Immunological Characterization of Patients with Idiopathic Inflammatory Myopathies: Anti-CCAR1 Antibodies in Patients With and Without Malignancy and Their Association with Anti-TIF1γ Antibodies

Idiopathic inflammatory myopathies (IIM) are rare autoimmune disorders in which malignancy represents a major cause of morbidity and mortality, particularly in cancer-associated myositis (CAM). Up to 25% of patients with IIM are diagnosed with cancer within three years before or after myositis onset. Anti-TIF1γ antibodies, detected in 7 -31% of adults with dermatomyositis, are among the strongest predictors of cancer risk. However, 25 -50% of anti-TIF1γ-positive patients do not develop cancer. Recent evidence suggests that additional autoantibodies may modulate this risk. In particular, anti-CCAR1 antibodies have been associated with reduced cancer risk and longer latency to cancer diagnosis.The researcher will assess anti-CCAR1 antibodies in a single-center cohort of nearly 200 patients with IIM and investigate their relationship with anti-TIF1γ positivity and cancer occurrence.