Metabolic Mechanisms of Neutrophil Phagocytic Activity in Patients with Widespread Purulent Peritonitis Bacterial Peritonitis Before and After Surgery

Bacterial peritonitis (BP) remains a significant clinical challenge due to its high risk of multiple organ failure and associated mortality. Neutrophils are central effectors of innate immunity, and their functional activity and metabolism may influence the progression and outcomes of immunoinflammatory diseases. To investigate the phagocytic activity and intracellular metabolic profiles of neutrophils in patients with BP and to evaluate their relationship with postoperative clinical outcomes, 51 patients with BP (23 men, 28 women; mean age 49.6 ± 9.4 years) were examined. Blood samples were collected preoperatively and on postoperative day 7. Phagocytic activity of total, actively, and weakly phagocytic neutrophils was assessed using flow cytometry. Intracellular activity of NAD(P)- and NAD(P)H-dependent oxidoreductases and dehydrogenases was measured by bioluminescence. Patients were stratified according to postoperative outcome: favorable (n = 32) or unfavorable (n = 19). Seventy healthy individuals served as controls. Preoperatively, the proportion and phagocytic activity of neutrophils were markedly elevated in all patients. Postoperatively, the proportion of phagocytosing neutrophils remained high; however, phagocytic activity increased in patients with favorable outcomes but decreased to control levels in those with unfavorable outcomes. Neutrophil metabolism before surgery exhibited activation of both anaerobic and aerobic pathways, accompanied by reduced glucose-6-phosphate dehydrogenase activity. Postoperative metabolic adaptations differed according to outcome: patients with favorable outcomes demonstrated normalization of energy metabolism, whereas patients with unfavorable outcomes exhibited enhanced anaerobic metabolism, persistent aerobic activity, increased substrate flux towards glutamate/glutamine synthesis, and intensified lipid peroxidation. Phagocytic activity and metabolic profiles of neutrophils in BP are outcome-dependent. Effective postoperative anti-inflammatory responses, including reverse migration of activated neutrophils, are associated with favorable outcomes, whereas persistent metabolic activation and oxidative stress correlate with unfavorable prognosis. Neutrophil functional and metabolic parameters may serve as prognostic biomarkers and potential targets for therapeutic modulation in BP.