Comparative analysis of clinical features and survival outcomes in patients with anti-MDA5 antibody-positive dermatomyositis versus ant-synthetase syndrome following COVID-19 infection: a retrospective cohort study

Objective Both anti-melanoma differentiation-associated protein 5 antibody positive dermatomyositis (MDA5 + DM) and anti-synthetase syndrome (ASS) can progress to associated rapidly progressive interstitial lung disease (RP-ILD), significantly impacting patient prognosis and outcomes. The aim of this study was to investigate the clinical characteristics and survival analysis of patients who developed MDA5 + DM and ASS after COVID-19 infection, with a view to providing preventive and therapeutic strategies for the clinic. Methods A retrospective review was conducted on the complete clinical data of hospitalized patients diagnosed with MDA5 + DM ( n = 71) and ASS ( n = 77) at the Third Affiliated Hospital of Zunyi Medical University between December 2021 and December 2024. All patients in both groups had a documented history of COVID-19 infection. First, the baseline characteristics, clinical features, and examination results of the two patient groups were analyzed and compared. Subsequently, logistic regression analysis was used to assess the correlation of clinical features between the two groups. The diagnostic value of combined clinical indicators was evaluated using receiver operating characteristic (ROC) curve analysis. Finally, Kaplan-Meier survival analysis was employed to compare the impact of relevant factors on survival time. Results This study found that ILD was the most common complication in patients with MDA5 + DM and ASS, accounting for 87.3% and 79.2% of cases, respectively. Significant differences were observed between the two groups in terms of clinical features, auxiliary examinations, treatment strategies, and prognosis. Multivariate logistic regression analysis revealed that, compared to the ASS group, patients in the MDA5 + DM group were more likely to experience limb weakness (*** P < 0.001) and joint pain (** P < 0.01). Additionally, white blood cell count, and lymphocyte count were significantly lower in the MDA5 + DM group (*** P < 0.001), while activated partial thromboplastin time (APTT) and thrombin time (TT) were relatively prolonged (* P < 0.01 and P < 0.05, respectively). ROC curve analysis of the aforementioned six statistically significant indicators revealed that the combination of these indicators holds clinical utility for the early identification and diagnosis of MDA5 + DM and ASS (AUC = 0.937). Kaplan-Meier survival analysis conducted at 30 days post-admission revealed that the survival rate in the MDA5 + DM group was significantly lower than ASS group ( P = 0.01). Conclusions COVID-19 infection may increase the risk of developing MDA5 + DM and ASS, thereby contributing to the onset of ILD. Patients presenting with joint pain, limb weakness, prolonged APTT and TT, as well as reduced white blood cell and lymphocyte counts, are at a higher risk of MDA5 + DM compared to ASS. Furthermore, patients with MDA5 + DM exhibit longer hospital stays and poorer prognoses.