Background: Occult hepatitis B infection is defined by negative hepatitis B surface antigen (HBsAg) and detectable hepatitis B virus (HBV DNA, with or without hepatitis B core antibody (anti-HBc). HBV reactivation is most commonly reported in patients receiving cancer chemotherapy for haematological malignancies or hematopoietic stem cell transplantation (HSCT) recipients.

Objective: In this study, we aimed to determine the prevalence & reactivation of occult HBV infection in hematological cancer patients on & before receiving chemotherapy.

Methods: The study was conducted in patients admitted in hematology department RGGGH, Madras medical college, Chennai for a time period from September 2018 to December 2018.Blood samples collected from newly diagnosed hematological malignancy and patients with diagnosed hematological malignancy on chemotherapy  who were previously negative for HBsAg, were tested for HBsAg &  anti-HBc antibodies. The samples that were negative for HBsAg but positive for anti-HBc also examined for HBV-DNA by polymerase chain reaction (PCR).

Results: Out of the 80 patients tested, 23 (28%) samples were positive for anti-HBc antibodies. HBV-DNA was detected in 5(6%) of anti-HBc positive samples. Reactivation of HBV occurred in 11% of patients. Reactivation was more frequent with chemotherapy drugs like Rituximab & daunorubicin. There was no significant difference in HBc antibody positivity based on gender, age, previous blood transfusions, biochemical parameters (ALT) (P>0.05).

Conclusion: The prevalence of occult HBV infection is 6% with isolated anti HBC positivity being 28%.Reactivation of HBV was seen in 9 patients (11%) Screening of occult HBV infection by HBsAg, HBV DNA and anti HB core antibody should be made mandatory before starting patients on immunosuppressants in cancer patients.

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A R Venkateshwaran

Director and Head of Department, Institute of Medical Gastroenterology, Madras Medical College Chennai