Diagnosis and treatment of clinically amyopathic dermatomyositis (CADM): a case series and literature review

Abstract

The objective of this study was to report the clinical course of a cohort of patients with clinically amyopathic dermatomyositis (CADM) in correlation to the presence or absence of anti-melanoma differentiation-associated gene 5 (MDA-5) antibody. Five patients with CADM presented to our rheumatology unit between September 1, 2011 and March 31, 2014. We hereby present their clinical course, laboratory findings, imaging modalities, functional tests, and treatments regimens. Our cohort included five patients, with a mean age of 41.8 ± 17.7. Three patients, all anti-MDA-5 antibody positive, developed rapidly progressive interstitial lung disease (ILD) within 4.3 ± 4.5 months of presentation. Two of these patients succumbed to their disease within 30 months of diagnosis despite intensive immunosuppressive therapy. The third anti-MDA-5-positive patient with ILD is still stable, 20 months from disease onset, on massive combination therapy. One patient developed CADM associated with the anti-p155/140 antibody, a year after completing chemotherapy for non-seminomatous germ cell tumor. He presented with a benign clinical course with no evidence of ILD and no recurrence of malignancy after 20 months of follow-up. The fifth patient in our cohort, who is anti-MDA-5 negative and has no evidence of malignancy, also enjoys a benign clinical course. The presence of anti-MDA-5 antibodies in CADM patients is associated with rapidly progressive ILD and a poor prognosis. The serologic profile of patients with CADM should be routinely evaluated and integrated with clinical data in the management of these patients.

Cyclophosphamide Versus Obinutuzumab for the Treatment of Anti-MDA5 Positive Inflammatory Myopathy with Interstitial Lung Disease: A Study Protocol and Literature Review

“…In our local IIM patients in Hong Kong, 66.7% of patients with positive anti-MDA5 would develop RP-ILD, compared with only 8.8% of those tested negative for the antibody [11]. Similar association between anti-MDA5 and life-threatening RP-ILD has also been reported in the Caucasians recently [12,13]. A meta-analysis revealed that the pooled sensitivity and specificity of anti-MDA5 in identifying RP-ILD in DM patients were 77% and 86%, respectively [14].…”

Autoimmune Myopathies: Updates on Evaluation and Treatment

“…Antibodies directed against melanoma differentiationassociation protein 5 (MDA5) occur in approximately 15% of patients with DM [74,75]. Anti-MDA5 antibodies are usually associated with minimal muscle involvement (amyopathic or hypomyopathic DM), severe vasculopathy often with digital ulcerations, and rapidly progressive ILD [74][75][76][77]. Antibodies directed against transcriptional intermediary factor 1-ϒ (TIF1-ϒ), also known as anti-p155/140 antibody, have a prevalence of 14 to 31% in DM and strongly predict risk of malignancy, showing 89% specificity and 78% sensitivity for malignancy diagnosis, with a positive predictive value of 58% and a negative predictive value of 95% [78][79][80].…”

Die Diagnose liegt auf der Hand

“…Die Prävalenz scheint in der asiatischen Bevölkerung höher zu sein [8]. Eine Assoziation mit Malignität konnte im Gegensatz zu anderen Autoantikörpern bislang nicht nachgewiesen werden [6,9].…”

“…Meist werden in der HRCT Milchglastrübungen, Retikulationen und Konsolidierungen mit Betonung der Lungenbasis beschrieben. Die BAL ist teils lymphozytär geprägt, und in der transbronchialen Biopsie lassen sich Histologien ähnlich der nicht-spezifischen interstitiellen Pneumonie oder der organisierenden Pneumonie finden [9].…”