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Dixon L, McNamara C, Dhasmana D, Taylor GP, Davies N. Imaging Spectrum of HTLV-1–Related Neurologic Disease. Neurol Clin Pract 2023; 13:e200147. [PMID: 37066106 PMCID: PMC10092304 DOI: 10.1212/cpj.0000000000200147] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 01/23/2023] [Indexed: 03/29/2023]
Abstract
Purpose of ReviewHuman T-cell lymphotropic virus type 1 (HTLV-1)–associated myelopathy (HAM) is a well-recognized neurologic complication of HTLV-1. Beyond HAM, several other neurologic manifestations are increasingly recognized, including acute myelopathy, encephalopathy, and myositis. The clinical and imaging features of these presentations are less well understood and potentially underdiagnosed. In this study, we summarize the imaging features of HTLV-1–related neurologic disease, providing both a pictorial review and pooled series of the less well-recognized presentations.Recent Findings35 cases of acute/subacute HAM and 12 cases of HTLV-1–related encephalopathy were found. In subacute HAM, cervical and upper thoracic longitudinally extensive tranverse myelitis was noted, while in HTLV-1–related encephalopathy, confluent lesions in the frontoparietal white matter and along the corticospinal tracts were the most prevalent finding.SummaryThere are varied clinical and imaging presentations of HTLV-1–related neurologic disease. Recognition of these features aids early diagnosis where therapy may have the greatest benefit.
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Affiliation(s)
- Luke Dixon
- Department of Neuroradiology (LD, CM), Imperial College Healthcare NHS Trust, London, UK; National Centre for Human Retrovirology (DD, GPT, ND), Imperial College Healthcare NHS Trust, London, UK; Section of Virology, Department of Infectious Disease (GPT), Imperial College London, UK; Department of Neurology (GPT), Imperial College Healthcare NHS Trust, London, UK; Department of Neurology (GPT), Chelsea and Westminster Hospital NHS Trust, London, UK
| | - Cillian McNamara
- Department of Neuroradiology (LD, CM), Imperial College Healthcare NHS Trust, London, UK; National Centre for Human Retrovirology (DD, GPT, ND), Imperial College Healthcare NHS Trust, London, UK; Section of Virology, Department of Infectious Disease (GPT), Imperial College London, UK; Department of Neurology (GPT), Imperial College Healthcare NHS Trust, London, UK; Department of Neurology (GPT), Chelsea and Westminster Hospital NHS Trust, London, UK
| | - Divya Dhasmana
- Department of Neuroradiology (LD, CM), Imperial College Healthcare NHS Trust, London, UK; National Centre for Human Retrovirology (DD, GPT, ND), Imperial College Healthcare NHS Trust, London, UK; Section of Virology, Department of Infectious Disease (GPT), Imperial College London, UK; Department of Neurology (GPT), Imperial College Healthcare NHS Trust, London, UK; Department of Neurology (GPT), Chelsea and Westminster Hospital NHS Trust, London, UK
| | - Graham P Taylor
- Department of Neuroradiology (LD, CM), Imperial College Healthcare NHS Trust, London, UK; National Centre for Human Retrovirology (DD, GPT, ND), Imperial College Healthcare NHS Trust, London, UK; Section of Virology, Department of Infectious Disease (GPT), Imperial College London, UK; Department of Neurology (GPT), Imperial College Healthcare NHS Trust, London, UK; Department of Neurology (GPT), Chelsea and Westminster Hospital NHS Trust, London, UK
| | - Nicholas Davies
- Department of Neuroradiology (LD, CM), Imperial College Healthcare NHS Trust, London, UK; National Centre for Human Retrovirology (DD, GPT, ND), Imperial College Healthcare NHS Trust, London, UK; Section of Virology, Department of Infectious Disease (GPT), Imperial College London, UK; Department of Neurology (GPT), Imperial College Healthcare NHS Trust, London, UK; Department of Neurology (GPT), Chelsea and Westminster Hospital NHS Trust, London, UK
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Rocamonde B, Hasan U, Mathieu C, Dutartre H. Viral-induced neuroinflammation: Different mechanisms converging to similar exacerbated glial responses. Front Neurosci 2023; 17:1108212. [PMID: 36937670 PMCID: PMC10017484 DOI: 10.3389/fnins.2023.1108212] [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: 11/25/2022] [Accepted: 02/10/2023] [Indexed: 03/06/2023] Open
Abstract
There is increasing evidence that viral infections are the source/origin of various types of encephalitis, encephalomyelitis, and other neurological and cognitive disorders. While the involvement of certain viruses, such as the Nipah virus and measles virus, is known, the mechanisms of neural invasion and the factors that trigger intense immune reactions are not fully understood. Based on recent publications, this review discusses the role of the immune response, interactions between viruses and glial cells, and cytokine mediators in the development of inflammatory diseases in the central nervous system. It also highlights the significant gaps in knowledge regarding these mechanisms.
