Interleukin-1 receptor antagonist in newborn babies and pregnant women.
We have investigated the possible role of the interleukin-1 receptor antagonist (IL-1ra) in the attenuated fever response in the newborn. Umbilical cord blood was collected from normal full-term infants (n = 12), and venous blood was obtained from afebrile, non-pregnant adults, of both genders (n = 12) and women in late pregnancy (n = 12). Plasma IL-1ra, and IL-1ra produced in vitro by peripheral blood monocytes stimulated with IL-1 alpha or LPS, were assayed by ELISA. Significantly higher concentrations of IL-1ra (P < 0.01, t test) were found in umbilical cord plasma than in plasma of non-pregnant adults. Furthermore concentrations of IL-1ra in the plasma of women in late pregnancy were significantly higher than in the plasma of neonates and non-pregnant adults (P < 0.01, Mann-Whitney rank-sum test). Neonatal monocytes failed to produce significant amounts of IL-1ra upon stimulation in vitro. The monocytes of pregnant women produced much higher concentrations of IL-1ra than the monocytes of non-pregnant adults (P < 0.01 Mann-Whitney rank-sum test). We speculate that IL-1ra may attenuate the febrile response to Gram-negative pyrogens in women in late pregnancy, and by crossing the placenta, also in the newborn.
Pillay
V
V
Department of Physiology, University of Witwatersrand, Parktown, South Africa.
Savage
N
N
Laburn
H
H
D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007375:Interleukin-1 / Q000378:metabolism*; D008297:Male; D011247:Pregnancy; D018123:Receptors, Interleukin / Q000037:antagonists & inhibitors*
D007375:Interleukin-1; D018123:Receptors, Interleukin