title: Alterations of retinol-binding protein 4 species in patients with different stages of chronic kidney disease and their relation to lipid parameters.
abstract: Retinol-binding protein 4 (RBP4) is elevated in patients with chronic kidney disease (CKD) and has been discussed as marker of kidney function. In addition to an elevated concentration, the existence of truncated RBP4 species, RBP4-L (truncated at last C-terminal leucine) and RBP4-LL (truncated at both C-terminal leucines), has been reported in serum of hemodialysis patients. Since little is known about the occurrence of RBP4 species during the progression of CKD it was the aim of this study to analyse this possible association. The presence of RBP4, RBP4-L, RBP4-LL and transthyretin (TTR) was assessed in serum of 45 healthy controls and 52 patients with stage 2-5 of CKD using ELISA and RBP4 immunoprecipitation with subsequent MALDI-TOF-MS analysis. A reduction of glomerular filtration rate was accompanied by a gradual elevation of RBP4 serum levels and relative amounts of RBP4-LL. Correlation analysis revealed a strong association of the RBP4-TTR ratio with parameters of lipid metabolism and with diabetes-related factors. In conclusion, RBP4 serum concentration and the appearance of RBP4-LL seem to be influenced by kidney function. Furthermore, the RBP4-TTR ratio may provide diagnostic potential with regard to metabolic complications in CKD patients.
authors.affiliation: Institute of Nutritional Science, University of Potsdam, 14558 Nuthetal Potsdam, Germany. henze@rz.uni-potsdam.de
authors.forename: Andrea
authors.initials: A
authors.lastname: Henze
authors.forename: Simone K
authors.initials: SK
authors.lastname: Frey
authors.forename: Jens
authors.initials: J
authors.lastname: Raila
authors.forename: Alexandra
authors.initials: A
authors.lastname: Scholze
authors.forename: Joachim
authors.initials: J
authors.lastname: Spranger
authors.forename: Martin O
authors.initials: MO
authors.lastname: Weickert
authors.forename: Martin
authors.initials: M
authors.lastname: Tepel
authors.forename: Walter
authors.initials: W
authors.lastname: Zidek
authors.forename: Florian J
authors.initials: FJ
authors.lastname: Schweigert
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood / Q000737:chemistry / Q000378:metabolism; D002908:Chronic Disease; D003920:Diabetes Mellitus / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D047468:Immunoprecipitation; D007674:Kidney Diseases / Q000097:blood* / Q000175:diagnosis / Q000503:physiopathology*; D050356:Lipid Metabolism; D008297:Male; D008875:Middle Aged; D011228:Prealbumin / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D054839:Retinol-Binding Proteins, Plasma / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D055815:Young Adult
chemical_list: D015415:Biomarkers; D011228:Prealbumin; C101326:RBP4 protein, human; D054839:Retinol-Binding Proteins, Plasma