Differential levels of interleukin 6 in maternal and cord sera and placenta in women with pre-eclampsia

Background: Interleukin 6 (IL-6) is a T helper 2 cytokine with a variety of properties including pro-inflammatory characteristics. It has, therefore, been implicated in the pathophysiology of abnormal pregnancies. Objective: To investigate the association between IL-6 and pre-eclampsia by estimating the differential levels of IL-6 in maternal and cord serum and supernatant of homogenized placental tissue. Methods: 50 primigravidae with pre-eclampsia and 50 matched normotensive primigravidae served as controls. At delivery, maternal and cord blood were collected and the serum extracted. Placental blocks were homogenized and sonicated in RPMI solution and the supernatant collected. The total protein concentration was determined and IL-6 levels assayed with an ELISA technique. Results: Placental IL-6 (170 and 186 pg/mg protein) was threefold that in the maternal (64 and 58 pg/mg protein) and cord serum (63 and 72 pg/mg protein; p < 0.01). There was no significant difference in the mean IL-6 levels in maternal and cord serum or placenta in both pre-eclamptic women and normotensive controls nor in pre-eclamptic patients with babies with intra-uterine growth restriction or in pre-eclamptic patients with babies with an appropriate birth weight and in normotensive controls. Conclusion: There are no differences in the maternal and cord sera and placental levels of IL-6 in pre-eclamptic and normotensive women, indicating that IL-6 may not have a role in the pathophysiology of pre-eclampsia. Copyright © 2001 S. Karger AG, Basel.