Antihistone and Other Autoantibodies in β-Thalassemia major Patients Receiving Iron Chelators

Abstract

This study was designed to find out the incidence of various autoantibodies in patients receiving iron chelators. Two groups were studied for comparison. One group consisted of thalassemia major cases on deferiprone (L1) and the second group were those receiving desferrioxamine therapy. Various autoantibodies such as antihistone antibodies and its subfractions H1, H2A-H4B, H2B, H3, ANF, anti-dsDNA, anti-nRNP, anti-Sm, ANCA and rheumatoid factor were tested. Out of 180 patients 50 patients (27.8%) were on desferrioxamine therapy, and 60 patients (33.3%) were taking deferiprone, whereas 70 patients (38.9%) were untreated. Antihistone antibodies were found in 30% of patients receiving deferiprone and 48% in the desferrioxamine group, respectively, as compared to control thalassemics (14.3%). Also, the levels of antihistone antibody were significantly elevated in the chelator groups as compared to controls. When antibodies to subfractions of the histone molecule were studied, it was observed that antibodies to H1 were most commonly seen and IgG was the major immunoglobulin subclass. Anti-dsDNA and anti-Sm antibodies, which are the diagnostic markers of idiopathic SLE, were absent in these patients. β-Thalassemia major patients on iron chelators such as desferrioxamine and deferiprone show changes in their autoimmune profile suggestive of some humoral immune alterations.