Management of MDA-5 antibody positive clinically amyopathic dermatomyositis associated interstitial lung disease: A systematic review

Anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive clinically amyopathic dermatomyositis (CADM) is frequently associated with rapidly progressive interstitial lung disease (RP-ILD) and high mortality rates. There is a lack of data on management of this often fatal condition. The aim of this systematic review was to evaluate current evidence that assesses the available management options and discuss the associated management challenges.This systematic review was conducted according to PRISMA guidelines. Online databases were searched from inception to April of 2021 using the search terms: "dermatomyositis" OR "amyopathic dermatomyositis" OR "clinically amyopathic dermatomyositis" AND "MDA-5″ OR "melanoma differentiation-associated gene-5″ OR "CADM-140″ AND "management" OR "treatment" OR "therapy" OR "therapeutics". Articles assessing the use of pharmacologic agents on 10 or more patients with MDA5-antibody positive CADM associated with ILD were included. Narrative or systematic reviews and meta-analyses were not eligible for inclusion.A total of 15 eligible studies and 399 unique patients were selected. We identified only one open-label randomized controlled trial (RCT) that examined the management of anti-MDA5 antibody CADM/DM-ILD. Further, 3 cohort studies with prospective arms matched against historical controls, 10 retrospective cohort studies, and 1 retrospective case series were included. A combined therapeutic regimen of high-dose systemic glucocorticoids and other immunosuppressive agents such as calcineurin inhibitors and/or cyclophosphamide, administered early, appears to give the highest rates of survival in those with RP-ILD, while additional therapies such as plasma exchange can be added for refractory disease. Further, tofacitinib and rituximab might have a place in the therapeutic armamentarium of this challenging to treat condition. Early detection and treatment are of extreme importance, given the risk for rapid decline and high mortality in this subset of patients.There are limited RCTs evaluating the treatment of ILD associated with MDA5-antibody positive CADM. Initiating a combined immunosuppressive therapeutic regimen early in the disease course improves overall morbidity and mortality. RCTs and larger prospective studies are needed to provide high-quality evidence to inform future treatment guidelines.