functions. However, how these different microglia subtypes are implicated in CNS disease is largely unresolved. Multiple sclerosis (MS) is a chronic demyelinating disease of the CNS, characterized by inflammation and axonal degeneration, ultimately leading to neurological decline. One way microglia are implicated in MS is through stimulation of remyelination. They facilitate efficient remyelination by phagocytosis of myelin debris. In addition, microglia recruit oligodendrocyte precursor cells (OPCs) to demyelinated areas and stimulate remyelination. The development of high-resolution technologies to profile individual cells has greatly contributed to our understanding of microglia heterogeneity and function under normal and pathological conditions. Gene expression profiling technologies have evolved from whole tissue RNA sequencing toward single-cell or nucleus sequencing. Single microglia proteomic profiles are also increasingly generated, offering another layer of high-resolution data. Here, we will review recent studies that have employed these technologies in the context of MS and their respective advantages and disadvantages. Moreover, recent developments that allow for (single) cell profiling while retaining spatial information and tissue context will be discussed.
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Affiliation(s)
- Anneke Miedema
- Section Molecular Neurobiology, Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Marion H C Wijering
- Section Molecular Neurobiology, Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Bart J L Eggen
- Section Molecular Neurobiology, Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Susanne M Kooistra
- Section Molecular Neurobiology, Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
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22
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Beaino W, Janssen B, Kooijman E, Vos R, Schuit RC, O'Brien-Brown J, Kassiou M, van Het Hof B, Vugts DJ, de Vries HE, Windhorst AD. PET imaging of P2X 7R in the experimental autoimmune encephalomyelitis model of multiple sclerosis using [ 11C]SMW139. J Neuroinflammation 2020; 17:300. [PMID: 33054803 PMCID: PMC7556947 DOI: 10.1186/s12974-020-01962-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 09/23/2020] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Non-invasive imaging of the activation status of microglia and the ability to identify a pro- or anti-inflammatory environment can provide valuable insights not only into pathogenesis of neuro-inflammatory and neurodegenerative diseases but also the monitoring of the efficacy of immunomodulatory therapies. P2X7R is highly expressed on pro-inflammatory microglia and [11C]SMW139, a specific P2X7R tracer for positron emission tomography imaging, showed good pharmacokinetics, stability, and brain permeability in vivo. Our objective was to evaluate the potential of [11C]SMW139 for PET imaging of neuroinflammation in vivo in the experimental autoimmune encephalomyelitis (EAE) model. METHODS We induced EAE in Lewis rats by immunization with MBP 69-88 in complete Freund's adjuvant (CFA). We determined the affinity of [11C]SMW139 to human and rat P2X7R using saturation binding assay. Using this tracer, PET imaging was performed at the peak of disease and in the recovery phase. In vivo blocking experiments were conducted to validate the specific brain uptake of the tracer. Immunohistochemistry staining and autoradiography were performed to evaluate the level of neuroinflammation and validate the specific binding of [11C]SMW139. RESULTS [11C]SMW139 showed good affinity for the rat P2X7R with a Kd of 20.6 ± 1.7 nM. The uptake of [11C]SMW139 was significantly higher in EAE animals at the peak of disease compared to the recovery phase but not in CFA control animals. The amplitude of increase of [11C]SMW139 uptake showed significant positive correlation with clinical scores mainly in the spinal cord (Pearson = 0.75, Spearman = 0.76; p < 0.0001). Treating EAE animals with P2X7R antagonist JNJ-47965567 blocked the uptake of [11C]SMW139 in the spinal cord, cerebellum, and brain stem, demonstrating specific accumulation of the tracer. P-glycoprotein blocking with tariquidar (30 mg/kg) did not affect tracer penetration in the brain showing that [11C]SMW139 is not a Pgp substrate. CONCLUSION Our data shows that [11C]SMW139 is a promising PET tracer for imaging neuroinflammation and evaluating the dynamics of pro-inflammatory microglia in the brain. This can provide crucial insights into the role of microglia in disease progression and enables the development of novel treatment strategies aimed at modulating the immune response in order to promote neuroprotection.
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Affiliation(s)
- Wissam Beaino
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, location VUmc, Amsterdam, The Netherlands.
| | - Bieneke Janssen
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, location VUmc, Amsterdam, The Netherlands.,Present address: Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Esther Kooijman
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, location VUmc, Amsterdam, The Netherlands
| | - Ricardo Vos
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, location VUmc, Amsterdam, The Netherlands
| | - Robert C Schuit
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, location VUmc, Amsterdam, The Netherlands
| | | | - Michael Kassiou
- School of Chemistry, The University of Sydney, Sydney, NSW, Australia
| | - Bert van Het Hof
- Department of Molecular Cell Biology and Immunology, AUMC MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam University Medical Center, Amsterdam, The Netherlands
| | - Danielle J Vugts
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, location VUmc, Amsterdam, The Netherlands
| | - Helga E de Vries
- Department of Molecular Cell Biology and Immunology, AUMC MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam University Medical Center, Amsterdam, The Netherlands
| | - Albert D Windhorst
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, location VUmc, Amsterdam, The Netherlands
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23
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Moccia M, van de Pavert S, Eshaghi A, Haider L, Pichat J, Yiannakas M, Ourselin S, Wang Y, Wheeler-Kingshott C, Thompson A, Barkhof F, Ciccarelli O. Pathologic correlates of the magnetization transfer ratio in multiple sclerosis. Neurology 2020; 95:e2965-e2976. [PMID: 32938787 DOI: 10.1212/wnl.0000000000010909] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 07/22/2020] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To identify pathologic correlates of magnetization transfer ratio (MTR) in multiple sclerosis (MS) in an MRI-pathology study. METHODS We acquired MTR maps at 3T from 16 fixed MS brains and 4 controls, and immunostained 100 tissue blocks for neuronal neurofilaments, myelin (SMI94), tissue macrophages (CD68), microglia (IBA1), B-lymphocytes, T-lymphocytes, cytotoxic T-lymphocytes, astrocytes (glial fibrillary acidic protein), and mitochondrial damage (COX4, VDAC). We defined regions of interest in lesions, normal-appearing white matter (NAWM), and cortical normal-appearing gray matter (NAGM). Associations between MTR and immunostaining intensities were explored using linear mixed-effects models (with cassettes nested within patients) and interaction terms (for differences between regions of interest and between cases and controls); a multivariate linear mixed-effects model identified the best pathologic correlates of MTR. RESULTS MTR was the lowest in white matter (WM) lesions (23.4 ± 9.4%) and the highest in NAWM (38.1 ± 8.7%). In MS brains, lower MTR was associated with lower immunostaining intensity for myelin (coefficient 0.31; 95% confidence interval [CI] 0.07-0.55), macrophages (coefficient 0.03; 95% CI 0.01-0.07), and astrocytes (coefficient 0.51; 95% CI 0.02-1.00), and with greater mitochondrial damage (coefficient 0.31; 95% CI 0.07-0.55). Based on interaction terms, MTR was more strongly associated with myelin in WM (coefficient 1.58; 95% CI 1.09-2.08) and gray matter (GM) lesions (coefficient 0.66; 95% CI 0.13-1.20), and with macrophages (coefficient 1.40; 95% CI 0.56-2.25), astrocytes (coefficient 2.66; 95% CI 1.31-4.01), and mitochondrial damage (coefficient -12.59; 95% CI -23.16 to -2.02) in MS brains than controls. In the multivariate model, myelin immunostaining intensity was the best correlate of MTR (coefficient 0.31; 95% CI 0.09-0.52; p = 0.004). CONCLUSIONS Myelin was the strongest correlate of MTR, especially in WM and cortical GM lesions, but additional correlates should be kept in mind when designing and interpreting MTR observational and experimental studies in MS.
