1
|
Huang Y, Chen T, Hu Y, Li Z. Muscular MRI and magnetic resonance neurography in spinal muscular atrophy. Clin Radiol 2024; 79:673-680. [PMID: 38945793 DOI: 10.1016/j.crad.2024.06.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 04/08/2024] [Accepted: 06/03/2024] [Indexed: 07/02/2024]
Abstract
Spinal muscular atrophy (SMA) is an autosomal recessive genetic disease caused by the degeneration of the α-motor neurons in the anterior horn of the spinal cord. SMA is clinically characterized by progressive and symmetrical muscle weakness and muscle atrophy and ends up with systemic multisystem abnormalities. Quantitative MRI (qMRI) has the advantages of non-invasiveness, objective sensitivity, and high reproducibility, and has important clinical value in evaluating the severity of neuromuscular diseases and monitoring the efficacy of treatment. This article summarizes the clinical use of muscular MRI and magnetic resonance neurography in assessing the progress of SMA.
Collapse
Affiliation(s)
- Y Huang
- Department of Radiology, Shenzhen Childrens Hospital, Shantou University Medical College Affiliated Shenzhen Childrens Hospital, Shenzhen, China
| | - T Chen
- Department of Radiology, Shenzhen Childrens Hospital, Shantou University Medical College Affiliated Shenzhen Childrens Hospital, Shenzhen, China; Department of Radiology, Shenzhen Children's Hospital, China Medical University, Shenzhen, China
| | - Y Hu
- Department of Radiology, Shenzhen Childrens Hospital, Shantou University Medical College Affiliated Shenzhen Childrens Hospital, Shenzhen, China; Department of Radiology, Shenzhen Children's Hospital, China Medical University, Shenzhen, China
| | - Z Li
- Department of Radiology, Shenzhen Childrens Hospital, Shantou University Medical College Affiliated Shenzhen Childrens Hospital, Shenzhen, China.
| |
Collapse
|
2
|
Wu M, Liu C, Sun D. Glucocorticoid-Induced Myopathy: Typology, Pathogenesis, Diagnosis, and Treatment. Horm Metab Res 2024; 56:341-349. [PMID: 38224966 DOI: 10.1055/a-2246-2900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2024]
Abstract
Glucocorticoid-induced myopathy is a non-inflammatory toxic myopathy typified by proximal muscle weakness, muscle atrophy, fatigue, and easy fatigability. These vague symptoms coupled with underlying disorders may mask the signs of glucocorticoid-induced myopathy, leading to an underestimation of the disease's impact. This review briefly summarizes the classification, pathogenesis, and treatment options for glucocorticoid-induced muscle wasting. Additionally, we discuss current diagnostic measures in clinical research and routine care used for diagnosing and monitoring glucocorticoid-induced myopathy, which includes gait speed tests, muscle strength tests, hematologic tests, bioelectrical impedance analysis (BIA), dual-energy X-ray absorptiometry (DXA), computed tomography (CT), magnetic resonance imaging (MRI), electromyography, quantitative muscle ultrasound, histological examination, and genetic analysis. Continuous monitoring of patients receiving glucocorticoid therapy plays an important role in enabling early detection of glucocorticoid-induced myopathy, allowing physicians to modify treatment plans before significant clinical weakness arises.
Collapse
Affiliation(s)
- Mengmeng Wu
- Department of Nephrology, Xuzhou Medical University Affiliated Hospital, Xuzhou, China
- Graduate School, Xuzhou Medical University, Xuzhou, China
| | - Caixia Liu
- Department of Nephrology, Xuzhou Medical University Affiliated Hospital, Xuzhou, China
| | - Dong Sun
- Department of Nephrology, Xuzhou Medical University Affiliated Hospital, Xuzhou, China
- Department of Internal Medicine and Diagnostics, Xuzhou Medical University, Xuzhou, China
| |
Collapse
|
3
|
Lapp HS, Freigang M, Hagenacker T, Weiler M, Wurster CD, Günther R. Biomarkers in 5q-associated spinal muscular atrophy-a narrative review. J Neurol 2023; 270:4157-4178. [PMID: 37289324 PMCID: PMC10421827 DOI: 10.1007/s00415-023-11787-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 05/15/2023] [Accepted: 05/16/2023] [Indexed: 06/09/2023]
Abstract
5q-associated spinal muscular atrophy (SMA) is a rare genetic disease caused by mutations in the SMN1 gene, resulting in a loss of functional SMN protein and consecutive degeneration of motor neurons in the ventral horn. The disease is clinically characterized by proximal paralysis and secondary skeletal muscle atrophy. New disease-modifying drugs driving SMN gene expression have been developed in the past decade and have revolutionized SMA treatment. The rise of treatment options led to a concomitant need of biomarkers for therapeutic guidance and an improved disease monitoring. Intensive efforts have been undertaken to develop suitable markers, and numerous candidate biomarkers for diagnostic, prognostic, and predictive values have been identified. The most promising markers include appliance-based measures such as electrophysiological and imaging-based indices as well as molecular markers including SMN-related proteins and markers of neurodegeneration and skeletal muscle integrity. However, none of the proposed biomarkers have been validated for the clinical routine yet. In this narrative review, we discuss the most promising candidate biomarkers for SMA and expand the discussion by addressing the largely unfolded potential of muscle integrity markers, especially in the context of upcoming muscle-targeting therapies. While the discussed candidate biomarkers hold potential as either diagnostic (e.g., SMN-related biomarkers), prognostic (e.g., markers of neurodegeneration, imaging-based markers), predictive (e.g., electrophysiological markers) or response markers (e.g., muscle integrity markers), no single measure seems to be suitable to cover all biomarker categories. Hence, a combination of different biomarkers and clinical assessments appears to be the most expedient solution at the time.
