Evolution of neutrophil apoptosis in septic shock survivors and nonsurvivors

Abstract

Purpose: The aims were to analyze the temporal evolution of neutrophil apoptosis, to determine the differences in neutrophil apoptosis among 28-day survivors and nonsurvivors, and to evaluate the use of neutrophil apoptosis as a predictor of mortality in patients with septic shock. Materials and Methods: Prospective multicenter observational study carried out between July 2006 and June 2009. The staining solution study included 80 patients with septic shock and 25 healthy volunteers. Neutrophil apoptosis was assessed by fluorescein isothiocyanate (FITC)–conjugated annexin V and aminoactinomycin D staining. Results: The percentage of neutrophil apoptosis was significantly decreased at 24 hours, 5 days, and 12 days after the diagnosis of septic shock (14.8% ± 13.4%, 13.4% ± 8.4%, and 15.4% ± 12.8%, respectively; P b .0001) compared with the control group (37.6% ± 12.8%). The difference in apoptosis between 28-day surviving and nonsurviving patients was nonsignificant (P N .05). The mortality rate at 28 days was 53.7%.The crude hazard ratio for mortality in patients with septic shock did not differ according to the percentage of apoptosis (hazard ratio, 1.006; 95% confidence interval, 0.98-1.03; P = .60). Conclusions: During the first 12 days of septic shock development, the level of neutrophil apoptosis decreases and does not recover normal values. No differences were observed between surviving and nonsurviving patients.