%0 Journal Article
%T Age-dependent decrease of circulating T follicular helper cells correlates with disease severity in elderly patients with COVID-19.
%A Wang Y
%A Wang Q
%A He F
%A Qiao N
%A Li X
%A Wei L
%A Sun L
%A Dai W
%A Li Y
%A Pang X
%A Hu J
%A Huang C
%A Yang G
%A Pang C
%A Hu Z
%A Xing M
%A Wan C
%A Zhou D
%J Clin Immunol
%V 266
%N 0
%D 2024 Sep 25
%M 39067679
%F 10.19
%R 10.1016/j.clim.2024.110329
%X 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.