Collapse
Affiliation(s)
- H S Lapp
- Department of Neurology, University Hospital Carl Gustav Carus at TU Dresden, Fetscherstraße 74, 01307, Dresden, Germany
| | - M Freigang
- Department of Neurology, University Hospital Carl Gustav Carus at TU Dresden, Fetscherstraße 74, 01307, Dresden, Germany
| | - T Hagenacker
- Department of Neurology and Center for Translational Neuro- and Behavioral Science (C-TNBS), University Medicine Essen, Essen, Germany
| | - M Weiler
- Department of Neurology, Heidelberg University Hospital, Heidelberg, Germany
| | - C D Wurster
- Department of Neurology, University Hospital Ulm, Ulm, Germany
- German Center for Neurodegenerative Diseases (DZNE) Ulm, Ulm, Germany
| | - René Günther
- Department of Neurology, University Hospital Carl Gustav Carus at TU Dresden, Fetscherstraße 74, 01307, Dresden, Germany.
- German Center for Neurodegenerative Diseases (DZNE) Dresden, Dresden, Germany.
| |
Collapse
|
4
|
Hooijmans MT, Habets LE, van den Berg‐Faay SAM, Froeling M, Asselman F, Strijkers GJ, Jeneson JAL, Bartels B, Nederveen AJ, van der Pol WL. Multi-parametric quantitative magnetic resonance imaging of the upper arm muscles of patients with spinal muscular atrophy. NMR IN BIOMEDICINE 2022; 35:e4696. [PMID: 35052014 PMCID: PMC9286498 DOI: 10.1002/nbm.4696] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 12/24/2021] [Accepted: 01/17/2022] [Indexed: 06/09/2023]
Abstract
Quantitative magnetic resonance imaging (qMRI) is frequently used to map the disease state and disease progression in the lower extremity muscles of patients with spinal muscular atrophy (SMA). This is in stark contrast to the almost complete lack of data on the upper extremity muscles, which are essential for carrying out daily activities. The aim of this study was therefore to assess the disease state in the upper arm muscles of patients with SMA in comparison with healthy controls by quantitative assessment of fat fraction, diffusion indices, and water T2 relaxation times, and to relate these measures to muscle force. We evaluated 13 patients with SMA and 15 healthy controls with a 3-T MRI protocol consisting of DIXON, diffusion tensor imaging, and T2 sequences. qMRI measures were compared between groups and related to muscle force measured with quantitative myometry. Fat fraction was significantly increased in all upper arm muscles of the patients with SMA compared with healthy controls and correlated negatively with muscle force. Additionally, fat fraction was heterogeneously distributed within the triceps brachii (TB) and brachialis muscle, but not in the biceps brachii muscle. Diffusion indices and water T2 relaxation times were similar between patients with SMA and healthy controls, but we did find a slightly reduced mean diffusivity (MD), λ1, and λ3 in the TB of patients with SMA. Furthermore, MD was positively correlated with muscle force in the TB of patients with SMA. The variation in fat fraction further substantiates the selective vulnerability of muscles. The reduced diffusion tensor imaging indices, along with the positive correlation of MD with muscle force, point to myofiber atrophy. Our results show the feasibility of qMRI to map the disease state in the upper arm muscles of patients with SMA. Longitudinal data in a larger cohort are needed to further explore qMRI to map disease progression and to capture the possible effects of therapeutic interventions.
Collapse
Affiliation(s)
- Melissa T. Hooijmans
- Department of Radiology and Nuclear Medicine, Amsterdam Movement SciencesAmsterdam University Medical CenterAmsterdamThe Netherlands
| | - Laura E. Habets
- Center for Child Development, Exercise and Physical Literacy, Wilhelmina Children's HospitalUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Sandra A. M. van den Berg‐Faay
- Department of Radiology and Nuclear Medicine, Amsterdam Movement SciencesAmsterdam University Medical CenterAmsterdamThe Netherlands
| | - Martijn Froeling
- Department of RadiologyUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Fay‐Lynn Asselman
- UMC Utrecht Brain Center, Department of Neurology and Neurosurgery, University Medical Center UtrechtUtrecht UniversityUtrechtThe Netherlands
| | - Gustav J. Strijkers
- Department of Biomedical Engineering and Physics, Amsterdam Movement SciencesAmsterdam University Medical CenterAmsterdamThe Netherlands
| | - Jeroen A. L. Jeneson
- Center for Child Development, Exercise and Physical Literacy, Wilhelmina Children's HospitalUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Bart Bartels
- Center for Child Development, Exercise and Physical Literacy, Wilhelmina Children's HospitalUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Aart J. Nederveen
- Department of Radiology and Nuclear Medicine, Amsterdam Movement SciencesAmsterdam University Medical CenterAmsterdamThe Netherlands
| | - W. Ludo van der Pol
- UMC Utrecht Brain Center, Department of Neurology and Neurosurgery, University Medical Center UtrechtUtrecht UniversityUtrechtThe Netherlands
| |
Collapse
|
5
|
Pino MG, Rich KA, Kolb SJ. Update on Biomarkers in Spinal Muscular Atrophy. Biomark Insights 2021; 16:11772719211035643. [PMID: 34421296 PMCID: PMC8371741 DOI: 10.1177/11772719211035643] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 07/07/2021] [Indexed: 11/25/2022] Open
Abstract
The availability of disease modifying therapies for spinal muscular atrophy (SMA) has created an urgent need to identify clinically meaningful biomarkers. Biomarkers present a means to measure and evaluate neurological disease across time. Changes in biomarkers provide insight into disease progression and may reveal biologic, physiologic, or pharmacologic phenomena occurring prior to clinical detection. Efforts to identify biomarkers for SMA, a genetic motor neuron disease characterized by motor neuron degeneration and weakness, have culminated in a number of putative molecular and physiologic markers that evaluate biological media (eg, blood and cerebrospinal fluid [CSF]) or nervous system function. Such biomarkers include SMN2 copy number, SMN mRNA and protein levels, neurofilament proteins (NFs), plasma protein analytes, creatine kinase (CK) and creatinine (Crn), and various electrophysiology and imaging measures. SMN2 copy number inversely correlates with disease severity and is the best predictor of clinical outcome in untreated individuals. SMN mRNA and protein are commonly measured in the blood or CSF of patients receiving SMA therapies, particularly those aimed at increasing SMN protein expression, and provide insight into current disease state. NFs have proven to be robust prognostic, disease progression, and pharmacodynamic markers for SMA infants undergoing treatment, but less so for adolescents and adults. Select plasma proteins are altered in SMA individuals and may track response to therapy. CK and Crn from blood correlate with motor function and disease severity status and are useful for predicting which individuals will respond to therapy. Electrophysiology measures comprise the most reliable means for monitoring motor function throughout disease course and are sensitive enough to detect neuromuscular changes before overt clinical manifestation, making them robust predictive and pharmacodynamic biomarkers. Finally, magnetic resonance imaging and muscle ultrasonography are non-invasive techniques for studying muscle structure and physiology and are useful diagnostic tools, but cannot reliably track disease progression. Importantly, biomarkers can provide information about the underlying mechanisms of disease as well as reveal subclinical disease progression, allowing for more appropriate timing and dosing of therapy for individuals with SMA. Recent therapeutic advancements in SMA have shown promising results, though there is still a great need to identify and understand the impact of biomarkers in modulating disease onset and progression.
