Chronic hepatitis B and occult infection in chemotherapy patients - evaluation in oncology and hemato-oncology settings: The CHOICE study.

BACKGROUND: Reactivation of hepatitis B virus (HBV) infection is a well-known risk that can occur spontaneously or following immunosuppressive therapies, including cancer chemotherapy. HBV reactivation can cause significant morbidity and even mortality, which are preventable if at-risk individuals are identified through screening and started on antiviral prophylaxis. AIM: To determine the prevalence of chronic HBV (CHB) and occult HBV infection (OBI) among oncology and hematology-oncology patients undergoing chemotherapy. METHODS: In this observational study, the prevalence of CHB and OBI was assessed among patients receiving chemotherapy. Serological markers of HBV infection [hepatitis B surface antigen (HBsAg)/anti-hepatitis B core antigen (HBc)] were evaluated for all patients. HBV DNA levels were assessed in those who tested negative for HBsAg but positive for total anti-HBc. RESULTS: The prevalence of CHB in the study cohort was determined to be 2.3% [95% confidence interval (95%CI): 1.0-4.2]. Additionally, the prevalence of OBI among the study participants was found to be 0.8% (95%CI: 0.2-2.3). CONCLUSION: The findings of this study highlight the importance of screening for hepatitis B infection in oncology and hematology-oncology patients undergoing chemotherapy. Identifying individuals with CHB and OBI is crucial for implementing appropriate antiviral prophylaxis to prevent the reactivation of HBV infection, which can lead to increased morbidity and mortality.

Whole Exome Sequencing Reveals Novel Variants in Unexplained Erythrocytosis.

Erythrocytosis is characterized by an increase in red cells in peripheral blood. Polycythemia vera, the commonest primary erythrocytosis, results from pathogenic variants in JAK2 in ∼98% of cases. Although some variants have been reported in JAK2-negative polycythemia, the causal genetic variants remain unidentified in ∼80% of cases. To discover genetic variants in unexplained erythrocytosis, we performed whole exome sequencing in 27 patients with JAK2-negative polycythemia after excluding the presence of any mutations in genes previously associated with erythrocytosis (EPOR, VHL, PHD2, EPAS1, HBA, and HBB). We found that the majority of patients (25/27) had variants in genes involved in epigenetic processes, including TET2 and ASXL1 or in genes related to hematopoietic signaling such as MPL and GFIB. Based on computational analysis, we believe that variants identified in 11 patients in this study could be pathogenic although functional studies will be required for confirmation. To our knowledge, this is the largest study reporting novel variants in individuals with unexplained erythrocytosis. Our results suggest that genes involved in epigenetic processes and hematopoietic signaling pathways are likely associated with unexplained erythrocytosis in individuals lacking JAK2 mutations. With very few previous studies targeting JAK2-negative polycythemia patients to identify underlying variants, this study opens a new avenue in evaluating and managing JAK2-negative polycythemia.