title: A multicentric evaluation of IDMS-traceable creatinine enzymatic assays.
abstract: Chronic kidney disease definition is based on glomerular filtration rate (GFR) estimations which are derived from creatinine-based equations. The accuracy of GFR estimation is thus largely dependent of those of serum creatinine assays. International recommendations highlight the need for traceable creatinine assays. The French Society of Clinical Biochemistry conducted a study for measuring accuracy of creatinine enzymatic methods. This evaluation involved 25 clinical laboratories. Creatinine was measured in serum pools ranging from 35.9±0.9 μmol/L to 174.5±3.1 μmol/L (IDMS determination) using 12 creatinine enzymatic methods. For all creatinine values greater than 74.4±1.4 μmol/L, the bias and imprecision did not exceed 5% and 5.9%, respectively. For the lowest value (35.9±0.9 μmol/L), the bias ranged from -1.8 to 9.9% (with one exception). At this level, the imprecision ranged from 1.9 to 7.8%. The true performances of the assays (couples of bias and relative standard deviation), were evaluated using Monte-Carlo simulations. Most of the assays fall within the maximum Total Error of 12% at all concentrations. This study demonstrates substantial improvements in the calibration, traceability and precision of the enzymatic methods, reaching the NKDEP recommendations. Moreover, most of these assays allowed accurate creatinine measurements for creatinine levels lower than 40 μmol/L.
authors.affiliation: Biochimie Métabolique, Groupe Hospitalier Pitié-Salpêtrière, APHP, Paris, France.
authors.forename: Laurence
authors.initials: L
authors.lastname: Piéroni
authors.forename: Pierre
authors.initials: P
authors.lastname: Delanaye
authors.forename: Anne
authors.initials: A
authors.lastname: Boutten
authors.forename: Anne-Sophie
authors.initials: AS
authors.lastname: Bargnoux
authors.forename: Eric
authors.initials: E
authors.lastname: Rozet
authors.forename: Vincent
authors.initials: V
authors.lastname: Delatour
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Carlier
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Hanser
authors.forename: Etienne
authors.initials: E
authors.lastname: Cavalier
authors.forename: Marc
authors.initials: M
authors.lastname: Froissart
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Cristol
mesh_terms: D002138:Calibration; D003404:Creatinine / Q000097:blood*; D005919:Glomerular Filtration Rate; D006801:Humans; D009010:Monte Carlo Method; D015203:Reproducibility of Results
chemical_list: D003404:Creatinine