Long term SARS-CoV-2-specific cellular immunity after COVID-19 in liver transplant recipients

Purpose: Long-term immunity after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in immunosuppressed patients is not well characterized. We aimed to explore the long-term natural immunity against SARS-CoV-2 in liver transplant (LT) recipients compared to the non-transplanted population (control group).Methods: Fifteen LT recipients and 15 controls matched according to variables associated with disease severity were included at 12 months following the coronavirus disease 2019 (COVID-19) onset. Peripheral blood mononuclear cells were stimulated with peptide pools covering spike (S), nucleocapside (N), and membrane (M) proteins. Reactive CD4+ and CD8+ T cells were identified using flow cytometry, and cytokine production was evaluated in the culture super-natants using cytometric bead array. Serum anti-N and anti-S IgG antibodies were detected with chemiluminescence.Results: The percentage of patients with a positive response in both CD4+ and CD8+ T cells against each viral protein and IL2, IL10, TNF-a, and IFN-g levels was similar between LT recip-ients and controls. IFN-g levels were positively correlated with the percentage of reactive CD4+ (p = 0.022) and CD8+ (p = 0.043) T cells to a mixture of M + N + S peptide pools. The prevalence and levels of anti-N and anti-S IgG antibodies were slightly lower in the LT re-cipients, but the difference was not statistically significant.Conclusion: LT recipients exhibited a similar T cell response compared to non-transplanted in-dividuals one year after COVID-19 diagnosis.Copyright 2023, Taiwan Society of Microbiology. Published by Elsevier Taiwan LLC. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

This study aimed to explore the long-term natural immunity against SARS-CoV-2 in liver transplant recipients compared to the non-transplanted population. The results showed similar T cell responses and antibody levels between liver transplant recipients and non-transplanted individuals, indicating comparable long-term immunity after COVID-19.