Reduced secretion of interleukin-1 and tumor necrosis factor-alpha by neonatal monocytes

Monocytes were isolated from peripheral blood of preterm and term newborn infants and adult controls, and their capacity to secrete the inflammatory mediators interleukin-1 (IL-1) and tumor necrosis factor-alpha (TNF-alpha) was investigated. Lipopolysaccharide (LPS)-stimulated neonatal monocytes secreted significantly less IL-1 (median: 1.1 U/ml) than monocytes from adult controls (median: 7.3 U/ml). In addition TNF-alpha production by LPS-stimulated neonatal monocytes (median: 610 pg/ml) was significantly lower when compared with controls (median: 2230 pg/ml). Our data provide evidence that neonatal monocytes have a profoundly impaired cytokine secretion.