Cytokine Levels in Critically Ill Children With Severe Sepsis and Their Relation With the Severity of Illness and Mortality

To study the baseline cytokine levels and their relation with the severity of illness and mortality in critically ill children with severe sepsis.Subgroup analysis of a randomized, double-blind, placebo-controlled trial.Pediatric intensive care unit of a tertiary level teaching hospital in India.Fifty children with severe sepsis aged 3 months to 12 years.Blood was collected at admission for estimation of pro-inflammatory (interleukin 6 [IL-6], IL-12p70, IL-17, and tumor necrotic factor α [TNF-α]) and anti-inflammatory (IL-10 and transforming growth factor β1 [TGF-β1]) cytokines.To find out correlation between cytokine levels and severity of illness scores (Pediatric Risk of Mortality [PRISM] III score, Sequential Organ Failure Assessment [SOFA], and Vasoactive-Inotropic Score [VIS]).To compare cytokine levels among survivors and nonsurvivors.Baseline pro-inflammatory cytokine levels (median [interquartile range]) were IL-6: 189 (35-285) pg/mL, IL-12p: 48 (28-98) pg/mL, IL-17: 240 (133-345) pg/mL, and TNF-α: 296 (198-430) pg/mL; anti-inflammatory cytokine levels were IL-10: 185 (62-395) pg/mL and TGF-β1: 204 (92-290) ng/mL. Pro-inflammatory cytokines showed positive correlation with PRISM III score: IL-6 (Spearman correlation coefficient, ρ = 0.273, P = .06), IL-12 (ρ = 0.367, P = .01), IL-17 (ρ = 0.197, P = .17), and TNF-α (ρ = 0.284, P = .05), and anti-inflammatory cytokines showed negative correlation: IL-10 (ρ = -0.257, P = .09) and TGF-β (ρ = -0.238, P = .11). Both SOFA and VIS also showed weak positive correlation with IL-12 (ρ = 0.32, P = .03 and ρ = 0.31, P = .03, respectively). Among nonsurvivors (n = 5), the levels of all the measured pro-inflammatory cytokines were significantly higher as compared to survivors, IL-6: 359 (251-499) pg/mL versus 157 (97-223) pg/mL, P < .0001, IL-12p70: 167 (133-196) pg/mL versus 66 (30-100) pg/mL, P < .0001, IL-17: 400 (333-563) pg/mL versus 237 (122-318) pg/mL, P = .009, and TNF-α: 409 (355-503) pg/mL versus 330 (198-415) pg/mL, P = .002, respectively.In critically ill children with severe sepsis, pro-inflammatory cytokines (especially IL-12p70) showed a weak positive correlation with severity of illness and were significantly higher among nonsurvivors.