Time-dependent changes in RPILD and mortality risk in anti-MDA5+DM patients: a cohort study of 272 cases in China

Objectives Anti-melanoma differentiation-associated gene 5 positive (anti-MDA5+) DM has a close relationship with rapidly progressive interstitial lung disease (RPILD) and is associated with high mortality. However, data regarding the time-dependent risk of RPILD and deaths during disease progression are limited. We conducted this study to investigate whether the risk of RPILD and death were time-dependent or not in anti-MDA5+ DM. Methods We assessed a cohort of 272 patients with anti-MDA5+ DM. The clinical characteristics of patients with anti-MDA5+ were collected, and COX regression was used to analyse independent risk factors for RPILD and death. We also described changes in risk of RPILD and death over time and their potential clinical implications. Results There were 272 anti-MDA5+ DM patients enrolled in this study. According to the multivariate cox regression analysis, short disease course, high CRP level, anti-Ro52 positive and anti-MDA5 titre (++similar to+++) were independent risk factors of RPILD. High creatine kinase level, high CRP level and RPILD were independent risk factors for death, and >90% RPILD and 84% mortality occurred in the first 6 months after disease onset. Notably, the first 3 months is a particularly high-risk period, with 50% of RPILD and 46% of deaths occurring. Hazards regarding RPILD and mortality diminished over time during a median follow-up of 12 months. Conclusion These results suggest significant, time-dependent changes in RPILD and mortality risk in anti-MDA5+ DM patients, providing a cut-off time window to estimate disease progression and poor prognosis.