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

Abstract

Purpose: The 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.

Methods: During 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.

Results: During 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 >32.3pg/mL, and sST2 >103ng/mL) had the poorest outcome.

Conclusions: In 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.

Keywords: Interleukin 1 receptor family; Interleukin 33; Natriuretic peptide; Procalcitonin; Transforming growth factor super family; Troponin.