Hindawi Publishing Corporation Journal of Biomedicine and Biotechnology Volume 2012, Article ID 305964, 8 pages doi:10.1155/2012/305964 Research Article Quantitative Proteomic (iTRAQ) Analysis of 1st Trimester Maternal Plasma Samples in Pregnancies at Risk for Preeclampsia Varaprasad Kolla, 1 Paul Jen¨ o, 2 Suzette Moes, 2 Olav Lapaire, 1 Irene Hoesli, 1 and Sinuhe Hahn 1, 3 1 Department of Biomedicine, University Women’s Hospital, 4031 Basel, Switzerland 2 Biozentrum, University of Basel, 4056 Basel, Switzerland 3 Laboratory for Prenatal Medicine, Department of Biomedicine, University Women’s Hospital, Hebelstrasse 20, CH 4031 Basel, Switzerland Correspondence should be addressed to Sinuhe Hahn, shahn@uhbs.ch Received 31 May 2011; Revised 26 December 2011; Accepted 28 December 2011 Academic Editor: Saulius Butenas Copyright © 2012 Varaprasad Kolla et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. A current major obstacle is that no reliable screening markers exist to detect pregnancies at risk for preeclampsia. Quantitative proteomic analysis employing isobaric labelling (iTRAQ) has been suggested to be suitable for the detection of potential plasma biomarkers, a feature we recently verified in analysis of pregnancies with Down syndrome foetuses. We have now examined whether this approach could yield biomarkers to screen pregnancies at risk for preeclampsia. In our study, we used maternal plasma samples obtained at 12 weeks of gestation, six from women who subsequently developed preeclampsia and six with uncomplicated deliveries. In our analysis, we observed elevations in 10 proteins out of 64 proteins in the preeclampsia study group when compared to the healthy control group. These proteins included clusterin, fibrinogen, fibronectin, and angiotensinogen, increased levels of which are known to be associated with preeclampsia. An elevation in the immune-modulatory molecule, galectin 3 binding protein, was also noted. Our pilot study, therefore, indicates that quantitative proteomic iTRAQ analysis could be a useful tool for the detection of new preeclampsia screening markers. 1. Introduction Preeclampsia is a major health concern, as it is a leading cause of fetal and maternal mortality and morbidity, worldwide [1]. A major clinical deficit is that no reliable screening markers exist to detect at-risk pregnancies, thereby offering no opportunity for intervening therapies prior to the onset of symptoms [2, 3]. This is especially relevant for severe cases of early onset forms of the disorder, resulting in the delivery of premature babies, who are frequently affected by intrauterine growth retardation. It is widely accepted that the underlying aetiology of this enigmatic disorder, characterised by sudden hypertension in previously normotensive pregnant women, involves the pla- centa. In this context, the placentae of early onset preeclamp- sia are usually characterised by abnormalities in trophoblast differentiation, lack of modification of the maternal spiral arteries, and ill-defined villous structure [4]. Recent studies have indicated that the clinical symptoms, such as hypertension and proteinuria, are largely brought about by alterations in the levels of angiogenic factors produced by the placenta such as placental growth factor (PIGF), vascular endothelial growth factor (VEGF), soluble Flt-1, and endoglin [5, 6] Although alterations in the levels of these cytokines do precede the onset of clinical symptoms, it is not clear how effective they will be as screening markers, as these changes occur relatively late in gestation. A considerable effort in prenatal medicine is being de- voted to the development of efficacious first trimester screen- ing tools, to detect pregnancies at risk for fetal aneuploidies, but also pregnancy-related disorders such as preeclampsia, as this would permit sufficient time for intervention. In this