Clinical Features and a Nomogram for Predicting Infection in Anti-MDA5 Antibody-Positive Dermatomyositis: A Single-Center Retrospective Study

Background : Anti-melanoma differentiation-associated gene 5 antibody-positive dermatomyositis (anti-MDA5+ DM) confers substantial mortality risk, among which infection predominates. This study aimed to delineate the clinical characteristics of MDA5+ DM and develop a nomogram for infection prediction. Methods: We retrospectively analyzed clinical data from 207 consecutive hospitalized patients with anti-MDA5+ DM. Patients were divided into infected and uninfected groups. Univariate and multivariate logistic regression analyses were performed to identify potential risk factors for infection. A nomogram was constructed to visualize the predictive model, with performance assessed via receiver operating characteristic (ROC) curve analysis and area under the curve (AUC) calculation. Results: Among 207 enrolled patients, 101 developed infections. Elevated C-reactive protein (CRP) and lactate dehydrogenase (LDH), lower levels of albumin (Alb), diabetes, mean daily glucocorticoid dose during the month preceding admission and cyclophosphamide exposure were identified as independent risk factors for infection. The prediction model incorporating these six factors yielded an AUC of 0.856. Conclusions: Independent risk factors for infection in MDA5+ DM included elevated CRP and LDH, lower levels of Alb, diabetes,mean daily glucocorticoid dose, and cyclophosphamide exposure. The derived nomogram exhibited favorable predictive performance and may facilitate individualized risk assessment.