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Affiliation(s)
- Marcello Moccia
- From the Department of Neuroinflammation, Queen Square MS Centre, NMR Research Unit, UCL Queen Square Institute of Neurology, Faculty of Brain Sciences (M.M., S.v.d.P., A.E., L.H., M.Y., Y.W., C.W.-K., A.T., F.B., O.C.), Centre for Medical Image Computing, Department of Medical Physics and Bioengineering (J.P., S.O.), and Translational Imaging Group, UCL Institute of Healthcare Engineering (F.B.), University College London, UK; Multiple Sclerosis Clinical Care and Research Centre, Department of Neurosciences (M.M.), Federico II University, Naples, Italy; Department of Radiology and Nuclear Medicine (F.B.), VU University Medical Center, Amsterdam, the Netherlands; and National Institute for Health Research University College London Hospitals Biomedical Research Centre (A.T., F.B., O.C.), UK
| | - Steven van de Pavert
- From the Department of Neuroinflammation, Queen Square MS Centre, NMR Research Unit, UCL Queen Square Institute of Neurology, Faculty of Brain Sciences (M.M., S.v.d.P., A.E., L.H., M.Y., Y.W., C.W.-K., A.T., F.B., O.C.), Centre for Medical Image Computing, Department of Medical Physics and Bioengineering (J.P., S.O.), and Translational Imaging Group, UCL Institute of Healthcare Engineering (F.B.), University College London, UK; Multiple Sclerosis Clinical Care and Research Centre, Department of Neurosciences (M.M.), Federico II University, Naples, Italy; Department of Radiology and Nuclear Medicine (F.B.), VU University Medical Center, Amsterdam, the Netherlands; and National Institute for Health Research University College London Hospitals Biomedical Research Centre (A.T., F.B., O.C.), UK
| | - Arman Eshaghi
- From the Department of Neuroinflammation, Queen Square MS Centre, NMR Research Unit, UCL Queen Square Institute of Neurology, Faculty of Brain Sciences (M.M., S.v.d.P., A.E., L.H., M.Y., Y.W., C.W.-K., A.T., F.B., O.C.), Centre for Medical Image Computing, Department of Medical Physics and Bioengineering (J.P., S.O.), and Translational Imaging Group, UCL Institute of Healthcare Engineering (F.B.), University College London, UK; Multiple Sclerosis Clinical Care and Research Centre, Department of Neurosciences (M.M.), Federico II University, Naples, Italy; Department of Radiology and Nuclear Medicine (F.B.), VU University Medical Center, Amsterdam, the Netherlands; and National Institute for Health Research University College London Hospitals Biomedical Research Centre (A.T., F.B., O.C.), UK
| | - Lukas Haider
- From the Department of Neuroinflammation, Queen Square MS Centre, NMR Research Unit, UCL Queen Square Institute of Neurology, Faculty of Brain Sciences (M.M., S.v.d.P., A.E., L.H., M.Y., Y.W., C.W.-K., A.T., F.B., O.C.), Centre for Medical Image Computing, Department of Medical Physics and Bioengineering (J.P., S.O.), and Translational Imaging Group, UCL Institute of Healthcare Engineering (F.B.), University College London, UK; Multiple Sclerosis Clinical Care and Research Centre, Department of Neurosciences (M.M.), Federico II University, Naples, Italy; Department of Radiology and Nuclear Medicine (F.B.), VU University Medical Center, Amsterdam, the Netherlands; and National Institute for Health Research University College London Hospitals Biomedical Research Centre (A.T., F.B., O.C.), UK
| | - Jonas Pichat
- From the Department of Neuroinflammation, Queen Square MS Centre, NMR Research Unit, UCL Queen Square Institute of Neurology, Faculty of Brain Sciences (M.M., S.v.d.P., A.E., L.H., M.Y., Y.W., C.W.-K., A.T., F.B., O.C.), Centre for Medical Image Computing, Department of Medical Physics and Bioengineering (J.P., S.O.), and Translational Imaging Group, UCL Institute of Healthcare Engineering (F.B.), University College London, UK; Multiple Sclerosis Clinical Care and Research Centre, Department of Neurosciences (M.M.), Federico II University, Naples, Italy; Department of Radiology and Nuclear Medicine (F.B.), VU University Medical Center, Amsterdam, the Netherlands; and National Institute for Health Research University College London Hospitals Biomedical Research Centre (A.T., F.B., O.C.), UK
| | - Marios Yiannakas
- From the Department of Neuroinflammation, Queen Square MS Centre, NMR Research Unit, UCL Queen Square Institute of Neurology, Faculty of Brain Sciences (M.M., S.v.d.P., A.E., L.H., M.Y., Y.W., C.W.-K., A.T., F.B., O.C.), Centre for Medical Image Computing, Department of Medical Physics and Bioengineering (J.P., S.O.), and Translational Imaging Group, UCL Institute of Healthcare Engineering (F.B.), University College London, UK; Multiple Sclerosis Clinical Care and Research Centre, Department of Neurosciences (M.M.), Federico II University, Naples, Italy; Department of Radiology and Nuclear Medicine (F.B.), VU University Medical Center, Amsterdam, the Netherlands; and National Institute for Health Research University College London Hospitals Biomedical Research Centre (A.T., F.B., O.C.), UK
| | - Sebastien Ourselin
- From the Department of Neuroinflammation, Queen Square MS Centre, NMR Research Unit, UCL Queen Square Institute of Neurology, Faculty of Brain Sciences (M.M., S.v.d.P., A.E., L.H., M.Y., Y.W., C.W.-K., A.T., F.B., O.C.), Centre for Medical Image Computing, Department of Medical Physics and Bioengineering (J.P., S.O.), and Translational Imaging Group, UCL Institute of Healthcare Engineering (F.B.), University College London, UK; Multiple Sclerosis Clinical Care and Research Centre, Department of Neurosciences (M.M.), Federico II University, Naples, Italy; Department of Radiology and Nuclear Medicine (F.B.), VU University Medical Center, Amsterdam, the Netherlands; and National Institute for Health Research University College London Hospitals Biomedical Research Centre (A.T., F.B., O.C.), UK
| | - Yi Wang
- From the Department of Neuroinflammation, Queen Square MS Centre, NMR Research Unit, UCL Queen Square Institute of Neurology, Faculty of Brain Sciences (M.M., S.v.d.P., A.E., L.H., M.Y., Y.W., C.W.-K., A.T., F.B., O.C.), Centre for Medical Image Computing, Department of Medical Physics and Bioengineering (J.P., S.O.), and Translational Imaging Group, UCL Institute of Healthcare Engineering (F.B.), University College London, UK; Multiple Sclerosis Clinical Care and Research Centre, Department of Neurosciences (M.M.), Federico II University, Naples, Italy; Department of Radiology and Nuclear Medicine (F.B.), VU University Medical Center, Amsterdam, the Netherlands; and National Institute for Health Research University College London Hospitals Biomedical Research Centre (A.T., F.B., O.C.), UK
| | - Claudia Wheeler-Kingshott
- From the Department of Neuroinflammation, Queen Square MS Centre, NMR Research Unit, UCL Queen Square Institute of Neurology, Faculty of Brain Sciences (M.M., S.v.d.P., A.E., L.H., M.Y., Y.W., C.W.-K., A.T., F.B., O.C.), Centre for Medical Image Computing, Department of Medical Physics and Bioengineering (J.P., S.O.), and Translational Imaging Group, UCL Institute of Healthcare Engineering (F.B.), University College London, UK; Multiple Sclerosis Clinical Care and Research Centre, Department of Neurosciences (M.M.), Federico II University, Naples, Italy; Department of Radiology and Nuclear Medicine (F.B.), VU University Medical Center, Amsterdam, the Netherlands; and National Institute for Health Research University College London Hospitals Biomedical Research Centre (A.T., F.B., O.C.), UK
| | - Alan Thompson
- From the Department of Neuroinflammation, Queen Square MS Centre, NMR Research Unit, UCL Queen Square Institute of Neurology, Faculty of Brain Sciences (M.M., S.v.d.P., A.E., L.H., M.Y., Y.W., C.W.-K., A.T., F.B., O.C.), Centre for Medical Image Computing, Department of Medical Physics and Bioengineering (J.P., S.O.), and Translational Imaging Group, UCL Institute of Healthcare Engineering (F.B.), University College London, UK; Multiple Sclerosis Clinical Care and Research Centre, Department of Neurosciences (M.M.), Federico II University, Naples, Italy; Department of Radiology and Nuclear Medicine (F.B.), VU University Medical Center, Amsterdam, the Netherlands; and National Institute for Health Research University College London Hospitals Biomedical Research Centre (A.T., F.B., O.C.), UK
| | - Frederik Barkhof
- From the Department of Neuroinflammation, Queen Square MS Centre, NMR Research Unit, UCL Queen Square Institute of Neurology, Faculty of Brain Sciences (M.M., S.v.d.P., A.E., L.H., M.Y., Y.W., C.W.-K., A.T., F.B., O.C.), Centre for Medical Image Computing, Department of Medical Physics and Bioengineering (J.P., S.O.), and Translational Imaging Group, UCL Institute of Healthcare Engineering (F.B.), University College London, UK; Multiple Sclerosis Clinical Care and Research Centre, Department of Neurosciences (M.M.), Federico II University, Naples, Italy; Department of Radiology and Nuclear Medicine (F.B.), VU University Medical Center, Amsterdam, the Netherlands; and National Institute for Health Research University College London Hospitals Biomedical Research Centre (A.T., F.B., O.C.), UK
| | - Olga Ciccarelli
- From the Department of Neuroinflammation, Queen Square MS Centre, NMR Research Unit, UCL Queen Square Institute of Neurology, Faculty of Brain Sciences (M.M., S.v.d.P., A.E., L.H., M.Y., Y.W., C.W.-K., A.T., F.B., O.C.), Centre for Medical Image Computing, Department of Medical Physics and Bioengineering (J.P., S.O.), and Translational Imaging Group, UCL Institute of Healthcare Engineering (F.B.), University College London, UK; Multiple Sclerosis Clinical Care and Research Centre, Department of Neurosciences (M.M.), Federico II University, Naples, Italy; Department of Radiology and Nuclear Medicine (F.B.), VU University Medical Center, Amsterdam, the Netherlands; and National Institute for Health Research University College London Hospitals Biomedical Research Centre (A.T., F.B., O.C.), UK.
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24
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Thorne MWD, Cash MK, Reid GA, Burley DE, Luke D, Pottie IR, Darvesh S. Imaging Butyrylcholinesterase in Multiple Sclerosis. Mol Imaging Biol 2020; 23:127-138. [PMID: 32926288 DOI: 10.1007/s11307-020-01540-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Revised: 07/30/2020] [Accepted: 09/01/2020] [Indexed: 10/23/2022]
Abstract
PURPOSE Molecular imaging agents targeting butyrylcholinesterase (BChE) have shown promise in other neurodegenerative disorders and may have utility in detecting changes to normal appearing white matter in multiple sclerosis (MS). BChE activity is present in white matter and localizes to activated microglia associated with MS lesions. The purpose of this study was to further characterize changes in the cholinergic system in MS pathology, and to explore the utility of BChE radioligands as potential diagnostic and treatment monitoring agents in MS. PROCEDURE Cortical and white matter lesions were identified using myelin staining, and lesions were classified based on microglial activation patterns. Adjacent brain sections were used for cholinesterase histochemistry and in vitro autoradiography using phenyl 4-[123I]-iodophenylcarbamate (123I-PIP), a previously described small-molecule cholinesterase-binding radioligand. RESULTS BChE activity is positively correlated with microglial activation in white matter MS lesions. There is no alteration in cholinesterase activity in cortical MS lesions. 123I-PIP autoradiography revealed uptake of radioactivity in normal white matter, absence of radioactivity within demyelinated MS lesions, and variable uptake of radioactivity in adjacent normal-appearing white matter. CONCLUSIONS BChE imaging agents have the potential to detect MS lesions and subtle pathology in normal-appearing white matter in postmortem MS brain tissue. The possibility of BChE imaging agents serving to supplement current diagnostic and treatment monitoring strategies should be evaluated.
