Clinical improvement in early onset interstitial lung disease using rituximab in children with anti-MDA5 positive juvenile dermatomyositis.

Abstract

Children with juvenile dermatomyositis (JDM) and antibodies to melanoma differentiation associated gene 5 (anti-MDA5) are at increased risk of severe disease complications, including interstitial lung disease (ILD). Data regarding treatment of disease complications in this patient population is limited. In this study, we examined the disease course of children with JDM and anti-MDA5 antibodies before and after treatment with rituximab (RTX). Patients (age 2-21 years) seen at the Children's Hospital at Montefiore between July 2012 and August 2021, with a diagnosis of JDM, positive anti-MDA5 positive antibodies, evidence of ILD, and who were treated with rituximab were eligible for inclusion. Retrospective clinical and laboratory data were reviewed. Five out of 8 patients with positive anti-MDA5 antibodies had evidence of ILD (62.5%). Four patients had data available for review. All patients received at least 5 courses of RTX infusions, with discontinuation of steroids by an average of 12 months after starting RTX and a decrease to fewer than two concurrent medications by fifth course of RTX. Indicators of ILD on high-resolution computed tomography (HRCT) and pulmonary function tests (PFTs) either improved or fully resolved over the course of RTX treatment for all patients. Patients also demonstrated resolution of active cutaneous manifestations and musculoskeletal disease activity. This is the first study to examine the use of RTX in children with JDM and anti-MDA5 antibodies, with notable improvements ILD, cutaneous and musculoskeletal manifestations. Further studies are needed to better understand the efficacy of RTX on JDM disease related complications.