Comparison between CRP and IL-6 as early markers of neonatal sepsis

Infection in neonates is difficult to identify solely on the basis of physical findings, because signs are not specific. C reactive protein (CRP) is an acute phase reactant which has been used in diagnosis of bacterial infection in neonates. IL-6 is a proinflammatory cytokine produced by monocytes and macrophages activated by bacterial infection. IL-6 can be detected in blood earlier than CRP during the course of bacterial infection. The objective of this study was to compare the usefulness of the level of interleukin-6 with CRP as early markers of neonatal sepsis. This was a queasy experimental study carried out in neonatal unit, Department of Pediatrics, Bangabandhu Sheikh Mujib Medical University (BSMMU) during the period of September 2005 to February 2006. Forty five cases of suspected septicemia were enrolled in the study and thirty healthy newborns were taken for comparison. On the 1st day of symptoms and 1st day of admission, complete blood count, blood for culture and sensitivity and interleukin-6 (IL-6) estimation were done. After 48-72 hours CRP was estimated. In suspected septic babies with high leukocyte count, IL-6 level was found to be raised with high sensitivity (85.71%), negative predictive value (95%). IL-6 was found to have high sensitivity (76.9%), specificity (73.68%), positive predictive value (80%) and negative predictive value (70%) in CRP positive suspected sepsis cases. So, the conclusion was that IL-6 is a very early marker of neonatal infection. IL-6 was mostly positive within 24 hours of onset of sepsis in comparison with other tests. So IL-6 is more useful than other markers for early detection of neonatal sepsis.