Idiopathic inflammatory myopathies are characterized by distinct myositis-specific autoantibodies that strongly predict clinical phenotypes, organ involvement, and prognosis. Match each myositis-specific autoantibody with its most characteristic clinical phenotype or primary disease association.
- Anti-Jo-1 (anti-histidyl-tRNA synthetase)Mechanic's hands, nonerosive arthritis, Raynaud phenomenon, and high risk of interstitial lung disease
- Anti-SRP (signal recognition particle)Severe, acute-onset immune-mediated necrotizing myopathy with profound weakness and cardiac involvement
- Anti-Mi-2 (nucleosome remodeling deacetylase complex)Classic dermatomyositis with prominent cutaneous manifestations and a generally favorable response to treatment
- Anti-MDA5 (melanoma differentiation-associated gene 5)Clinically amyopathic dermatomyositis characterized by cutaneous ulcerations and rapidly progressive interstitial lung disease
- Anti-TIF1-gamma (transcriptional intermediary factor 1-gamma)Severe dermatomyositis in older adults carrying a strong association with an underlying occult malignancy
Answer
Anti-Jo-1 matches with antisynthetase syndrome (mechanic's hands, ILD); Anti-SRP matches with severe necrotizing myopathy; Anti-Mi-2 matches with classic, steroid-responsive dermatomyositis; Anti-MDA5 matches with amyopathic dermatomyositis and rapidly progressive ILD; Anti-TIF1-gamma matches with malignancy-associated dermatomyositis.
Idiopathic inflammatory myopathies (IIMs) are heterogeneous. Myositis-specific antibodies (MSAs) allow for the categorization of IIMs into distinct clinical subsets. Recognizing these associations is critical for anticipating complications such as rapidly progressive interstitial lung disease (Anti-MDA5), occult malignancy (Anti-TIF1-gamma), or necrotizing autoimmune myopathy with cardiac involvement (Anti-SRP).
Step-by-Step Solution
Key Concept
Myositis-specific autoantibodies and their corresponding clinical phenotypes