Anti-synthetase syndrome with positive anti-PL-12 antibodies associated with autoimmune hepatitis: case report and literature review

Antisynthetase Syndrome (ASS) is a rare chronic autoimmune disorder, associated with interstitial lung diseases (the most important feature), such as Dermatomyositis (DM) and Polymyositis (PM). The cause of ASS is unknown. The hallmark of ASS is the presence of serum autoantibodies directed against aminoacyl-tRNA synthetases (anti-ARS involved in protein synthesis). Anti -Jo1 is the most common (20% - 30%); anti-PL12 is present in 2% - 5% of SAS, associated with Interstitial Lung Disease (ILD) in 90%, mainly as Non-Specific Interstitial Pneumonia (NSIP). Autoimmune hepatitis is related to rheumatological diseases (2.7% - 20% in systemic lupus erythematosus, 6% - 47% in primary Sjögren’s syndrome), however, is rare in patients with inflammatory myopathies, and there is no previous reported association with SAS. A literature search was carried out using the PubMed and EMBASE databases in English and Spanish. Our case, a 62-year-old woman who developed polyarthritis, with progressive dyspnea, facial and lower limb edema, proximal muscle weakness, and Raynaud’s phenomenon; high-resolution chest CT, showing pulmonary interstitial disease, consistent with Nonspecific Interstitial Pneumonia (NSIP). She had elevated transaminases and a prolonged prothrombin time, with positive anti-nuclear and anti-smooth muscle antibodies, and was made a diagnosis with autoimmune hepatitis type 1 (HAI). According to this presentation and reports of the literature review, anti-PL12 patients are characteristically associated with a severe phenotype of lung inflammation, that does not necessarily require myositis manifestation. To our knowledge, there is not any case of the antisynthetase syndrome and autoimmune hepatitis reported previously in the literature.