Anti-topoisomerase II alpha autoantibodies in systemic sclerosis-association with pulmonary hypertension and HLA-B35

We have previously detected autoantibodies against topoisomerase II alpha ( anti-topo II alpha) in sera from patients with idiopathic pulmonary fibrosi s. To determine whether anti-topo II alpha is also present in systemic scle rosis (SSc) patients with pulmonary involvement, we screened sera from 92 p atients and 34 healthy controls. Presence of anti-topo II alpha was investi gated with respect to clinical and serological features, including the freq uencies of HLA class I and II alleles. Anti-topo II alpha was detected in 2 0/92 (21.7%) patients. No association was found with either anti-topoisomer ase I (Scl-70 or anti-topo I) or anti-centromere antibodies. However, anti- topo II alpha was associated with the presence of pulmonary hypertension (P HT) (as opposed to pulmonary fibrosis), and with a decrease of carbon monox ide diffusing capacity. Anti-topo II alpha was strongly associated with the presence of the class I antigen HLA-B35. No significant association was fo und with HLA class II antigens. HLA-B35 also turned out to be associated wi th the presence of PHT. These results indicate that in SSc patients, the pr esence of anti-topo II alpha is associated with PHT, and that the simultane ous presence of HLA-B35 seems to add to the risk of developing PHT.