TY - JOUR
T1 - Inclusion body myositis
T2 - Correlation of clinical outcomes with histopathology, electromyography and laboratory findings
AU - Pinto, Marcus V.
AU - Laughlin, Ruple S.
AU - Klein, Christopher J.
AU - Mandrekar, Jay
AU - Naddaf, Elie
N1 - Publisher Copyright:
© 2021 The Author(s) 2021. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved.
PY - 2022/6/1
Y1 - 2022/6/1
N2 - Objective: To determine whether histopathological, electromyographic and laboratory markers correlate with clinical measures in inclusion body myositis (IBM). Methods: We reviewed our electronic medical records to identify patients with IBM according to European Neuromuscular Center (ENMC) 2011 criteria, seen between 2015 and 2020. We only included patients who had a muscle biopsy and needle electromyography (EMG) performed on the same muscle (opposite or same side). We used a detailed grading system [0 (normal) to 4 (severe)] to score histopathological and EMG findings. Clinical severity was assessed by the modified Rankin scale (mRS), muscle strength sum score (SSS), quadriceps strength and severity of dysphagia on swallow evaluation. Serum markers of interest were creatine kinase level and cN-1A antibodies. Results: We included 50 IBM patients, with a median age of 69 years; 64% were males. Median disease duration at diagnosis was 51 months. On muscle biopsy, endomysial inflammation mainly correlated with dysphagia, and inversely correlated with mRS. Vacuoles and congophilic inclusions did not correlate with any of the clinical measures. On EMG, the shortness of motor un it potential (MUP) duration correlated with all clinical measures. Myotonic discharges, and not fibrillation potentials, correlated with the severity of inflammation. Serum markers did not have a statistically significant correlation with any of the clinical measures. Conclusions: Dysphagia was the main clinical feature of IBM correlating with endomysial inflammation. Otherwise, inclusion body myositis clinical measures had limited correlation with histopathological features in this study. The shortness of MUP duration correlated with all clinical measures.
AB - Objective: To determine whether histopathological, electromyographic and laboratory markers correlate with clinical measures in inclusion body myositis (IBM). Methods: We reviewed our electronic medical records to identify patients with IBM according to European Neuromuscular Center (ENMC) 2011 criteria, seen between 2015 and 2020. We only included patients who had a muscle biopsy and needle electromyography (EMG) performed on the same muscle (opposite or same side). We used a detailed grading system [0 (normal) to 4 (severe)] to score histopathological and EMG findings. Clinical severity was assessed by the modified Rankin scale (mRS), muscle strength sum score (SSS), quadriceps strength and severity of dysphagia on swallow evaluation. Serum markers of interest were creatine kinase level and cN-1A antibodies. Results: We included 50 IBM patients, with a median age of 69 years; 64% were males. Median disease duration at diagnosis was 51 months. On muscle biopsy, endomysial inflammation mainly correlated with dysphagia, and inversely correlated with mRS. Vacuoles and congophilic inclusions did not correlate with any of the clinical measures. On EMG, the shortness of motor un it potential (MUP) duration correlated with all clinical measures. Myotonic discharges, and not fibrillation potentials, correlated with the severity of inflammation. Serum markers did not have a statistically significant correlation with any of the clinical measures. Conclusions: Dysphagia was the main clinical feature of IBM correlating with endomysial inflammation. Otherwise, inclusion body myositis clinical measures had limited correlation with histopathological features in this study. The shortness of MUP duration correlated with all clinical measures.
KW - IBM
KW - electromyography
KW - inclusion body myositis
KW - muscle biopsy
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U2 - 10.1093/rheumatology/keab754
DO - 10.1093/rheumatology/keab754
M3 - Article
C2 - 34617994
AN - SCOPUS:85131217011
SN - 1462-0324
VL - 61
SP - 2504
EP - 2511
JO - Rheumatology (United Kingdom)
JF - Rheumatology (United Kingdom)
IS - 6
ER -