Frequency of hepatitis B virus reactivation in cancer patients undergoing cytotoxic chemotherapy: a prospective study of 626 patients with identification of risk factors

Anti-CD20 monoclonal antibodies and associated viral hepatitis in hematological diseases

Over the past decade, the administration of anti-CD20 monoclonal antibodies such as rituximab has demonstrated various degrees of effectiveness and has improved patients’ outcomes during the treatment of autoimmune hematological disorders and hematological malignancies. However, the depletion of B-cells, the distribution of T-cell populations, and the reconstruction of host immunity resulting from the use of anti-CD20 monoclonal antibodies potentially lead to severe viral infections, such as hepatitis B virus (HBV), hepatitis C virus (HCV), parvovirus B19, and herpes viruses, in patients who are undergoing immune therapy or immunochemotherapy. Of these infections, HBV- and HCV-related hepatitis are a great concern in endemic areas because of the high morbidity and mortality rates in untreated patients. As a result, prophylaxis against HBV infection is becoming a standard of care in these areas. Parvovirus B19, a widespread pathogen that causes red blood cell aplasia in immunocompromised hosts, also causes hepatitis in healthy individuals. Recently, its association with hepatitis was recognized in a patient treated with rituximab. In addition, adenovirus, varicella-zoster virus, hepatitis E virus, and rituximab itself have been linked to the occurrence of hepatitis during or after rituximab treatments. The epidemiologies and pathogeneses of these etiologies remain unknown. Because of the increasing use of anti-CD20 monoclonal antibodies for the treatment of hematological malignancies or autoimmune hematological disorders, it is imperative that physicians understand and balance the risks of hepatotropic virus-associated hepatitis against the benefits of using anti-CD20 monoclonal antibodies.

Testing for hepatitis B infection in prospective chemotherapy patients: A retrospective study

AIM: To estimate hepatitis B virus (HBV) infection testing rate in cancer patients before chemotherapy with a focus on HBV reactivation.

METHODS: A retrospective study was conducted from January 1, 2009 to June 30, 2010. Inclusion required that patients be naïve to cancer chemotherapy but have indications for it. Patients who did not receive chemotherapy for any reason were excluded. Important clinical information, such as the levels of HBV DNA and serological markers were collected. HBV reactivation was defined as an increase in serum HBV DNA to > 1 log higher than that of the pre-exacerbation baseline, or serum HBV DNA conversion from negative to positive. HBV DNA levels > 1000 copies/mL were defined as HBV DNA positive. The χ² or Fisher’s exact test was used for analysis of categorized data. Multiple logistic regression analysis was used to estimate the odd ratio and 95%CI of the HBV screening rate.

RESULTS: Of 6646 patients, 5616 (84.5%) received chemotherapy. Only 17.1% of the cancer patients received pre-chemotherapy HBV testing (43.2% for hematological malignancies and 14.9% for solid tumors). Patients who had received rituximab therapy, had elevated aminotransferase levels, or had hematological malignancies were more likely to receive HBV testing. The prevalence of hepatitis B surface antigen (HBsAg) positivity was 13.4%. HBV reactivation (appearance of HBV DNA or an increase in HBV DNA levels by 1 log₁₀) was observed in 33.1% (53/160) of the patients after chemotherapy. Among patients without prophylactic antiviral therapy, the reactivation rate was 43.9% (43/98) in the solid tumor group. Two reactivation cases occurred in patients who were HBsAg negative, but positive for hepatitis B core antibody. HBV reactivation was more likely to occur in patients with lymphoma, high levels of HBV DNA, or hepatitis B e antigen, and in men.

CONCLUSION: Less than 20% of patients received HBV testing before chemotherapy. HBV reactivation would have occurred in about 50% of infected patients with solid tumors without antiviral prophylaxis.