Characteristics of Natural Killer (NK) Cell and T Lymphocyte in COVID-19 patients in Surabaya, Indonesia

The aim of the research is to analyze the differences in the subset of T lymphocytes and NK cells at various degrees of disease severity in order to be used in stratification of patients’ management and to predict outcomes for optimal treatment. The study sample of 123 patients with confirmed COVID-19 was classified based on the degree of severity: 50 patients with mild severity, 34 patients with moderate severity and 39 patients with severe to critical severity who were subjected to complete blood count and T lymphocyte subsets (CD3, CD4, CD8) and NK cells with Flowcytometry. There were significant differences in the number of CD 3 cells (p=0.000), CD4 (p=0.000), CD8 (p=0.000), and NK cells (p=0.000) in the three groups. In the severe to critical group there was a decrease in lymphocytes accompanied by decrease of the number of CD3, CD4, CD8 and NK cells as well as an increase in WBC and neutrophils. Based on the outcome, there were significant differences in the number of CD 3 cells (p=0.000), CD4 (p=0.001), CD8 (p=0.000), and NK cells (p=0.001) between the Discharged and death groups. The decrease in the number of CD3, CD4, CD8 and NK cells indicates a relationship between changes in lymphocyte subsets and the pathogenesis of SARS-CoV-2, namely immune system disorders such as SARS infection. Increased of WBC with a decrease in CD3, CD4, CD8 and NK cell counts are associated with poor patient outcome. A significant decrease in the number of CD3, CD4, CD8 and NK cells in COVID-19 patients with severe to critical and moderate symptoms compared to mild groups and associated with poor patient clinical outcome.