A 46-year-old woman with progressive skin thickening of the hands, Raynaud phenomenon, and new-onset severe hypertension (BP 210/120 mmHg) develops oliguric AKI over two weeks with microangiopathic haemolytic anaemia. Antinuclear antibody is positive with nucleolar pattern. Which antibody, if detected, best supports the diagnosis?
- A Anti-RNA polymerase III antibody ✓
- B Anti-centromere antibody
- C Anti-Scl-70 (topoisomerase I) antibody
- D ADAMTS13 inhibitor
Correct answer: A. Anti-RNA polymerase III antibody
Explanation
Scleroderma renal crisis presents as abrupt severe hypertension with AKI and MAHA in diffuse systemic sclerosis, and anti-RNA polymerase III antibodies identify the subset at highest risk of renal crisis. Prompt ACE inhibition improves survival. Anti-centromere marks limited cutaneous disease with low renal risk, and anti-Scl-70 correlates with pulmonary fibrosis rather than renal crisis. Severe ADAMTS13 deficiency defines thrombotic thrombocytopenic purpura, not scleroderma crisis.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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