Sequence Analysis of 'a' Determinant in Two Patients with De Novo HBV Infection after Renal Transplantation

Choe, Byung Hyun; Han, Kwang Hyub; Chung, Hyo Young; Paik, Yong Han; Chung, Jung Il; Kim, Yoo Sun; Chon, Chae Yoon; Moon, Young Myoung

Abstract

BACKGROUND/AIMS
HBV infection can be seen after organ transplantation. The presence of anti-Bs in serum means protection from HBV infection. If amino acids were mutated in 'a' determinant which was a common antigenic epitope of HBsAg, escape from humoral immunity can occur. Recently, in chronic HBV infected patients who received liver transplantation but reinfected by HBV, many authors reported mutations in 'a' determinant sequence. However, in renal transplantation, there were few reports about HBV infection and 'a' determinant mutation after transplantation. Therefore, we studied the incidence of HBV reinfection after renal transplantation and also tried to analyze 'a' determinant sequence in those patients. METHODS: We reviewed HBsAg-egative patients who received renal transplantation in our hospital, but turned HBsAg positive after transplantation. We selected two patients who were anti-Bs positive before transplantation but turned HBsAg positive after transplantation, and analyzed 'a' determinant of amino acid sequence of these patients. RESULTS: Among 1682 patients who were HBsAg negative before transplantation, 21 patients were turned HBsAg positive after transplantation. Among them, 6 patients were anti-Bs positive before transplantation. Sequence analysis of the 'a' determinant amino acid in two patients whose HBsAg turned positive after transplantation revealed no evidence of mutation in comparison with previously reported subtype 'a' determinant sequences.
CONCLUSION
In renal transplantation, HBV could be reinfected in patients who had been anti-Bs positive before transplantation even without mutation in 'a' determinant region.