Increased serum concentrations of soluble tumor necrosis factor receptors p55 and p75 in early onset neonatal sepsis.

Sepsis and pneumonia are major causes of morbidity and mortality in the neonatal period. The symptoms are variable and unspecific. So far, no reliable diagnostic test for neonatal infection has been found. In this study we measured serum levels of soluble tumor necrosis factor receptors (sTNFR) p55 and p75 in non-infected and infected neonates, and evaluated the diagnostic value of these mediators as tests for early detection of neonates with sepsis or pneumonia. Blood was collected on admission and after 3-4 days from 161 neonates consecutively admitted to the Neonatal Intensive Care Unit (NICU) during the first week of life. Twenty two neonates suffered from infection and 127 were classified as non-infected (controls). Samples were analyzed for p55 and p75, C-reactive protein (CRP) and white blood cell count with differential. Both preterm and term infected neonates had initially higher concentrations of p55 (both p <0.01) and p75 (p = 0.01 and p = 0.05, respectively) than controls. In non-infected neonates p55 levels decreased in the perinatal period, whereas p75 levels remained stable. Levels of both p55 and p75 decreased in neonates with infection during the perinatal period. CRP was a more specific parameter than p55 and p75 (CRP: 97%, p55: 65% and p75: 75%) whereas the sensitivity of all three parameters was at similar levels (CRP: 59%, p55: 70% and p75: 67%). We conclude that assessment of sTNFR may not improve accuracy in the diagnosis of early onset neonatal sepsis compared to the use of CRP.

Interleukin-6 concentrations in neonates evaluated for sepsis.

OBJECTIVES: This study was performed to determine serum concentrations of interleukin-6 (IL-6) during bacterial infections in the first week of life and to evaluate the usefulness of IL-6 as a diagnostic test for perinatal bacterial infections, alone and in combination with C-reactive protein (CRP). STUDY DESIGN: Blood was obtained from 241 newborn children on admission to the neonatal intensive care unit and at 3 to 4 days after admission. Both samples were analyzed for IL-6, CRP, and white blood cell count with differential. RESULTS: Twenty-four newborns were classified as having an infection. Increased serum IL-6 levels were detected in infected compared with noninfected newborns on admission (p < 0.0001). Detection of IL-6 (> or = 20 pg/ml) alone yielded a sensitivity of 78%, a specificity of 71%, a positive predictive value of 40%, and a negative predictive value of 93%. A combined parameter of IL-6 (> or = 50 pg/ml) and CRP (> or = 10 mg/L) yielded a sensitivity of 96%, a specificity of 74%, a positive predictive value of 49%, and a negative predictive value of 99%. CONCLUSIONS: Used in combination with CRP, IL-6 seems to be a valuable parameter in the early diagnosis of neonatal infections.