Association of T lymphocytes level and clinical severity in patients of COVID-19 in Shenzhen China

To explore the correlation between T lymphocytes and clinical severity in patients of COVID-19. A total of 183 COVID-19 patients were recruited in Shenzhen Third People’s Hospital from January 11 to February 16, 2020. According to the clinical classification criteria, they were divided into severe group (46 cases) and non-severe (137cases). T lymphocyte counts, lymphocyte subpopulation, IL-6 levels, and clinical outcomes were compared between the two groups. Compared with the non-severe group, the lymphocyte count, T lymphocyte count, T lymphocyte percentage, CD4 + T lymphocyte count, CD4 + T lymphocyte percentage, CD8 + T lymphocyte count, and CD8 + T lymphocyte percentage were lower in the severe group ( p < 0.05). Compared with the non-severe group, IL-6 were higher in the severe group ( p < 0.05). Compared with admission, the T lymphocyte count, CD4 + T lymphocyte count, and CD8 + T lymphocyte count were significantly increased upon discharge in severe patients, non-severe patients and all patients. Multivariate Logsitic regression analysis showed CD4 + T lymphocyte count (OR −0.011; 95% CI −0.041 to −0.001; p = 0.011), CD8 + T lymphocyte count (OR −0.14; 95% CI −0.048 to −0.003; p = 0.013) were closely correlated with the clinical severity in patients of COVID-19. Multivariate Logsitic regression analysis also showed CD4 + T lymphocyte count (OR −0.012; 95% CI −3.177 to 0.261; p = 0.021), CD8 + T lymphocyte count (OR −0.019; 95% CI −5.852 to 0.115; p = 0.004) were independent predictors of disease progressing to the composite endpoint. Subgroup analysis for critically ill patients: The T lymphocyte count, CD4 + T lymphocyte count, and CD8 + T lymphocyte count remained low in the death patients. The T lymphocyte count, CD4 + T lymphocyte count, and CD8 + T lymphocyte count recovered soon in the discharged patients. In the event of COVID-19 infection, the T-lymphoid system is the primary activated immune system. The T lymphocytes, CD4 + T lymphocytes, CD8 + T lymphocytes continued to be low may be significantly related to the deterioration of the disease, and may indicate a poor prognosis.