Collapse
Affiliation(s)
- Megan G Pino
- Department of Neurology, The Ohio State
University Wexner Medical Center, Columbus, OH, USA
| | - Kelly A Rich
- Department of Neurology, The Ohio State
University Wexner Medical Center, Columbus, OH, USA
| | - Stephen J Kolb
- Department of Neurology, The Ohio State
University Wexner Medical Center, Columbus, OH, USA
- Department of Biological Chemistry and
Pharmacology, The Ohio State University Wexner Medical Center, Columbus, OH,
USA
| |
Collapse
|
6
|
Kriss A, Jenkins T. Muscle MRI in motor neuron diseases: a systematic review. Amyotroph Lateral Scler Frontotemporal Degener 2021; 23:161-175. [PMID: 34151652 DOI: 10.1080/21678421.2021.1936062] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Objective: To summarize applications of muscle magnetic resonance imaging (MRI) in cross-sectional assessment and longitudinal monitoring of motor neuron diseases and evaluate associations with clinical assessment techniques.Methods: PubMed and Scopus were searched for research published up to May 2021 relating to muscle MRI in motor neuron diseases, according to predefined inclusion and exclusion criteria. Studies were systematically appraised for bias and data were extracted for discussion.Results: Twenty-eight papers met inclusion criteria. The studies assessed muscle T1- and T2-weighted signal, diffusion, muscle volume, and fat infiltration, employing quantitative, qualitative, and semi-quantitative approaches. Various regions of interest were considered; changes in thigh and calf muscles were most frequently reported. Preliminary evidence of concordance between clinical and radiological findings and utility as an objective longitudinal biomarker is emerging.Conclusion: Muscle MRI appears a promising objective, versatile, and practical biomarker to assess motor neuron diseases.
Collapse
Affiliation(s)
| | - Thomas Jenkins
- Sheffield Institute for Translational Neuroscience, University of Sheffield, UK
| |
Collapse
|
7
|
Otto LA, van der Pol W, Schlaffke L, Wijngaarde CA, Stam M, Wadman RI, Cuppen I, van Eijk RP, Asselman F, Bartels B, van der Woude D, Hendrikse J, Froeling M. Quantitative MRI of skeletal muscle in a cross-sectional cohort of patients with spinal muscular atrophy types 2 and 3. NMR IN BIOMEDICINE 2020; 33:e4357. [PMID: 32681555 PMCID: PMC7507182 DOI: 10.1002/nbm.4357] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 03/24/2020] [Accepted: 06/03/2020] [Indexed: 05/06/2023]
Abstract
The aim of this study was to document upper leg involvement in spinal muscular atrophy (SMA) with quantitative MRI (qMRI) in a cross-sectional cohort of patients of varying type, disease severity and age. Thirty-one patients with SMA types 2 and 3 (aged 29.6 [7.6-73.9] years) and 20 healthy controls (aged 37.9 [17.7-71.6] years) were evaluated in a 3 T MRI with a protocol consisting of DIXON, T2 mapping and diffusion tensor imaging (DTI). qMRI measures were compared with clinical scores of motor function (Hammersmith Functional Motor Scale Expanded [HFMSE]) and muscle strength. Patients exhibited an increased fat fraction and fractional anisotropy (FA), and decreased mean diffusivity (MD) and T2 compared with controls (all P < .001). DTI parameters FA and MD manifest stronger effects than can be accounted for the effect of fatty replacement. Fat fraction, FA and MD show moderate correlation with muscle strength and motor function: FA is negatively associated with HFMSE and Medical Research Council sum score (τ = -0.56 and -0.59; both P < .001) whereas for fat fraction values are τ = -0.50 and -0.58, respectively (both P < .001). This study shows that DTI parameters correlate with muscle strength and motor function. DTI findings indirectly indicate cell atrophy and act as a measure independently of fat fraction. Combined these data suggest the potential of muscle DTI in monitoring disease progression and to study SMA pathogenesis in muscle.
