TUMOR-NECROSIS-FACTOR-ALPHA DURING HUMAN-PREGNANCY AND LABOR - MATERNAL PLASMA AND AMNIOTIC-FLUID CONCENTRATIONS AND RELEASE FROM INTRAUTERINE TISSUES

The aims of this study were: to quantify immunoreactive tumour necrosi s factor alpha (TNF-alpha) concentrations in maternal plasma and amnio tic fluid obtained from women during pregnancy and labour, both at ter m and preterm; and to establish the effects of bacterial endotoxin and cytokines on the in vitro release of TNF-alpha from intrauterine tiss ues. Maternal plasma TNF-alpha concentrations did not change during pr egnancy (457.2 +/- 102.9ng/l, mean +/- SEM, N = 52) or at the time of labour (543.5+/-138.6 ng/l, N=43). In contrast, amniotic fluid TNF-cr concentrations increased significantly (p < 0.05) during pregnancy (ea rly pregnancy, EP, 93.0 +/- 24.8 ng/l, N = 7; preterm not-in-labour, P NIL, 186.8 +/- 42.9 ng/l, N = 16; term not-in-labour, TNIL, 499.7 +/- 150.9 ng/l, N = 13) and in association with preterm labour (preterm in -labour, PIL, 958.7 +/- 575.6 ng/l, N = 5 vs PNIL, 186.8 +/- 42.9 ng/l , N = 16). Choriodecidual and placental explants (N = 3) maintained in in vitro culture released TNF-alpha. Furthermore, the release of TNF- alpha was increased significantly (p < 0.05) by bacterial endotoxin (l ipopolysaccharide, 10 ng/l-10 mg/l) but was not affected by the follow ing cytokines at the indicated doses: interleukin-1 alpha (0.28 nmol/l ), interleukin-6 (12.5 nmol/l), granulocyte colony-stimulating factor (2.5 nmol/l), granulocyte-macrophage colony-stimulating factor (35 nmo l/l), macrophage colony-stimulating factor (1.2 nmol/l), leukaemia inh ibitory factor (0.45 nmol/l) and transforming growth factor-p (0.4 nmo l/l). The data obtained in this study are consistent with a role for T NF-alpha in both preterm labour and normal labour at term.