title: Absence of increased alpha1-microglobulin in IgA nephropathy proteinuria.
abstract: To search for biomarkers of IgA nephropathy, protein profiles of urine samples from patients with IgA nephropathy and normal volunteers were compared using two-dimensional DIGE. Most of the 172 spots identified in the urine were serum proteins, and their amounts in IgA nephropathy urine were much higher than those in normal urine; this can be explained as proteinuria caused by glomerular dysfunction. However, only alpha(1)-microglobulin, also one of the major serum proteins, in IgA nephropathy urine was not higher in amount than that in normal urine. We confirmed using ELISA analysis that the amounts of transferrin and albumin in IgA nephropathy and diabetic nephropathy urine were much higher than those in normal urine, whereas the amount of alpha(1)-microglobulin in IgA nephropathy urine was not higher than that in normal urine and was much lower than that in diabetic nephropathy urine. Approximately 50% of alpha(1)-microglobulin forms a complex with IgA in serum. These results suggest that alpha(1)-microglobulin in IgA nephropathy urine is a characteristic protein and might be a biomarker for IgA nephropathy and that alpha(1)-microglobulin might have a relationship with IgA nephropathy pathology.
authors.affiliation: Astellas Pharm Inc., 21 Miyukigaoka, Tsukuba-shi 305-8585, Japan. hiroyuki.yokota@jp.astellas.com
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yokota
authors.forename: Masashi
authors.initials: M
authors.lastname: Hiramoto
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Okada
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Kanno
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Yuri
authors.forename: Shuji
authors.initials: S
authors.lastname: Morita
authors.forename: Masanori
authors.initials: M
authors.lastname: Naitou
authors.forename: Atsushi
authors.initials: A
authors.lastname: Ichikawa
authors.forename: Masao
authors.initials: M
authors.lastname: Katoh
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Suzuki
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000418:Albumins / Q000302:isolation & purification; D000510:Alpha-Globulins / Q000302:isolation & purification / Q000652:urine*; D015415:Biomarkers / Q000652:urine; D016022:Case-Control Studies; D002648:Child; D015180:Electrophoresis, Gel, Two-Dimensional; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005914:Globins / Q000302:isolation & purification / Q000652:urine; D005922:Glomerulonephritis, IGA / Q000652:urine*; D006801:Humans; D008297:Male; D008875:Middle Aged; D040081:Protein Array Analysis; D011507:Proteinuria / Q000652:urine; D040901:Proteomics; D012177:Retinol-Binding Proteins / Q000302:isolation & purification / Q000652:urine; D054839:Retinol-Binding Proteins, Plasma; D014168:Transferrin / Q000302:isolation & purification / Q000652:urine
chemical_list: D000418:Albumins; D000510:Alpha-Globulins; D015415:Biomarkers; C101326:RBP4 protein, human; D012177:Retinol-Binding Proteins; D054839:Retinol-Binding Proteins, Plasma; D014168:Transferrin; C016001:alpha-1-microglobulin; D005914:Globins