Expression pattern of cytokines in the different compartments of the feto-maternal unit under various conditions

Concentrations of five cytokines, GM-CSF, G-CSF, IL-1, IL-6 and IL-8, were determined within five compartments under four different conditions: at the time of a Caesarean section performed between 25 and 38 weeks' gestational age in normal pregnancy without uterine contraction (n = 12), in normal pregnancy with labour already established (n = 8), in pregnancy complicated by amniotic infection (n = 11), or under the conditions of preeclampsia with fetal intrauterine dystrophy (n = 13), cytokine concentrations were determined in fetal arterial and venous blood, in amniotic fluid, and in retroplacentally obtained maternal blood and peripheral maternal blood. With dystrophy, the concentrations of GM-CSF, G-CSF and IL-1 were about 20-50% lower (P < 0.01) in the amniotic fluid, and IL-6 and IL-8 were elevated in maternal peripheral blood (P < 0.01) but not within maternal retroplacental blood. Thus, preeclampsia/intrauterine dystrophy is characterized by reduction of some cytokines within the amniotic fluid compartment and concomitant reactive augmentations of other cytokines within the maternal and fetal organism. With amniotic fluid infection, concentrations of G-CSF, IL-6 and IL-8 were elevated in all compartments (P < 0.001) but GM-CSF and IL-1 showed a significant rise only within amniotic fluid and retroplacental maternal blood (P < 0.001), a rise that was apparently not transmitted to peripheral maternal or fetal blood. Care was taken to exclude the presence of uterine contractions in the group of controls, because this condition by itself causes severe elevation of cytokine concentrations, which are pronounced within amniotic fluid.