Hepatitis B virus reactivation in patients receiving cancer chemotherapy: natural history, pathogenesis, and management.
ABSTRACT Chronic hepatitis B virus (HBV) infection is endemic in the Asian-Pacific region, and reactivation of HBV post-cancer chemotherapy has become an emerging clinical challenge. Patients with detectable serum HBV DNA before chemotherapy and those receiving intensive chemotherapy are particularly at a risk of HBV reactivation. Most patients with HBV reactivation are positive for hepatitis B surface antigen (HBsAg) and are, therefore, easily identified by recommended serological screening before chemotherapy. However, a small, but significant proportion of subjects who have apparently recovered from HBV infection as reflected by HBsAg negativity and hepatitis B core antibody positivity in HBV endemic areas may also experience reactivation when host immunity is severely compromised by cancer chemotherapy. Serum alanine aminotransferase, HBsAg, and/or HBV DNA should be monitored closely in these subjects and antiviral therapy should be administered immediately when any evidence of HBV reactivation is detected during chemotherapy. The prophylactic use of nucleos(t)ide analogs before chemotherapy and its continuation until reconstitution of host immunity remain the mainstay of effective prevention of hepatitis B reactivation in this special clinical entity.
- Bone Marrow Transplantation 04/2006; 37(6):625-6. · 3.54 Impact Factor
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ABSTRACT: Reactivation of hepatitis B virus (HBV) has been reported as a fatal complication following systemic chemotherapy or other immunosuppressive therapy. The risk of HBV reactivation differs according to both the patient's HBV infection status prior to systemic chemotherapy and the degree of immunosuppression due to chemotherapy. For establishing an optimal strategy for hepatitis prevention and treatment, it is necessary to understand the characteristics, the clinical course and the risk factors for HBV reactivation and to recognize the difference between hepatitis B surface antigen (HBsAg)-positive and -negative patients with HBV reactivation. Among the important viral risk factors, HBV-DNA level and HBV-related serum markers have been reported to be associated with HBV reactivation in addition to cccDNA, genotypes and gene mutations. Rituximab-plus-steroid combination chemotherapy has recently been identified as a host risk factor for HBV reactivation in hepatitis B core antibody (anti-HBc)-positive and/or hepatitis B surface antibody (anti-HBs) positive--but nonetheless HBsAg-negative--lymphoma patients. For these patients with resolved hepatitis B, preemptive therapy guided by serial HBV-DNA monitoring is a reasonable strategy to enable early diagnosis of HBV reactivation and initiation of antiviral therapy. In this review, we summarize the characteristics of HBV reactivation following rituximab-plus-steroid combination chemotherapy, mainly in HBsAg-negative lymphoma patients, and propose a strategy for managing HBV reactivation.Journal of Gastroenterology 10/2010; 46(1):9-16. · 3.79 Impact Factor
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ABSTRACT: We have analyzed the molecular bases of the persistence of hepatitis B virus (HBV) DNA in serum and peripheral blood mononuclear cells (PBMC) in the absence of detectable hepatitis B surface antigen (HBsAg) in hemodialysis patients and dialysis-unit staff members who had suffered acute hepatitis B that resolved previously. HBV DNA was found in both compartments by polymerase chain reaction (PCR) using primers of the pre-S/S region. Viral DNA was transcriptionally active in PBMC, because the covalently closed circular (ccc) HBV DNA, the template for the viral RNA transcription, was detected in 47% of the samples. Furthermore, all PBMC had HBV RNA. HBsAg-negative cases had statistically lower levels of HBV DNA in serum and PBMC than a control group of chronic HBsAg carriers. We have also studied the presence of immune complexes and the existence of mutations in the pre-S/S gene to explain the lack of detection of HBsAg in these cases. No serum HBsAg/hepatitis B surface antigen antibody (anti-HBs) immune complexes or mutations in the "a determinant of the S gene were found. However, we have observed that all HBsAg-negative cases were infected by a mixture of the wild-type virus and a deletion mutant in the pre-S1 region. This deletion (amino acids 58-118) affects the S gene promoter, and previous in vitro studies have shown that it produces a reduction of the HBsAg synthesis. In conclusion, this work shows that the lack of detection of HBsAg in the presence of low viral levels of replication may be caused by the existence of viral genomes harboring deletions in the pre-S1 region that affect the S promoter.Hepatology 08/2000; 32(1):116-23. · 12.00 Impact Factor