Differential levels of T helper cytokines in preeclampsia: pregnancy, labor and puerperium.

BACKGROUND: There are suggestions that T helper 1 cytokines may be detrimental to early pregnancy and T helper 2 cytokines protective of the pregnancy. Their role in preeclamptic pregnancy, labor and puerperium, is not clear. MATERIALS AND METHODS: Twenty-eight preeclamptic women and their matched controls were evaluated, at the Departments of Obstetrics and Gynecology, Faculty of Medicine, Kuwait University and Maternity Hospital, Kuwait. Outcome measures evaluated were serum levels of TNF alpha and interleukin-4 at 12, 24, 36 weeks of gestation, advanced labor and at 1 hour and daily postpartum until they were undetectable, using ELISA technique. RESULTS: T helper cytokines showed higher serum levels in preeclampsia than normotensive pregnancy (p < 0.01, 0.01), in established labor (p < 0.05) and at 1 hour postpartum (p < 0.01 for IL-4) and p < 0.02 for TNF alpha. There was significant increase of IL-4 between 12 to 24 weeks in normal pregnancy compared to preeclampsia (p < 0.001) but not for TNF alpha. By 24 hours postpartum, IL-4 was still detectable in eight parturients compared to one patient with detectable TNF alpha (p < 0.04). Detectable IL-4 levels after 24 hours postpartum were associated with intrauterine growth retardation (p < 0.03). CONCLUSION: IL-4 has a dichotomous role in pregnancy. Normotensive pregnancy is associated with high increase in IL-4 in the first half of the pregnancy, but in the second half of pregnancy and puerperium, high levels of IL-4 are associated with preeclampsia.