Evaluation of the Risk of Hepatitis B Reactivation Among Patients with Chronic Myeloid Leukemia Treated with Tyrosine Kinase Inhibitors

Background: Immunosuppressive therapy is a known risk factor for hepatits B reactivation. The highest risk is reported in hematologic patients treated with anti-CD20 monoclonal antibodies, glucocorticoids and hematopoietic stem cell transplantation. Currently, treatment with tyrosine kinase inhibitors (TKIs) in the vast majority of chronic myeloid leukemia (CML) patients is life-long. Recently healthcare professionals were advised to test for hepatitis B infection before initializing therapy with TKIs and closely monitor HBV carriers. The risk is considered class effect with all TKIs and recommendations are based on case reports.

Aim: The aim of the current study was to evaluate the risk of hepatitis B reactivation in patients with CML treated with TKIs.

Methods: The records of patients with CML treated with TKIs from a single center were systematically reviewed for hepatitis B serology and serum biochemistry.

Results: One hundred eighty one patients diagnosed with CML between the years 1983 and 2016 were evaluated. The median age at diagnosis was 49.7 years (range 18-89), 117/181 (65%) males, with median duration of follow up with TKI therapy of 5.3 years (range 0.4 to 33 years). Over a total of 1195 years of therapy with TKIs no cases of HBV reactivation were identified. Among 114 patients with hepatitis serology, 11 patients (10%) had evidence of prior resolved HBV infection (HBsAg negative/anti-HBc positive). Two of them had anti-HBs positive serology, one had negative PCR for HBV DNA and other two patients received lamivudine prophylaxis. Only one patient had HBsAg positive serology. None of the patients with positive hepatitis serology had clinical or biochemistry evidence of hepatitis B reactivation. The 67 patients without available hepatitis serology had normal liver transaminases at 6 months of TKI therapy and at last day of follow up, confirming that no overt hepatitis B reactivation occurred.

Conclusions: We evaluated hepatitis B reactivation in a rather large cohort of CML patients, treated with TKIs. Although there were no cases of HBV reactivation during long term follow up, it should be emphasized that even a low incidence may exert a significant risk due to the long duration of treatment in a chronic disease with lifelong therapy. Our study infers that patients with serology of prior resolved HBV infection are at low risk for hepatitis B reactivation. Larger cohorts of patients with positive hepatitis B serology in a multicenter long term evaluation should be performed in order to address current recommendations for patients' safety and concerns.