Background: Despite the large impact of ultrasonographic and biochemical markers on prenatal screening, the ability to accurately diagnose Down syndrome (DS) is still limited and better diagnostic testing is needed.Methods: Plasma from 8 women carrying a DS foetus and 12 with non‐DS foetuses matched for gestational age, maternal age and ethnicity, in the second trimester of pregnancy, was analysed by two‐dimensional gel electrophoresis (2‐DE) and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF‐MS) in order to identify biomarkers for DS.Results: Gel comparison revealed nine proteins differentially expressed in maternal plasma in women with DS foetuses. Eight proteins, transthyretin (TTHY), ceruloplasmin (CERU), afamin (AFAM), alpha‐1‐microglobulin (AMBP), apolipoprotein E (APOE), serum amyloid P‐component (SAMP), histidine‐rich glycoprotein (HRG) and alpha‐1‐antitrypsin (A1AT) were up‐regulated and one, clusterin (CLUS), down‐regulated. All nine proteins are known to be involved in foetal growth and development. APOE, SAMP, AFAM and CLUS are associated with the DS phenotype. Western blot and densitometric analysis of APOE and SAMP confirmed the increase of both proteins by 19 and 48% respectively.Conclusions: All differentially expressed proteins are candidate biomarkers for DS, providing opportunities for the development of non‐invasive prenatal diagnosis. As these are preliminary findings, follow‐up experiments are needed for their evaluation. Copyright © 2008 John Wiley & Sons, Ltd.

The infliximab (IFX) has dramatically improved the treatment of Crohn's disease (CD). However, the need for predictive factors, indicative of patients' response to IFX, has yet to be met. In the current study, proteomics technologies were employed in order to monitor for differences in protein expression in a cohort of patients following IFX administration, aiming at identifying a panel of candidate protein biomarkers of CD, symptomatic of response to treatment. We enrolled 18 patients, who either had achieved clinical and serological remission (Rm, n=6), or response (Rs, n=6) and/or were PNRs (n=6), to IFX. Serum samples were subjected to two-dimensional Gel Electrophoresis. Following evaluation of densitometrical data, protein spots exhibiting differential expression among the groups, were further characterized by MALDI-TOF-MS. Identified proteins where evaluated by immunoblot analysis while functional network association was carried out to asses significance. Proteins apolipoprotein A-I (APOA1), apolipoprotein E (APOE), complement C4-B (CO4B), plasminogen (PLMN), serotransferrin (TRFE), beta-2-glycoprotein 1 (APOH), and clusterin (CLUS) were found to be up-regulated in the PNR and Rs groups whereas their levels displayed no changes in the Rm group when compared to baseline samples. Additionally, leucine-rich alpha-2-glycoprotein (A2GL), vitamin D-binding protein (VTDB), alpha-1B-glycoprotein (A1BG) and complement C1r subcomponent (C1R) were significantly increased in the serum of the Rm group. Through the incorporation of proteomics technologies, novel serum marker-molecules demonstrating high sensitivity and specificity are introduced, hence offering an innovative approach regarding the evaluation of CD patients' response to IFX therapy.