MDA-5 Antibodies and Juvenile Dermatomyositis Save
A multicentre, retrospective study examined MSA profiles (by immunoprecipitation) from 96 juvenile idiopathic inflammatory myopathies (JIIM) at nine pediatric rheumatology centres in Japan. MSA were found in 85 of 96 cases with over 90% of patients having one of the following three MSA types:
- MDA5 (anti-melanoma differentiation-associated protein 5) (n = 31)
- TIF1γ (anti-transcriptional intermediary factor 1 alpha and/or gamma subunits) (n = 25)
- NXP1 (anti-nuclear matrix protein 2) (n = 25) antibodies.
While all had Gottron papules and periungual capillary abnormalities, other clinical associations were seen. Interstitial lung disease (ILD) was most associated with anti-MDA5 antibodies.MDA5 antibody positive patients were more likely to receive multiple medications (including iv CYC), achieve drug-free remission (29 vs 21%) and less likely to relapse (26 vs 44%) than others.