Number of natural killer cells and cytokine levels in peripheral blood at various degrees of severity

This study aims to investigate NK cell number and cytokines level in various degrees of severity in COVID-19 cases. A total of 63 COVID-19 patient aged >18 y were divided into mild-moderate and severe-critical groups. Patient characteristics and peripheral blood count were obtained from medical records. NK cells number, levels of IFN-?, IL-10, and IL-12 in peripheral blood were examined by means of flow cytometry. The severe-critical group had leukocytosis, neutrophilia, lymphopenia, higher Neutrophil Lymphocyte Ratio, lower NK cell number and higher level of IL-10. In severe-critical group, those aged >60 years had higher IL-10. In both groups, patients with diabetes comorbidities had a higher number of NK cells (p<0.05). NK cell number and IL-10 in peripheral blood have potential as a predictor of severe COVID-19 patients.