The postoperative serum interleukin-15 concentration correlates with organ dysfunction and the prognosis of septic patients following emergency gastrointestinal surgery.

OBJECTIVE: To clarify the time course of changes in the serum interleukin-15 (IL-15) concentrations in septic patients undergoing emergency surgery for abdominal infection and to investigate whether the serum IL-15 levels correlate with the postoperative clinical course of septic patients.

METHODS: Twenty-four septic patients who had intra-abdominal infection and who underwent an emergency operation were enrolled in this study. The serum IL-15 levels were measured before surgery, and on postoperative d 1 (POD1), POD3, and POD5, and the relationship between the serum IL-15 levels and the postoperative clinical course estimated by the Systemic Inflammatory Response Syndrome (SIRS) criteria, Acute Physiology and Chronic Health Evaluation (APACHE-II) score, the parameters of organ function, and the 30-d mortality were evaluated.

RESULTS: The time course of changes of the serum IL-15 levels were significantly different between survivors and non-survivors (P < 0.05, by repeated measures analysis of variance [ANOVA]). There was a statistically significant relationship between the serum IL-15 levels on POD1 or POD3 and the duration of SIRS (R = 0.50, P < 0.05, R = 0.65, P < 0.01, respectively). Furthermore, a significant positive correlation was observed between the serum IL-15 levels on POD1 and the creatinine levels on POD1 or POD3 (R = 0.48, P < 0.05, R = 0.50, P < 0.05, respectively), and a significant negative correlation between the serum IL-15 levels on POD1 or POD 3 and the PaO(2)/FiO(2) on POD3 (R = -0.51, P < 0.05, R = -0.69, P < 0.01, respectively).

CONCLUSIONS: The measurement of postoperative serum level of IL-15 might be useful for predicting the severity of SIRS and organ dysfunction, especially renal and pulmonary dysfunction.