Collapse
Affiliation(s)
- Louise A.M. Otto
- Department of Neurology, UMC Utrecht Brain Center, University Medical Center UtrechtUtrecht Universitythe Netherlands
| | - W‐Ludo van der Pol
- Department of Neurology, UMC Utrecht Brain Center, University Medical Center UtrechtUtrecht Universitythe Netherlands
| | - Lara Schlaffke
- Department of NeurologyBG‐University Hospital Bergmannsheil, Ruhr‐University BochumBochumGermany
| | - Camiel A. Wijngaarde
- Department of Neurology, UMC Utrecht Brain Center, University Medical Center UtrechtUtrecht Universitythe Netherlands
| | - Marloes Stam
- Department of Neurology, UMC Utrecht Brain Center, University Medical Center UtrechtUtrecht Universitythe Netherlands
| | - Renske I. Wadman
- Department of Neurology, UMC Utrecht Brain Center, University Medical Center UtrechtUtrecht Universitythe Netherlands
| | - Inge Cuppen
- Department of Neurology and Child Neurology, UMC Utrecht Brain CenterUniversity Medical Center Utrecht, Utrecht Universitythe Netherlands
| | - Ruben P.A. van Eijk
- Department of Neurology, UMC Utrecht Brain Center, University Medical Center UtrechtUtrecht Universitythe Netherlands
- Biostatistics & Research Support, Julius Center for Health Sciences and Primary CareUniversity Medical Center Utrecht, Utrecht UniversityUtrechtThe Netherlands
| | - Fay‐Lynn Asselman
- Department of Neurology, UMC Utrecht Brain Center, University Medical Center UtrechtUtrecht Universitythe Netherlands
| | - Bart Bartels
- Department of Child Development and Exercise CenterUniversity Medical Center Utrecht, Utrecht Universitythe Netherlands
| | - Danny van der Woude
- Department of Child Development and Exercise CenterUniversity Medical Center Utrecht, Utrecht Universitythe Netherlands
| | - Jeroen Hendrikse
- Department of RadiologyUniversity Medical Center Utrecht, Utrecht Universitythe Netherlands
| | - Martijn Froeling
- Department of RadiologyUniversity Medical Center Utrecht, Utrecht Universitythe Netherlands
| |
Collapse
|
8
|
MRI patterns of muscle involvement in type 2 and 3 spinal muscular atrophy patients. J Neurol 2019; 267:898-912. [DOI: 10.1007/s00415-019-09646-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 11/05/2019] [Accepted: 11/18/2019] [Indexed: 12/17/2022]
|
9
|
Bonati U, Holiga Š, Hellbach N, Risterucci C, Bergauer T, Tang W, Hafner P, Thoeni A, Bieri O, Gerlach I, Marquet A, Khwaja O, Sambataro F, Bertolino A, Dukart J, Fischmann A, Fischer D, Czech C. Longitudinal characterization of biomarkers for spinal muscular atrophy. Ann Clin Transl Neurol 2017; 4:292-304. [PMID: 28491897 PMCID: PMC5420809 DOI: 10.1002/acn3.406] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 03/05/2017] [Indexed: 12/27/2022] Open
Abstract
Objective Recent advances in understanding Spinal Muscular Atrophy (SMA) etiopathogenesis prompted development of potent intervention strategies and raised need for sensitive outcome measures capable of assessing disease progression and response to treatment. Several biomarkers have been proposed; nevertheless, no general consensus has been reached on the most feasible ones. We observed a wide range of measures over 1 year to assess their ability to monitor the disease status and progression. Methods 18 SMA patients and 19 healthy volunteers (HV) were followed in this 52‐weeks observational study. Quantitative‐MRI (qMRI) of both thighs and clinical evaluation of motor function was performed at baseline, 6, 9 and 12 months follow‐up. Blood samples were taken in patients for molecular characterization at screening, 9 and 12 month follow‐up. Progression, responsiveness and reliability of collected indices were quantified. Correlation analysis was performed to test for potential associations. Results QMRI indices, clinical scales and molecular measures showed high to excellent reliability. Significant differences were found between qMRI of SMA patients and HV. Significant associations were revealed between multiple qMRI measures and functional clinical scales. None of the qMRI, clinical, or molecular measures was able to detect significant disease progression over 1 year. Interpretation We probed a variety of quantitative measures for SMA in a slowly‐progressing disease population over 1 year. The presented measures demonstrated potential to provide a closer link to underlying disease biology as compared to conventional functional scales. The proposed biomarker framework can guide implementation of more sensitive endpoints in future clinical trials and prove their utility in search for novel disease‐modifying therapies.
Collapse
Affiliation(s)
- Ulrike Bonati
- Division of Neuropediatrics University of Basel Children's Hospital Spitalstrasse 334056 Basel Switzerland.,Department of Neurology University of Basel Hospital Petersgraben 44031 Basel Switzerland
| | - Štefan Holiga
- Roche Pharma and Early Development Neuroscience, Ophthalmology and Rare Diseases Roche Innovation Center Basel F. Hoffmann-La Roche Ltd Grenzacherstrasse 1244070 Basel Switzerland.,Max Planck Institute for Human Cognitive and Brain Sciences Stephan str. 1A04103 Leipzig Germany
| | - Nicole Hellbach
- Roche Pharma and Early Development Neuroscience, Ophthalmology and Rare Diseases Roche Innovation Center Basel F. Hoffmann-La Roche Ltd Grenzacherstrasse 1244070 Basel Switzerland
| | - Céline Risterucci
- Roche Pharma and Early Development Neuroscience, Ophthalmology and Rare Diseases Roche Innovation Center Basel F. Hoffmann-La Roche Ltd Grenzacherstrasse 1244070 Basel Switzerland
| | - Tobias Bergauer
- Roche Pharma and Early Development Neuroscience, Ophthalmology and Rare Diseases Roche Innovation Center Basel F. Hoffmann-La Roche Ltd Grenzacherstrasse 1244070 Basel Switzerland
| | - Wakana Tang
- Roche Molecular Diagnostics Research Genomics & Oncology Roche Molecular Systems Inc.4300 Hacienda Dr Pleasanton 94588 California USA
| | - Patricia Hafner
- Division of Neuropediatrics University of Basel Children's Hospital Spitalstrasse 334056 Basel Switzerland.,Department of Neurology University of Basel Hospital Petersgraben 44031 Basel Switzerland.,University Clinics of Internal Medicine Kantonsspital Baselland Bruderholz 4101 Switzerland
