Transfer of hepatitis B immunity occurs upon the transfer of immunologically active cells from the donor to the recipient by means of an organ graft. This has been repeatedly demonstrated for bone marrow and liver transplantations. Evidence is now presented for the transfer of anti-hepatitis B surface antibodies (anti-HBs) after kidney transplantation in rats. Kidney donors from one syngeneic and two allogeneic rat strains were immunized twice with 4 microg of recombinant hepatitis B vaccine. In week 6 after the first vaccination, kidney grafts were transplanted into Lewis (LEW) rats. Half of the recipients underwent daily immunosuppressive treatment with cyclosporin A (CsA). All recipients were vaccinated either after 10 weeks or 1 week postoperatively. Anti-HBs titer was measured weekly. Effective anti-HBs titers (10-227 mIU/ml, lasting for 1-7 weeks) were detected in 86% (25/29) of recipient rats, whose corresponding donors all had a titer above 15,000 mIU/ml. Immunosuppression enhanced the donor-derived immunity in terms of recipient-to-donor titer ratio, maximal titer and titer persistence.
