Pre-operative neutrophil and monocyte activation state predicts post- operative neutrophil and monocyte function

Objective: To find out if the in vitro responses of neutrophils (PMN) and monocytes preoperatively can predict their activation postoperatively. Design: Prospective open study. Setting: Teaching hospital, Ireland. Subjects: 46 Patients (32 men, 14 women, mean age 65 years, range 33-85) who were to undergo elective major vascular or gastrointestinal operations for benign (n = 18) or malignant (n = 28) diseases. Interventions: Measurement by flow cytometry of functional (PMN and monocyte respiratory burst activity) and phenotypic (expression of PMN CD 11b adhesion receptors and monocyte CD14 receptors) markers of activation. Main outcome measures: Correlation between mean channel fluorescence (MCF) preoperatively and postoperatively. Results: In 24 patients PMN respiratory burst activity was increased before operation and had decreased significantly (p < 0.01) on postoperative day 1 (high responders group). In the remaining 22 patients (low responders group) respiratory burst activity was low before operation and had increased significantly (p < 0.05) on postoperative day 1. PMN CD 11b activity followed a similar trend. Monocyte activity responded similarly (in the high group mean (SEM) MCF preoperatively was 69.14 (13.15) compared with 58.23 (10.8) on day 1, and in the low group the corresponding figures were 38.5 (7.01) and 8.43 (5.2). Expression of CD14 did not differ between the groups and was less postoperatively than preoperatively. The groups did not differ in age, sex, APACHE 11 scorns, smoking habits or types of disease and there was no major infective complications in either group. Conclusion: There are two distinct patterns of PMN and monocyte responses to injury that are independant of age, sex and severity of operation. These may be associated with the degree of stress preoperatively or with genetic factors.