The Magnitude and Functionality of SARS-CoV-2 Reactive Cellular and Humoral Immunity in Transplant Population Is Similar to the General Population Despite Immunosuppression

Background The ability of transplant (Tx)-patients to generate a protective antiviral response under immunosuppression is pivotal in COVID-19 infection. However, analysis of immunity against SARS-COV-2 is currently lacking. Methods Here, we analyzed T cell immunity directed against SARS-CoV-2 spike-, membrane-, and nucleocapsid-protein by flow cytometry and spike-specific neutralizing antibodies in ten Tx in comparison to 26 nonimmunosuppressed (non-Tx) COVID-19 patients. Results Tx-patients (seven renal, one lung, and two combined pancreas-kidney transplants) were recruited in this study during the acute phase of COVID-19 with a median time after SARS-CoV-2-positivity of 3 and 4 days for non-Tx- and Tx-patients, respectively. Despite immunosuppression, we detected antiviral CD4 T cell-response in 90% of Tx-patients. SARS-CoV-2-reactive CD4 T cells produced multiple pro-inflammatory cytokines, indicating their potential protective capacity. Neutralizing antibody-titers did not differ between groups. SARS-CoV-2-reactive CD8+ T cells targeting membrane- and spike-protein were lower in Tx-patients, albeit without statistical significance. However, frequencies of anti-nucleocapsid-protein-reactive, and anti-SARS-CoV-2 polyfunctional CD8 T cells, were similar between patient cohorts. Tx-patients showed features of a prematurely aged adaptive immune system, but equal frequencies of SARS-CoV-2-reactive memory T cells. Conclusions In conclusion, a polyfunctional T cell immunity directed against SARS-CoV-2-proteins as well as neutralizing antibodies can be generated in Tx-patients despite immunosuppression. In comparison to nonimmunosuppressed-patients, no differences in humoral and cellular antiviral-immunity were found. Our data presenting the ability to generate SARS-CoV-2-specific immunity in immunosuppressed patients has implications for the handling of SARS-CoV-2-infected Tx patients and raises hopes for effective vaccination in this cohort.Supplemental Visual Abstract; http://links.lww.com/TP/C186.