Diffuse cutaneous systemic sclerosis (dcSSc) is associated with which antibody most predictive of scleroderma renal crisis?

• A Anti-topoisomerase I (anti-Scl-70)
• B Anti-centromere antibody (ACA)
• C Anti-U1 RNP antibody
• D Anti-RNA polymerase III antibody ✓

Explanation

Anti-RNA polymerase III antibody is strongly associated with diffuse cutaneous SSc and carries the highest risk of scleroderma renal crisis (SRC), characterised by acute hypertension and thrombotic microangiopathy. Anti-Scl-70 (anti-topoisomerase I) is associated with dcSSc and ILD but not specifically with SRC. Anti-centromere is associated with limited cutaneous SSc (lcSSc/CREST syndrome) and pulmonary arterial hypertension. Anti-U1 RNP suggests mixed connective tissue disease. ACE inhibitors are the treatment of choice for SRC and should not be withheld.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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