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Affiliation(s)
- M W D Thorne
- Department of Medical Neuroscience, Dalhousie University, Halifax, NS, Canada.,Department of Medicine (Neurology), Dalhousie University, Halifax, NS, Canada
| | - M K Cash
- Department of Medical Neuroscience, Dalhousie University, Halifax, NS, Canada
| | - G A Reid
- Department of Medical Neuroscience, Dalhousie University, Halifax, NS, Canada
| | - D E Burley
- Department of Medical Neuroscience, Dalhousie University, Halifax, NS, Canada
| | - D Luke
- Department of Medical Neuroscience, Dalhousie University, Halifax, NS, Canada
| | - I R Pottie
- Department of Chemistry and Physics, Mount Saint Vincent University, Halifax, NS, Canada.,Department of Chemistry, Saint Mary's University, Halifax, NS, Canada
| | - S Darvesh
- Department of Medical Neuroscience, Dalhousie University, Halifax, NS, Canada. .,Department of Medicine (Neurology), Dalhousie University, Halifax, NS, Canada. .,Department of Chemistry and Physics, Mount Saint Vincent University, Halifax, NS, Canada.
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25
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Filippi M, Preziosa P, Langdon D, Lassmann H, Paul F, Rovira À, Schoonheim MM, Solari A, Stankoff B, Rocca MA. Identifying Progression in Multiple Sclerosis: New Perspectives. Ann Neurol 2020; 88:438-452. [PMID: 32506714 DOI: 10.1002/ana.25808] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 05/18/2020] [Accepted: 05/25/2020] [Indexed: 01/10/2023]
Abstract
The identification of progression in multiple sclerosis is typically retrospective. Given the profound burden of progressive multiple sclerosis, and the recent development of effective treatments for these patients, there is a need to establish measures capable of identifying progressive multiple sclerosis early in the disease course. Starting from recent pathological findings, this review assesses the state of the art of potential measures able to predict progressive multiple sclerosis. Future promising biomarkers that might shed light on mechanisms of progression are also discussed. Finally, expansion of the concept of progressive multiple sclerosis, by including an assessment of cognition, patient-reported outcomes, and comorbidities, is considered. ANN NEUROL 2020;88:438-452.
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Affiliation(s)
- Massimo Filippi
- Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy.,Neurology Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy.,Neurophysiology Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy.,Vita-Salute San Raffaele University, Milan, Italy
| | - Paolo Preziosa
- Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy.,Neurology Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Dawn Langdon
- Royal Holloway, University of London, London, United Kingdom
| | - Hans Lassmann
- Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Friedemann Paul
- NeuroCure Clinical Research Center and Experimental and Clinical Research Center, Max Delbrueck Center for Molecular Medicine and Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Àlex Rovira
- Neuroradiology Section, Department of Radiology, Vall d'Hebron University Hospital and Research Institute, Autonomous University of Barcelona, Barcelona, Spain
| | - Menno M Schoonheim
- Department of Anatomy and Neurosciences, Multiple Sclerosis Center Amsterdam, Amsterdam Neuroscience, Amsterdam University Medical Center, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Alessandra Solari
- Unit of Neuroepidemiology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Bruno Stankoff
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute - ICM, Inserm, CNRS, APHP, Paris, France
| | - Maria A Rocca
- Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy.,Neurology Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy
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26
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Sridharan S, Raffel J, Nandoskar A, Record C, Brooks DJ, Owen D, Sharp D, Muraro PA, Gunn R, Nicholas R. Confirmation of Specific Binding of the 18-kDa Translocator Protein (TSPO) Radioligand [ 18F]GE-180: a Blocking Study Using XBD173 in Multiple Sclerosis Normal Appearing White and Grey Matter. Mol Imaging Biol 2020; 21:935-944. [PMID: 30796709 DOI: 10.1007/s11307-019-01323-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
PURPOSE Measurements of non-displaceable binding (VND) of positron emission tomography (PET) ligands are not often made in vivo in humans because they require ligands to displace binding to target receptors and there are few readily available, safe ones to use. A technique to measure VND for ligands for the 18-kDa translocator protein (TSPO) has recently been developed which compares the total volume of distribution (VT) before and after administration of the TSPO ligand XBD173. Here, we used XBD173 with an occupancy plot to quantify VND for two TSPO radiotracers, [18F]GE-180 and [11C]PBR28, in cohorts of people with multiple sclerosis (MS). Additionally, we compared plots of subjects carrying high (HAB) or mixed binding (MAB) affinity polymorphisms of TSPO to estimate VND without receptor blockade. PROCEDURES Twelve people with MS underwent baseline MRI and 90-min dynamic [18F]GE-180 PET or [11C]PBR28 PET (n = 6; three HAB, three MAB each). Arterial blood sampling was used to generate plasma input functions for the two-tissue compartment model. VND was calculated using two independent methods: the occupancy plot (by modelling the differences in signal post XBD173) and the polymorphism plot (by modelling the differences in signal across presence and absence of rs6971 genotypes). RESULTS Whole brain VT (mean ± standard deviation) was 0.29 ± 0.17 ml/cm3 for [18F]GE-180 and 5.01 ± 1.88 ml/cm3 for [11C]PBR28. Using the occupancy and polymorphism plots respectively, VND for [18F]GE-180 was 0.11 ml/cm3 (95 % CI = 0.02, 0.16) and 0.20 ml/cm3 (0.16, 0.34), accounting for, on average, 55 % of VT in the whole brain. For [11C]PBR28, these values were 3.81 ml/cm3 (3.02, 4.21) and 3.49 ml/cm3 (1.38, 4.27), accounting for 67 % of average whole brain VT. CONCLUSIONS Although VT for [18F]GE-180 is low, indicating low brain penetration, half the signal shown by MS subjects reflected specific TSPO binding. VT for [11C]PBR28 was higher and two thirds of the binding was non-specific. No brain ROIs were devoid of specific signal, further confirming that true reference tissue approaches are potentially problematic for estimating TSPO levels.
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Affiliation(s)
- Sujata Sridharan
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK.
| | - Joel Raffel
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK
| | - Ashwini Nandoskar
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK
| | - Chris Record
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK
| | - David J Brooks
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK.,Institute of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Institute of Neuroscience, Newcastle upon Tyne University, Newcastle upon Tyne, UK
| | - David Owen
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK
| | - David Sharp
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK
| | - Paolo A Muraro
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK
| | | | - Richard Nicholas
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK
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27
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Nutma E, Stephenson JA, Gorter RP, de Bruin J, Boucherie DM, Donat CK, Breur M, van der Valk P, Matthews PM, Owen DR, Amor S. A quantitative neuropathological assessment of translocator protein expression in multiple sclerosis. Brain 2020; 142:3440-3455. [PMID: 31578541 PMCID: PMC6821167 DOI: 10.1093/brain/awz287] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 06/11/2019] [Accepted: 07/25/2019] [Indexed: 01/09/2023] Open
Abstract
The 18 kDa translocator protein (TSPO) is increasingly used to study brain and spinal cord inflammation in degenerative diseases of the CNS such as multiple sclerosis. The enhanced TSPO PET signal that arises during disease is widely considered to reflect activated pathogenic microglia, although quantitative neuropathological data to support this interpretation have not been available. With the increasing interest in the role of chronic microglial activation in multiple sclerosis, characterising the cellular neuropathology associated with TSPO expression is of clear importance for understanding the cellular and pathological processes on which TSPO PET imaging is reporting. Here we have studied the cellular expression of TSPO and specific binding of two TSPO targeting radioligands (3H-PK11195 and 3H-PBR28) in tissue sections from 42 multiple sclerosis cases and 12 age-matched controls. Markers of homeostatic and reactive microglia, astrocytes, and lymphocytes were used to investigate the phenotypes of cells expressing TSPO. There was an approximate 20-fold increase in cells double positive for TSPO and HLA-DR in active lesions and in the rim of chronic active lesion, relative to normal appearing white matter. TSPO was uniformly expressed across myeloid cells irrespective of their phenotype, rather than being preferentially associated with pro-inflammatory microglia or macrophages. TSPO+ astrocytes were increased up to 7-fold compared to normal-appearing white matter across all lesion subtypes and accounted for 25% of the TSPO+ cells in these lesions. To relate TSPO protein expression to ligand binding, specific binding of the TSPO ligands 3H-PK11195 and 3H-PBR28 was determined in the same lesions. TSPO radioligand binding was increased up to seven times for 3H-PBR28 and up to two times for 3H-PK11195 in active lesions and the centre of chronic active lesions and a strong correlation was found between the radioligand binding signal for both tracers and the number of TSPO+ cells across all of the tissues examined. In summary, in multiple sclerosis, TSPO expression arises from microglia of different phenotypes, rather than being restricted to microglia which express classical pro-inflammatory markers. While the majority of cells expressing TSPO in active lesions or chronic active rims are microglia/macrophages, our findings also emphasize the significant contribution of activated astrocytes, as well as smaller contributions from endothelial cells. These observations establish a quantitative framework for interpretation of TSPO in multiple sclerosis and highlight the need for neuropathological characterization of TSPO expression for the interpretation of TSPO PET in other neurodegenerative disorders.
