Blood interleukin 12 as preoperative predictor of fatal postoperative sepsis after neoadjuvant radiochemotherapy

Introduction: The value of preoperative whole-blood interleukin (IL) 12 levels in predicting death from postoperative sepsis was evaluated, in patients stratified by underlying malignancy, neoadjuvant tumour treatment and surgical procedure. Methods: Blood samples were collected from 1444 patients before major surgery. Whole blood was incubated with Escherichia coli lipopolysaccharide (LPS) and IL-12 production in supernatants was assessed by enzyme-linked immunosorbent assay. The prognostic impact of ability to synthesize IL-12 before surgery was investigated in patient subgroups with respect to sepsis-related mortality using multivariate binary logistic regression analysis. Results: IL-12 synthesizing capability in patients who survived sepsis was significantly higher than that in patients who developed fatal sepsis (P = 0.006). In multivariate analysis only IL-12 was associated with a lethal outcome from postoperative sepsis (P = 0.006). The prognostic impact of IL-12 was evident in patients with underlying malignancy (P = 0.011) and in those who had undergone neoadjuvant tumour treatment (P = 0.008). When patients were analysed according to the type of neoadjuvant therapy, preoperative ability to synthesize IL-12 had a significant prognostic impact in patients who had neoadjuvant radiochemotherapy (P = 0.026), but not in those who had neoadjuvant chemotherapy. Conclusion: IL-12 production alter stimulation of whole blood with LPS appears to be useful for the preoperative assessment of risk of sepsis-related death after operation in patients who have undergone neoadjuvant radiochemotherapy.