A 58-year-old male is diagnosed with diffuse cutaneous systemic sclerosis (dcSSc) with rapidly progressive skin thickening and early interstitial lung disease. Which of the following autoantibodies is most likely to be positive in this patient and is associated with a poorer prognosis?

Explanation

Anti-Scl-70 (topoisomerase I) antibodies are strongly associated with diffuse cutaneous systemic sclerosis (dcSSc) and are linked to a higher risk of interstitial lung disease and a generally poorer prognosis compared to limited cutaneous systemic sclerosis. Anti-centromere antibodies are characteristic of limited cutaneous systemic sclerosis (lcSSc) and CREST syndrome. Anti-RNA polymerase III antibodies are associated with dcSSc, rapid skin progression, and a high risk of scleroderma renal crisis, but anti-Scl-70 is more classically linked with ILD and overall poorer prognosis in dcSSc. Anti-U1-RNP antibodies are characteristic of mixed connective tissue disease.