Severe Acute Respiratory Syndrome Coronavirus 2 Cross-Reactive B and T Cell Responses in Kidney Transplant Patients

Background. Immune responses to seasonal endemic coronaviruses might have a pivotal role in protection against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Those SARS-CoV-2-crossreactive T cells were recently described in immunocompetent individuals. Still, data on cross-reactive humoral and cellular immunity in kidney transplant recipients is cur-rently lacking. Methods. The pre-existing, cross-reactive antibody B and T cell immune responses against SARS-CoV-2 in unexposed adults with kidney transplantation (Tx, n = 14) and without (non -Tx, n = 12) sampled before the pandemic were compared with 22 convalescent patients with COVID-19 (Cp) applying enzyme-linked immunosorbent assay and flow cytometry.Results. In both unexposed groups, SARS-CoV-2 IgG antibodies were not detectable. Mem-ory B cells binding spike (S) protein SARS-CoV-2 were detected in unexposed individuals (64% among Tx; 50% among non-Tx) and higher frequencies after infection (80% Cp). The numbers of SARS-CoV-2-reactive T cells were comparable between patients who had undergone Tx and those who had not. SARS-CoV-2-reactive follicular T helper cells were present in 61% of the unexposed cohort in both patients who had undergone Tx and those who had not.Conclusions. Cross-reactive memory B and T cells against SARS-CoV-2 exist also in trans-planted adults, suggesting a primed adaptive immunity. The effect on the disease course may depend on the concomitant immunosuppressive drugs.

Automated summary

The study found that cross-reactive memory B and T cells against SARS-CoV-2 exist in kidney transplant recipients, suggesting a primed adaptive immunity. The impact on the disease course may depend on the concomitant use of immunosuppressive drugs.