The Role of Myositis-Specific Autoantibodies and the Management of Interstitial Lung Disease in Idiopathic Inflammatory Myopathies: A Systematic Review

To evaluate the role of myositis-specific autoantibodies (MSAs) in interstitial lung disease (ILD), management of idiopathic inflammatory myopathies (IIM) associated ILD, and if there is a role for MSA specific management of ILD.A systematic review was performed examining how MSAs relate to ILD manifestations in IIM patients and comparing treatment outcomes with varying immunosuppressive regimens.112 papers were included in this analysis. Patients with anti-aminoacyl tRNA synthetase (anti-ARS) and anti-melanoma differentiation-associated gene 5 (anti-MDA5) antibodies had consistently higher rates of ILD than other MSA groups. Anti-ARS positive patients had higher rates of chronic ILD whereas anti-MDA5 positive patients had higher rates of rapidly progressive ILD (RP-ILD). The most common high-resolution computed tomography (HRCT) patterns for ILD in anti-ARS and anti-MDA5 positive patients were nonspecific interstitial pneumonia (NSIP) and unclassifiable respectively. Anti-transcription intermediary factor 1-gamma (anti-TIF1-γ), anti-Mi-2, anti-nuclear matrix protein 2 (anti-NXP-2), and anti-3-hydroxy-3-methylglutaryl coenzyme A reductase (anti-HMGCR) antibodies were associated with a decreased risk of ILD. Small sample sizes, a lack of head-to-head trials, and non-randomized designs prevented drawing meaningful conclusions with respect to immunosuppressive management.Clear relationships exist with regards to the ILD manifestations of certain MSAs. Standard therapy for IIM associated ILD (IIM-ILD) is glucocorticoids with the addition of others immunosuppressives in patients with or at risk of RP-ILD as well as in refractory cases. Immunosuppressives should be preferentially used in MSA populations in which they have been studied and shown to be efficacious.