Clinical PotpourriInterleukin 6, galectin 3, growth differentiation factor 15, and soluble ST2 for mortality prediction in critically ill patients

PurposeThe aim of this study was to compare the prognostic value of interleukin 6 (IL-6), galectin 3, growth differentiation factor 15 (GDF-15), and soluble ST2 (sST2) in an unselected cohort of critically ill patients.MethodsDuring a study period of 1 year, we recruited 530 consecutive patients admitted to a medical intensive care unit of a tertiary care hospital. We examined a combination of inflammatory, renal, and cardiac biomarkers for the prediction of 90-day all-cause mortality.ResultsDuring follow-up, 118 patients died (22%). In univariate analyses, increased IL-6, galectin 3, GDF-15, and sST2 plasma concentrations at baseline were strong prognostic markers. However, in the multivariate models, only IL-6 and sST2 remained independent biomarkers adding additional prognostic information to the routinely used Simplified Acute Physiology Score (SAPS) II. Using a simple multimarker approach, patients with increased SAPS II, IL-6, and sST2 (ie, SAPS II > 35, IL-6 > 32.3 pg/mL, and sST2 > 103 ng/mL) had the poorest outcome.ConclusionsIn this heterogeneous group of critically ill patients, only SAPS II, IL-6, and sST2 remained independent and additive prognostic markers for 90-day all-cause mortality. A combination of the SAPS II with the 2 complementary biomarkers might provide a valuable tool for risk stratification of critically ill patients.