Cytokine levels in midtrimester amniotic fluid in normal pregnancy and in the prediction of pre-eclampsia

Abstract

Midtrimester amniotic fluid cytokines may reflect the function of the maternal immune system in the maternal-fetal interface and thus be predictive of pre-eclampsia. We determined the concentrations of interleukin (IL)-6, IL-8, IL-10, IL-11, IL-12, IL- 15, tumour necrosis factor (TNF)-α and transforming growth factor (TGF)-β in amniotic fluid at 14-16 weeks of gestation from women with normal pregnancies and from those who subsequently developed severe pre-eclampsia. The concentrations of the cytokines in amniotic fluid did not significantly differ between patients and normal controls. The median concentration of IL-6 was 950 pg/ml in normal pregnant women and 578 pg/ml in the patient group. The median concentration of IL-8 was 606 pg/ml in normal controls and 294 pg/ml in the patient group. The levels of IL-6, IL-8 and TGF-β correlated positively with each other. TNF-α concentrations were low and similar in both groups. IL-10 and IL-12 were detected at very low levels in 37 and 7% of the samples, respectively. No difference was found in IL-15 concentrations between the groups. IL-11 was found only at low levels in both groups. Although none of the cytokines measured was predictive of pre-eclampsia, this study provides information of cytokines in amniotic fluid during the period when the spiral arteries are remodelled.