| | - Alain Thoeni
- MIAC AG c/o University of Basel Hospital Mittlere-Strasse 834031 Basel Switzerland.,Department of Radiology University of Basel Hospital Petersgraben 44031 Basel Switzerland
| | - Oliver Bieri
- Department of Radiology University of Basel Hospital Petersgraben 44031 Basel Switzerland
| | - Irene Gerlach
- Roche Pharma and Early Development Neuroscience, Ophthalmology and Rare Diseases Roche Innovation Center Basel F. Hoffmann-La Roche Ltd Grenzacherstrasse 1244070 Basel Switzerland
| | - Anne Marquet
- Roche Pharma and Early Development Neuroscience, Ophthalmology and Rare Diseases Roche Innovation Center Basel F. Hoffmann-La Roche Ltd Grenzacherstrasse 1244070 Basel Switzerland
| | - Omar Khwaja
- Roche Pharma and Early Development Neuroscience, Ophthalmology and Rare Diseases Roche Innovation Center Basel F. Hoffmann-La Roche Ltd Grenzacherstrasse 1244070 Basel Switzerland
| | - Fabio Sambataro
- Roche Pharma and Early Development Neuroscience, Ophthalmology and Rare Diseases Roche Innovation Center Basel F. Hoffmann-La Roche Ltd Grenzacherstrasse 1244070 Basel Switzerland
| | - Alessandro Bertolino
- Roche Pharma and Early Development Neuroscience, Ophthalmology and Rare Diseases Roche Innovation Center Basel F. Hoffmann-La Roche Ltd Grenzacherstrasse 1244070 Basel Switzerland
| | - Juergen Dukart
- Roche Pharma and Early Development Neuroscience, Ophthalmology and Rare Diseases Roche Innovation Center Basel F. Hoffmann-La Roche Ltd Grenzacherstrasse 1244070 Basel Switzerland
| | - Arne Fischmann
- Department of Radiology University of Basel Hospital Petersgraben 44031 Basel Switzerland.,Hirslanden Klinik St. Anna St. Anna-Strasse 326006 Luzern Switzerland
| | - Dirk Fischer
- Division of Neuropediatrics University of Basel Children's Hospital Spitalstrasse 334056 Basel Switzerland.,Department of Neurology University of Basel Hospital Petersgraben 44031 Basel Switzerland
| | - Christian Czech
- Roche Pharma and Early Development Neuroscience, Ophthalmology and Rare Diseases Roche Innovation Center Basel F. Hoffmann-La Roche Ltd Grenzacherstrasse 1244070 Basel Switzerland
| |
Collapse
|
10
|
Kölbel H, Hauffa BP, Wudy SA, Bouikidis A, Della Marina A, Schara U. Hyperleptinemia in children with autosomal recessive spinal muscular atrophy type I-III. PLoS One 2017; 12:e0173144. [PMID: 28278160 PMCID: PMC5344335 DOI: 10.1371/journal.pone.0173144] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 02/15/2017] [Indexed: 01/10/2023] Open
Abstract
Background Autosomal-recessive proximal spinal muscular atrophies (SMA) are disorders characterized by a ubiquitous deficiency of the survival of motor neuron protein that leads to a multisystemic disorder, which mostly affects alpha motor neurons. Disease progression is clinically associated with failure to thrive or weight loss, mainly caused by chewing and swallowing difficulties. Although pancreatic involvement has been described in animal models, systematic endocrinological evaluation of the energy metabolism in humans is lacking. Methods In 43 patients with SMA type I-III (8 type I; 22 type II; 13 type III), aged 0.6–21.8 years, auxological parameters, pubertal stage, motor function (Motor Function Measurement 32 –MFM32) as well as levels of leptin, insulin glucose, hemoglobin A1c, Homeostasis Model Assessment index and an urinary steroid profile were determined. Results Hyperleptinemia was found in 15/35 (43%) of our patients; 9/15 (60%) of the hyperleptinemic patients were underweight, whereas 1/15 (7%) was obese. Hyperleptinemia was associated with SMA type (p = 0.018). There was a significant association with decreased motor function (MFM32 total score in hyperleptinemia 28.5%, in normoleptinemia 54.7% p = 0.008, OR 0.969; 95%-CI: 0.946–0.992). In addition, a higher occurrence of hirsutism, premature pubarche and a higher variability of the urinary steroid pattern were found. Conclusion Hyperleptinemia is highly prevalent in underweight children with SMA and is associated with disease severity and decreased motor function. Neuronal degradation of hypothalamic cells or an increase in fat content by muscle remodeling could be the cause of hyperleptinemia.
Collapse
Affiliation(s)
- Heike Kölbel
- Department of Neuropediatrics, Developmental Neurology and Social Pediatrics, Children’s Hospital 1, University of Duisburg-Essen, Essen, Germany
- * E-mail:
| | - Berthold P. Hauffa
- Department of Pediatric Endocrinology, Children’s Hospital 2, University of Duisburg-Essen, Essen, Germany
| | - Stefan A. Wudy
- Steroid Research and Mass Spectrometry Unit, Division of Pediatric Endocrinology and Diabetology, Center of Child and Adolescent Medicine, Justus Liebig University, Giessen, Germany
| | - Anastasios Bouikidis
- Department of Pediatric Pulmonology, Children’s Hospital 3, University of Duisburg-Essen, Essen, Germany
| | - Adela Della Marina
- Department of Neuropediatrics, Developmental Neurology and Social Pediatrics, Children’s Hospital 1, University of Duisburg-Essen, Essen, Germany
| | - Ulrike Schara
- Department of Neuropediatrics, Developmental Neurology and Social Pediatrics, Children’s Hospital 1, University of Duisburg-Essen, Essen, Germany
| |
Collapse
|
11
|
Simon NG, Noto YI, Zaidman CM. Skeletal muscle imaging in neuromuscular disease. J Clin Neurosci 2016; 33:1-10. [PMID: 27612670 DOI: 10.1016/j.jocn.2016.01.041] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 01/04/2016] [Indexed: 02/06/2023]
Abstract
Skeletal muscle imaging is increasingly used as a complement to clinical and electrophysiological examination in neuromuscular disease. Ultrasound and MRI have developed as the modalities of choice, each with strengths and limitations. Characteristic changes of muscle denervation and myopathy are seen on imaging which may delineate the nature of the disease process or help guide muscle biopsy. Identifying patterns of muscle involvement in hereditary myopathies may inform genetic testing. This review discusses skeletal muscle imaging in neuromuscular disease focusing on practical applications of current and emerging ultrasound and MRI techniques.
