title: Urinary FSP1 is a biomarker of crescentic GN.
abstract: Fibroblast-specific protein 1 (FSP1)-expressing cells accumulate in damaged kidneys, but whether urinary FSP1 could serve as a biomarker of active renal injury is unknown. We measured urinary FSP1 in 147 patients with various types of glomerular disease using ELISA. Patients with crescentic GN, with or without antinuclear cytoplasmic antibody-associated GN, exhibited elevated levels of urinary FSP1. This assay had a sensitivity of 91.7% and a specificity of 90.2% for crescentic GN in this sample of patients. Moreover, we found that urinary FSP1 became undetectable after successful treatment, suggesting the possible use of FSP1 levels to monitor disease activity over time. Urinary FSP1 levels correlated positively with the number of FSP1-positive glomerular cells, predominantly podocytes and cellular crescents, the likely source of urinary FSP1. Even in patients without crescent formation, patients with high levels of urinary FSP1 had large numbers of FSP1-positive podocytes. Taken together, these data suggest the potential use of urinary FSP1 to screen for active and ongoing glomerular damage, such as the formation of cellular crescents.
authors.affiliation: Division of Nephrology, Department of General Medicine, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193 Japan. miwano@u-fukui.ac.jp
authors.forename: Masayuki
authors.initials: M
authors.lastname: Iwano
authors.forename: Yukinari
authors.initials: Y
authors.lastname: Yamaguchi
authors.forename: Takaaki
authors.initials: T
authors.lastname: Iwamoto
authors.forename: Kimihiko
authors.initials: K
authors.lastname: Nakatani
authors.forename: Masaru
authors.initials: M
authors.lastname: Matsui
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kubo
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Akai
authors.forename: Toshio
authors.initials: T
authors.lastname: Mori
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Saito
mesh_terms: D015415:Biomarkers; D002135:Calcium-Binding Proteins / Q000097:blood / Q000652:urine*; D003404:Creatinine / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay; D005921:Glomerulonephritis / Q000175:diagnosis* / Q000652:urine; D006801:Humans; D000071999:S100 Calcium-Binding Protein A4; D012680:Sensitivity and Specificity
chemical_list: D015415:Biomarkers; D002135:Calcium-Binding Proteins; D000071999:S100 Calcium-Binding Protein A4; C077591:S100A4 protein, human; D003404:Creatinine
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