Association of Peripheral Lymphocyte Subset with the Severity and Prognosis of Septic Shock

Abstract

Background: A dramatic decrease in circulating lymphocyte number is observed after septic shock. In this study, we assessed whether circulating lymphocyte subpopulations influence the severity and prognosis of septic shock. Methods: 133 patients (median 65 years, range 27−88; male 63.2%) receiving intensive care for septic shock were enrolled in this study. Flow cytometry phenotyping of circulating lymphocyte subpopulations, including helper T cells, suppressor T cells, total B cells, and natural killer (NK) cells, was performed within 24 hours after the diagnosis of septic shock. After measuring the white blood cell (WBC) and differential leukocyte count, the lymphocyte subsets were analyzed. The following data were recorded: general characteristics, severity of illness as assessed by the Sequential Organ Failure Assessment (SOFA) score, and 28-day mortality. Results: The overall mortality rate at 28 days was 33.8%. SOFA score was negatively correlated with the T cell count (r = −0.175) and helper T cell count (r = −0.223). However, only low a helper T cell count was associated with the severity of septic shock (odds ratio 0.995, 95% confidence interval 0.992−0.999, p = 0.014). Using multiple logistic regression analysis for 28-day mortality, there was no significant prognostic factor among the lymphocyte subset. Conclusions: The low helper T cell count appeared to be associated with severity, but did not show significant association with mortality.