Assay of bradykinin metabolites in human body fluids by CE-LIF coupled with transient ITP preconcentration

Contact System Activation and Bradykinin Generation in Angioedema: Laboratory Assessment and Biomarker Utilization

The role of contact system activation has been clearly established in the pathogenesis of hereditary angioedema due to C1 inhibitor deficiency (HAE-C1INH). C1 inhibitor (C1INH)-protease complexes, levels of functional C1INH, plasma kallikrein activation, and cleavage of high-molecular-weight kininogen have each been associated with disease activity. More recently, HAE with normal levels of C1INH (HAE-nl-C1INH) has been recognized. Six genetic mutations have been identified which are linked to HAE-nl-C1INH phenotypes. The majority of individuals with HAE-nl-C1INH fall into the unknown category. There is substantial evidence that bradykinin generation underlies the recurrent attacks of swelling in some of these cohorts.

Study on urinary profile of inborn errors of metabolism by 18-crown-6 modified capillary electrophoresis with laser-induced fluorescence detection

Newborn screening in urine is important for the diagnosis of many inborn errors of metabolism (IEM). Capillary electrophoresis with laser-induced fluorescence detection (CE-LIF) is a major technological advance in screening IEM. It has the advantage of sensitive and simultaneous multiple disease screening with minimal sample requirement. The analytes were derivatized with fluorescein isothiocyanate (FITC) prior to CE-LIF analysis. In urine samples, free amino acids (AAs) were well separated from other coexisting components, exhibiting a linear calibration over the concentration range 0.01-5.0μmol/L with the limits of detection (LODs) ranging from 0.005 to 0.010μmol/L. The relative standard deviations (RSDs) were in the range 0.1-1.0% for peak area, and 0.2-1.0% for migration time, respectively. Under optimized conditions, the method presented here has been successfully used for the simultaneous and sensitive analysis of seven AAs in urine samples of newborn babies, and evaluating the effect of therapy as well.

Contribution of CE to the analysis of protein or peptide biomarkers

Biomarker analysis is pivotal for disease diagnosis and one important class of biomarkers is constituted by proteins and peptides. This review focuses on protein and peptide analyses from biological fluids performed by capillary electrophoresis. The various strategies that have been reported to prevent difficulties due to the handling of real samples are described. Innovative techniques to overcome the complexity of the sample, to prevent the adsorption of the analytes on the inner capillary wall, and to increase the sensibility of the analysis are summarized and illustrated by different applications. To fully illustrate the contribution of CE to the analysis of biomarkers from human sample, two detailed protocols are given: the analysis from CSF of five amyloid peptide, biomarkers of the Alzheimer disease, and the analysis of sialoforms of transferrin from human serum.