Hepatitis B reactivation in a renal transplant patient due to a surface antigen mutant strain: a case report

Reactivation of hepatitis B virus (HBV) is a complication of immunosuppressive treatment in patients with a history of HBV exposure.

Herein we have reported a case of reactivation after renal transplantation in a 52-year-old male chronic HBV carrier who was treated with hepatitis B immunoglobulin (HBIg) prophylaxis immediately after transplantation in addition to cyclosporine, mycophenolate mofetil and prednisolone for maintenance immunosuppression. After application of rituximab, the patient developed clinical hepatitis with a high load of HBV DNA. Sequence analysis of the surface (S) antigen corresponding to the amino acid residues 101-186 (including the a-determinant region) revealed a genotype D mutant strain, subtype ayw3 with a single amino acid substitution D144E within the S gene.

This case suggested that immunosuppressive treatment enhanced with rituximab promoted the emergence of an HBV mutant within the determinant region of the S antigen, which escaped HBIg immunoprophylaxis causing HBV reactivation in a kidney transplant recipient.