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Affiliation(s)
- Brenda Rocamonde
- Centre International de Recherche en Infectiologie, Équipe d’Oncogenèse Rétrovirale, INSERM U1111 - Université Claude Bernard Lyon 1, CNRS, UMR 5308, École Normale Supérieure de Lyon, Université Lyon, Lyon, France
- Equipe Labellisée par la Fondation pour la Recherche Médicale, Labex Ecofect, Lyon, France
- *Correspondence: Brenda Rocamonde,
| | - Uzma Hasan
- Centre International de Recherche en Infectiologie, Team Enveloped Viruses, Vectors and Immunotherapy INSERM U1111 - Université Claude Bernard Lyon 1, CNRS, UMR 5308, École Normale Supérieure de Lyon, Université Lyon, Lyon, France
- The Lyon Immunotherapy for Cancer Laboratory (LICL), Centre de Recherche en Cancérologie de Lyon (CRCL, UMR INSERM 1052 – CNRS 5286) Centre Léon Bérard, Lyon, France
| | - Cyrille Mathieu
- Centre International de Recherche en Infectiologie Équipe Neuro-Invasion, Tropism and Viral Encephalitis, INSERM U1111 - Université Claude Bernard Lyon 1, CNRS, UMR 5308, École Normale Supérieure de Lyon, Université Lyon, Lyon, France
- Cyrille Mathieu,
| | - Hélène Dutartre
- Centre International de Recherche en Infectiologie, Équipe d’Oncogenèse Rétrovirale, INSERM U1111 - Université Claude Bernard Lyon 1, CNRS, UMR 5308, École Normale Supérieure de Lyon, Université Lyon, Lyon, France
- Equipe Labellisée par la Fondation pour la Recherche Médicale, Labex Ecofect, Lyon, France
- Hélène Dutartre,
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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: 15] [Impact Index Per Article: 7.5] [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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Fang YHD, McConathy JE, Yacoubian TA, Zhang Y, Kennedy RE, Standaert DG. Image Quantification for TSPO PET with a Novel Image-Derived Input Function Method. Diagnostics (Basel) 2022; 12:1161. [PMID: 35626315 PMCID: PMC9140104 DOI: 10.3390/diagnostics12051161] [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: 03/29/2022] [Revised: 05/02/2022] [Accepted: 05/03/2022] [Indexed: 01/27/2023] Open
Abstract
There is a growing interest in using 18F-DPA-714 PET to study neuroinflammation and microglial activation through imaging the 18-kDa translocator protein (TSPO). Although quantification of 18F-DPA-714 binding can be achieved through kinetic modeling analysis with an arterial input function (AIF) measured with blood sampling procedures, the invasiveness of such procedures has been an obstacle for wide application. To address these challenges, we developed an image-derived input function (IDIF) that noninvasively estimates the arterial input function from the images acquired for 18F-DPA-714 quantification. Methods: The method entails three fully automatic steps to extract the IDIF, including a segmentation of voxels with highest likelihood of being the arterial blood over the carotid artery, a model-based matrix factorization to extract the arterial blood signal, and a scaling optimization procedure to scale the extracted arterial blood signal into the activity concentration unit. Two cohorts of human subjects were used to evaluate the extracted IDIF. In the first cohort of five subjects, arterial blood sampling was performed, and the calculated IDIF was validated against the measured AIF through the comparison of distribution volumes from AIF (VT,AIF) and IDIF (VT,IDIF). In the second cohort, PET studies from twenty-eight healthy controls without arterial blood sampling were used to compare VT,IDIF with VT,REF measured using a reference region-based analysis to evaluate whether it can distinguish high-affinity (HAB) and mixed-affinity (MAB) binders. Results: In the arterial blood-sampling cohort, VT derived from IDIF was found to be an accurate surrogate of the VT from AIF. The bias of VT, IDIF was −5.8 ± 7.8% when compared to VT,AIF, and the linear mixed effect model showed a high correlation between VT,AIF and VT, IDIF (p < 0.001). In the nonblood-sampling cohort, VT, IDIF showed a significance difference between the HAB and MAB healthy controls. VT, IDIF and standard uptake values (SUV) showed superior results in distinguishing HAB from MAB subjects than VT,REF. Conclusions: A novel IDIF method for 18F-DPA-714 PET quantification was developed and evaluated in this study. This IDIF provides a noninvasive alternative measurement of VT to quantify the TSPO binding of 18F-DPA-714 in the human brain through dynamic PET scans.
