The hepatitis B antigen and antibody were sought in the serum of 117 patients with rheumatic fever and 40 healthy controls by the RIA technique. HB_s antigen was found to be positive in nine of the 46 patients (19.5%) with active rheumatic heart diseases, six of 51 patients (11.7%) with chronic rheumatic heart disease and five of the the 20 patients (25%) with acute rheumatic arthritis without carditis. Of the 40 healthy controls, only two (5%) were found to have positive hepatitis HBs antigen in the serum. Anti HBs was found to be positive in twelve of forty-six patients (26%) with active rheumatic heart disease, sixteen of fifty patients (32%) with chronic rheumatic heart disease, four of eighteen patients (22.2%) with acute rheumatic arthritis without carditis and thirteen of forty healthy controls (32.5%).

Statistical comparisons for HBs antigen frequency between patients with rheumatic fever and healthy controls revealed a significant difference. However, there was no statistically significant difference between rheumatic fever patients and controls for anti HBs frequency.

For the tissue studies, samples were taken from 27 chronic rheumatic valvular heart disease patients. In eight (29.9%) of these specimens, HBs antigen and complement C3(B1C) were found to be positive by the immunofluorescent technique. In five of the eight specimens, IgM and IgA were stained to be positive while in three of them IgG was positive. Based on these results, the possible role of HB virus in the pathogenesis of this disease was discussed.

Keywords: hepatitis B surface antigen, immuno-fluorescent study, rheumatic fever