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Affiliation(s)
- Erik Nutma
- Department of Pathology, Amsterdam UMC, Location VUmc, The Netherlands
| | - Jodie A Stephenson
- Department of Pathology, Amsterdam UMC, Location VUmc, The Netherlands.,Centre for Neuroscience and Trauma, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, UK
| | - Rianne P Gorter
- Department of Pathology, Amsterdam UMC, Location VUmc, The Netherlands
| | - Joy de Bruin
- Department of Pathology, Amsterdam UMC, Location VUmc, The Netherlands
| | | | | | - Marjolein Breur
- Department of Pathology, Amsterdam UMC, Location VUmc, The Netherlands
| | - Paul van der Valk
- Department of Pathology, Amsterdam UMC, Location VUmc, The Netherlands
| | - Paul M Matthews
- Department of Brain Sciences, Imperial College London, UK.,UK Dementia Research Institute, Imperial College London, UK
| | - David R Owen
- Department of Brain Sciences, Imperial College London, UK
| | - Sandra Amor
- Department of Pathology, Amsterdam UMC, Location VUmc, The Netherlands.,Centre for Neuroscience and Trauma, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, UK
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Tavazzi E, Zivadinov R, Dwyer MG, Jakimovski D, Singhal T, Weinstock-Guttman B, Bergsland N. MRI biomarkers of disease progression and conversion to secondary-progressive multiple sclerosis. Expert Rev Neurother 2020; 20:821-834. [PMID: 32306772 DOI: 10.1080/14737175.2020.1757435] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
INTRODUCTION Conventional imaging measures remain a key clinical tool for the diagnosis multiple sclerosis (MS) and monitoring of patients. However, most measures used in the clinic show unsatisfactory performance in predicting disease progression and conversion to secondary progressive MS. AREAS COVERED Sophisticated imaging techniques have facilitated the identification of imaging biomarkers associated with disease progression, such as global and regional brain volume measures, and with conversion to secondary progressive MS, such as leptomeningeal contrast enhancement and chronic inflammation. The relevance of emerging imaging approaches partially overcoming intrinsic limitations of traditional techniques is also discussed. EXPERT OPINION Imaging biomarkers capable of detecting tissue damage early on in the disease, with the potential to be applied in multicenter trials and at an individual level in clinical settings, are strongly needed. Several measures have been proposed, which exploit advanced imaging acquisitions and/or incorporate sophisticated post-processing, can quantify irreversible tissue damage. The progressively wider use of high-strength field MRI and the development of more advanced imaging techniques will help capture the missing pieces of the MS puzzle. The ability to more reliably identify those at risk for disability progression will allow for earlier intervention with the aim to favorably alter the disease course.
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Affiliation(s)
- Eleonora Tavazzi
- Buffalo Neuroimaging Analysis Center, Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York , Buffalo, NY, USA
| | - Robert Zivadinov
- Buffalo Neuroimaging Analysis Center, Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York , Buffalo, NY, USA.,Translational Imaging Center, Clinical and Translational Science Institute, University at Buffalo, The State University of New York , Buffalo, NY, USA
| | - Michael G Dwyer
- Buffalo Neuroimaging Analysis Center, Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York , Buffalo, NY, USA
| | - Dejan Jakimovski
- Buffalo Neuroimaging Analysis Center, Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York , Buffalo, NY, USA
| | - Tarun Singhal
- PET Imaging Program in Neurologic Diseases and Partners Multiple Sclerosis Center, Ann Romney Center for Neurologic Disease, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School , Boston, MA, USA
| | - Bianca Weinstock-Guttman
- Jacobs Comprehensive MS Treatment and Research Center, Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York , Buffalo, NY, USA
| | - Niels Bergsland
- Buffalo Neuroimaging Analysis Center, Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York , Buffalo, NY, USA.,IRCCS, Fondazione Don Carlo Gnocchi , Milan, Italy
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29
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Cavaliere C, Tramontano L, Fiorenza D, Alfano V, Aiello M, Salvatore M. Gliosis and Neurodegenerative Diseases: The Role of PET and MR Imaging. Front Cell Neurosci 2020; 14:75. [PMID: 32327973 PMCID: PMC7161920 DOI: 10.3389/fncel.2020.00075] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 03/13/2020] [Indexed: 12/16/2022] Open
Abstract
Glial activation characterizes most neurodegenerative and psychiatric diseases, often anticipating clinical manifestations and macroscopical brain alterations. Although imaging techniques have improved diagnostic accuracy in many neurological conditions, often supporting diagnosis, prognosis prediction and treatment outcome, very few molecular imaging probes, specifically focused on microglial and astrocytic activation, have been translated to a clinical setting. In this context, hybrid positron emission tomography (PET)/magnetic resonance (MR) scanners represent the most advanced tool for molecular imaging, combining the functional specificity of PET radiotracers (e.g., targeting metabolism, hypoxia, and inflammation) to both high-resolution and multiparametric information derived by MR in a single imaging acquisition session. This simultaneity of findings achievable by PET/MR, if useful for reciprocal technical adjustments regarding temporal and spatial cross-modal alignment/synchronization, opens still debated issues about its clinical value in neurological patients, possibly incompliant and highly variable from a clinical point of view. While several preclinical and clinical studies have investigated the sensitivity of PET tracers to track microglial (mainly TSPO ligands) and astrocytic (mainly MAOB ligands) activation, less studies have focused on MR specificity to this topic (e.g., through the assessment of diffusion properties and T2 relaxometry), and only few exploiting the integration of simultaneous hybrid acquisition. This review aims at summarizing and critically review the current state about PET and MR imaging for glial targets, as well as the potential added value of hybrid scanners for characterizing microglial and astrocytic activation.
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30
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Vo SV, Banister SD, Freelander I, Werry EL, Reekie TA, Ittner LM, Kassiou M. Reversing binding sensitivity to A147T translocator protein. RSC Med Chem 2020; 11:511-517. [PMID: 33479652 PMCID: PMC7489257 DOI: 10.1039/c9md00580c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 02/22/2020] [Indexed: 11/21/2022] Open
Abstract
The translocator protein (TSPO) is a target for the development of neuroinflammation imaging agents. Clinical translation of TSPO PET ligands, such as [11C]DPA-713, has been hampered by the presence of a common polymorphism (A147T TSPO), at which all second-generation TSPO ligands lose affinity. Little is known about what drives binding at A147T compared to WT TSPO. This study aimed to identify moieties in DPA-713, and related derivatives, that influence binding at A147T compared to WT TSPO. We found changes to the nitrogen position and number in the heterocyclic core influences affinity to WT and A147T to a similar degree. Hydrogen bonding groups in molecules with an indole core improve binding at A147T compared to WT, a strategy that generated compounds that possess up to ten-times greater affinity for A147T. These results should inform the future design of compounds that bind both A147T and WT TSPO for use in neuroinflammation imaging.
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Affiliation(s)
- Sophie V Vo
- Faculty of Medicine and Health , The University of Sydney , Sydney , New South Wales 2006 , Australia
| | - Samuel D Banister
- The Lambert Initiative for Cannabinoid Therapeutics , Brain and Mind Centre , The University of Sydney , Camperdown , NSW 2050 , Australia
- School of Chemistry , The University of Sydney , Sydney , New South Wales 2006 , Australia .
| | - Isaac Freelander
- School of Chemistry , The University of Sydney , Sydney , New South Wales 2006 , Australia .
| | - Eryn L Werry
- School of Chemistry , The University of Sydney , Sydney , New South Wales 2006 , Australia .
| | - Tristan A Reekie
- Research School of Chemistry , The Australian National University , Canberra , Australian Capital Territory 2600 , Australia
| | - Lars M Ittner
- Department of Biomedical Sciences , Faculty of Medicine and Health Sciences , Macquarie University , 2 Technology Place , North Ryde , New South Wales 2109 , Australia
| | - Michael Kassiou
- School of Chemistry , The University of Sydney , Sydney , New South Wales 2006 , Australia .
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31
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Margoni M, Franciotta S, Poggiali D, Riccardi A, Rinaldi F, Nosadini M, Sartori S, Anglani MG, Causin F, Perini P, Gallo P. Cerebellar gray matter lesions are common in pediatric multiple sclerosis at clinical onset. J Neurol 2020; 267:1824-1829. [PMID: 32140864 DOI: 10.1007/s00415-020-09776-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 02/20/2020] [Accepted: 02/22/2020] [Indexed: 01/06/2023]
Abstract
BACKGROUND No data are available on the occurrence of gray matter lesions (GML) in the cerebellum of pediatric multiple sclerosis (pedMS). OBJECTIVES We analyzed frequency, number and topography of GML, and their correlation with cerebellar-related disability in pedMS at clinical onset. METHODS Fifteen adolescents with pedMS (12F/3M; mean age 14.9 ± 2.2, range 11-17) were studied. Neurological and cognitive evaluations were done by means of EDSS, Trail Making Test-Part B (TMT-B) and Symbol Digit Modalities Test-oral version (SDMT). Cerebellar GML were investigated with double inversion recovery (DIR) and phase-sensitive inversion recovery (PSIR) sequences obtained with a 3 T-MRI scan. RESULTS All patients had white matter lesions (WML) and/or GML in the cerebellum. A significantly higher GML number was observed on PSIR compared to DIR (mean 2.3 ± 2.3 vs 1.1 ± 1.6; median 2.0 (IQR 1.0-2.0) vs 1.0 (IQR 0.0-1.5); p = 0.004). GML were observed in 14/15 (93.3%) patients and were more frequent in the posterior than in the anterior lobe (mean 1.8 ± 2.2 vs 0.47 ± 0.74; median 2.0 (IQR 0.5-2.0) vs 0.0 (IQR 0.0-1.0); p = 0.044). No correlation was found between lesion number or topography and EDSS (r = 0.12, p = 0.69), TMT-B and SDMT. CONCLUSION At clinical onset, cerebellar GML are common in pedMS, are very often asymptomatic, do not correlate with physical and cognitive disability, and more frequently affect the posterior lobe.
