Reduction of ACE2 Serum Concentrations by Telbivudine in Chronic Hepatitis B Patients

Background Coronavirus disease 2019, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has wreaked havoc worldwide since December 2019. Currently, no effective medical treatments have been approved. As the epidemic continues to spread, SARS-CoV-2 mutants emerge, some of which become more infectious with increasing vaccine resistance. The main route for SARS-CoV-2 to enter the host cells is by binding its spike protein to the host receptor, angiotensin-converting enzyme 2 (ACE2). Besides the membrane-bound form of ACE2, the soluble form of ACE2 (sACE2) can also bind SARS-CoV-2 for viral endocytosis. Objective Previously, we found that telbivudine reduced the concentrations of ACE1 in blood. Therefore, we speculated that this drug might also reduce the concentrations of sACE2. Methods In this retrospective study, serum samples from 39 hepatitis B patients receiving telbivudine were collected and examined for sACE2 concentrations using an ELISA kit. Results It was found that the serum concentrations of sACE2 were significantly declined in chronic hepatitis B patients treated with telbivudine. Conclusion Telbivudine treatment reduced sACE2 concentrations, which could potentially reduce the infection risk of SARS-CoV-2.