Production of IL-6 (BSF-2/IFN β2) by mononuclear cells in premature and term infants

The production of interleukin 6 (IL-6) was examined in premature neonates (48 cases, including 3 miscarried fetuses) and fullterm neonates (20 cases). The IL-6 production by mononuclear cells was measured after stimulation with Staphylococcus aureus Cowan Strain I (SAC), phytohemagglutinin (PHA) or lipopolysaccharide (LPS). The production in full-term neonates was similar to that in healthy adults, whereas it was significantly lower in premature neonates without premature rupture of the membrane (PROM). However, in premature infants with PROM a normal level of IL-6 production was observed in mononuclear cells stimulated with SAC, PHA and LPS. Furthermore, there was a positive correlation between the IgM concentration in the cord serum and IL-6 production by LPS-stimulated mononuclear cells.