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Affiliation(s)
- Monica Margoni
- Multiple Sclerosis Centre of the Veneto Region (CeSMuV), University Hospital of Padua, Via Giustiniani 2, 35128, Padua, Italy. .,Padova Neuroscience Centre (PNC), University of Padua, Padua, Italy.
| | - Silvia Franciotta
- Multiple Sclerosis Centre of the Veneto Region (CeSMuV), University Hospital of Padua, Via Giustiniani 2, 35128, Padua, Italy
| | - Davide Poggiali
- Padova Neuroscience Centre (PNC), University of Padua, Padua, Italy.,Department of Mathematics, University of Padua, Padua, Italy
| | - Alice Riccardi
- Multiple Sclerosis Centre of the Veneto Region (CeSMuV), University Hospital of Padua, Via Giustiniani 2, 35128, Padua, Italy
| | - Francesca Rinaldi
- Multiple Sclerosis Centre of the Veneto Region (CeSMuV), University Hospital of Padua, Via Giustiniani 2, 35128, Padua, Italy
| | | | | | | | | | - Paola Perini
- Multiple Sclerosis Centre of the Veneto Region (CeSMuV), University Hospital of Padua, Via Giustiniani 2, 35128, Padua, Italy
| | - Paolo Gallo
- Multiple Sclerosis Centre of the Veneto Region (CeSMuV), University Hospital of Padua, Via Giustiniani 2, 35128, Padua, Italy.,Department of Neurosciences, Medical School, University of Padua, Padua, Italy
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32
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Bodini B, Poirion E, Tonietto M, Benoit C, Palladino R, Maillart E, Portera E, Battaglini M, Bera G, Kuhnast B, Louapre C, Bottlaender M, Stankoff B. Individual Mapping of Innate Immune Cell Activation Is a Candidate Marker of Patient-Specific Trajectories of Worsening Disability in Multiple Sclerosis. J Nucl Med 2020; 61:1043-1049. [PMID: 32005777 DOI: 10.2967/jnumed.119.231340] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Accepted: 11/19/2019] [Indexed: 11/16/2022] Open
Abstract
Our objective was to develop a novel approach to generate individual maps of white matter (WM) innate immune cell activation using 18F-DPA-714 translocator protein PET and to explore the relationship between these maps and individual trajectories of worsening disability in patients with multiple sclerosis (MS). Methods: Patients with MS (n = 37), whose trajectories of worsening disability over the 2 y preceding study entry were calculated, and healthy controls (n = 19) underwent MRI and 18F-DPA-714 PET. A threshold for significant activation of 18F-DPA-714 binding was calculated with a voxelwise randomized permutation-based comparison between patients and controls and used to classify each WM voxel in all subjects as characterized by a significant activation of innate immune cells (DPA+) or not. Individual maps of innate immune cell activation in the WM were used to calculate the extent of activation in WM regions of interests and to classify each WM lesion as DPA-active, DPA-inactive, or unclassified. Results: Compared with the WM of healthy controls, patients with MS had a significantly higher percentage of DPA+ voxels in the normal-appearing WM (NAWM) (NAWM in patients, 24.6% ± 1.4%; WM in controls, 14.6% ± 2.0%; P < 0.001). In patients with MS, the percentage of DPA+ voxels increased significantly from the NAWM to the perilesional areas, T2 hyperintense lesions, and T1 hypointense lesions (38.1% ± 2.6%, 45.0% ± 2.6%, 51.8% ± 2.6%, respectively; P < 0.001). Among the 1,379 T2 lesions identified, 512 were defined as DPA-active and 258 as DPA-inactive. A higher number of lesions classified as DPA-active (odds ratio, 1.13; P = 0.009), a higher percentage of DPA+ voxels in the NAWM (odds ratio, 1.16; P = 0.009), and a higher percentage of DPA+ voxels in T1 spin-echo lesions (odds ratio, 1.06; P = 0.036) were significantly associated with a retrospectively more severe clinical trajectory in patients with MS. Conclusion: A more severe trajectory of disability worsening in MS is associated with innate immune cell activation inside and around WM lesions. 18F-DPA-714 PET may provide a promising biomarker to identify patients at risk of a severe clinical trajectory.
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Affiliation(s)
- Benedetta Bodini
- Sorbonne Universités, Institut du Cerveau et de la Moelle épinière, ICM, Hôpital de la Pitié Salpêtrière, INSERM UMR S 1127, CNRS UMR 7225, Paris, France.,Assistance Publique des Hôpitaux de Paris, France
| | - Emilie Poirion
- Sorbonne Universités, Institut du Cerveau et de la Moelle épinière, ICM, Hôpital de la Pitié Salpêtrière, INSERM UMR S 1127, CNRS UMR 7225, Paris, France
| | - Matteo Tonietto
- Sorbonne Universités, Institut du Cerveau et de la Moelle épinière, ICM, Hôpital de la Pitié Salpêtrière, INSERM UMR S 1127, CNRS UMR 7225, Paris, France
| | - Charline Benoit
- Sorbonne Universités, Institut du Cerveau et de la Moelle épinière, ICM, Hôpital de la Pitié Salpêtrière, INSERM UMR S 1127, CNRS UMR 7225, Paris, France
| | - Raffaele Palladino
- School of Public Health, Imperial College of London, London, United Kingdom.,University "Federico II" of Naples, Naples, Italy
| | - Elisabeth Maillart
- Sorbonne Universités, Institut du Cerveau et de la Moelle épinière, ICM, Hôpital de la Pitié Salpêtrière, INSERM UMR S 1127, CNRS UMR 7225, Paris, France.,Assistance Publique des Hôpitaux de Paris, France
| | - Erika Portera
- Sorbonne Universités, Institut du Cerveau et de la Moelle épinière, ICM, Hôpital de la Pitié Salpêtrière, INSERM UMR S 1127, CNRS UMR 7225, Paris, France
| | - Marco Battaglini
- Department of Neurological Sciences, University of Siena, Siena, Italy; and
| | - Geraldine Bera
- Sorbonne Universités, Institut du Cerveau et de la Moelle épinière, ICM, Hôpital de la Pitié Salpêtrière, INSERM UMR S 1127, CNRS UMR 7225, Paris, France.,Assistance Publique des Hôpitaux de Paris, France
| | - Bertrand Kuhnast
- CEA, Université Paris Sud, Université Paris-Saclay, Service Hospitalier Frédéric Joliot, Orsay, France
| | - Céline Louapre
- Sorbonne Universités, Institut du Cerveau et de la Moelle épinière, ICM, Hôpital de la Pitié Salpêtrière, INSERM UMR S 1127, CNRS UMR 7225, Paris, France.,Assistance Publique des Hôpitaux de Paris, France
| | - Michel Bottlaender
- CEA, Université Paris Sud, Université Paris-Saclay, Service Hospitalier Frédéric Joliot, Orsay, France
| | - Bruno Stankoff
- Sorbonne Universités, Institut du Cerveau et de la Moelle épinière, ICM, Hôpital de la Pitié Salpêtrière, INSERM UMR S 1127, CNRS UMR 7225, Paris, France .,Assistance Publique des Hôpitaux de Paris, France
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Assessing the interactions between radiotherapy and antitumour immunity. Nat Rev Clin Oncol 2019; 16:729-745. [PMID: 31243334 DOI: 10.1038/s41571-019-0238-9] [Citation(s) in RCA: 158] [Impact Index Per Article: 31.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/28/2019] [Indexed: 12/17/2022]
Abstract
Immunotherapy, specifically the introduction of immune checkpoint inhibitors, has transformed the treatment of cancer, enabling long-term tumour control even in individuals with advanced-stage disease. Unfortunately, only a small subset of patients show a response to currently available immunotherapies. Despite a growing consensus that combining immune checkpoint inhibitors with radiotherapy can increase response rates, this approach might be limited by the development of persistent radiation-induced immunosuppression. The ultimate goal of combining immunotherapy with radiotherapy is to induce a shift from an ineffective, pre-existing immune response to a long-lasting, therapy-induced immune response at all sites of disease. To achieve this goal and enable the adaptation and monitoring of individualized treatment approaches, assessment of the dynamic changes in the immune system at the patient level is essential. In this Review, we summarize the available clinical data, including forthcoming methods to assess the immune response to radiotherapy at the patient level, ranging from serum biomarkers to imaging techniques that enable investigation of immune cell dynamics in patients. Furthermore, we discuss modelling approaches that have been developed to predict the interaction of immunotherapy with radiotherapy, and highlight how they could be combined with biomarkers of antitumour immunity to optimize radiotherapy regimens and maximize their synergy with immunotherapy.
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Chronic inflammation in multiple sclerosis - seeing what was always there. Nat Rev Neurol 2019; 15:582-593. [PMID: 31420598 DOI: 10.1038/s41582-019-0240-y] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/09/2019] [Indexed: 12/18/2022]
Abstract
Activation of innate immune cells and other compartmentalized inflammatory cells in the brains and spinal cords of people with relapsing-remitting multiple sclerosis (MS) and progressive MS has been well described histopathologically. However, conventional clinical MRI is largely insensitive to this inflammatory activity. The past two decades have seen the introduction of quantitative dynamic MRI scanning with contrast agents that are sensitive to the reduction in blood-brain barrier integrity associated with inflammation and to the trafficking of inflammatory myeloid cells. New MRI imaging sequences provide improved contrast for better detection of grey matter lesions. Quantitative lesion volume measures and magnetic resonance susceptibility imaging are sensitive to the activity of macrophages in the rims of white matter lesions. PET and magnetic resonance spectroscopy methods can also be used to detect contributions from innate immune activation in the brain and spinal cord. Some of these advanced research imaging methods for visualization of chronic inflammation are practical for relatively routine clinical applications. Observations made with the use of these techniques suggest ways of stratifying patients with MS to improve their care. The imaging methods also provide new tools to support the development of therapies for chronic inflammation in MS.
