ADVERSE EFFECT OF ABDOMINAL OPERATIONS ON PRODUCTION OF INTERFERON-GAMMA

Objective: To assess the effects of abdominal operations on the produc tion of cytokines as one of the mechanisms of postoperative immunosupp ression. Design: Prospective study. Setting: University hospital, Belg ium. Subjects: 19 Selected patients who underwent operations for benig n (n = 10) or malignant (n = 9) diseases. Interventions: Whole blood w as collected in heparinised tubes before operation and on postoperativ e days 1, 2, 3, 5, 7, and 9. After 1/10 dilution in culture medium the whole blood cells were stimulated with 5 mu g/ml phytohaemagglutinin and 25 mu g/ml lipopolysaccharide, and incubated at 37 degrees C in 5% carbon dioxide. Concentrations of interleukin 1 (IL-1), tumour necros is factor alpha (TNF alpha), and interleukin 6 (IL-6) were measured at 24 hours, and interferon-gamma and interleukin 2 (IL-2) were measured at 72 hours, with commercially available assays. Outcome measures: Pr oduction of the monokines IL-1, TNF alpha and IL-6, and of the lymphok ines IL-2 and interferon-gamma, postoperatively. The monokines were ex pressed as a percentage of the preoperative values/monocyte, and the l ymphokines as a percentage of preoperative values/lymphocyte. Results: Production of IL-1 and TNF alpha but not IL-6, decreased immediately after operation then returned to preoperative values. Production of IL -2 and interferon-gamma were significantly reduced immediately after o peration, and that of interferon-gamma was still depressed on, the nin th postoperative day. Conclusion: Cytokine production is altered after abdominal operations. The production of interferon-gamma may be a mor e sensitive indicator of altered immune response and vulnerability to infections and tumour growth than concentrations of other cytokines.