Background Bioactive proteins,such as cytokines and chemokines,have not been systematically evaluated in healthy and preeclamptic pregnancies.We aimed to investigate the difference of these proteins between healthy and preeclamptic pregnancies in order to help clarify their potential roles in the pathogenesis of hypertension and proteinuria in preeclampsia.Methods Samples of amniotic fluid and matal/umbilical cord blood were collected from normal pregnancies and women with preeclampsia for examination of bioactive proteins.Fifty-three pregnant women were enrolled in this study.Of them,30 pregnant women were recruited as healthy controls,and 23 pregnant women were diagnosed with preeclampsia.An antibody array was used to screen for higher levels of cytokines and related proteins in amniotic fluid than in the blood samples,and these proteins were then selected for quantification by immunoassay.Results Interleukin-1 receptor 4,hepatocyte growth factor,and urokinase plasminogen activator receptor were significantly elevated in the blood of preeclampsia patients.In particular,interleukin-1 receptor 4 was 8-fold higher in preeclampsia patients than in the healthy pregnancies.Moreover,in cord blood samples hepatocyte growth factor and interleukin-8 were significantly higher in preeclampsia patients.Conclusions Because of the biologic activities,Interleukin-1 receptor 4,hepatocyte growth factor,urokinase plasminogen activator receptor and interleukin-8 in matal and/or cord blood could play a role in the pathogenesis of hypertension and proteinuria in preeclampsia.