Interleukin-6 at discharge predicts all-cause mortality in patients with sepsis

Purpose: Interleukin-6 (IL-6) is a proinflammatory cytokine that plays a central role in the pathogenesis of sepsis. We aim to investigate the association between IL-6 and all-cause mortality in patients with sepsis. Methods: A cohort of 40 elderly patients with sepsis was identified between March 2009 and June 2010 at Rambam Health Medical Campus, Haifa, Israel. The cohort was followed up for all-cause mortality occurring during the 6 months after hospital discharge. Cox proportional hazard model was used to assess the association between IL-6 and all-cause mortality. Results: Iinterleukin-6 at discharge had a higher predictive accuracy for all-cause mortality when compared with IL-6 at admission. The area under the curve was 0.752 (P =.015) and 0.545 (P =.661), respectively. Eleven (27.5%) patients died during follow-up; the subjects who died have higher IL-6 levels at discharge (median, 50.6 pg/mL [interquartile range, 39.6-105.9]) compared with survivors at the end of follow-up (median, 35.4 [interquartile range, 15.8-49]; P =.014). The risk of all-cause mortality was higher in subjects with IL-6 levels above the median compared with subjects with lower IL-6 levels (log-rank P =.017). On multivariate Cox proportional analysis, adjusting for the potential confounders, IL-6 at discharge remained an independent predictor for 6 month all-cause mortality (hazard ratio, 6.05 [1.24-24.20]) for levels above the median compared with lower levels. Conclusions: Iinterleukin-6 at discharge is an independent predictor of all-cause mortality in patients with sepsis. Compared with IL-6 at admission, IL-6 at discharge better predicts all-cause mortality.