title: Correlation of serum levels of complement C4a desArg with pathologically estimated severity of glomerular lesions and mesangial hypercellularity scores in patients with IgA nephropathy.
abstract: The aim of the present study was to explore serum biomarkers for the pathology of IgA nephropathy using serum proteomics. The subjects were 57 patients with IgA nephropathy who were divided into two groups (group 1, n=25; group 2, n=32) and 14 healthy controls. Serum protein profiles were analyzed using the ProteinChip surface-enhanced laser desorption ionization (SELDI) system. Associations between signal intensities of proteins and histological findings in patients with IgA nephropathy were studied in group 1. Serum levels of a candidate biomarker protein (complement component C4a desArg) for IgA nephropathy were determined by enzyme linked-immunosorbent assay (ELISA) in group 2 and the relationships of these levels with histological findings were evaluated. There were significant differences in 93 protein signals between patients in group 1 and controls. Among these signals, 3 proteins at 8592, 8757 and 8806 m/z were significantly correlated with the severity of glomerular lesions. The protein at 8592 m/z was identified as C4a desArg and the signal intensity of 8592 m/z was strongly correlated with serum C4a levels, including C4a desArg, determined by ELISA. In addition, the serum levels of C4a (mainly C4a desArg) were significantly higher in patients in group 2 compared to controls and were correlated with the severity of glomerular lesions and with mesangial hypercellularity scores. In conclusion, the serum levels of complement C4a desArg are significantly higher in patients with IgA nephropathy compared to healthy controls and are significantly correlated with the severity of glomerular lesions and mesangial hypercellularity scores. Thus, serum C4a desArg is a potential biomarker for the severity of histological findings in patients with IgA nephropathy.
authors.affiliation: Digestive and Lifestyle Diseases, Department of Human and Environmental Sciences, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890-8544, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Sogabe
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Uto
authors.forename: Shuji
authors.initials: S
authors.lastname: Kanmura
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Nosaki
authors.forename: Miki
authors.initials: M
authors.lastname: Oyamada
authors.forename: Koki
authors.initials: K
authors.lastname: Tokunaga
authors.forename: Chika
authors.initials: C
authors.lastname: Nishida
authors.forename: Mayumi
authors.initials: M
authors.lastname: Fukumoto
authors.forename: Manei
authors.initials: M
authors.lastname: Oku
authors.forename: Kiichiro
authors.initials: K
authors.lastname: Nishimoto
authors.forename: Shozo
authors.initials: S
authors.lastname: Takenouchi
authors.forename: Akio
authors.initials: A
authors.lastname: Ido
authors.forename: Yuko
authors.initials: Y
authors.lastname: Shimada
authors.forename: Hirohito
authors.initials: H
authors.lastname: Tsubouchi
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D015934:Complement C4a / Q000276:immunology / Q000378:metabolism*; D005260:Female; D005920:Glomerular Mesangium / Q000276:immunology / Q000473:pathology*; D005922:Glomerulonephritis, IGA / Q000097:blood* / Q000276:immunology / Q000473:pathology*; D006801:Humans; D007678:Kidney Glomerulus / Q000276:immunology / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D055815:Young Adult
chemical_list: D015415:Biomarkers; C051066:complement C4a, des-Arg; D015934:Complement C4a