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.