In diffuse systemic sclerosis, the antibody most associated with pulmonary fibrosis and worst prognosis is:

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

Explanation

Anti-topoisomerase I (anti-Scl-70) antibodies are found in 30–40% of diffuse systemic sclerosis patients and are associated with diffuse skin thickening, pulmonary interstitial fibrosis, and overall worse prognosis. Anti-centromere antibodies (ACA) are associated with limited SSc/CREST syndrome and pulmonary arterial hypertension (better prognosis overall). Anti-RNA polymerase III is associated with diffuse skin disease and renal crisis. Anti-U1 RNP is associated with mixed connective tissue disease.

Reference: Neena Khanna Illustrated Synopsis of Dermatology & STD, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.