Match each patient's clinical presentation with the myositis-specific autoantibody that is most strongly associated with their clinical phenotype.
- A 68-year-old man with a heliotrope rash, progressive proximal muscle weakness, a 15-lb unintentional weight loss, and a newly discovered right lower lobe lung mass.Anti-TIF1-γ (Anti-transcriptional intermediary factor 1-gamma)
- A 42-year-old woman with exertional dyspnea, dry cough, basilar crackles, proximal weakness, and hyperkeratotic fissuring on the radial aspects of her fingers.Anti-Jo-1 (Anti-histidyl-tRNA synthetase)
- A 35-year-old man with rapidly progressive weakness causing inability to walk, extremely elevated creatine kinase (12,000 U/L), and muscle biopsy showing extensive necrosis with sparse inflammation.Anti-SRP (Anti-signal recognition particle)
- A 50-year-old woman with a prominent V-neck macular erythematous rash (shawl sign), Gottron papules, and mild weakness that resolves completely with a short course of oral corticosteroids.Anti-Mi-2 (Anti-nuclear helicase)
Answer
The correct pairings map the cancer-associated dermatomyositis presentation to Anti-TIF1-γ, the antisynthetase syndrome presentation to Anti-Jo-1, the immune-mediated necrotizing myopathy to Anti-SRP, and the classic, highly steroid-responsive dermatomyositis to Anti-Mi-2.
Each myositis-specific autoantibody defines a distinct clinical subgroup. Anti-TIF1-γ is linked to malignancy; Anti-Jo-1 to antisynthetase syndrome (ILD, mechanic's hands); Anti-SRP to profound, rapidly progressive necrotizing myopathy; and Anti-Mi-2 to classic, steroid-responsive dermatomyositis.
Step-by-Step Solution
Key Concept
Myositis-specific autoantibodies and their corresponding distinct clinical phenotypes (antisynthetase syndrome, immune-mediated necrotizing myopathy, cancer-associated dermatomyositis).