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Background and Objective: Endothelial dysfunction in diabetes mellitus (DM) is an important factor in the pathogenesis of micro and macrovascular complications. We aimed to measure soluble endothelial protein C receptor (sEPCR) and high sensitivity C reactive protein (hsCRP) levels as markers of endothelial damage in both types of diabetes mellitus and to determine if they can be used as predictors of vascular complications., Methods: Fifty patients with DM, 20 with type 1 and 30 with type 2 as well as 30 healthy subjects were included. All were subjected to measurement of sEPCR and hsCRP by enzyme linked immunosorbent assay., Results: sEPCR and hsCRP were significantly increased when compared to the control group in both types of DM. sEPCR was a significant predictor of macrovascular complications and thrombosis in type 1 p=0.02, and p=0.015, respectively. hsCRP was a significant predictor of macrovascular complications in type 2 p=0.04., Conclusion: Patients with type 1 and type 2 DM exhibit higher sEPCR and hsCRP levels compared to healthy controls which suggesting endothelial damage. sEPCR could be used as a predictor of macrovascular complications and thrombosis in type 1 DM, whereas, hsCRP might be used as a predictor of macrovascular complications in type 2 DM., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

Libraries of random peptides displayed by bacteriophage can be screened to select phage expressing peptides that specifically bind antibodies, so that the peptide sequence motifs expressed by the phage can help to define the epitopes of the antibodies. It is often desirable to screen antibody-selected phage for binding of the selecting antibody in an immunoassay in order to verify the specificity of the interaction. Enzyme-linked immunosorbent assays (ELISAs) are commonly used for this purpose. However, for many antibodies, the best techniques for measuring specific, high affinity interactions are immuno-precipitation assays. Immuno-precipitation was therefore investigated as a means of measuring interactions between antibodies and phage clones selected from random peptide display libraries. Three mouse monoclonal antibodies specific for glutamic acid decarboxylase were used to select peptides as 9-mers on T7 phage, linear 12-mers on pIII of M13 phage, or constrained 15-mers on pVIII of M13 phage. Following the cloning and sequencing of selected phage, mixtures of antibody and phage were incubated in solution and the immune complexes were precipitated with Protein G bound to Sepharose beads. In order to detect and quantitate the phage that had formed immune complexes and been precipitated, advantage was taken of the biological properties of the phage by inducing infection of Escherichia coli by the precipitated phage. The aim was to quantitate the phage precipitated by determining the number of plaques produced, which would therefore be proportional to the degree of interaction between the phage and the antibody in solution. The results presented here indicate that this method of measuring monoclonal antibody interactions with phage selected for expression of peptides recognised by the monoclonal antibody is highly specific and sensitive.