Evaluation of Hepatitis B Seroprevalence and Hepatitis B Reactivation Frequency in Rheumatology Patients Using Biological Drug Therapy

Objective: The presence of hepatitis B virus (HBV) infection in patients using biological drug therapy may cause reactivation. There is insufficient data on the frequency of HBV reactivation, especially after the use of new biological drugs such as tofacitinib, tocilizumab, and secukinumab. This study aims to examine HBV seroprevalence in rheumatology patients using biological drug therapy and investigate the frequency of reactivation in patients with previous HBV infection. Methods: The charts of 275 patients who were followed up in the rheumatology department and used biological drug therapy were examined to evaluate the HBsAg, anti-HBc IgG, and anti-HBs test results. The frequency of reactivation was investigated by examining the HBV DNA test results before and after the biological drug therapy and the alanin aminotransferase test results were checked throughout the biological drug therapy in anti-HBc IgG-positive patients. Results: Among the patients, HBsAg was positive in 0.4%, anti-HBs in 34.4%, and anti-HBc IgG in 25.1%. The reactivation frequency was investigated in 53 biological drug therapies applied in 41 patients. The use of prophylactic antiviral drugs, where reactivation was evaluated, was found as 28.6% in TNF inhibitors, 100% in rituximab, 75.0% in tofacitinib, 0% in tocilizumab, 50% in abatacept, and 0% in secukinumab. Reactivation was detected in one of the fifty-three biological drug therapies. The reactivation case was a patient with isolated anti-HBc IgG and initial HBV DNA tests positive, using tocilizumab and cortisone, and not using entecavir prophylactic treatment regularly. Conclusions: The frequency of previous HBV infection is high in patients using biological therapy. Although prophylactic antiviral drug therapy for HBV has not been used frequently during the use of biological drug therapies other than rituximab in anti-HBc IgG positive patients, reactivation is rare. The risk of reactivation may be low in those receiving tofacitinib and secukinumab therapy and high in those receiving tocilizumab therapy.