Dynamic monitoring of circulating CD8 T and NK cell function in patients with septic shock.

Background: Septic shock is a great threat to human life. Our aim is to explore the immune status and dynamic changes of circulating cytotoxic cells in septic shock patients.

Methods: Forty-eight septic shock patients (9 non-survivors and 39 survivors) and 30 healthy controls (HCs) were enroled in our study. The function of cytotoxic cells was dynamically monitored by flow cytometry.

Results: The number of circulating CD8 T and NK cells decreased significantly in septic shock patients, while the number of CD8 T cells rose in survivors 5 days after admission. The frequency of HLA-DRCD8 T/ NK cells increased in both groups after admission but decreased in non-survivors on day 3. Moreover, the frequency of GrA/GrB/perforinNK and GrBCD8 T cells decreased to varying degrees in both groups, and the frequency of GrB/perforinCD8 T cells on the second day of non-survivors was significantly lower than that of survival patients. Besides, the frequency of CXCR3CD8 T/ NK cells was decreased in both groups and remained low in non-survivors, but remarkably increased in survivors after day 3. And the concentrations of cytokines IL-6, IL-10, TNF-α and IFN-γ were significantly increased in septic shock patients.

Conclusions: Circulating CD8 T and NK cells reduced but activation function was compensatory enhanced in septic shock patients. The frequency of GrB/PFPCD8 T and CXCR3CD8 T/NK cells may predict the progression of septic shock patients 2-3 days after admission.