{Reference Type}: Journal Article
{Title}: Age-dependent decrease of circulating T follicular helper cells correlates with disease severity in elderly patients with COVID-19.
{Author}: Wang Y;Wang Q;He F;Qiao N;Li X;Wei L;Sun L;Dai W;Li Y;Pang X;Hu J;Huang C;Yang G;Pang C;Hu Z;Xing M;Wan C;Zhou D;
{Journal}: Clin Immunol
{Volume}: 266
{Issue}: 0
{Year}: 2024 Sep 25
{Factor}: 10.19
{DOI}: 10.1016/j.clim.2024.110329
{Abstract}: Overwhelming evidence has shown that aging is a significant risk factor for COVID-19-related hospitalizations, death and other adverse health outcomes. Particular T cell subsets that susceptible to aging and associated with COVID-19 disease severity requires further elucidation. Our study recruited 57 elderly patients with acute COVID-19 and 27 convalescent donors. Adaptive immunity was assessed across the COVID-19 severity spectrum. Patients underwent age-dependent CD4+ T lymphopenia, preferential loss of circulating T follicular regulatory cells (cTfh) subsets including cTfh-em, cTfh-cm, cTfh1, cTfh2, cTfh17 and circulating T follicular regulatory cells (cTfr), which regulated antibody production through different pathways and correlated with COVID-19 severity, were observed. Moreover, vaccination improved cTfh-cm, cTfh2, cTfr proportion and promoted NAb production. In conclusion, the elderly had gone through age-dependent cTfh subsets deficiency, which impeded NAb production and enabled aggravation of COVID-19 to critical illness, whereas SARS-CoV-2 vaccine inoculation helped to rejuvenate cTfh, cTfr and intensify NAb responses.