Monocyte phagocytosis as a reliable parameter for predicting early-onset sepsis in very low birthweight infants

Background: Septic complications lead to a high mortality rate in very low birthweight infants (VLBWI). Therefore, prognostic markers for the development of sepsis attach importance to start an efficient therapy as early as possible. Aims: Functional and phenotypical variables of blood monocytes in the cord and peripheral blood were investigated to evaluate the parameters for predicting early-onset and late-onset sepsis (nosocomial infections). Study design: In a prospective study, 25 VLBWI were investigated. Methods: In the cord blood taken immediately after birth, the capacity of the monocytes to phagocytose non-opsonized E. coli bacteria by flow cytometry and the ex-vivo production of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta and IL-6 (enzyme-linked immunoassay (ELISA)) after lipopolysaccharide (LPS) stimulation were measured. At the third day, the HLA-DR expression on the monocytes (flow cytometry) and the LPS-induced cytokine production were measured from the peripheral blood. Results: Five VLBWI already developed early septic complications after 24-72 h, while the other three infants had late-onset sepsis 10-18 days after birth. The prognostic significance for early-onset sepsis was highest for the decreased monocyte phagocytic capacity (sensitivity and specificity: 100%) and for the LPS-induced formation of TNF-alpha and IL-1beta in cord blood. Moreover, in septic VLBWI, the HLA-DR expression on the monocytes was lowered on day 3 after birth. The prognostic significance for late-onset sepsis was highest for TNF-alpha and IL-1beta levels in the peripheral blood on the third day after birth. Conclusions: The determination of phagocytosis in the cord blood seems to be a reliable parameter for predicting early-onset sepsis and offers the possibility for a forward start of an antibiotic therapy. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.