DECREASED ALLOREACTIVITY AFTER VACCINATION AGAINST HEPATITIS-B

The beneficial effect of blood transfusions on renal allografts disapp eared at about the same time when hepatitis B vaccination was introduc ed in dialysis patients. To determine possible immunosuppressive effec ts of hepatitis B vaccination, we studied alloreactivity during the co urse of immunization. Fourteen healthy subjects without serological ev idence of hepatitis B were routinely immunized against hepatitis B sur face antigen. Plasma and mononuclear cells were isolated and frozen be fore immunization and after vaccination, respectively. Mean alloreacti vity measured by [H-3]thymidine uptake decreased from 64,772 cpm befor e immunization to 40,213 cpm after the third immunization. In crossove r experiments, cellular modulation and plasma-dependent modulation of alloreactivity were observed. The immunosuppressive effect of plasma t aken 4 weeks after the third vaccination correlated (r=0.9) highly sig nificantly (P<0.005) with the anti-hepatitis B surface antigen antibod y titer. Taken together, our data strongly suggest that hepatitis B va ccination is capable of reducing allogenic reactivity.