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Recent Developments in TSPO PET Imaging as A Biomarker of Neuroinflammation in Neurodegenerative Disorders. Int J Mol Sci 2019; 20:ijms20133161. [PMID: 31261683 PMCID: PMC6650818 DOI: 10.3390/ijms20133161] [Citation(s) in RCA: 144] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 05/20/2019] [Accepted: 05/20/2019] [Indexed: 12/12/2022] Open
Abstract
Neuroinflammation is an inflammatory response in the brain and spinal cord, which can involve the activation of microglia and astrocytes. It is a common feature of many central nervous system disorders, including a range of neurodegenerative disorders. An overlap between activated microglia, pro-inflammatory cytokines and translocator protein (TSPO) ligand binding was shown in early animal studies of neurodegeneration. These findings have been translated in clinical studies, where increases in TSPO positron emission tomography (PET) signal occur in disease-relevant areas across a broad spectrum of neurodegenerative diseases. While this supports the use of TSPO PET as a biomarker to monitor response in clinical trials of novel neurodegenerative therapeutics, the clinical utility of current TSPO PET radioligands has been hampered by the lack of high affinity binding to a prevalent form of polymorphic TSPO (A147T) compared to wild type TSPO. This review details recent developments in exploration of ligand-sensitivity to A147T TSPO that have yielded ligands with improved clinical utility. In addition to developing a non-discriminating TSPO ligand, the final frontier of TSPO biomarker research requires developing an understanding of the cellular and functional interpretation of the TSPO PET signal. Recent insights resulting from single cell analysis of microglial phenotypes are reviewed.
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Sucksdorff M, Tuisku J, Matilainen M, Vuorimaa A, Smith S, Keitilä J, Rokka J, Parkkola R, Nylund M, Rinne J, Rissanen E, Airas L. Natalizumab treatment reduces microglial activation in the white matter of the MS brain. NEUROLOGY-NEUROIMMUNOLOGY & NEUROINFLAMMATION 2019; 6:e574. [PMID: 31355310 PMCID: PMC6624093 DOI: 10.1212/nxi.0000000000000574] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 04/02/2019] [Indexed: 01/31/2023]
Abstract
Objective To evaluate whether natalizumab treatment reduces microglial activation in MS. Methods We measured microglial activation using the 18-kDa translocator protein (TSPO)-binding radioligand [11C]PK11195 and PET imaging in 10 patients with MS before and after 1 year treatment with natalizumab. Microglial activation was evaluated as the distribution volume ratio (DVR) of the specifically bound radioligand in brain white and gray matter regions of interest. MRI and disability measurements were performed for comparison. Evaluation was performed identically with 11 age- and sex-matched patients with MS who had no MS therapy. Results Natalizumab treatment reduced microglial activation in the normal-appearing white matter (NAWM; baseline DVR vs DVR after 1 year of treatment 1.25 vs 1.22, p = 0.014, Wilcoxon) and at the rim of chronic lesions (baseline DVR vs DVR after 1 year of treatment 1.24 vs 1.18, p = 0.014). In patients with MS with no treatment, there was an increase in microglial activation at the rim of chronic lesions (1.23 vs 1.27, p = 0.045). No alteration was observed in microglial activation in gray matter areas. In the untreated patient group, higher microglial activation at baseline was associated with more rapid disability progression during an average of 4 years of follow-up. Conclusions TSPO-PET imaging can be used as a tool to assess longitudinal changes in microglial activation in the NAWM and in the perilesional areas in the MS brain in vivo. Natalizumab treatment reduces the diffuse compartmentalized CNS inflammation related to brain resident innate immune cells.
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Affiliation(s)
- Marcus Sucksdorff
- Turku PET Centre (M.S., J.T., M.M., A.V., S.S., J.K., J. Rokka, M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; Division of Clinical Neurosciences (M.S., M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; and Department of Radiology (R.P.), University Hospital and University of Turku, Finland
| | - Jouni Tuisku
- Turku PET Centre (M.S., J.T., M.M., A.V., S.S., J.K., J. Rokka, M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; Division of Clinical Neurosciences (M.S., M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; and Department of Radiology (R.P.), University Hospital and University of Turku, Finland
| | - Markus Matilainen
- Turku PET Centre (M.S., J.T., M.M., A.V., S.S., J.K., J. Rokka, M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; Division of Clinical Neurosciences (M.S., M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; and Department of Radiology (R.P.), University Hospital and University of Turku, Finland
| | - Anna Vuorimaa
- Turku PET Centre (M.S., J.T., M.M., A.V., S.S., J.K., J. Rokka, M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; Division of Clinical Neurosciences (M.S., M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; and Department of Radiology (R.P.), University Hospital and University of Turku, Finland
| | - Sarah Smith
- Turku PET Centre (M.S., J.T., M.M., A.V., S.S., J.K., J. Rokka, M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; Division of Clinical Neurosciences (M.S., M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; and Department of Radiology (R.P.), University Hospital and University of Turku, Finland
| | - Joonas Keitilä
- Turku PET Centre (M.S., J.T., M.M., A.V., S.S., J.K., J. Rokka, M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; Division of Clinical Neurosciences (M.S., M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; and Department of Radiology (R.P.), University Hospital and University of Turku, Finland
| | - Johanna Rokka
- Turku PET Centre (M.S., J.T., M.M., A.V., S.S., J.K., J. Rokka, M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; Division of Clinical Neurosciences (M.S., M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; and Department of Radiology (R.P.), University Hospital and University of Turku, Finland
| | - Riitta Parkkola
- Turku PET Centre (M.S., J.T., M.M., A.V., S.S., J.K., J. Rokka, M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; Division of Clinical Neurosciences (M.S., M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; and Department of Radiology (R.P.), University Hospital and University of Turku, Finland
| | - Marjo Nylund
- Turku PET Centre (M.S., J.T., M.M., A.V., S.S., J.K., J. Rokka, M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; Division of Clinical Neurosciences (M.S., M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; and Department of Radiology (R.P.), University Hospital and University of Turku, Finland
| | - Juha Rinne
- Turku PET Centre (M.S., J.T., M.M., A.V., S.S., J.K., J. Rokka, M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; Division of Clinical Neurosciences (M.S., M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; and Department of Radiology (R.P.), University Hospital and University of Turku, Finland
| | - Eero Rissanen
- Turku PET Centre (M.S., J.T., M.M., A.V., S.S., J.K., J. Rokka, M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; Division of Clinical Neurosciences (M.S., M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; and Department of Radiology (R.P.), University Hospital and University of Turku, Finland
| | - Laura Airas
- Turku PET Centre (M.S., J.T., M.M., A.V., S.S., J.K., J. Rokka, M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; Division of Clinical Neurosciences (M.S., M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; and Department of Radiology (R.P.), University Hospital and University of Turku, Finland
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Bauckneht M, Capitanio S, Raffa S, Roccatagliata L, Pardini M, Lapucci C, Marini C, Sambuceti G, Inglese M, Gallo P, Cecchin D, Nobili F, Morbelli S. Molecular imaging of multiple sclerosis: from the clinical demand to novel radiotracers. EJNMMI Radiopharm Chem 2019; 4:6. [PMID: 31659498 PMCID: PMC6453990 DOI: 10.1186/s41181-019-0058-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 03/21/2019] [Indexed: 12/13/2022] Open
Abstract
Background Brain PET imaging with different tracers is mainly clinically used in the field of neurodegenerative diseases and brain tumors. In recent years, the potential usefulness of PET has also gained attention in the field of MS. In fact, MS is a complex disease and several processes can be selected as a target for PET imaging. The use of PET with several different tracers has been mainly evaluated in the research setting to investigate disease pathophysiology (i.e. phenotypes, monitoring of progression) or to explore its use a surrogate end-point in clinical trials. Results We have reviewed PET imaging studies in MS in humans and animal models. Tracers have been grouped according to their pathophysiological targets (ie. tracers for myelin kinetic, neuroinflammation, and neurodegeneration). The emerging clinical indication for brain PET imaging in the differential diagnosis of suspected tumefactive demyelinated plaques as well as the clinical potential provided by PET images in view of the recent introduction of PET/MR technology are also addressed. Conclusion While several preclinical and fewer clinical studies have shown results, full-scale clinical development programs are needed to translate molecular imaging technologies into a clinical reality that could ideally fit into current precision medicine perspectives.
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Affiliation(s)
- Matteo Bauckneht
- Nuclear Medicine Unit, IRCCS Ospedale Policlinico San Martino, Largo R. Benzi 10, 16132, Genoa, Italy.
