# When viral infections meet the anti-MDA5 antibody-positive dermatomyositis

## TL;DR

This review explores how viral infections might trigger anti-MDA5 antibodies in a specific type of dermatomyositis linked to severe lung disease.

## Contribution

The paper highlights the potential mechanisms by which viral infections induce anti-MDA5 antibody formation in dermatomyositis.

## Key findings

- Anti-MDA5+ DM is associated with severe lung disease and poor outcomes.
- Viral infections may trigger the production of anti-MDA5 antibodies.
- SARS-CoV-2 infection has been linked to the presence of anti-MDA5 antibodies.

## Abstract

Anti-melanoma differentiation-related gene 5 (MDA5) antibody-positive dermatomyositis (anti-MDA5+ DM) is recognized as a distinct subtype of dermatomyositis, characterized by its frequent association with interstitial lung disease (ILD), particularly rapidly progressive ILD (RP-ILD), which is associated with a poor prognosis and high mortality. MDA5 functions as a cytoplasmic sensor for viral double-stranded RNA. The expression level of anti-MDA5 antibodies is positively correlated with disease severity. Notably, anti-MDA5 antibodies have been detected in patients infected with SARS-CoV-2. While the mechanisms underlying the generation of anti-MDA5 antibodies and their pathogenic role remain incompletely understood, accumulating data support the hypothesis that viral infections may trigger the production of these antibodies. This review provides a comprehensive analysis of the interplay between anti-MDA5 antibodies and viral infections in patients with anti-MDA5+ dermatomyositis (DM), with a focus on the potential mechanisms by which viral infections induce autoantibody formation.