Neutrophil CD11b expression and circulating interleukin-8 as diagnostic markers for early-onset neonatal sepsis.
OBJECTIVE
To assess neutrophil CD11b and circulating interleukin 8 (IL-8) as markers of early-onset infection in neonates.


METHODS
The study comprised 39 neonates, with a gestational age of 29 to 41 weeks, suspected of infection within 48 hours of life. Neutrophil surface expression of CD11b was quantified with flow cytometry and plasma IL-8 with an enzyme-linked immunosorbent assay. Both data were available from 35 of 39 neonates. Serum C-reactive protein was determined at initial evaluation and, later, on the basis of the clinical picture. Neonates were allocated retrospectively into 2 groups. In the sepsis group (N = 22), 4 had culture-proven sepsis, and 14 had an antenatal risk factor for infection. In the possible-infection group (N = 13), each neonate had a noninfective disorder, but co-occurring infection remained a possibility. Twelve healthy term infants served as controls.


RESULTS
CD11b expression and IL-8 levels both increased in order of sepsis > possible infection > healthy. Sensitivity and specificity by the CD11b test for sepsis were equal, at 1.00, and those by the IL-8 test 0.91 and 1.00, respectively; 6 (17.1%) of the 35 neonates had CD11b and IL-8 below cutoff levels.


CONCLUSIONS
Measuring neutrophil CD11b expression and circulating IL-8 provides a means to identify early-onset neonatal sepsis. The findings may be helpful in planning strategies to safely reduce the use of antimicrobials in neonates.
Nupponen
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Hospital for Children and Adolescents, University of Helsinki, Finland. irmeli.nupponen@kolumbus.fi
Andersson
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Järvenpää
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Kautiainen
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Repo
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D015415:Biomarkers / Q000097:blood; D018845:CD11 Antigens / Q000097:blood*; D006801:Humans; D007231:Infant, Newborn; D016209:Interleukin-8 / Q000097:blood*; D009504:Neutrophils / Q000276:immunology*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D018805:Sepsis / Q000175:diagnosis* / Q000276:immunology*; D013997:Time Factors
D015415:Biomarkers; D018845:CD11 Antigens; D016209:Interleukin-8