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Affiliation(s)
- Yu-Hua Dean Fang
- Department of Radiology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA;
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA; (T.A.Y.); (D.G.S.)
| | - Jonathan E. McConathy
- Department of Radiology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA;
| | - Talene A. Yacoubian
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA; (T.A.Y.); (D.G.S.)
| | - Yue Zhang
- Department of Medicine, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA; (Y.Z.); (R.E.K.)
| | - Richard E. Kennedy
- Department of Medicine, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA; (Y.Z.); (R.E.K.)
| | - David G. Standaert
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA; (T.A.Y.); (D.G.S.)
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Alagaratnam J, Winston A. Molecular neuroimaging of inflammation in HIV. Clin Exp Immunol 2021; 210:14-23. [PMID: 35020855 PMCID: PMC9585552 DOI: 10.1093/cei/uxab013] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 09/13/2021] [Accepted: 11/03/2021] [Indexed: 01/12/2023] Open
Abstract
People with HIV now have near-normal life expectancies due to the success of effective combination antiretroviral therapy (cART). Following cART initiation, immune recovery occurs, and opportunistic diseases become rare. Despite this, high rates of non-infectious comorbidities persist in treated people with HIV, hypothesized to be related to persistent immuno-activation. One such comorbidity is cognitive impairment, which may partly be driven by ongoing neuro-inflammation in otherwise effectively treated people with HIV. In order to develop therapeutic interventions to address neuro-inflammation in effectively treated people with HIV, a deeper understanding of the pathogenic mechanisms driving persistent neuro-inflammatory responses and the ability to better characterize and measure neuro-inflammation in the central nervous system is required. This review highlights recent advances in molecular neuroimaging techniques which have the potential to assess neuro-inflammatory responses within the central nervous system in HIV disease. Proton magnetic resonance spectroscopy (1H-MRS) has been utilized to assess neuro-inflammatory responses since early in the HIV pandemic and shows promise in recent studies assessing different antiretroviral regimens. 1H-MRS is widely available in both resource-rich and some resource-constrained settings and is relatively inexpensive. Brain positron emission tomography (PET) imaging using Translocator Protein (TSPO) radioligands is a rapidly evolving field; newer TSPO-radioligands have lower signal-to-noise ratio and have the potential to localize neuro-inflammation within the brain in people with HIV. As HIV therapeutics evolve, people with HIV continue to age and develop age-related comorbidities including cognitive disorders. The use of novel neuroimaging modalities in the field is likely to advance in order to rapidly assess novel therapeutic interventions and may play a role in future clinical assessments.
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Affiliation(s)
- Jasmini Alagaratnam
- Correspondence: Jasmini Alagaratnam, Clinical Trials Centre, Winston Churchill Wing, St. Mary’s Hospital, Praed Street, London W2 1NY, UK.
| | - Alan Winston
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, UK,Department of Genitourinary Medicine & HIV, St Mary’s Hospital, Imperial College Healthcare NHS Trust, London, UK
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Aceves-Serrano L, Sossi V, Doudet DJ. Comparison of Invasive and Non-invasive Estimation of [ 11C]PBR28 Binding in Non-human Primates. Mol Imaging Biol 2021; 24:404-415. [PMID: 34622422 DOI: 10.1007/s11307-021-01661-6] [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: 03/15/2021] [Revised: 09/22/2021] [Accepted: 09/28/2021] [Indexed: 11/28/2022]
Abstract
PURPOSE To identify a reliable alternative to the full blood [11C]PBR28 quantification method that would be easily replicated in multiple research and clinical settings. PROCEDURES Ten [11C]PBR28 scans were acquired from 7 healthy non-human primates (NHP). Arterial input functions (AIFs) were averaged to create a population template input function (TIF). Population-based input functions were created by scaling the TIF with injected activity per body weight (PBIF) or unmetabolized tracer activity in blood at 15-,30-, and 60-min post-injection (PBIF15, PBIF30, and PBIF60). Two additional input functions were used: the native unmetabolized total plasma activity (Totals) and the Totals curve metabolite corrected by a scaled template parent fraction from a 30-min sample (TPF30-IF). Total distribution volumes (VTs) were calculated using PBIF, PBIF30, PBIF15, PBIF60, Totals, TPF30-IF, and the individual AIF (VTAIF). Distribution volume ratios (DVR) were computed using the cerebellum and the centrum semiovale (CSO), as pseudo-reference regions (DVRCereb, DVRCSO). Results obtained with each method were compared to VTAIF. Applicability of these alternative methods was tested on an independent pharmacological challenge dataset of microglial activation and depletion. Evaluation was carried at baseline, immediately after intervention (acute), and weeks post-intervention (post-recovery). RESULTS VTs computed using PBIF15 and PBIF30 showed the best correlation to VTAIF (r > 0.90), while VT derived from the blood-free-scaled PBIF showed poor correlation (r = 0.46) and DVRCSO correlated the least (r = 0.26). In the pharmacological challenge study, most population-derived VT values were comparable to VTAIF at baseline and showed varied sensitivity to challenges at acute and post-recovery evaluation. DVR values did not detect relevant changes. CONCLUSIONS Population-based input functions scaled with a single blood sample might be a useful alternative to using AIF to compute [11C]PBR28 binding in healthy NHPs or animals with comparable metabolism and overall perform better than pseudo-reference regions approaches.
