Evaluation of interleukin-6, tumour necrosis factor-alpha and interleukin-1 beta for early diagnosis of neonatal sepsis

The objective of this study was to assess the contribution of interleukin-6 (IL-6), tumour necrosis factor-alpha (TNF-alpha) and interIeukin-1 beta (I L-1 beta) to an early diagnosis of early-onset neonatal sepsis. A cohort of 117 newborn infants delivered during a 1-y period had IL-6, TNF-alpha and IL-1 beta, blood and cerebrospinal fluid (CSF) cultures, leucocyte and plat elet count collected on the initial evaluation of possible early-onset seps is. They were divided into four groups: I, positive blood and/or CSF cultur es; II, probably infected with clinical sepsis but negative cultures; III, same as group II but mother received antibiotic antepartum; and IV, newborn infants that did not receive any antibiotic therapy. There were no differe nces among the four groups with respect to mean gestational ages and birthw eights, median Apgar scores, type of delivery, or number of newborn infants with leucocyte count <5000 mm(-3) or >25 000 mm(-3), platelet count <100 0 00 mm(-3), immature/total neutrophil ratio >0.2, absolute neutrophil count <1000 mm(-3) and median IL-1 beta levels. Median IL-6 and TNF-alpha levels were significantly higher in groups with patients with a diagnosis of clini cal sepsis than in controls. The optimal cut-off point was 32 pg ml(-1) for IL-6 and 12 pg ml(-1) for TNF-alpha. The combination of both provided a se nsitivity of 98.5%. In conclusion, the combination of IL-6 and TNF-alpha is a highly sensitive marker of sepsis in the immediate postnatal period.