| | - Selene Capitanio
- Nuclear Medicine Unit, IRCCS Ospedale Policlinico San Martino, Largo R. Benzi 10, 16132, Genoa, Italy
| | - Stefano Raffa
- Department of Health Sciences (DISSAL), University of Genova, Genoa, Italy
| | - Luca Roccatagliata
- Department of Health Sciences (DISSAL), University of Genova, Genoa, Italy.,Neuroradiology, IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Matteo Pardini
- Clinical Neurology, Department of Neuroscience (DINOGMI), University of Genoa, Genoa, Italy.,Clinica Neurologica, IRCCS Ospedale Policlinico, San Martino, Genoa, Italy
| | - Caterina Lapucci
- Clinical Neurology, Department of Neuroscience (DINOGMI), University of Genoa, Genoa, Italy
| | - Cecilia Marini
- Nuclear Medicine Unit, IRCCS Ospedale Policlinico San Martino, Largo R. Benzi 10, 16132, Genoa, Italy.,CNR Institute of Molecular Bioimaging and Physiology, Milan, Italy
| | - Gianmario Sambuceti
- Nuclear Medicine Unit, IRCCS Ospedale Policlinico San Martino, Largo R. Benzi 10, 16132, Genoa, Italy.,Department of Health Sciences (DISSAL), University of Genova, Genoa, Italy
| | - Matilde Inglese
- Clinical Neurology, Department of Neuroscience (DINOGMI), University of Genoa, Genoa, Italy.,Clinica Neurologica, IRCCS Ospedale Policlinico, San Martino, Genoa, Italy
| | - Paolo Gallo
- Multiple Sclerosis Centre of the Veneto Region, Department of Neurosciences DNS, University of Padua, Padua, Italy
| | - Diego Cecchin
- Nuclear Medicine Unit, Department of Medicine-DIMED, Padova University Hospital, Padua, Italy.,Padua Neuroscience Center, University of Padua, Padua, Italy
| | - Flavio Nobili
- Clinical Neurology, Department of Neuroscience (DINOGMI), University of Genoa, Genoa, Italy.,Clinica Neurologica, IRCCS Ospedale Policlinico, San Martino, Genoa, Italy
| | - Silvia Morbelli
- Nuclear Medicine Unit, IRCCS Ospedale Policlinico San Martino, Largo R. Benzi 10, 16132, Genoa, Italy.,Department of Health Sciences (DISSAL), University of Genova, Genoa, Italy
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Bodini B, Stankoff B. PET is necessary to make the next step forward in understanding MS pathophysiology – Yes. Mult Scler 2019; 25:1086-1087. [DOI: 10.1177/1352458519828298] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Benedetta Bodini
- Sorbonne Universités, UPMC Paris 06, Institut du Cerveau et de la Moelle épinière, ICM, Hôpital de la Pitié Salpêtrière, Inserm UMR S 1127, CNRS UMR 7225, Paris, France/AP-HP, Hôpital Saint-Antoine, Paris, France
| | - Bruno Stankoff
- Sorbonne Universités, UPMC Paris 06, Institut du Cerveau et de la Moelle épinière, ICM, Hôpital de la Pitié Salpêtrière, Inserm UMR S 1127, CNRS UMR 7225, Paris, France/AP-HP, Hôpital Saint-Antoine, Paris, France
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Femminella GD, Dani M, Wood M, Fan Z, Calsolaro V, Atkinson R, Edginton T, Hinz R, Brooks DJ, Edison P. Microglial activation in early Alzheimer trajectory is associated with higher gray matter volume. Neurology 2019; 92:e1331-e1343. [PMID: 30796139 PMCID: PMC6511099 DOI: 10.1212/wnl.0000000000007133] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 11/14/2018] [Indexed: 12/11/2022] Open
Abstract
Objective To investigate the influence of microglial activation in the early stages of Alzheimer's disease trajectory, we assessed the relationship between microglial activation and gray matter volume and hippocampal volume in patients with mild cognitive impairment (MCI). Methods In this study, 55 participants (37 with early stages of MCI and 18 controls) underwent [11C]PBR28 PET, a marker of microglial activation; volumetric MRI to evaluate gray matter and hippocampal volumes as well as clinical and neuropsychometric evaluation. [11C]PBR28 VT (volume of distribution) was calculated using arterial input function and Logan graphical analysis. Gray matter volume and hippocampal volumes were calculated from MRI for each participant. Statistical parametric mapping software was used to perform voxel-wise correlations and biological parametric mapping analysis. Amyloid status was assessed using [18F]flutemetamol PET. Results Higher [11C]PBR28 VT in different cortical areas correlated with higher gray matter volume in both amyloid-positive and -negative MCI. In addition, higher hippocampal volume correlated with higher cortical [11C]PBR28 Logan VT. Conclusions In this in vivo study, we have demonstrated that microglial activation quantified using [11C]PBR28 PET was associated with higher gray matter volume and higher hippocampal volume in patients with MCI. This might suggest that microglial activation may not always be associated with neuronal damage, and indeed it may have a beneficial effect in the early stages of the Alzheimer trajectory. While further longitudinal studies are necessary, these findings have significant implications on therapeutic strategies targeting microglial activation.
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Affiliation(s)
- Grazia Daniela Femminella
- From the Department of Medicine (G.D.F., M.D., M.W., Z.F., V.C., R.A., D.J.B., P.E.), Imperial College London; Department of Psychology (T.E.), University of London, London; Wolfson Molecular Imaging Centre (R.H.), University of Manchester, UK; and Department of Nuclear Medicine (D.J.B.), Aarhus University, Denmark
| | - Melanie Dani
- From the Department of Medicine (G.D.F., M.D., M.W., Z.F., V.C., R.A., D.J.B., P.E.), Imperial College London; Department of Psychology (T.E.), University of London, London; Wolfson Molecular Imaging Centre (R.H.), University of Manchester, UK; and Department of Nuclear Medicine (D.J.B.), Aarhus University, Denmark
| | - Melanie Wood
- From the Department of Medicine (G.D.F., M.D., M.W., Z.F., V.C., R.A., D.J.B., P.E.), Imperial College London; Department of Psychology (T.E.), University of London, London; Wolfson Molecular Imaging Centre (R.H.), University of Manchester, UK; and Department of Nuclear Medicine (D.J.B.), Aarhus University, Denmark
| | - Zhen Fan
- From the Department of Medicine (G.D.F., M.D., M.W., Z.F., V.C., R.A., D.J.B., P.E.), Imperial College London; Department of Psychology (T.E.), University of London, London; Wolfson Molecular Imaging Centre (R.H.), University of Manchester, UK; and Department of Nuclear Medicine (D.J.B.), Aarhus University, Denmark
| | - Valeria Calsolaro
- From the Department of Medicine (G.D.F., M.D., M.W., Z.F., V.C., R.A., D.J.B., P.E.), Imperial College London; Department of Psychology (T.E.), University of London, London; Wolfson Molecular Imaging Centre (R.H.), University of Manchester, UK; and Department of Nuclear Medicine (D.J.B.), Aarhus University, Denmark
| | - Rebecca Atkinson
- From the Department of Medicine (G.D.F., M.D., M.W., Z.F., V.C., R.A., D.J.B., P.E.), Imperial College London; Department of Psychology (T.E.), University of London, London; Wolfson Molecular Imaging Centre (R.H.), University of Manchester, UK; and Department of Nuclear Medicine (D.J.B.), Aarhus University, Denmark
| | - Trudi Edginton
- From the Department of Medicine (G.D.F., M.D., M.W., Z.F., V.C., R.A., D.J.B., P.E.), Imperial College London; Department of Psychology (T.E.), University of London, London; Wolfson Molecular Imaging Centre (R.H.), University of Manchester, UK; and Department of Nuclear Medicine (D.J.B.), Aarhus University, Denmark
| | - Rainer Hinz
- From the Department of Medicine (G.D.F., M.D., M.W., Z.F., V.C., R.A., D.J.B., P.E.), Imperial College London; Department of Psychology (T.E.), University of London, London; Wolfson Molecular Imaging Centre (R.H.), University of Manchester, UK; and Department of Nuclear Medicine (D.J.B.), Aarhus University, Denmark
| | - David J Brooks
- From the Department of Medicine (G.D.F., M.D., M.W., Z.F., V.C., R.A., D.J.B., P.E.), Imperial College London; Department of Psychology (T.E.), University of London, London; Wolfson Molecular Imaging Centre (R.H.), University of Manchester, UK; and Department of Nuclear Medicine (D.J.B.), Aarhus University, Denmark
| | - Paul Edison
- From the Department of Medicine (G.D.F., M.D., M.W., Z.F., V.C., R.A., D.J.B., P.E.), Imperial College London; Department of Psychology (T.E.), University of London, London; Wolfson Molecular Imaging Centre (R.H.), University of Manchester, UK; and Department of Nuclear Medicine (D.J.B.), Aarhus University, Denmark.
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Zinnhardt B, Belloy M, Fricke IB, Orije J, Guglielmetti C, Hermann S, Wagner S, Schäfers M, Van der Linden A, Jacobs AH. Molecular Imaging of Immune Cell Dynamics During De- and Remyelination in the Cuprizone Model of Multiple Sclerosis by [ 18F]DPA-714 PET and MRI. Theranostics 2019; 9:1523-1537. [PMID: 31037121 PMCID: PMC6485187 DOI: 10.7150/thno.32461] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 01/07/2019] [Indexed: 12/27/2022] Open
Abstract
Background: Activation and dysregulation of innate, adaptive and resident immune cells in response to damage determine the pathophysiology of demyelinating disorders. Among the plethora of involved cells, microglia/macrophages and astrocytes play an important role in the pathogenesis of demyelinating disorders. The in-depth investigation of the spatio-temporal profile of these cell types in vivo may inform about the exact disease state and localization as well as may allow to monitor therapeutic modulation of the components of the neuroinflammatory response during the course of multiple sclerosis (MS). In this study, we aimed to non-invasively decipher the degree and temporal profile of neuroinflammation (TSPO - [18F]DPA-714 PET) in relation to selected magnetic resonance imaging (MRI) parameters (T2 maps) in the cuprizone (CPZ)-induced model of demyelination. Methods: C57Bl6 (n=30) mice were fed with a standard chow mixed with 0.2% (w/w) CPZ for 4 (n=10; demyelination) and 6 weeks (n=10; spontaneous remyelination). The degree of neuroinflammation at de- and remyelination was assessed by [18F]DPA-714 PET, multi-echo T2 MRI, autoradiography and immunohistochemistry. Results: CPZ-induced brain alterations were confirmed by increase of T2 relaxation times in both white and grey matter after 3 and 5 weeks of CPZ. Peak [18F]DPA-714 was found in the corpus callosum (CC, white matter), the hippocampus (HC, grey matter) and thalamus (grey matter) after 4 weeks of CPZ treatment and declined after 6 weeks of CPZ. Ex vivo autoradiography and dedicated immunofluorescence showed demyelination/remyelination with corresponding increased/decreased TSPO levels in the CC and hippocampus, confirming the spatial distribution of [18F]DPA-714 in vivo. The expression of TSPO microglia and astrocytes is time-dependent in this model. Microglia predominantly express TSPO at demyelination, while the majority of astrocytes express TSPO during remyelination. The combination of PET- and MRI-based imaging biomarkers demonstrated the regional and temporal development of the CPZ model-associated neuroinflammatory response in grey and white matter regions. Conclusions: The combination of [18F]DPA-714 PET and T2 mapping may allow to further elucidate the regional and temporal profile of inflammatory signals depending on the myelination status, although the underlying inflammatory microenvironment changes. A combination of the described imaging biomarkers may facilitate the development of patient-tailored strategies for immunomodulatory and neuro-restorative therapies in MS.
