Anti-MDA5 antibody–positive dermatomyositis with anti-Ro52 ups ILD, mortality risks

Patients with dermatomyositis (DM) who are positive for antimelanoma differentiation-associated gene 5 antibody (anti-MDA5) are more likely to have anti-Ro52 antibodies as well, and such coexistence appears to heighten the risks of rapidly progressive interstitial lung disease (ILD) and mortality, suggests a recent study.

In addition, patients with a short disease course, with increased inflammation, and without rash tend to have a poor prognosis.

A cohort of 246 patients with anti-MDA5-positive DM were evaluated in this study. The authors calculated hazard ratios and 95 percent confidence intervals (CIs) for rapidly progressive ILD and death while controlling for potential confounders. They included variables selected by univariate Cox regression analysis in a multivariate Cox regression model with the stepwise forward-selection method.

Of the patients (mean age 53.1 years, 70 males), 158 (64.2 percent) had anti-Ro52 antibodies. Those with anti-MDA5-positive DM who were also positive for anti-Ro52 had excess rates of rapidly progressive ILD (log-ran p<0.001) and mortality (log-ran p=0.01). Additionally, those with a short disease course and high inflammation had higher risks of rapidly progressive ILD and death.

“Anti-Ro52 antibodies were highly prevalent in patients with anti-MDA5-positive DM, and their coexistence correlated with a higher rate of rapidly progressive ILD and mortality,” the authors said, noting however that the appearance of active rash was independently protective against mortality.

“ILD is a common extramuscular complication contributing to significant morbidity and mortality in patients with DM who are positive for anti-MDA5,” they said.