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Affiliation(s)
- Lucero Aceves-Serrano
- Department of Medicine, Division of Neurology, University of British Columbia, Rm M36 Purdy Pavilion, 2221 Wesbrook Mall, Vancouver, BC, V6T 2B5, Canada.
| | - Vesna Sossi
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada
| | - Doris J Doudet
- Department of Medicine, Division of Neurology, University of British Columbia, Rm M36 Purdy Pavilion, 2221 Wesbrook Mall, Vancouver, BC, V6T 2B5, Canada
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Aghajanian S, Teymoori-Rad M, Molaverdi G, Mozhgani SH. Immunopathogenesis and Cellular Interactions in Human T-Cell Leukemia Virus Type 1 Associated Myelopathy/Tropical Spastic Paraparesis. Front Microbiol 2020; 11:614940. [PMID: 33414779 PMCID: PMC7783048 DOI: 10.3389/fmicb.2020.614940] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 11/17/2020] [Indexed: 01/15/2023] Open
Abstract
HTLV-1-Associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP) is a neuropathological disorder in 1–3% of individuals infected with Human T-lymphotropic virus 1 (HTLV-1). This condition is characterized by progressive spastic lower limb weakness and paralysis, lower back pain, bladder incontinence, and mild sensory disturbances resembling spinal forms of multiple sclerosis. This disease also causes chronic disability and is therefore associated with high health burden in areas where HTLV-1 infection is endemic. Despite various efforts in understanding the virus and discovery of novel diagnostic markers, and cellular and viral interactions, HAM/TSP management is still unsatisfactory and mainly focused on symptomatic alleviation, and it hasn’t been explained why only a minority of the virus carriers develop HAM/TSP. This comprehensive review focuses on host and viral factors in association with immunopathology of the disease in hope of providing new insights for drug therapies or other forms of intervention.
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Affiliation(s)
- Sepehr Aghajanian
- Student Research Committee, Alborz University of Medical Sciences, Karaj, Iran
| | - Majid Teymoori-Rad
- Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Ghazale Molaverdi
- Student Research Committee, Alborz University of Medical Sciences, Karaj, Iran
| | - Sayed-Hamidreza Mozhgani
- Non-communicable Diseases Research Center, Alborz University of Medical Sciences, Karaj, Iran.,Department of Microbiology, School of Medicine, Alborz University of Medical Sciences, Karaj, Iran
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Abstract
This article discusses mimics of multiple sclerosis (MS). Excluded in this discussion are neuromyelitis optica and vasculitis, discussed in other articles in this journal. Covered entities include posterior reversible encephalopathy syndrome, reversible vasoconstriction syndrome, acute disseminated encephalomyelitis, Sussac's Syndrome, and chronic idiopathic demyelinating polyneuropathy. There are also multiple infectious entities that mimic MS including; progressive multi-focal leukoencephalopathy (PML), Toxoplasmosis, Tuberculosis, Herpes Simplex Virus, Cytomegalovirus, Varicella zoster virus, Epstein Barr virus, Cryptococcus and Human immunodeficiency virus. In addition, there are leukoencephalopathies that can present in adulthood including Adrenoleukodystrophy, Metachromatic leukodystrophy, Cerebral autosomal dominant idiopathic leukoencephalopathy, Leigh's and Alexanders disease that could be mistaken for MS.
