Ursodeoxycholic acid does not reduce SARS-CoV-2 infection in newly allogeneic hematopoietic stem cell transplantation recipients: a prospective NICHE cohort

Introduction Retrospective studies have suggested that Ursodeoxycholic Acid (UDCA) provide a protective effect against SARS-CoV-2 infection, particularly in patients with liver disease. However, it is uncertain whether this finding can be extended to the allogeneic hematopoietic stem cell transplantation (allo-HSCT) cohort. Therefore, we aim to examine the protective potential of UDCA against SARS-CoV-2 infection in recently received allo-HSCT patients.Methods During the initial Omicron variant wave in China (December 2022 to February 2023), we conducted a prospective observational study involving 91 hospitalized patients who had undergone allo-HSCT within the previous 6 months as part of the National Longitudinal Cohort of Hematological Diseases (NICHE). Throughout hospitalization, we continuously monitored the status of COVID-19 using SARS-CoV-2 PCR kits or SARS-CoV-2 Antigen Rapid Tests.Results Among these patients, 67.0% (n = 61) were confirmed to have contracted SARS-CoV-2 infection. For the 52 patients evaluated, 23.1% experienced a severe or critical clinical course. There was no difference in the infection rate or severity of COVID-19 between the UDCA group and the non-UDCA group. We found that only patients transplanted between 3 and 6 months ago demonstrated a higher risk of SARS-CoV-2 infection compared to those who received allo-HSCT within 3 months (Odds Ratio [OR]: 3.241, 95% Confidence Interval [CI]: 1.287-8.814, P = 0.016). But other clinical factors, such as administration of UDCA, showed no difference. Notably, only age >= 38 years old remained as an independent risk factor for a severe clinical course of SARS-CoV-2 infection (OR: 3.664, 95% CI: 1.129-13.007, P = 0.035).Conclusion The effectiveness of UDCA in protecting newly allo-HSCT recipients against SARS-CoV-2 infection remains unconfirmed. Presently, the most effective strategy appears to be minimizing exposure to SARS-CoV-2.Clinical trial registration https://clinicaltrials.gov/ct2/show/NCT04645199, identifier NCT04645199.