Plasma cytokine response to surgical stress in schizophrenic patients

Schizophrenic patients are reported to have immunological dysfunction, howe ver, the immune response to surgery in schizophrenic patients remains uncle ar. We measured plasma interleukin-6 (IL-6), interleukin-8 (IL-8) and tumou r necrosis factor-alpha (TNF-alpha) before, during and after colectomy, hem icolectomy and sigmoidectomy in 25 chronic schizophrenic patients (Group S) and 25 control patients (Group C) using ELISA assays. We could find no sig nificant difference in the baseline plasma concentrations of IL-6, IL-8 and TNF-alpha between Group S and Group C. Plasma IL-6 concentrations (32.1 (3 0.3) and 15.8 (9.6) pg/ml) in Group S at the end of the operation and 24 h after surgery were significantly lower than 76.9 (37.1) and 35.1 (21.5) pg/ ml of Group C. Plasma IL-8 concentration (6.1 (2.8)) in Group S at the end of the operation was significantly lower than 8.7 (4.2) pg/ml of Group C. T here were no significant changes in plasma TNF-alpha concentration througho ut the study period in either group. Plasma cortisol concentrations of schi zophrenic patients during surgery were significantly lower than those of co ntrol patients. The plasma IL-6 concentrations correlated with plasma corti sol concentrations in either group. We conclude that proinflammatory cytoki ne response to abdominal surgery is inhibited in schizophrenic patients.