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.

Infections in neonates delivered at term are associated with increased serum levels of ICAM-1 and E-selectin.

All newborn infants consecutively admitted to the Neonatal Intensive Care Unit (NICU) at the University Hospital of Trondheim during 1993 were eligible to participate in the study. In total, 241 neonates were included, for whom anamnestic, clinical and laboratory characteristics were recorded. Peripheral blood was retrieved at admittance, and serum levels of soluble intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and E-selectin were determined. Newborn infants were classified as infected or non-infected according to selected criteria, and 24 newborn infants fulfilled the criteria of having an infection, whereas 168 newborn infants were classified as non-infected. ICAM-1, VCAM-1 and E-selectin were detected in all neonatal samples. Serum concentrations of E-selectin varied by gestational age (GA), higher levels were found in non-infected term (GA > or = 37 weeks) neonates (n = 53) than in those (n = 115) delivered prematurely (GA < 37 weeks) without infection (p < 0.0001), whereas ICAM-1 and VCAM-1 concentrations did not differ between groups of non-infected term and preterm newborn infants. Similarly, newborn infants delivered at term (n = 16) demonstrated higher levels of E-selectin than premature infants (n = 8) in association with infection (p < 0.001). Both ICAM-1 and E-selectin were increased in term newborn infants with infection (n = 16) compared to the non-infected term group (n = 53) (both p < 0.01), whereas VCAM-1 concentrations did not differ between the two groups. In the premature groups of infected (n = 8) and non-infected (n = 115) neonates, no differences in ICAM-1, VCAM-1 and E-selectin concentrations were observed. The use of ICAM-1 concentration (cut-off level: 250 micrograms l-1) as a diagnostic test for infection in term neonates yielded a sensitivity of 80% and a specificity of 61%, whereas a sensitivity of 70% and a specificity of 79% were found when E-selectin concentration (cut-off level: 150 micrograms l-1) was used. Conclusively, increased shedding of soluble ICAM-1 and E-selectin is one component of infection-induced neonatal immune response after full-time pregnancies. Our data suggest that the ability of increased shedding of soluble ICAM-1 and E-selectin molecules is developed during the final weeks of pregnancy. Assessment of ICAM-1 and E-selectin concentrations may be used as diagnostic tools with a high sensitivity and a moderate specificity in term neonates suspected of infection.