title: Increased serum levels of S100A12 in patients with MPO-ANCA-associated glomerulonephritis.
abstract: BACKGROUND
  Increased serum levels of S100A12, a proinflammatory protein secreted by activated neutrophils, have recently been shown in patients with active inflammatory diseases, such as rheumatoid arthritis and Kawasaki disease. In this study, we investigated serum levels of S100A 12 in patients with small-vessel vasculitis, myeloperoxidase anti-neutrophil cytoplasmic antibodies- (MPO-ANCA) associated pauci-immune glomerulonephritis.
  
  
  METHODS
  Serum S100A12 concentrations were measured by a sandwich enzyme-linked immunosorbent assay (ELISA) in 46 patients with MPO-ANCA-associated glomerulonephritis and 29 healthy controls. We analyzed correlations between serum S100A12 levels and a clinical index of vasculitis activity, the Birmingham Vasculitis Activity Score (BVAS), various laboratory parameters, and pathological activity scores in the patients. We also analyzed changes of serum S100A12 levels in 10 patients after treatment.
  
  
  RESULTS
  ELISA showed about 4-fold higher levels of serum S100A12 in patients with MPO-ANCA-associated glomerulonephritis than healthy controls. Serum S100A12 levels correlated with the BVAS scores, the peripheral white blood cell count, levels of serum C-reactive protein and creatinine, and pathological activity scores in the patients, but did not correlate with serum MPO-ANCA titers. Serum S100A12 levels after treatment decreased in all the 10 patients examined.
  
  
  CONCLUSIONS
  We demonstrated that increased serum S100A12 levels correlate with clinical, laboratory and pathological parameters of disease activity in patients with MPO-ANCA-associated glomerulonephritis. Serum S100A12 level may be one of the useful markers of disease activity in MPO-ANCA-associated glomerulonephritis.
authors.affiliation: Third Department of Internal Medicine, Akita University School of Medicine, Akita, Japan. komatsud@med.akita-u.ac.jp
authors.forename: A
authors.initials: A
authors.lastname: Komatsuda
authors.forename: H
authors.initials: H
authors.lastname: Ohtani
authors.forename: H
authors.initials: H
authors.lastname: Wakui
authors.forename: K A
authors.initials: KA
authors.lastname: Chyzh
authors.forename: T
authors.initials: T
authors.lastname: Hatakeyama
authors.forename: K
authors.initials: K
authors.lastname: Iwamoto
authors.forename: N
authors.initials: N
authors.lastname: Maki
authors.forename: T
authors.initials: T
authors.lastname: Kimura
authors.forename: J
authors.initials: J
authors.lastname: Hitomi
authors.forename: K
authors.initials: K
authors.lastname: Sawada
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000097:blood; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005921:Glomerulonephritis / Q000097:blood* / Q000201:enzymology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009195:Peroxidase / Q000097:blood; D009418:S100 Proteins / Q000097:blood*; D000067616:S100A12 Protein
chemical_list: D019268:Antibodies, Antineutrophil Cytoplasmic; D015415:Biomarkers; D009418:S100 Proteins; D000067616:S100A12 Protein; C090441:S100A12 protein, human; D009195:Peroxidase