title: Accuracy of GFR predictive equations using ID-MS traceable creatinine: compensated Jaffe and enzymatic.
abstract: BACKGROUND
  New ID-MS traceable creatinine kits including enzymatic creatinine (e-creat) and compensated Jaffe (j-creat) has been developed by Olympus.
  
  
  METHODS
  Analytical performances of these reagents were tested on an AU 640 analyzer. A comparison study was performed against the method used in our laboratory (Randox creatinine enzymatic). Values of the glomerular filtration rate estimated (eGFR) from ID-MS traceable equation were compared to the GFR measured (mGFR) by a reference isotope method in a kidney transplant cohort.
  
  
  RESULTS
  Total intra- and inter-assay variation coefficients were below 4%. Creatinine values were correlated with the Randox enzymatic method (e-creat = 0.98 Randox - 0.48 and j-creat = 0.99 Randox - 1.44, r2 = 0.98). Values of eGFR obtained with both e-creat and j-creat were well correlated to mGFR in our population of renal transplants.
  
  
  CONCLUSIONS
  The new ID-MS traceable methods improved estimation of GFR by predictive equations. However, the limitation of the Jaffe method in specific populations such as paediatric and elderly patients needs further investigations.
authors.affiliation: Department of Biochemistry, University of Montpellier 1, Montpellier, France.
authors.forename: Anne-Sophie
authors.initials: AS
authors.lastname: Bargnoux
authors.forename: Noémie
authors.initials: N
authors.lastname: Simon
authors.forename: Valérie
authors.initials: V
authors.lastname: Garrigue
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Dupuy
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Badiou
authors.forename: Georges
authors.initials: G
authors.lastname: Mourad
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Cristol
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D016477:Artifacts; D003124:Colorimetry / Q000379:methods; D003404:Creatinine / Q000097:blood*; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007668:Kidney / Q000503:physiopathology*; D016030:Kidney Transplantation; D008297:Male; D013058:Mass Spectrometry / Q000379:methods; D008875:Middle Aged; D011865:Radioisotope Dilution Technique; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D011933:Reagent Kits, Diagnostic; D015203:Reproducibility of Results; D012727:Sex Characteristics; D016284:Technetium Tc 99m Pentetate / Q000493:pharmacokinetics
chemical_list: D019275:Radiopharmaceuticals; D011933:Reagent Kits, Diagnostic; D003404:Creatinine; D016284:Technetium Tc 99m Pentetate