org . americanscience . www :// http ) 12 ( 6 ; 2010 , Science Journal of American Serum levels of placental growth factor and retinol-binding protein-4 in pregnancy-induced hypertensive women Adel F. Al-Kholy 1 , Mamdouh Z. Abadier 1 , Ebrahem M. Rageh 2 , Hany El-Kallaf 3 1 Department of Medical Biochemistry, Faculty of Medicine, Benha University 2 Department of Clinical Pathology, Faculty of Medicine, Benha University 3 Department of Obstetrics & Gynecology, Faculty of Medicine, Benha University adeladel59@yahoo.com Abstract: To investigate the relationship between clinical parameters of pre-eclampsia (PE) and serum levels of Retinol binding protein4 (RBP4) and Placental growth factor (PlGF). Patients and Methods: The study included 90 pregnant women categorized as Group I: Control group (n= 20), included pregnant women who continued their pregnancy without development of PE manifestations, Group II: included patients had Mild PE (n=56) and group III included patients had Severe PE (n=14). After clinical evaluation and ultrasonographic examination, samples of maternal peripheral blood were obtained either at time of diagnosis of PE in groups II and III or at time of delivery in control group for ELISA estimation of serum RBP4 and PlGF. Results: PE patients had significantly lower serum PlGF, but significantly higher serum RBP4 levels when compared to the corresponding levels of the control group. Serum levels of PlGF showed negative correlation with systolic and diastolic blood pressures (SBP and DBP) and extent of proteinuria, but showed positive significant correlation with birth weight, while serum levels of RBP4 showed positive significant correlation with DBP, extent of proteinuria and patients' body weight measures. Conclusions: RBP4 and PlGF were associated with the development and severity of PE. [Adel F. Al-Kholy, Mamdouh Z. Abadier, Ebrahem M. Rageh, Hany El-Kallaf. Serum levels of placental growth factor and retinol-binding protein-4 in pregnancy-induced hypertensive women. Journal of American Science 2010;6(12):448-455]. (ISSN: 1545-1003). Keywords: Pre-eclampsia, Placental growth factor, Retinol-binding protein 1. Introduction Pregnancy is a physiological situation where major changes in energy homeostasis occur to meet the nutrient demands of fetal growth. The energy needs are met by increased food intake and/or mobilization of stored fuels and decreased sensitivity of maternal tissues to insulin. This change in insulin sensitivity allows for decreased glucose utilization and a shift to fat metabolism by maternal peripheral tissues and increased availability to the feto-placental unit. The pregnant state parallels the insulin-resistant states of obesity and type-2 diabetes, which are also characterized by insulin resistance, and can become manifested as gestational diabetes in humans (Herrera, 2000, Di Cianni et al., 2003). Pre-eclampsia is the major cause of maternal and fetal morbidity and mortality, involving 15% to 20% of pregnancies in developed countries and even more in less developed parts of the world. Superficial placentation driven by immune maladaptation, with subsequently reduced concentrations of angiogenic growth factors and increased placental debris in the maternal circulation, are likely responsible (Dechend and Luft, 2008). Retinol (vitamin A) bound to its specific transport protein, retinol-binding protein (RBP), is the predominant (95% or more) retinoid form in the fasting circulation. Postprandially, retinyl ester packaged in chylomicrons and chylomicron remnants can constitute a large percentage of the total retinoid present in the circulation. As RBP is the sole specific transport protein for retinol, it has been proposed to play an important role in the delivery of retinoid from mother to fetus. However, the mechanisms and the physiology of maternal-fetal vitamin A transfer are not fully understood (Soprano and Blaner, 1994, Sapin et al., 1998). Dysregulation of maternal circulating adipokines has been implicated in several "great obstetrical syndromes" including pre-eclampsia, small-for-gestational age, neonate and fetal death. It has been suggested that adipokines provide a molecular link between metabolic derangements and inflammatory response in complicated pregnancies. Retinol binding protein 4, a novel adipokine, plays a role in obesity- related disorders, as well as in the regulation of the immune response (Vaisbuch et al., 2009). Solini et al., (2009) determined serum RBP4, 448