Circulating cytokine concentrations and cytokine production by monocytes from newborn babies and adults

Abstract

As a possible factor responsible for reduced fever responses in the newborn, we measured plasma cytokine concentrations and cytokine production by neonatal monocytes after lipopolysaccharide or IL (interleukin)-1 alpha stimulation in vitro and compared these data with those obtained from adult plasma and monocytes. Whole blood was collected from afebrile adults (n = 12) and the umbilical cord of normal term infants (n = 12). Plasma and peripheral blood monocytes were prepared by conventional techniques. Significantly lower concentrations of IL-1 alpha, IL-1 beta (P < 0.05, t-test) and IL-6 (P < 0.01, t-test) were found in the plasma of newborn babies compared with that of adults. There was no significant difference in plasma tumour necrosis factor (TNF) concentrations between the adults and newborn babies. Monocytes from newborn babies had the capacity to produce IL-1 alpha and IL-1 beta as readily as adult cells after stimulation with lipopolysaccharide or IL-1 alpha, and produced significantly lower concentrations of TNF and IL-6 than those produced by stimulated adult monocytes (P < 0.01, ANOVA). Our results suggest that the reduced production of IL-6 by monocytes of the newborn during infection could be partly responsible for attenuated fever responses observed in the neonate.

Enhancement of Neonatal Innate Defense: Effects of Adding an N-Terminal Recombinant Fragment of Bactericidal/Permeability-Increasing Protein on Growth and Tumor Necrosis Factor-Inducing Activity of Gram-Negative Bacteria Tested in Neonatal Cord Blood Ex Vivo

“…Some studies have documented reduced responses of newborn leukocytes to endotoxin (27,28,32). In contrast, our study, which employs a whole-blood assay system using whole, live bacteria, demonstrates that newborn cord blood releases quantities of the cytokine TNF-␣ similar to those of adult blood (Fig.…”

Alveolar macrophage immaturity in infants and young children

“…For example, neonatal rabbit AM spontaneously release less IL-1-a than adult T-cells, but exhibit increased IL-1a release with LPS [20]. On the other hand, LPS-stimulated IL-1b release by AM is impaired in the immature rat [21], and in the human several studies have reported the reduced ability of neonatal monocytes to release TNF-a in response to inflammatory stimuli, and their differential ability to release IL-1 and IL-6 [22,23].…”

Ureaplasma urealyticumModulates Endotoxin-Induced Cytokine Release by Human Monocytes Derived from Preterm and Term Newborns and Adults

“…Previous studies have reported conflicting findings concerning the responsiveness of LPS-stimulated neonatal monocytes. LPS-stimulated cord blood monocytes from term infants produced amounts of IL-6 similar to (41,51,74) or less than (47) those produced by adult monocytes. LPS-stimulated monocytes from preterm cord blood produced significantly less IL-6 (41, 51) than stimulated monocytes from term infants or adults.…”

“…In contrast, Kavelaars et al (31) reported similar capacities to produce IL-6 from 26 to 41 weeks gestation. Newborn cells have a reduced capacity to produce other cytokines, including TNF-␣ (13,47,52,72). Monocytes from term infants stimulated with LPS produce less IL-10 than stimulated adult cells (5,37).…”