Collapse
Affiliation(s)
- Neil G Simon
- St Vincent's Clinical School, University of New South Wales, Level 5 deLacy Building, St Vincent's Hospital, Victoria Street, Darlinghurst, NSW 2010, Australia; Department of Neurology, St Vincent's Hospital, Darlinghurst, NSW, Australia.
| | - Yu-Ichi Noto
- Department of Neurology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan; Brain and Mind Centre, Sydney Medical School, The University of Sydney, NSW, Australia
| | - Craig M Zaidman
- Department of Neurology, Washington University in St. Louis, St Louis, MO, USA
| |
Collapse
|
12
|
Lorenzana DJ, Mueske NM, Ryan DD, Van Speybroeck AL, Wren TAL. Quantitative Analysis of Lower Leg Adipose Tissue Distribution in Youth with Myelomeningocele. J Child Neurol 2016; 31:979-84. [PMID: 26961265 PMCID: PMC4925233 DOI: 10.1177/0883073816634858] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 01/11/2016] [Indexed: 01/02/2023]
Abstract
Children with myelomeningocele have a high prevalence of obesity and excess fat accumulation in their lower extremities. However, it is not known if this is subcutaneous or intramuscular fat, the latter of which has been associated with insulin resistance and metabolic disorders. This study quantified lower leg bone, muscle, and adipose tissue volume in children with myelomeningocele, classifying adipose as subcutaneous or muscle-associated. Eighty-eight children with myelomeningocele and 113 children without myelomeningocele underwent lower leg computed tomographic scans. Subcutaneous and muscle-associated adipose were classified based on location relative to the crural fascia. No differences were seen in subcutaneous adipose. Higher level disease severity was associated with increased muscle-associated adipose volume and decreased muscle volume. Bone volume tended to decrease with higher levels of involvement. Increases in lower leg adiposity in children with myelomeningocele are primarily attributable to accumulation of muscle-associated adipose, which may signify increased risk for metabolic disorders.
Collapse
Affiliation(s)
- Daniel J Lorenzana
- Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Nicole M Mueske
- Children's Orthopaedic Center, Children's Hospital Los Angeles, Los Angeles, CA, USA
| | - Deirdre D Ryan
- Keck School of Medicine, University of Southern California, Los Angeles, CA, USA Children's Orthopaedic Center, Children's Hospital Los Angeles, Los Angeles, CA, USA
| | | | - Tishya A L Wren
- Keck School of Medicine, University of Southern California, Los Angeles, CA, USA Children's Orthopaedic Center, Children's Hospital Los Angeles, Los Angeles, CA, USA
| |
Collapse
|
13
|
Describing nutrition in spinal muscular atrophy: A systematic review. Neuromuscul Disord 2016; 26:395-404. [PMID: 27241822 DOI: 10.1016/j.nmd.2016.05.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Revised: 05/06/2016] [Accepted: 05/06/2016] [Indexed: 01/27/2023]
Abstract
Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disease of variable severity. Progressive muscle wasting and impairment in functional ability in SMA have a profound influence on nutritional outcomes. This systematic review summarises the existing evidence on nutrition in SMA. The search strategy was conducted across five databases in August 2014, and updated in March 2016, using key terms relating to growth, nutrition requirements, dietary intake and nutrition management. Studies were selected for inclusion using a two pass method, and data systematically extracted using standardised forms. Thirty-nine studies met eligibility criteria. Body composition is abnormal in patients with SMA, and feeding and swallowing issues are prevalent among sufferers of SMA types I and II. Nutritional management practices vary internationally. There is a paucity of literature regarding nutrition requirements in SMA, although it appears that energy expenditure may be reduced. Children with SMA require individualised nutritional management in order to address their growth and nutrition requirements. There is an urgent need for larger, coordinated, prospective intervention studies of nutrition in SMA.
Collapse
|
14
|
El Mendili MM, Lenglet T, Stojkovic T, Behin A, Guimarães-Costa R, Salachas F, Meininger V, Bruneteau G, Le Forestier N, Laforêt P, Lehéricy S, Benali H, Pradat PF. Cervical Spinal Cord Atrophy Profile in Adult SMN1-Linked SMA. PLoS One 2016; 11:e0152439. [PMID: 27089520 PMCID: PMC4835076 DOI: 10.1371/journal.pone.0152439] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 03/14/2016] [Indexed: 12/14/2022] Open
Abstract
PURPOSE The mechanisms underlying the topography of motor deficits in spinal muscular atrophy (SMA) remain unknown. We investigated the profile of spinal cord atrophy (SCA) in SMN1-linked SMA, and its correlation with the topography of muscle weakness. MATERIALS AND METHODS Eighteen SMN1-linked SMA patients type III/V and 18 age/gender-matched healthy volunteers were included. Patients were scored on manual muscle testing and functional scales. Spinal cord was imaged using 3T MRI system. Radial distance (RD) and cord cross-sectional area (CSA) measurements in SMA patients were compared to those in controls and correlated with strength and disability scores. RESULTS CSA measurements revealed a significant cord atrophy gradient mainly located between C3 and C6 vertebral levels with a SCA rate ranging from 5.4% to 23% in SMA patients compared to controls. RD was significantly lower in SMA patients compared to controls in the anterior-posterior direction with a maximum along C4 and C5 vertebral levels (p-values < 10-5). There were no correlations between atrophy measurements, strength and disability scores. CONCLUSIONS Spinal cord atrophy in adult SMN1-linked SMA predominates in the segments innervating the proximal muscles. Additional factors such as neuromuscular junction or intrinsic skeletal muscle defects may play a role in more complex mechanisms underlying weakness in these patients.