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18F-PBR06 Versus 11C-PBR28 PET for Assessing White Matter Translocator Protein Binding in Multiple Sclerosis. Clin Nucl Med 2018; 43:e289-e295. [PMID: 30004939 DOI: 10.1097/rlu.0000000000002179] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND AND PURPOSE F-PBR06 and C-PBR28 are second-generation PET radioligands targeting the 18-kd translocator protein to assess microglial activation. We directly compared F-PBR06 and C-PBR28 for detecting brain translocator protein binding in multiple sclerosis (MS). METHODS Six patients with MS (4 women; mean age ± SD, 32.1 ± 4.9 [range, 23.5-37.4 years]; Expanded Disability Status Scale score 2.3 ± 1.2 [range, 1.0-4.0]) underwent brain PET with both ligands, along with 3-T MRI. MRI was coregistered to the summed 60- to 90-minute PET images. SUV ratios (SUVRs), derived by normalization to global brain radioactivity, were obtained for whole-brain white matter (WM), supratentorial WM, normal-appearing WM (NAWM), and T2 (fluid-attenuated inversion recovery) hyperintense and T1 hypointense MS WM lesions. The highest mean SUVR for the fluid-attenuated inversion-recovery lesional slices was defined as SUVRmax. RESULTS F-PBR06 and C-PBR28 were moderately intercorrelated for whole-brain WM SUVR (r = 0.83, P = 0.04) and supratentorial WM SUVR (r = 0.81, P = 0.05) but not for SUVRs of NAWM, T1 lesions, T2 lesions, or SUVRmax. Both tracers demonstrated that SUVR was higher in NAWM than in T1 and T2 lesions (all P < 0.05). F-PBR06 (but not C-PBR28) demonstrated a higher SUVR in T1 versus T2 lesions (0.85 ± 0.07 vs 0.78 ± 0.03, P = 0.03). F-PBR06-derived (but not C-PBR28) SUVRmax correlated with both Expanded Disability Status Scale score (r = 0.82, P = 0.04) and timed 25-ft walking speed (r = 0.89, P = 0.01). CONCLUSIONS Our preliminary results suggest an association between microglial activation and physical disability in MS. Microglial detection in lesions was not interchangeable between the tracers, with a higher clinical relevance suggested for F-PBR06.
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Stankoff B, Poirion E, Tonietto M, Bodini B. Exploring the heterogeneity of MS lesions using positron emission tomography: a reappraisal of their contribution to disability. Brain Pathol 2018; 28:723-734. [PMID: 30020560 PMCID: PMC8099240 DOI: 10.1111/bpa.12641] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2018] [Accepted: 07/09/2018] [Indexed: 12/22/2022] Open
Abstract
The biological mechanisms driving disability worsening in multiple sclerosis (MS) are only partly understood. Monitoring changes in lesion load on MRI has a limited predictive value on the progression of clinical disability, and there is an essential need for novel imaging markers specific for the main candidate mechanisms underlying neurodegeneration which include failing myelin repair, innate immune cell activation and gray matter neuronal damage. Positron Emission Tomography (PET) is an imaging technology based on the injection of radiotracers directed against specific molecular targets, which has recently allowed the selective quantification in-vivo of the key biological mechanisms relevant to MS pathophysiology. Pilot PET studies performed in patients with all forms of MS allowed to revisit the contribution of MS lesions to disability worsening and showed that the evolution of lesions toward chronic activation, together with their remyelination profile were relevant predictors of disability worsening. PET offers the opportunity to bridge a critical gap between neuropathology and in-vivo imaging. This technique provides an original approach to disentangle some of the most relevant pathological components driving MS progression, to follow-up their temporal evolution, to investigate their clinical relevance and to evaluate novel therapeutics aimed to prevent disease progression.
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Affiliation(s)
- Bruno Stankoff
- Sorbonne UniversitésUPMC Paris 06Institut du Cerveau et de la Moelle épinièreICMHôpital de la Pitié SalpêtrièreInserm UMR S 1127CNRS UMR 7225ParisFrance
- AP‐HPHôpital Saint‐AntoineParisFrance
| | - Emilie Poirion
- Sorbonne UniversitésUPMC Paris 06Institut du Cerveau et de la Moelle épinièreICMHôpital de la Pitié SalpêtrièreInserm UMR S 1127CNRS UMR 7225ParisFrance
| | - Matteo Tonietto
- Sorbonne UniversitésUPMC Paris 06Institut du Cerveau et de la Moelle épinièreICMHôpital de la Pitié SalpêtrièreInserm UMR S 1127CNRS UMR 7225ParisFrance
| | - Benedetta Bodini
- Sorbonne UniversitésUPMC Paris 06Institut du Cerveau et de la Moelle épinièreICMHôpital de la Pitié SalpêtrièreInserm UMR S 1127CNRS UMR 7225ParisFrance
- AP‐HPHôpital Saint‐AntoineParisFrance
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Airas L, Nylund M, Rissanen E. Evaluation of Microglial Activation in Multiple Sclerosis Patients Using Positron Emission Tomography. Front Neurol 2018; 9:181. [PMID: 29632509 PMCID: PMC5879102 DOI: 10.3389/fneur.2018.00181] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 03/08/2018] [Indexed: 01/24/2023] Open
Abstract
Understanding the mechanisms underlying progression in multiple sclerosis (MS) is one of the key elements contributing to the identification of appropriate therapeutic targets for this under-managed condition. In addition to plaque-related focal inflammatory pathology typical for relapsing remitting MS there are, in progressive MS, widespread diffuse alterations in brain areas outside the focal lesions. This diffuse pathology is tightly related to microglial activation and is co-localized with signs of neurodegeneration. Microglia are brain-resident cells of the innate immune system and overactivation of microglia is associated with several neurodegenerative diseases. Understanding the role of microglial activation in relation to developing neurodegeneration and disease progression may provide a key to developing therapies to target progressive MS. 18-kDa translocator protein (TSPO) is a mitochondrial molecule upregulated in microglia upon their activation. Positron emission tomography (PET) imaging using TSPO-binding radioligands provides a method to assess microglial activation in patients in vivo. In this mini-review, we summarize the current status of TSPO imaging in the field of MS. In addition, the review discusses new insights into the potential use of this method in treatment trials and in clinical assessment of progressive MS.
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Affiliation(s)
- Laura Airas
- Division of Clinical Neurosciences, Turku University Hospital and University of Turku, Turku, Finland.,Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland
| | - Marjo Nylund
- Division of Clinical Neurosciences, Turku University Hospital and University of Turku, Turku, Finland.,Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland
| | - Eero Rissanen
- Division of Clinical Neurosciences, Turku University Hospital and University of Turku, Turku, Finland.,Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland
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Stangel M, Kuhlmann T, Matthews PM, Kilpatrick TJ. Achievements and obstacles of remyelinating therapies in multiple sclerosis. Nat Rev Neurol 2017; 13:742-754. [PMID: 29146953 DOI: 10.1038/nrneurol.2017.139] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Remyelination in the CNS is the natural process of damage repair in demyelinating diseases such as multiple sclerosis (MS). However, remyelination becomes inadequate in many people with MS, which results in axonal degeneration and clinical disability. Enhancement of remyelination is a logical therapeutic goal; nevertheless, all currently licensed therapies for MS are immunomodulatory and do not support remyelination directly. Several molecular pathways have been identified as potential therapeutic targets to induce remyelination, and some of these have now been assessed in proof-of-concept clinical trials. However, trial design faces several obstacles: optimal clinical or paraclinical outcome measures to assess remyelination remain ill-defined, and identification of the ideal timing of therapy is also a crucial issue. In addition, realistic expectations are needed concerning the probable benefits of such therapies. Nevertheless, approaches that enhance remyelination are likely to be protective for axons and so could prevent long-term neurodegeneration. Future MS treatment paradigms, therefore, are likely to comprise a combinatorial approach that involves both immunomodulatory and regenerative treatments.
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Affiliation(s)
- Martin Stangel
- Clinical Neuroimmunology and Neurochemistry, Department of Neurology, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany
| | - Tanja Kuhlmann
- Institute of Neuropathology, University Hospital Münster, Pottkamp 2, 48149 Münster, Germany
| | - Paul M Matthews
- Division of Brain Sciences, Department of Medicine, and UK Dementia Research Institute, Imperial College London, Burlington Danes, Hammersmith Hospital, DuCane Road, London W12 0NN, UK
| | - Trevor J Kilpatrick
- Department of Anatomy and Neuroscience and Melbourne Neuroscience Institute, University of Melbourne, 30 Royal Parade, Parkville, Victoria 3010, Australia
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Boscutti G, Huiban M, Passchier J. Use of carbon-11 labelled tool compounds in support of drug development. DRUG DISCOVERY TODAY. TECHNOLOGIES 2017; 25:3-10. [PMID: 29233265 DOI: 10.1016/j.ddtec.2017.11.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 11/15/2017] [Accepted: 11/16/2017] [Indexed: 06/07/2023]
Abstract
The pharmaceutical industry is facing key challenges to improve return on R&D investment. Positron emission tomography (PET), by itself or in combination with complementary technologies such as magnetic resonance imaging (MRI), provides a unique opportunity to confirm a candidate's ability to meet the so-called 'three pillars' of drug development. Positive confirmation provides confidence for go/no-go decision making at an early stage of the development process and enables informed clinical progression. Whereas fluorine-18 has probably gained wider use in the community, there are benefits to using carbon-11 given the greater flexibility the use of this isotope permits in adaptive clinical study design. This review explores the scope of available carbon-11 chemistries and provides clinical examples to highlight its value in PET studies in support of drug development.
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Affiliation(s)
- Giulia Boscutti
- Imanova Ltd., Burlington Danes Building, Imperial College London, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
| | - Mickael Huiban
- Imanova Ltd., Burlington Danes Building, Imperial College London, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
| | - Jan Passchier
- Imanova Ltd., Burlington Danes Building, Imperial College London, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK.
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