Changes in peroxisome proliferator-activated receptor-gamma activity in children with septic shock

To assess changes in peroxisome proliferator-activated receptor-gamma (PPAR gamma) in peripheral blood mononuclear cells (PBMC) from critically ill children with sepsis. Additionally, to investigate the effects of sepsis on the endogenous activator of PPAR gamma, 15-deoxy-a dagger(12,14)-PGJ(2) (15d-PGJ(2)), and the downstream targets of PPAR gamma activity, adiponectin and resistin. Single-center, prospective case-control study in critically ill children with systemic inflammatory response syndrome, sepsis or septic shock. PPAR gamma nuclear protein expression was decreased but PPAR gamma activity was increased in PBMC from children with septic shock compared with controls. PPAR gamma activity on day 1 was significantly higher in patients with higher pediatric risk of mortality (PRISM) score compared with controls [mean 0.22 optical density (OD) +/- A standard error of the mean (SEM) 0.03 versus 0.12 OD +/- A 0.02; p < 0.001]. Patients with resolved sepsis had increased levels of the endogenous PPAR gamma ligand, 15d-PGJ(2), compared with patients with systemic inflammatory response syndrome (SIRS) and septic shock (77.7 +/- A 21.7 versus 58 +/- A 16.5 pg/ml; p = 0.03). Plasma high-molecular-weight adiponectin (HMWA) and resistin levels were increased in patients with septic shock on day 1 and were significantly higher in patients with higher PRISM scores. Nonsurvivors from sepsis had higher resistin levels on the first day of hospitalization compared with survivors from septic shock [660 ng/ml, interquartile range (IQR) 585-833 ng/ml versus 143 ng/ml, IQR 66-342 ng/ml; p < 0.05]. Sepsis is associated with altered PPAR gamma expression and activity in PBMC. Plasma adipokines correlate with risk of mortality scores in sepsis and may be useful biomarkers. Further studies are needed to understand the mechanisms underlying changes in PPAR gamma in sepsis.