Plasma YKL-40 and CHI3L1 in systemic inflammation and sepsis-Experience from two prospective cohorts

YKL-40, derived from the CHI3L1 gene, has been associated with outcome of infectious and inflammatory diseases. We hypothesized that plasma YKL-40 concentrations and CHI3L1 genotype could be used as prognostic biomarkers in the assessment of systemic inflammatory response syndrome (SIRS) and sepsis. The objective of the study was to assess the prognostic value of plasma YKL-40 and CHI3L1 genotype in patients with SIRS and sepsis. Plasma YKL-40 and CHI3L1 genotype (rs4950928) were analyzed at time of admission to intensive care units (ICU), in two prospective cohorts of consecutive SIRS patients (cohort 1, n=272; cohort 2, n=502). The plasma YKL-40 cut-off for predicting survival was determined in cohort 1 by receiver operator characteristic analyses and validated in cohort 2. In cohort 1 patients with plasma YKL-40 ≤505ng/ml (area under the curve 0.64 (95% confidence interval (CI) 0.57-0.70), p