IL-1 beta and IL-3-like activity in preterm infants.

The capacity of peripheral blood mononuclear cells (PBMC) of preterm neonates to release IL-1 beta and IL-3-like activity (IL-3-LA) has been investigated. In the present study it was found that this capacity is significantly lower than that of their mothers and of control adults. In addition, the results showed that preterm serum has a lower stimulatory effect on IL-1 beta production and an inhibitory effect on IL-3-LA secretion by PBMC of adult controls, in comparison with maternal and adult sera. These findings suggest an additional feedback mechanism for control of haematopoiesis in premature neonates. It is possible that the lower production of IL-1 beta and IL-3-LA may be involved in the increased susceptibility to infections of preterm newborns.