Changes in humoral immune response after SARS-CoV-2 infection in liver transplant recipients compared to immunocompetent patients

The protective capacity and duration of humoral immunity after SARS-CoV-2 infection is not yet understood in solid organ transplant recipients. A prospective multicenter study was performed to evaluate the persistence of anti-nucleocapsid IgG antibodies in liver transplant recipients 6 months after coronavirus disease 2019 (COVID-19) resolution. A total of 71 liver transplant recipients were matched with 71 immunocompetent controls by a propensity score including variables with a well-known prognostic impact in COVID-19. Paired case-control serological data was also available in 62 liver transplant patients and 62 controls at month 3 after COVID-19. Liver transplant recipients showed a lower incidence of anti-nucleocapsid IgG antibodies at 3 months (77.4% vs. 100%, p<0.001) and at 6 months (63.4% vs. 90.1%, p<0.001). Lower levels of antibodies were also observed in liver transplant patients at 3 (p=0.001) and 6 months (p<0.001) after COVID-19. In transplant patients, female gender (OR=13.49, 95%CI 2.17-83.8), a longer interval since transplantation (OR=1.19, 95%CI 1.03-1.36), and therapy with renin-angiotensin-aldosterone system inhibitors (OR=7.11, 95%CI 1.47-34.50) were independently associated with persistence of antibodies beyond 6 months after COVID-19. Therefore, as compared with immunocompetent patients, liver transplant recipients show a lower prevalence of anti-SARS-CoV-2 antibodies and more pronounced antibody levels decline.