Prophylaxis With Valganciclovir in Anti–Melanoma Differentiation Associated 5 Gene Antibody Dermatomyositis: A Cohort Study in China

Background: Cytomegalovirus (CMV) infection is prevalent in patients with anti–melanoma differentiation-associated 5 gene antibody-positive dermatomyositis (MDA5+DM) and affects the prognosis. This study aimed to evaluate the efficacy of valganciclovir prophylaxis during MDA5+DM treatment. Methods: Adult patients with active MDA5+DM were consecutively recruited from May 1, 2023 to December 31, 2023, and followed up for 6 months. Participants were categorized into 2 groups based on whether they received valganciclovir or not. The incidence of CMV infection and changes in disease activity were analyzed. Results: This study included 49 patients with active MDA5+DM. Prophylaxis with valganciclovir was administered to 18 patients, including 9 patients with rapidly progressive interstitial lung disease (RP-ILD). Of the remaining 31 patients, 15 had RP-ILD. During the follow-up, no CMV infection, discomfort, or abnormal laboratory findings associated with valganciclovir were observed during the prophylaxis period. Nine patients in the control group were infected with CMV (p = 0.032). In the survival analysis, 2 and 9 patients with RP-ILD died in the valganciclovir and control groups, respectively (p = 0.084). No significant difference in disease activity and glucocorticoid dosage was observed between two groups at 3 and 6 months. Furthermore, the use of biological and targeted synthetic disease-modifying antirheumatic drugs at the initiation of treatment was identified as a risk factor for CMV infection in active MDA5+DM patients in the control group (p = 0.007). Conclusion: Prophylaxis with valganciclovir can reduce the incidence of CMV infection during MDA5+DM treatment. It exerts a potential auxiliary effect on MDA5+DM treatment.