Anti-topoisomerase I is marker of:: (A) Systemic sclerosis, (B) Classic polyaeritis nodosa, (C) Nephrotic syndrome, (D) Rheumatoid ahritis
Answer is A. Two ANAs strongly associated with systemic sclerosis are as follows:- One of these,directed against DNA topoisomerase I (anti-Scl 70), is highly specific. Patients who have this antibody are more likely to have pulmonary fibrosis and peripheral vascular disease. The other, an anti-centromere antibody, is found in 20% to 30% of patients, who tend to have the CREST syndrome.