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Aiello M, Cavaliere C, Fiorenza D, Duggento A, Passamonti L, Toschi N. Neuroinflammation in Neurodegenerative Diseases: Current Multi-modal Imaging Studies and Future Opportunities for Hybrid PET/MRI. Neuroscience 2019; 403:125-135. [DOI: 10.1016/j.neuroscience.2018.07.033] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 07/18/2018] [Accepted: 07/19/2018] [Indexed: 12/28/2022]
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Selvaraj S, Bloomfield PS, Cao B, Veronese M, Turkheimer F, Howes OD. Brain TSPO imaging and gray matter volume in schizophrenia patients and in people at ultra high risk of psychosis: An [ 11C]PBR28 study. Schizophr Res 2018; 195:206-214. [PMID: 28893493 PMCID: PMC6027955 DOI: 10.1016/j.schres.2017.08.063] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 08/31/2017] [Accepted: 08/31/2017] [Indexed: 12/12/2022]
Abstract
Patients with schizophrenia show whole brain and cortical gray matter (GM) volume reductions which are progressive early in their illness. Microglia, the resident immune cells in the CNS, phagocytose neurons and synapses. Some post mortem and in vivo studies in schizophrenia show evidence for elevated microglial activation compared to matched controls. However, it is currently unclear how these results relate to changes in cortical structure. METHODS Fourteen patients with schizophrenia and 14 ultra high risk for psychosis (UHR) subjects alongside two groups of age and genotype matched healthy controls received [11C]PBR28 PET scans to index TSPO expression, a marker of microglial activation and a 3T MRI scan. We investigated the relationship between the volume changes of cortical regions and microglial activation in cortical GM (as indexed by [11C]PBR28 distribution volume ratio (DVR). RESULTS The total cortical GM volume was significantly lower in SCZ than the controls [mean (SD)/cm3: SCZ=448.83 (39.2) and controls=499.6 (59.2) (p=0.02) but not in UHR (mean (SD)=503.06 (57.9) and controls=524.46 (45.3) p=0.3). Regression model fitted the total cortical GM DVR values with the cortical regional volumes in SCZ (r=0.81; p<0.001) and in UHR (r=0.63; p=0.02). We found a significant negative correlation between the TSPO signal and total cortical GM volume in SCZ with the highest absolute correlation coefficient in the right superior-parietal cortex (r=-0.72; p=0.006). CONCLUSIONS These findings suggest that microglial activity is related to the altered cortical volume seen in schizophrenia. Longitudinal investigations are required to determine whether microglial activation leads to cortical gray matter loss.
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Affiliation(s)
- Sudhakar Selvaraj
- Department of Psychiatry and Behavioural Sciences, The University of Texas Health Science Center at Houston, Houston, TX 77054, USA; Psychiatric Imaging Group, MRC Clinical Sciences Centre, Institute of Clinical Sciences, Imperial College London, Hammersmith Hospital, London, W12 0NN, UK.
| | - Peter S Bloomfield
- Psychiatric Imaging Group, MRC Clinical Sciences Centre, Institute of Clinical Sciences, Imperial College London, Hammersmith Hospital, London, W12 0NN, UK
| | - Bo Cao
- Department of Psychiatry and Behavioural Sciences, The University of Texas Health Science Center at Houston, Houston, TX 77054, USA
| | - Mattia Veronese
- Centre for Neuroimaging Sciences, IoPPN, King's College London, Box PO89, De Crespigny Park, London SE5 8AF, UK
| | - Federico Turkheimer
- Centre for Neuroimaging Sciences, IoPPN, King's College London, Box PO89, De Crespigny Park, London SE5 8AF, UK
| | - Oliver D Howes
- Psychiatric Imaging Group, MRC Clinical Sciences Centre, Institute of Clinical Sciences, Imperial College London, Hammersmith Hospital, London, W12 0NN, UK; Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, De Crespigny Park, London SE5 8AF, UK
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Schain M, Zanderigo F, Ogden RT, Kreisl WC. Non-invasive estimation of [11C]PBR28 binding potential. Neuroimage 2018; 169:278-285. [DOI: 10.1016/j.neuroimage.2017.12.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 12/01/2017] [Indexed: 01/14/2023] Open
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Human T-cell lymphotropic virus (HTLV)-associated encephalopathy: an under-recognised cause of acute encephalitis? Case series and literature review. J Neurol 2018; 265:871-879. [PMID: 29423617 PMCID: PMC5878187 DOI: 10.1007/s00415-018-8777-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 01/29/2018] [Accepted: 01/30/2018] [Indexed: 01/08/2023]
Abstract
