Examkin

Question

Difficulty: HardRheumatology and Immunology

Match each clinical presentation of a systemic autoimmune condition with its most highly associated specific autoantibody.

  • A 45-year-old woman with skin thickening extending to the trunk, bibasilar crackles, and a restrictive pattern on pulmonary function tests.Anti-topoisomerase I (anti-Scl-70) antibody
  • A 52-year-old woman with sclerodactyly, telangiectasias, exertional dyspnea, a loud P2 on cardiac auscultation, and normal lung parenchyma.Anti-centromere antibody
  • A 48-year-old man with rapid-onset diffuse skin thickening, a blood pressure of 210/110 mm Hg, acute kidney injury, and schistocytes on peripheral smear.Anti-RNA polymerase III antibody
  • A 38-year-old woman with proximal muscle weakness, bibasilar crackles, and hyperkeratotic, fissured skin on the radial aspects of her index fingers.Anti-histidyl-tRNA synthetase (anti-Jo-1) antibody
  • A 24-year-old woman with a photosensitive facial rash, inflammatory polyarthritis, pedal edema, and red blood cell casts on urinalysis.Anti-double-stranded DNA (anti-dsDNA) antibody

Answer

The presentations map to their distinct prognostic autoantibodies based on specific organ involvement and disease phenotype.
Each clinical presentation describes a classic phenotype strongly associated with a specific autoantibody. Diffuse systemic sclerosis with pulmonary fibrosis correlates with anti-topoisomerase I (anti-Scl-70). Limited systemic sclerosis with pulmonary arterial hypertension correlates with anti-centromere. Scleroderma renal crisis is strongly predicted by anti-RNA polymerase III. Antisynthetase syndrome is characterized by anti-Jo-1. Lupus nephritis correlates with anti-dsDNA.

Step-by-Step Solution

1
Analyze the clinical vignette for the first patient to determine the underlying diagnosis and its complications.
The combination of diffuse skin thickening and restrictive lung disease indicates diffuse cutaneous systemic sclerosis with interstitial lung disease.
Identifying the specific subset of systemic sclerosis and the primary organ involvement is necessary to match the correct autoantibody.
2
Evaluate the second patient's presentation focusing on isolated pulmonary vascular disease without parenchymal lung involvement.
Sclerodactyly and telangiectasias with signs of right heart strain (loud P2) but clear lungs indicate limited cutaneous systemic sclerosis complicated by pulmonary arterial hypertension.
Differentiating interstitial lung disease from pulmonary arterial hypertension determines the prognostic antibody.
3
Identify the acute, life-threatening complication in the third patient.
Malignant hypertension, acute kidney injury, and schistocytes in a patient with rapidly progressive skin thickening are hallmark features of scleroderma renal crisis.
Certain scleroderma-specific antibodies strongly predict the occurrence of renal crisis.
4
Characterize the unique dermatologic and systemic findings in the fourth patient.
Proximal muscle weakness, lung crackles, and 'mechanic's hands' define antisynthetase syndrome.
Recognizing this specific triad points directly to myositis-specific autoantibodies.
5
Recognize the classic multisystem presentation in the fifth patient.
A photosensitive rash, arthritis, and red blood cell casts are indicative of systemic lupus erythematosus with active lupus nephritis.
Lupus nephritis is strongly associated with specific serological markers that correlate with disease activity.

Key Concept

In rheumatologic and autoimmune conditions, specific autoantibodies do not merely confirm a diagnosis; they serve as critical prognostic markers that predict the pattern of organ involvement (e.g., distinguishing risk for interstitial lung disease versus pulmonary arterial hypertension in systemic sclerosis).
Estimated Time:2m 0s
Rate this question

Topics

Rheumatology and Immunology

More questions from this topic