Dynamic changes of peripheral blood T lymphocytes in COVID-19 patients / 中华微生物学和免疫学杂志

ABSTRACT

Objective:To analyze the dynamic changes of T lymphocytes in patients with COVID-19.Methods:Blood samples were collected from 40 COVID-19 cases and 40 healthy controls in Beihai People′s Hospital from January to February, 2020. The counts of CD4 + T and CD8 + T lymphocytes were detected by flow cytometry. Moreover, the T lymphocyte counts in 24 convalescent patients with two consecutive negative nucleic acid test results were also detected. Results:The leukocytes and lymphocytes in the patients with acute COVID-19 were significantly lower than those in the healthy controls [(4.71±1.54)×10 9 cell/L vs (6.26±1.44)×10 9 cell/L, (1.13±0.41)×10 9 cell/L vs (1.51±0.39)×10 9 cell/L; both P<0.05]. The counts of CD4 + T and CD8 + T lymphocytes in the patients with acute COVID-19 were significantly lower than those in the healthy controls [(447.15±144.42) cell/μl vs (592.83±146.76) cell/μl, (309.35±173.05) cell/μl vs (397.20±136.94) cell/μl; both P<0.05], while no significant difference was observed in the CD4 + /CD8 + T cell ratio ( P>0.05). In the 24 convalescent COVID-19 patients, the counts of CD4 + T and CD8 + T lymphocytes were higher during convalescence than in the acute phase [(598.08±138.71) cell/μl vs (420.67±147.38) cell/μl, (439.08±166.94) cell/μl vs (296.67±151.06) cell/μl; both P<0.05], but there was no significant difference in the T lymphocyte counts between the convalescent patients and the healthy controls ( P>0.05). Conclusions:A transient immune deficiency occurred in patients with acute COVID-19, but the impaired immune function could restore to normal level during recovery.