RESUMO
BACKGROUND: Hydroxyl radical, one of the most potent of all reactive oxygen species, is known to modify adenine and thymine in cellular DNA, producing some modified DNA fragments (ROS-DNA) with different antigenic properties. Despite several in vitro studies about ROS-DNA, data regarding their clinical significance are scanty. The aim of our study was to seek out the presence and clinical significance of the anti poly(dT) auto-antibodies in a group of patients suspected of autoimmune disease. METHODS: We initially evaluated more than 900 consecutive sera of hospitalized patients (range age from 6 to 70 yrs) referred to our laboratory during 18 months. Anti n-DNA, anti-ENA and poly(dT) autoantibodies were performed on 158 ANA positive sera and 28 ANA negative sera from patients strongly suspected of rheumatic diseases or affected by HCV infection. RESULTS: Anti poly (dT) were found in 22 out of 186 sera. As regards the clinical evaluation, 8 patients were affected by SLE, 5 by Scleroderma, 3 by HCV-related chronic hepatitis, 4 by recurrent abortions (without presence of the anti-cardiolipin antibodies and other clinical symptoms). In two patients the ACR criteria and the clinical aspects did not allow a definite diagnosis. Anti-Histones were detected in 18 out of 22 poly (dT) positive patients. CONCLUSIONS: Our data suggest that anti poly(dT) autoantibodies are sensitive markers of various autoimmune diseases, but with a minor specificity as compared to anti n-DNA for the diagnosis of SLE.
