The Italian data on SARS-CoV-2 infection in transplanted patients support an organ specific immune response in liver recipients
Authors: Rendina Maria , Barone Michele , Lillo Chiara , Trapani Silvia , Masiero Lucia , Trerotoli Paolo , Puoti Francesca , Lupo Luigi Giovanni , Tandoi Francesco , Agnes Salvatore , Grieco Antonio , Andorno Enzo , Marenco Simona , Giannini Edoardo Giovanni , Baccarani Umberto , Toniutto Pierluigi , Carraro Amedeo , Colecchia Antonio , Cescon Matteo , Morelli Maria Cristina , Cillo Umberto , Burra Patrizia , Angeli Paolo , Colledan Michele , Fagiuoli Stefano , De Carlis Luciano , Belli Luca , De Simone Paolo , Carrai Paola , Di Benedetto Fabrizio , De Maria Nicola , Ettorre Giuseppe Maria , Giannelli Valerio , Gruttadauria Salvatore , Volpes Riccardo , Corsale Sveva , Mazzaferro Vincenzo , Bhoori Sherrie , Romagnoli Renato , Martini Silvia , Rossi Giorgio , Caccamo Lucio , Donato Maria Francesca , Rossi Massimo , Ginanni Corradini Stefano , Spada Marco , Maggiore Giuseppe , Tisone Giuseppe , Lenci Ilaria , Vennarecci Giovanni , Tortora Raffaella , Vivarelli Marco , Svegliati Baroni Gianluca , Zamboni Fausto , Mameli Laura , Tafuri Silvio , Simone Simona , Gesualdo Loreto , Cardillo Massimo , Di Leo Alfredo 
Published: July 2023

IntroductionThe study of immune response to SARSCoV-2 infection in different solid organ transplant settings represents an opportunity for clarifying the interplay between SARS-CoV-2 and the immune system. In our nationwide registry study from Italy, we specifically evaluated, during the first wave pandemic, i.e., in non-vaccinated patients, COVID-19 prevalence of infection, mortality, and lethality in liver transplant recipients (LTRs), using non-liver solid transplant recipients (NL-SOTRs) and the Italian general population (GP) as comparators.MethodsCase collection started from February 21 to June 22, 2020, using the data from the National Institute of Health and National Transplant Center, whereas the data analysis was performed on September 30, 2020.To compare the sex- and age-adjusted distribution of infection, mortality, and lethality in LTRs, NL-SOTRs, and Italian GP we applied an indirect standardization method to determine the standardized rate.ResultsAmong the 43,983 Italian SOTRs with a functioning graft, LTRs accounted for 14,168 patients, of whom 89 were SARS-CoV-2 infected. In the 29,815 NL-SOTRs, 361 cases of SARS-CoV-2 infection were observed. The geographical distribution of the disease was highly variable across the different Italian regions. The standardized rate of infection, mortality, and lethality rates in LTRs resulted lower compared to NL-SOTRs [1.02 (95%CI 0.81-1.23) vs. 2.01 (95%CI 1.8-2.2); 1.0 (95%CI 0.5-1.5) vs. 4.5 (95%CI 3.6-5.3); 1.6 (95%CI 0.7-2.4) vs. 2.8 (95%CI 2.2-3.3), respectively] and comparable to the Italian GP.DiscussionAccording to the most recent studies on SOTRs and SARS-CoV-2 infection, our data strongly suggest that, in contrast to what was observed in NL-SOTRs receiving a similar immunosuppressive therapy, LTRs have the same risk of SARS-CoV-2 infection, mortality, and lethality observed in the general population. These results suggest an immune response to SARS-CoV-2 infection in LTRS that is different from NL-SOTRs, probably related to the ability of the grafted liver to induce immunotolerance.