title: LC-QTOF-MS-based targeted metabolomics of arginine-creatine metabolic pathway-related compounds in plasma: application to identify potential biomarkers in pediatric chronic kidney disease.
abstract: Chronic kidney disease (CKD) is a major epidemiologic problem which causes several disturbances in adults and in pediatrics. Despite being a worldwide public health problem, information available for CKD in the pediatric population is scarce. For that reason, an ion-pair reversed-phase liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) method has been developed and validated in order to analyze 16 amino acids, amino acid derivatives, and analogous compounds related to the arginine-creatine metabolic pathway that are suspicious of being increased or decreased in plasma from patients with CKD. The analytical method involved the addition of dithiothreitol, a reducing agent which reduces disulfide and thus giving total aminothiol concentration, as well as a simple precipitation of plasma proteins. Moreover, despite amino acids being usually derivatized to improve their retention time and to enhance their signal, for this method, an ion-pairing reagent was used, thus avoiding the need for derivatization. Subsequently, analysis of plasma from pediatric patients suffering from CKD and control pediatrics was carried out. As a result, glycine, citrulline, creatinine, asymmetric dimethylarginine (ADMA), and symmetric dimethylarginine (SDMA) were significantly increased in patients with CKD, regardless of their creatinine level, whereas in addition to these compounds dimethylglycine was also increased when CKD patients had plasma creatinine concentrations above 12 μg mL(-1), thus all are suggested as potential biomarkers for renal impairment.
authors.affiliation: Department of Analytical Chemistry, Faculty of Pharmacy, University of the Basque Country (UPV/EHU), Paseo de la Universidad 7, 01006, Vitoria-Gasteiz, Spain.
authors.forename: Sandra
authors.initials: S
authors.lastname: Benito
authors.affiliation: Central Service of Analysis (SGiker), University of the Basque Country (UPV/EHU), Paseo de la Universidad 7, 01006, Vitoria-Gasteiz, Spain.
authors.forename: Alicia
authors.initials: A
authors.lastname: Sánchez
authors.affiliation: Department of Analytical Chemistry, Faculty of Pharmacy, University of the Basque Country (UPV/EHU), Paseo de la Universidad 7, 01006, Vitoria-Gasteiz, Spain.
authors.forename: Nora
authors.initials: N
authors.lastname: Unceta
authors.affiliation: Group of Metabolism, BioCruces Health Research Institute, CIBER de Enfermedades Raras (CIBERER), Plaza de Cruces 12, 48903, Barakaldo, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Andrade
authors.affiliation: Group of Metabolism, BioCruces Health Research Institute, CIBER de Enfermedades Raras (CIBERER), Plaza de Cruces 12, 48903, Barakaldo, Spain.
authors.forename: Luis
authors.initials: L
authors.lastname: Aldámiz-Echevarria
authors.affiliation: Department of Analytical Chemistry, Faculty of Pharmacy, University of the Basque Country (UPV/EHU), Paseo de la Universidad 7, 01006, Vitoria-Gasteiz, Spain.
authors.forename: M Aránzazu
authors.initials: MA
authors.lastname: Goicolea
authors.affiliation: Department of Analytical Chemistry, Faculty of Pharmacy, University of the Basque Country (UPV/EHU), Paseo de la Universidad 7, 01006, Vitoria-Gasteiz, Spain. r.barrio@ehu.es.
authors.forename: Ramón J
authors.initials: RJ
authors.lastname: Barrio
mesh_terms: D000293:Adolescent; D000328:Adult; D001120:Arginine / Q000097:blood* / Q000378:metabolism; D015415:Biomarkers / Q000097:blood; D002648:Child; D002675:Child, Preschool; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003401:Creatine / Q000097:blood* / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D013058:Mass Spectrometry / Q000379:methods*; D055432:Metabolomics / Q000379:methods*; D051436:Renal Insufficiency, Chronic / Q000097:blood* / Q000378:metabolism
chemical_list: D015415:Biomarkers; D001120:Arginine; D003401:Creatine
keywords: Arginine-creatine metabolic pathway; Biomarkers; Chronic kidney disease (CKD); LC-QTOF-MS; Plasma