Effect of ursodeoxycholic acid on preventing SARS-CoV-2 infection in patients with liver transplantation: a multicenter retrospective cohort study

Background: Immunosuppressed recipients of liver transplantation (LT) are more likely to develop coronavirus disease 2019 (COVID-19) and may have an increased risk of developing worse outcomes. Aim: To assess the effect of ursodeoxycholic acid (UDCA) on preventing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in LT recipients. Design: Adult patients (aged >= 18 years) who underwent LT between January 1st, 2015, and December 31st, 2022, were included and categorized into two groups according to their use of UDCA. Methods: The prevalence and severity of COVID-19 among transplantation patients between the UDCA and non-UDCA groups were estimated and compared. Results: Among the 897 LT patients who met the inclusion criteria, infection rate of SARS-CoV-2 was 78.4%, and the rate of severe illness was 5.1% from January 2022 to January 2023 in China. In the multivariate analysis, only UDCA treatment (P = 0.006) was found to be a protective factor against SARS-CoV-2 infection. After propensity score matching, the SARS-CoV-2 infection rate in the UDCA group was lower than that in the non-UDCA group (74.1% vs. 84.6%, P = 0.002). This rate was further reduced to 62.1% (P = 0.002) when the oral administration dose was greater than 15 mg/kg/d. There was no difference in the rates of severe COVID-19 illness, ICU admission, or ventilation rate or length of hospital stay with or without UDCA treatment (all P > 0.05). Conclusions: The use of UDCA in LT patients significantly reduced the SARS-CoV-2 infection rate and showed a dose-dependent protective effect.