[en] 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.
Laboratory medicine & medical technology
Author, co-author :
DELANAYE, Pierre ; Centre Hospitalier Universitaire de Liège - CHU > Néphrologie
Rozet, Eric ; Université de Liège - ULiège > Département de pharmacie > Chimie analytique
CAVALIER, Etienne ; Centre Hospitalier Universitaire de Liège - CHU > Chimie médicale
A multicentric evaluation of IDMS-traceable creatinine enzymatic assays
National Kidney Foundation K/DOQI clinical practice guidelines for chronic kidney disease: evaluation, classification, and stratification. Am J Kidney Dis 2002, 39:S1-S266.
Levey A.S., Eckardt K.U., Tsukamoto Y., et al. Definition and classification of chronic kidney disease: a position statement from Kidney Disease: Improving Global Outcomes (KDIGO). Kidney Int 2005, 67:2089-2100.
Coresh J., Eknoyan G., Levey A.S. Estimating the prevalence of low glomerular filtration rate requires attention to the creatinine assay calibration. J Am Soc Nephrol 2002, 13:2811-2812.
Seronie-Vivien S., Galteau M.M., Carlier M.C., et al. Impact of standardized calibration on the inter-assay variation of 14 automated assays for the measurement of creatinine in human serum. Clin Chem Lab Med 2005, 43:1227-1233.
Miller W.G., Myers G.L., Ashwood E.R., et al. Creatinine measurement: state of the art in accuracy and interlaboratory harmonization. Arch Pathol Lab Med 2005, 129:297-304.
Delanghe J.R., Cobbaert C., Galteau M.M., et al. Trueness verification of actual creatinine assays in the European market demonstrates a disappointing variability that needs substantial improvement. An international study in the framework of the EC4 creatinine standardization working group. Clin Chem Lab Med 2008, 46:1319-1325.
Myers G.L., Miller W.G., Coresh J., et al. Recommendations for improving serum creatinine measurement: a report from the laboratory working group of the national kidney disease education program. Clin Chem 2006, 52:5-18.
Dodder N.G., Tai S.S., Sniegoski L.T., Zhang N.F., Welch M.J. Certification of creatinine in a human serum reference material by GC-MS and LC-MS. Clin Chem 2007, 53:1694-1699.
Murthy K., Stevens L.A., Stark P.C., Levey A.S. Variation in the serum creatinine assay calibration: a practical application to glomerular filtration rate estimation. Kidney Int 2005, 68:1884-1887.
Cobbaert C.M., Baadenhuijsen H., Weykamp C.W. Prime time for enzymatic creatinine methods in pediatrics. Clin Chem 2009, 55:549-558.
Panteghini M. Enzymatic assays for creatinine: time for action. Scand J Clin Lab Invest Suppl 2008, 241:84-88.
Thienpont L.M., Van Landuyt K.G., Stockl D., De Leenheer A.P. Candidate reference method for determining serum creatinine by isocratic HPLC: validation with isotope dilution gas chromatography-mass spectrometry and application for accuracy assessment of routine test kits. Clin Chem 1995, 41:995-1003.
Levey A.S., Coresh J., Greene T., et al. Using standardized serum creatinine values in the modification of diet in renal disease study equation for estimating glomerular filtration rate. Ann Intern Med 2006, 145:247-254.
Levey A.S., Stevens L.A., Hostetter T. Automatic reporting of estimated glomerular filtration rate-just what the doctor ordered. Clin Chem 2006, 52:2188-2193.
Levey A.S., Coresh J., Greene T., et al. Expressing the modification of diet in renal disease study equation for estimating glomerular filtration rate with standardized serum creatinine values. Clin Chem 2007, 53:766-772.
Stevens L.A., Manzi J., Levey A.S., et al. Impact of creatinine calibration on performance of GFR estimating equations in a pooled individual patient database. Am J Kidney Dis 2007, 50:21-35.
Delanaye P., Cavalier E., Chapelle J.P., Krzesinski J.M. Importance of the creatinine calibration in the estimation of GFR by MDRD equation. Nephrol Dial Transplant 2006, 21:1130.
Lawson N., Lang T., Broughton A., Prinsloo P., Turner C., Marenah C. Creatinine assays: time for action?. Ann Clin Biochem 2002, 39:599-602.
Van Biesen W., Vanholder R., Veys N., et al. The importance of standardization of creatinine in the implementation of guidelines and recommendations for CKD: implications for CKD management programmes. Nephrol Dial Transplant 2005, 21:77-83.
Levey A.S., Stevens L.A., Schmid C.H., et al. A new equation to estimate glomerular filtration rate. Ann Intern Med 2009, 150:604-612.
Kytzia H.J. How to implement traceability of creatinine results: a manufacturer's experience. Scand J Clin Lab Invest Suppl 2008, 241:64-66.
Myers G.L. Standardization of serum creatinine measurement: theory and practice. Scand J Clin Lab Invest Suppl 2008, 241:57-63.
Stockl D., Libeer J.C., Reinauer H., Thienpont L.M., De Leenheer A.P. Accuracy-based assessment of proficiency testing results with serum from single donations: possibilities and limitations. Clin Chem 1996, 42:469-470.
Carobene A., Ferrero C., Ceriotti F., et al. Creatinine measurement proficiency testing: assignment of matrix-adjusted ID GC-MS target values. Clin Chem 1997, 43:1342-1347.