The prognostic value of leukocyte apoptosis in patients with severe sepsis at the emergency department

Background and aim Cell apoptosis in critically ill patients plays a pivotal role in the pathogenesis of sepsis. This study aimed to determine the prognostic value of leukocyte apoptosis in patients with severe sepsis. Methods Leukocyte apoptosis was determined by flow cytometry. The values of annexin V, APO2.7, and 7-amino-actinomycin D (7AAD) for each subtype of leukocyte were analyzed in 87 patients with severe sepsis and 27 controls. Results The percentages of apoptosis (APO2.7 [%]) in the leukocyte subsets were significantly higher in the patients with severe sepsis than in the controls. The percentages of APO2.7 in leukocyte apoptosis, APO2.7 in lymphocytes apoptosis, and annexin V + 7AAD in monocytes apoptosis were significantly higher in non-survivors than in survivors. Levels of APO2.7 in lymphocytes apoptosis, annexin V + 7AAD in monocytes apoptosis, and serum lactate were all independently predictive of mortality. Conclusion Leukocyte apoptosis is significantly higher in patients with severe sepsis. The percentages of late lymphocyte and monocyte apoptosis may be predictive of outcome in such patients. Aside from serum lactate, APO2.7 level in lymphocyte apoptosis is also a useful predictor of outcome on admission to the emergency department.