title: Soluble transferrin receptor in urine, a new biomarker for IgA nephropathy and Henoch-Schönlein purpura nephritis.
abstract: OBJECTIVE
  IgA nephropathy (IgAN) and Henoch-Schönlein purpura nephritis (HSPN) might represent different ends of a continuous spectrum of glomerular disease. In both conditions, upregulated soluble transferrin receptor (sTfR) might be excreted in urine, which could be a potential biomarker to monitor disease activity and therapeutic response.
  
  
  METHODS
  In this pilot study, 132 Caucasian patients consulting the Nephrology Department at the Ghent University Hospital because of a glomerulopathy and 50 normal controls were included. Urinary sTfR concentrations were determined in concentrated urine using a newly developed latex-enhanced immunonephelometric assay.
  
  
  RESULTS
  Median urinary sTfR concentration was higher in patients with a primary glomerulopathy than in healthy subjects (p<0.0001). More importantly, absolute median levels of urinary sTfR were markedly higher in patients with active IgAN or HSPN [10μg/L, 95% confidence interval (CI): 6-18μg/L] in comparison with those with other morphological types of glomerulopathy (2μg/L, 95%CI: 1-4μg/L) (p<0.0001). A statistically significant difference in urinary sTfR concentration was observed between patients with active IgAN or HSPN and patients who had achieved partial or complete remission (p<0.0001). Multiple regression analysis with urinary sTfR as dependent variable revealed that proteinuria was the main predictor of urinary sTfR concentration (r(2)=0.52, p<0.001).
  
  
  CONCLUSIONS
  Determination of sTfR in urine is a new and sensitive method for a potential biomarker of IgAN and HSPN.
authors: Department of Clinical Chemistry, Ghent University Hospital, Gent, Belgium.
authors: Sigurd E
authors: SE
authors: Delanghe
authors: Marijn M
authors: MM
authors: Speeckaert
authors: Hannah
authors: H
authors: Segers
authors: Kaat
authors: K
authors: Desmet
authors: Johan
authors: J
authors: Vande Walle
authors: Steven Van
authors: SV
authors: Laecke
authors: Raymond
authors: R
authors: Vanholder
authors: Joris R
authors: JR
authors: Delanghe
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000652:urine*; D005260:Female; D005922:Glomerulonephritis, IGA / Q000150:complications / Q000652:urine*; D006801:Humans; D011695:IgA Vasculitis / Q000150:complications / Q000652:urine*; D008297:Male; D008875:Middle Aged; D009393:Nephritis / Q000209:etiology; D011507:Proteinuria / Q000175:diagnosis*; D011990:Receptors, Transferrin / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D011990:Receptors, Transferrin