Lack of correlation between soluble CD14 and IL-6 in meningococcal septic shock

Abstract

Meningococcal sepsis is a good model to study the dynamic response of cytokines and other soluble factors in vivo in the early stages of the disease. Levels of soluble CD14, interleukin-6 (IL-6), IL-6 receptor (IL-6R), and C-reactive protein (CRP) have been measured in plasma from 26 children with septic shock (nine of whom had disseminated intravascular coagulation) and from ten control children. All samples were collected at the onset, before treatment, and, when possible, 24 and 48 hours later. At admission, patients had significantly higher levels of IL-6 (p < 0.001) and CRP (p < 0.001), and lower levels of IL-6R (p < 0.005) than normal controls. After 24 hours, there was a significant increase of sCD24 (p < 0.05) and CRP (p < 0.001). Although IL-6 showed a progressive decline since the onset, its levels were always higher than controls. There was an inverse correlation between IL-6 and both IL-6R (p < 0.001) and CRP (p < 0.001), probably due to the later increase of CRP. Nevertheless, sCD14 did not correlate with IL-6 levels. We have confirmed the finding of IL-6 as a sensitive and reliable inflammatory marker in septic shock. Moreover, the ratio IL-6/IL-6R may have a prognostic value, given a putative role of IL-6R in modulating the effects of IL-6 in meningococcal sepsis.