Association of neutrophil-to-lymphocyte ratio and natural killer cell activity revealed by measurement of interferon-gamma levels in a healthy population.

Abstract

While a method of assaying natural killer (NK) cell activity by measuring the amount of interferon (IFN)-γ released from NK cells has been proposed, no data are available about the factors that influence IFN-γ levels related to NK cell activity. NLR has recently been reported to be a predictor of several diseases. In the present study, we investigated the pre-analytical variables for NK cell activity using measurements of IFN-γ and the relationship between NLR and NK cell activity. The NK cell activity was assessed with the measurement of IFN-γ after stimulation with an NK cell-specific stimulant (NK Vue™ , ATgen, Sungnam, Korea). One hundred and six adult volunteers were recruited and analysis of their complete blood count data and serum C-reactive protein was done. Blood sample from 59 of the participants was also used for analysis of lymphocyte subpopulations. Natural killer cell activity varied widely (range, 44.2-1775.6pg/mL). NK cell activity was higher in females than in males (P=0.014). NK cell activity decreased with increasing NLR (P=0.004, r=-0.32) but NK cell activity showed no significant association with NK cell count or other lymphocyte subpopulations. NK cell activity levels according to CRP quartile were significantly different (P=0.025). We have observed that NK cell activity when assessed by IFN-γ level measurement was negatively correlating with NLR. This result can be helpful in interpreting or predicting NK cell activity in the clinical environment.