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Zorluk: ZorRheumatology and Immunology

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)

Cevap

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.

Adım Adım Çözüm

1
Analyze the first clinical vignette for distinctive features.
The patient has dermatomyositis signs (heliotrope rash) alongside clear symptoms of a malignancy (weight loss, lung mass).
Identifying the paraneoplastic nature of the presentation isolates Anti-TIF1-γ as the most appropriate autoantibody.
2
Analyze the second clinical vignette for syndromic patterns.
The patient exhibits interstitial lung disease and mechanic's hands.
These are the hallmark findings of antisynthetase syndrome, which is driven by antibodies against aminoacyl-tRNA synthetases, most notably Anti-Jo-1.
3
Examine the third clinical vignette's biopsy and laboratory findings.
The presentation involves severe, rapid weakness with massive CK elevation and a non-inflammatory necrotizing biopsy.
This confirms immune-mediated necrotizing myopathy (IMNM), which is classically associated with Anti-SRP or Anti-HMGCR antibodies.
4
Review the fourth clinical vignette for classic diagnostic criteria.
The patient has classic cutaneous dermatomyositis that responds perfectly to standard corticosteroid therapy.
Anti-Mi-2 is linked to this classic presentation, predicting an excellent response to treatment and a low risk for severe systemic complications.

Anahtar Kavram

Myositis-specific autoantibodies and their corresponding distinct clinical phenotypes (antisynthetase syndrome, immune-mediated necrotizing myopathy, cancer-associated dermatomyositis).
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