Management and outcomes of interstitial lung disease associated with anti-synthetase syndrome: a systematic literature review

Anti-synthetase syndrome (ASS) is a chronic autoimmune condition, with interstitial lung disease (ILD) being a key feature. This systematic literature review (SLR; CRD42023416414) aimed to summarize treatments and outcomes of ILD associated with ASS (ASS-ILD). Databases were searched for articles discussing ASS-ILD management and outcomes, published 1946-September 2023. Screening and data extraction were performed by two reviewers. Meta-analysis, using a random effects model, and paired t-tests were undertaken where appropriate to evaluate post-treatment-change in pulmonary function tests. Ten articles were included, comprising 514 patients: 67.8% female, mean age 52.4 years (s.d. 4.6). Baseline high-resolution CT was documented in 447 patients (86.9%); the most common pattern was non-specific interstitial pneumonia (n = 220; 49.2%). The most common myositis-associated autoantibody was anti-Jo1 (48%), with 27.8% having associated anti-Ro52 antibodies. Pooled estimate, after meta-analysis, for baseline forced vital capacity (FVC) was 60.8% predicted (s.e. 2.1) and for diffusion capacity of lungs for carbon monoxide (DLco) was 49.8% (s.e. 3.5). After 1 year, pooled improvement in FVC was 14.1% from baseline (s.e. 3.1) and in DLco was 15.1% (s.e. 2.8). Paired t-test demonstrated significant overall improvement in FVC (P = 0.007) and DLco (P = 0.002). Patients receiving rituximab had 12.2% improvement in FVC and 2.9% increase in DLco at 1 year; for patients receiving CYC, there was 17% improvement and 6.3% increase, respectively. Twenty-eight deaths were reported. Our SLR, the first to summarize management and outcomes of ASS-ILD, found no conclusive difference between effectiveness of treatments. More robust trials are required to reduce morbidity and mortality resulting from ASS-ILD.