Elevated interleukin-1 receptor antagonist levels in pediatric sepsis syndrome

Objective: To measure plasma levels of interleukin-1β, interleukin-1 receptor antagonist (IL-1ra), and tumor necrosis factor alpha in children with sepsis syndrome. Study design: A prospective, observational study of 14 patients aged 5 months to 13 years with sepsis syndrome admitted to a pediatric intensive care unit. Cytokine levels were measured by enzyme-linked immunosorbent assay at baseline and at 12, 24, and 48 hours and compared with the levels of 21 age-matched control subjects. Results: The mean pediatric risk of mortality score was 16.1. Bacterial and viral sepsis was confirmed in five and three patients, respectively. Compared with the levels in the control subjects (mean level of IL-1ra: 654 pg/ml), the IL-1ra levels were elevated in the septic patients, with mean values of 17855 ( p < 0.001), 12771 ( p < 0.001), 9182 ( p < 0.01), and 2296 pg/ml ( p = not significant) at baseline and at 12, 24, and 48 hours, respectively. The IL-1ra level was greater than 1000-fold higher than the IL-1β level at all time points in 13 of 14 septic patients. Conclusions: At the time of hospital admission, circulating IL-1ra levels in a cohort of children with sepsis syndrome were at concentrations known to block IL-1 receptors. Thus additional benefit from exogenous IL-1ra therapy would be questionable. Further studies are indicated to determine whether there is a population of patients with sepsis who could benefit from administration of exogenous IL-1ra. (J Pediatr 1997;131:587-91)