Soluble receptors for tumor necrosis factor: occurrence in association with normal delivery at term.
OBJECTIVE
To compare levels of tumor necrosis factor (TNF) and interleukin 1 (IL-1) and 6 (IL-6) with levels of the soluble receptors for TNF in maternal and neonatal urine and amniotic fluid (AF).


METHODS
Levels of soluble TNF receptors (p55, p75) in AF and urine from 21 women and their newborns were measured by immunoassay. The amniotic concentrations of IL-1 and IL-6 were assessed by biologic assays, whereas an immunoassay was used to measure TNF levels. The comparison between receptor concentrations in different compartments was performed by one-way analysis of variance, and Student t test was used to compare pairs of groups. Correlation studies were performed when indicated.


RESULTS
A high correlation was observed between the concentrations of p55 and p75 in all compartments. The concentration of p55 in AF was significantly higher than that in both maternal and neonatal urine, but the correlation between TNF receptor concentrations in the AF samples and the concomitant levels of cytokines was not statistically significant.


CONCLUSIONS
The high concentration of receptors in the AF compared to those of other biologic compartments suggests that the pregnancy-associated increased receptor shedding takes place in intrauterine tissues. Physiologic levels of cytokines, such as those accompanying normal delivery at term, did not seem to influence the soluble TNF receptor release.
Austgulen
R
R
Department of Pediatrics, University Hospital of Trondheim, Norway.
Johnsen
H
H
Kjøllesdal
A M
AM
Liabakk
N B
NB
Espevik
T
T
D000653:Amniotic Fluid / Q000737:chemistry*; D005260:Female; D006801:Humans; D007231:Infant, Newborn / Q000652:urine*; D007375:Interleukin-1 / Q000032:analysis; D015850:Interleukin-6 / Q000032:analysis; D007743:Labor, Obstetric / Q000378:metabolism*; D011247:Pregnancy; D011956:Receptors, Cell Surface / Q000032:analysis*; D018124:Receptors, Tumor Necrosis Factor; D012995:Solubility; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis* / Q000652:urine
D007375:Interleukin-1; D015850:Interleukin-6; D011956:Receptors, Cell Surface; D018124:Receptors, Tumor Necrosis Factor; D014409:Tumor Necrosis Factor-alpha