Collapse
Affiliation(s)
- Mohamed-Mounir El Mendili
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, INSERM, Laboratoire d’Imagerie Biomédicale, F-75013, Paris, France
| | - Timothée Lenglet
- APHP, Hôpital Pitié-Salpêtriere, Département des Maladies du Système Nerveux, Centre référent SLA, Paris, France
- APHP, Hôpital Pitié-Salpêtriere, Service d’Explorations Fonctionnelles, Paris, France
| | - Tanya Stojkovic
- APHP, Centre de Référence Maladies Neuromusculaires Paris-Est, Institut de Myologie, Paris, France
| | - Anthony Behin
- APHP, Centre de Référence Maladies Neuromusculaires Paris-Est, Institut de Myologie, Paris, France
| | - Raquel Guimarães-Costa
- APHP, Centre de Référence Maladies Neuromusculaires Paris-Est, Institut de Myologie, Paris, France
| | - François Salachas
- APHP, Hôpital Pitié-Salpêtriere, Département des Maladies du Système Nerveux, Centre référent SLA, Paris, France
| | - Vincent Meininger
- APHP, Hôpital Pitié-Salpêtriere, Département des Maladies du Système Nerveux, Centre référent SLA, Paris, France
| | - Gaelle Bruneteau
- APHP, Hôpital Pitié-Salpêtriere, Département des Maladies du Système Nerveux, Centre référent SLA, Paris, France
| | - Nadine Le Forestier
- APHP, Hôpital Pitié-Salpêtriere, Département des Maladies du Système Nerveux, Centre référent SLA, Paris, France
| | - Pascal Laforêt
- APHP, Centre de Référence Maladies Neuromusculaires Paris-Est, Institut de Myologie, Paris, France
| | - Stéphane Lehéricy
- APHP, Hôpital Pitié-Salpêtriere, Service de Neuroradiologie, Paris, France
- Sorbonne Universités, UPMC Univ Paris 06, UMR-S975, Inserm U975, CNRS UMR7225, Centre de recherche de l’Institut du Cerveau et de la Moelle épinière–CRICM, Centre de Neuroimagerie de Recherche–CENIR, Paris, France
| | - Habib Benali
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, INSERM, Laboratoire d’Imagerie Biomédicale, F-75013, Paris, France
| | - Pierre-François Pradat
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, INSERM, Laboratoire d’Imagerie Biomédicale, F-75013, Paris, France
- APHP, Hôpital Pitié-Salpêtriere, Département des Maladies du Système Nerveux, Centre référent SLA, Paris, France
| |
Collapse
|
15
|
Ng KW, Connolly AM, Zaidman CM. Quantitative muscle ultrasound measures rapid declines over time in children with SMA type 1. J Neurol Sci 2015; 358:178-82. [PMID: 26432577 DOI: 10.1016/j.jns.2015.08.1532] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 08/10/2015] [Accepted: 08/25/2015] [Indexed: 12/14/2022]
Abstract
Muscles are small in spinal muscular atrophy (SMA). It is not known if muscle size changes over time in SMA type 1. We quantified changes over time in muscle size and echointensity during two repeated ultrasound examinations of unilateral proximal (biceps brachii/brachialis and quadriceps) and distal (anterior forearm flexors and tibialis anterior) muscles in three children with SMA type 1. We compared muscle thickness (MT) to body weight-dependent normal reference values. Children were 1, 6, and 11months old at baseline and had 2, 2 and 4 months between ultrasound examinations, respectively. At baseline, MT was normal for weight in all muscles except an atrophic quadriceps in the oldest child. MT decreased and echointensity increased (worsened) over time. At follow up, MT was below normal for weight in the quadriceps in all three children, in the biceps/brachioradialis in two, and in the anterior forearm in one. Tibialis anterior MT remained normal for weight in all three children. Muscle echointensity increased over time in all muscles and, on average, more than doubled in two children. In children with SMA type 1, muscle atrophies and becomes hyperechoic over time. Quantitative muscle ultrasound measures disease progression in SMA type 1 that warrants additional study in more children.
Collapse
Affiliation(s)
- Kay W Ng
- Washington University School of Medicine, Department of Neurology, St. Louis, MO 63110, United States
| | - Anne M Connolly
- Washington University School of Medicine, Department of Neurology, St. Louis, MO 63110, United States; Washington University School of Medicine, Department of Pediatrics, St. Louis, MO 63110, United States
| | - Craig M Zaidman
- Washington University School of Medicine, Department of Neurology, St. Louis, MO 63110, United States; Washington University School of Medicine, Department of Pediatrics, St. Louis, MO 63110, United States.
