Antisynthetase Syndrome With Classic Features and Anti‑PL‑7 Positivity: A Rare Immunologic Variant

Antisynthetase syndrome (ASyS) is a rare and heterogeneous subtype of idiopathic inflammatory myopathies, characterized by the presence of autoantibodies against aminoacyl-tRNA synthetases. Among these, anti-PL-7 antibodies are infrequent and associated with variable clinical expression. We present the case of a 71-year-old woman who developed progressive proximal muscle weakness. Physical examination revealed a heliotrope rash and mechanic's hands. Laboratory tests showed markedly elevated creatine kinase levels, and chest computed tomography findings were consistent with interstitial lung disease. Serological testing confirmed the presence of anti-PL-7 antibodies, leading to the diagnosis of ASyS. This case highlights the diagnostic challenges of ASyS, particularly when rare autoantibodies such as anti-PL-7 are involved. Recognition of characteristic clinical features and serological findings is essential for timely diagnosis and appropriate management.