Human T-cell lymphotropic virus (HTLV)-1-associated myelopathy (HAM) is well described. Clinical features are predominantly consistent with cord pathology, though imaging and autopsy studies also demonstrate brain inflammation. In general, this is subclinical; however, six cases have previously been reported of encephalopathy in HTLV-1-infected patients, without alternative identified aetiology. We describe three further cases of encephalitis in the UK HAM cohort (n = 142), whereas the annual incidence of acute encephalitis in the general population is 0.07-12.6 per 100,000. Clinical features included reduced consciousness, fever/hypothermia, headaches, seizures, and focal neurology. Investigation showed: raised CSF protein; pleocytosis; raised CSF:peripheral blood mononuclear cell HTLV-1 proviral load ratio; and MRI either normal or showing white matter changes in brain and cord. Four of the six previous case reports of encephalopathy in HTLV-infected patients also had HAM. Histopathology, reported in three, showed perivascular predominantly CD8+ lymphocytic infiltrates in the brain. One had cerebral demyelination, and all had cord demyelination. We have reviewed the existing six cases in the literature, together with our three new cases. In all seven with HAM, the spastic paraparesis deteriorated sub-acutely preceding encephalitis. Eight of the nine were female, and four of the seven treated with steroids improved. We propose that HTLV-associated encephalopathy may be part of the spectrum of HTLV-1-induced central nervous system disease.
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Evidence of fatigue, disordered sleep and peripheral inflammation, but not increased brain TSPO expression, in seasonal allergy: A [ 11C]PBR28 PET study. Brain Behav Immun 2018; 68:146-157. [PMID: 29054675 DOI: 10.1016/j.bbi.2017.10.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 10/07/2017] [Accepted: 10/16/2017] [Indexed: 02/05/2023] Open
Abstract
Allergy is associated with non-specific symptoms such as fatigue, sleep problems and impaired cognition. One explanation could be that the allergic inflammatory state includes activation of immune cells in the brain, but this hypothesis has not been tested in humans. The aim of the present study was therefore to investigate seasonal changes in the glial cell marker translocator protein (TSPO), and to relate this to peripheral inflammation, fatigue and sleep, in allergy. We examined 18 patients with severe seasonal allergy, and 13 healthy subjects in and out-of pollen season using positron emission tomography (n = 15/13) and the TSPO radioligand [11C]PBR28. In addition, TNF-α, IL-5, IL-6, IL-8 and IFN-γ were measured in peripheral blood, and subjective ratings of fatigue and sleepiness as well as objective and subjective sleep were investigated. No difference in levels of TSPO was seen between patients and healthy subjects, nor in relation to pollen season. However, allergic subjects displayed both increased fatigue, sleepiness and increased percentage of deep sleep, as well as increased levels of IL-5 and TNF-α during pollen season, compared to healthy subjects. Allergic subjects also had shorter total sleep time, regardless of season. In conclusion, allergic subjects are indicated to respond to allergen exposure during pollen season with a clear pattern of behavioral disruption and peripheral inflammatory activation, but not with changes in brain TSPO levels. This underscores a need for development and use of more specific markers to understand brain consequences of peripheral inflammation that will be applicable in human subjects.
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Abstract
Human T cell leukemia virus type 1 (HTLV-1), also known as human T lymphotropic virus type 1, was the first exogenous human retrovirus discovered. Unlike the distantly related lentivirus HIV-1, HTLV-1 causes disease in only 5-10% of infected people, depending on their ethnic origin. But whereas HIV-1 infection and the consequent diseases can be efficiently contained in most cases by antiretroviral drug treatment, there is no satisfactory treatment for the malignant or inflammatory diseases caused by HTLV-1. The purpose of the present article is to review recent advances in the understanding of the mechanisms by which the virus persists in vivo and causes disabling or fatal diseases.
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Affiliation(s)
- Charles R M Bangham
- Division of Infectious Diseases, Faculty of Medicine, Imperial College, London W2 1PG, United Kingdom;
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15
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Scott G, Mahmud M, Owen DR, Johnson MR. Microglial positron emission tomography (PET) imaging in epilepsy: Applications, opportunities and pitfalls. Seizure 2017; 44:42-47. [DOI: 10.1016/j.seizure.2016.10.023] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 10/27/2016] [Indexed: 10/20/2022] Open
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