Published online Oct 7, 2013. doi: 10.3748/wjg.v19.i37.6214
Revised: July 24, 2013
Accepted: August 4, 2013
Published online: October 7, 2013
Processing time: 174 Days and 2.2 Hours
AIM: To investigate characteristics of hepatitis B virus (HBV) implicated in HBV reactivation in patients with hematological malignancies receiving immunosuppressive therapy.
METHODS: Serum samples were collected from 53 patients with hematological malignancies negative for hepatitis B surface antigen (HBsAg) before the start of and throughout the chemotherapy course. HBV reactivation was diagnosed when the HBsAg status changed from negative to positive after the initiation of chemotherapy and/or when HBV DNA was detected by real-time detection polymerase chain reaction (RTD-PCR). For detecting the serological markers of HBV infection, HBsAg as well as antibodies to the core antigen (anti-HBc) and to the surface antigen were measured in the sera by CEIA. Nucleic acids were extracted from sera, and HBV DNA sequences spanning the S gene were amplified by RTD-PCR. The extracted DNA was further subjected to PCR to amplify the complete genome as well as the specific genomic sequences bearing the enhancer II/core promoter/pre-core/core regions (nt 1628-2364). Amplicons were sequenced directly.
RESULTS: Thirty-five (66%) of the 53 HBsAg-negative patients were found to be negative serologically for anti-HBc, and the remaining 18 (34%) patients were positive for anti-HBc. Five of the 53 (9.4%) patients with hematologic malignancies experienced HBV reactivation. Genotype D1 was detected in all five patients. Four types of mutant strains were detected in the S gene product of HBV strains and were isolated from 3 patients with HBV reactivation: T/S120, L143, and I126. HBV DNA was detected in the pretreatment HBsAg-negative samples in one of the five patients with HBV reactivation. In this patient, sequences encompassing the HBV full genome obtained from sera before the start of chemotherapy and at the time of de novo HBV hepatitis were detected and it showed 100% homology. Furthermore, in the phylogenetic tree, the sequences were clustered together, thereby indicating that this patient developed reactivation from an occult HBV infection.
CONCLUSION: Past infection with HBV is a risk factor for HBV reactivation in Egypt. Mandatory anti-HBc screening prior to chemotherapy in patients with hematological malignancies is recommended.
Core tip: The study aimed to investigate characteristics of hepatitis B virus (HBV) implicated in HBV reactivation in patients with hematological malignancies receiving immunosuppressive therapy in Egypt. Fifty-three hepatitis B surface antigen (HBsAg)-negative patients treated with chemotherapy were included in the study. The incidence of HBV reactivation was 9.4% among the studied cohort, and all of the affected individuals were positive for HBsAg as well as antibodies to the hepatitis B core antigen. The present study provides further evidence via molecular evolutionary analysis of the development of HBV reactivation from an occult HBV infection. Past infection with HBV is a risk factor for HBV reactivation in Egypt. Mandatory antibodies to the core antigen screening prior to chemotherapy in patients with hematological malignancies is suggested.