EVALUATION OF THE ACTIVITY OF PERIPHERAL BLOOD NATURAL KILLER CELLS IN HEALTHY SUBJECTS AND BREAST CANCER PATIENTS

Abstract

Objectives: To study Natural Killer (NK) cell activity (NK-IFNg) and some indicators related to immunological characteristics of peripheral blood NK cells in healthy people and breast cancer patients. Methods: We evaluated NK cell activity through its secretory characteristics (NK-IFNg) using ATGen's commercial NK VUE TestÒ (ATGen kit) on 35 healthy subjects (medical staff) and 132 cancer patients treated at Vietnam National Cancer Hospital from August 2020 to February 2023. At the same time, we collected peripheral blood samples to conduct immunological characterization of peripheral blood NK cells based on the flow cytometer system (number, expression of the activation and inhibitory receptors such as NKG2A, NKG2D), and some other biomarkers (CEA, CA 15.3). Results: The secretory activity of peripheral blood NK cells (NKA-IFNγ) in breast cancer patients (1,013.46 ± 1,115.87 pg/mL) was statistically significantly lower than that in the healthy group ( 2,571.38 ± 827.52 pg/mL) ( ± SD) (p < 0.001). The proportion of breast cancer patients with NKA-IFNγ activity of a very low level (≤ 200 pg/mL) was 40.9% and that of the healthy subjects was 0%. There was no relationship between NKA-IFNγ and peripheral blood NK cell count, and the expression levels of the activating receptor NKG2D and the inhibitory receptor NKG2A. Patients with CEA and CA 15.3 serum levels above the normal limits accounted for relatively low percentages (10.6% and 6.1%). Conclusion: Breast cancer patients with very low NK cell activity accounted for a significant proportion (40.9%). NKA-IFNγ activity could be used as a potential tool for monitoring the immune system health status of breast cancer patients before and after receiving treatment interventions.