Immune paralysis of T cells and monocytes during postoperative abdominal sepsis. Correlation of immune functions with outcome

In vitro functions of stimulated peripheral T cells and monocytes were inve stigated in patients experiencing sepsis following major visceral surgery. Cell culture supernatants were analyzed by ELISA for IL-2, IFN-gamma, IL-4, IL-10, TNF-alpha, IL-1 beta, and IL-12 p40. In addition, monocyte HLA clas s II expression was determined by flow cytometry. T cell secretion of IL-2, TNF-alpha, and in part IFN-gamma (but not IL-4) was significantly diminish ed in non-survivors throughout the entire course of sepsis, compared to con trols and sepsis survivors. Production of IL-1 beta and IL-12 p40 by monocy tes was strongly reduced in both survivors and non-survivors at the onset o f sepsis. Persistence of depressed monocyte cytokine secretion correlated w ith lethality. Thus, overall suppression of cytokine production by T cells and monocytes was already observed at the beginning of postoperative sepsis . HLA class II expression by monocytes exhibited a strong and sustained dow n-regulation with no significant differences between sepsis survivors and n on-survivors. In summary, suppression of both T cell and monocyte functions develops early during postoperative sepsis. Recovery of immune functions a nd severity of immune defects are associated with outcome.