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

J Microbiol Immunol Infect. 2023 Jun;56(3):526-536. doi: 10.1016/j.jmii.2023.03.003. Epub 2023 Mar 17.

Abstract

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 supernatants 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-α, and IFN-γ levels was similar between LT recipients and controls. IFN-γ 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 recipients, but the difference was not statistically significant.

Conclusion: LT recipients exhibited a similar T cell response compared to non-transplanted individuals one year after COVID-19 diagnosis.

Keywords: Flow cytometry; Humoral immunity; Liver transplantation; Reactive T cells; SARS-CoV-2.

MeSH terms

  • Antibodies, Viral
  • COVID-19 Testing
  • COVID-19*
  • Humans
  • Immunity, Cellular
  • Immunoglobulin G
  • Leukocytes, Mononuclear
  • Liver Transplantation*
  • SARS-CoV-2

Substances

  • Immunoglobulin G
  • Antibodies, Viral