| |
Collapse
|
16
|
Kobayashi DT, Shi J, Stephen L, Ballard KL, Dewey R, Mapes J, Chung B, McCarthy K, Swoboda KJ, Crawford TO, Li R, Plasterer T, Joyce C, Chung WK, Kaufmann P, Darras BT, Finkel RS, Sproule DM, Martens WB, McDermott MP, De Vivo DC, Walker MG, Chen KS. SMA-MAP: a plasma protein panel for spinal muscular atrophy. PLoS One 2013; 8:e60113. [PMID: 23565191 PMCID: PMC3615018 DOI: 10.1371/journal.pone.0060113] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Accepted: 02/21/2013] [Indexed: 12/12/2022] Open
Abstract
Objectives Spinal Muscular Atrophy (SMA) presents challenges in (i) monitoring disease activity and predicting progression, (ii) designing trials that allow rapid assessment of candidate therapies, and (iii) understanding molecular causes and consequences of the disease. Validated biomarkers of SMA motor and non-motor function would offer utility in addressing these challenges. Our objectives were (i) to discover additional markers from the Biomarkers for SMA (BforSMA) study using an immunoassay platform, and (ii) to validate the putative biomarkers in an independent cohort of SMA patients collected from a multi-site natural history study (NHS). Methods BforSMA study plasma samples (N = 129) were analyzed by immunoassay to identify new analytes correlating to SMA motor function. These immunoassays included the strongest candidate biomarkers identified previously by chromatography. We selected 35 biomarkers to validate in an independent cohort SMA type 1, 2, and 3 samples (N = 158) from an SMA NHS. The putative biomarkers were tested for association to multiple motor scales and to pulmonary function, neurophysiology, strength, and quality of life measures. We implemented a Tobit model to predict SMA motor function scores. Results 12 of the 35 putative SMA biomarkers were significantly associated (p<0.05) with motor function, with a 13th analyte being nearly significant. Several other analytes associated with non-motor SMA outcome measures. From these 35 biomarkers, 27 analytes were selected for inclusion in a commercial panel (SMA-MAP) for association with motor and other functional measures. Conclusions Discovery and validation using independent cohorts yielded a set of SMA biomarkers significantly associated with motor function and other measures of SMA disease activity. A commercial SMA-MAP biomarker panel was generated for further testing in other SMA collections and interventional trials. Future work includes evaluating the panel in other neuromuscular diseases, for pharmacodynamic responsiveness to experimental SMA therapies, and for predicting functional changes over time in SMA patients.
Collapse
Affiliation(s)
- Dione T Kobayashi
- Spinal Muscular Atrophy Foundation, New York, New York, United States of America.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Abstract
Bench to bedside progress has been widely anticipated for a growing number of neurodegenerative disorders. Of these, spinal muscular atrophy (SMA) is perhaps the best poised to capitalize on advances in targeted therapeutics development over the next few years. Several laboratories have achieved compelling success in SMA animal models using sophisticated methods for targeted delivery, repair, or increased expression of the survival motor neuron protein, SMN. The clinical community is actively collaborating to identify, develop, and validate outcome measures and biomarkers in parallel with laboratory efforts. Innovative trial design and synergistic approaches to maximize proactive care in conjunction with treatment with one or more of the promising pharmacologic and biologic therapies currently in the pipeline will maximize our chances to achieve meaningful outcomes for patients. This review highlights recent promising scientific and clinical advances bringing us ever closer to effective treatment(s) for our patients with SMA.
Collapse
|
18
|
Sproule DM, Montgomery MJ, Punyanitya M, Shen W, Dashnaw S, Montes J, Dunaway S, Finkel R, Darras B, Vivo DCD, Kaufmann P. Thigh muscle volume measured by magnetic resonance imaging is stable over a 6-month interval in spinal muscular atrophy. J Child Neurol 2011; 26:1252-9. [PMID: 21572051 DOI: 10.1177/0883073811405053] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Changes in thigh muscle volume over 6 months were assessed using magnetic resonance imaging in 11 subjects aged 6 to 47 years with spinal muscular atrophy (4 type 2 and 7 type 3; 4 ambulatory and 3 nonambulatory). Muscle volume with normal and abnormal signal was measured using blinded, semiautomated analysis of reconstructed data. Volumes at baseline and 6 months were correlated with clinical function at each epoch. There was minimal increase in normal (0.3 ± 1.4 mL/cm) and total (0.1 ± 1.3 mL/cm) muscle. Muscle volume correlated closely with clinical function. Minimal interval change in muscle volume is consistent with the established clinical history of minimal disease progression over intervals shorter than 1 year. Relative constancy of muscle volume estimation and correlation with established functional measures suggest a role for segmental magnetic resonance imaging as a biomarker of treatment effect in future therapeutic trials.
Collapse
Affiliation(s)
- Douglas M Sproule
- Division of Pediatric Neurosciences, Department of Neurology, SMA Clinical Research Center, Columbia University Medical Center, New York, NY 10032-3791, USA.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Utility of survival motor neuron ELISA for spinal muscular atrophy clinical and preclinical analyses. PLoS One 2011; 6:e24269. [PMID: 21904622 PMCID: PMC3164180 DOI: 10.1371/journal.pone.0024269] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2011] [Accepted: 08/04/2011] [Indexed: 01/24/2023] Open
Abstract
OBJECTIVES Genetic defects leading to the reduction of the survival motor neuron protein (SMN) are a causal factor for Spinal Muscular Atrophy (SMA). While there are a number of therapies under evaluation as potential treatments for SMA, there is a critical lack of a biomarker method for assessing efficacy of therapeutic interventions, particularly those targeting upregulation of SMN protein levels. Towards this end we have engaged in developing an immunoassay capable of accurately measuring SMN protein levels in blood, specifically in peripheral blood mononuclear cells (PBMCs), as a tool for validating SMN protein as a biomarker in SMA. METHODS A sandwich enzyme-linked immunosorbent assay (ELISA) was developed and validated for measuring SMN protein in human PBMCs and other cell lysates. Protocols for detection and extraction of SMN from transgenic SMA mouse tissues were also developed. RESULTS The assay sensitivity for human SMN is 50 pg/mL. Initial analysis reveals that PBMCs yield enough SMN to analyze from blood volumes of less than 1 mL, and SMA Type I patients' PBMCs show ∼90% reduction of SMN protein compared to normal adults. The ELISA can reliably quantify SMN protein in human and mouse PBMCs and muscle, as well as brain, and spinal cord from a mouse model of severe SMA. CONCLUSIONS This SMN ELISA assay enables the reliable, quantitative and rapid measurement of SMN in healthy human and SMA patient PBMCs, muscle and fibroblasts. SMN was also detected in several tissues in a mouse model of SMA, as well as in wildtype mouse tissues. This SMN ELISA has general translational applicability to both preclinical and clinical research efforts.
Collapse
|