LAUSR

INTRODUCTION Three treatment-naïve cases with chronic hepatitis B (CHB) were reported in terms of a partial response to tenofovir disoproxil (TDF) monotherapy and antiviral-drug resistance. METHODOLOGY In this retrospective, case series study, patients who were treated for CHB at the departments of infectious diseases and clinical microbiology, University of Medical Science Bakırköy Dr. Sadi Konuk Training and Research Hospital were evaluated. RESULTS A 26-year-old female patient and a 59-year-old male patient achieved sustained viral response with TDF (245 mg) or tenofovir alafenamide (TAF, 25 mg) + entekavir (ETV, 1 mg) combination therapy after failure with TDF monotherapy. The son of the female patient who was diagnosed with CHB infection due to a probable mother-to-child transmission did not achieve a complete viral response with interferon alfa-2b therapy for three months followed by lamivudine therapy for 19 months. CONCLUSIONS A TDF (245 mg) or TAF (25 mg) + ETV (1 mg) combination therapy is effective in the treatment of naïve patients with a partial response to the TDF monotherapy. A combination therapy including tenofovir and entecavir should be initiated to mothers with a primary partial response to the tenofovir monotherapy after the initial 32 weeks of pregnancy, as CHB may cause cirrhosis in the children due to a persistent inflammation in the liver subsequent to a vertical transmission.