Variation in the serum creatinine assay calibration: A practical application to glomerular filtration rate estimation

Murthy, K. Krishna; Stevens, Lesley A.; Stark, Paul C.; Levey, Andrew S.

doi:10.1111/j.1523-1755.2005.00608.x

Cited by 129 publications

(99 citation statements)

References 14 publications

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“…The impact of the calibration on the MDRD results is far from negligible, especially in the high GFR range [7,9,[17][18][19]. The MDRD study equation has even been modified to be useful with IDMS traceable creatinine [13,15].…”

Section: Discussionmentioning

confidence: 99%

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A multicentric evaluation of IDMS-traceable creatinine enzymatic assays

Piéroni

Delanaye

Boutten³

et al. 2011

Clinica Chimica Acta

109

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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.

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Section: Discussionmentioning

confidence: 99%

“…The calibration of sCr methods improved the accuracy of GFR estimation and Murthy et al recommended that the GFR would be estimated below 60 mL/min/1.73 m 2 only, unless the method has been calibrated [9].…”

Section: Introductionmentioning

confidence: 99%

A multicentric evaluation of IDMS-traceable creatinine enzymatic assays

Piéroni

Delanaye

Boutten³

et al. 2011

Clinica Chimica Acta

109

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“…While, extensive evaluation of the MDRD Study equation showed good performance in populations with lower levels of GFR but variable performance in those with higher levels [17]. Variability among clinical laboratories in calibration of Scr assays [18] introduces error in GFR estimates, especially at high levels of GFR [19]. Thus, the National Kidney Disease Education Program (NKDEP) has initiated a creatinine standardization program to improve and normalize Scr results used in estimating equations [14].…”

Section: Discussionmentioning

confidence: 99%

Underestimation of Impaired Kidney Function with Serum Creatinine

2010

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Serum creatinine (SCr) levels are frequently used as a screening test to assess impaired renal function; however, patients can have significantly decreased glomerular filtration rate (GFR) with normal SCr values and making the recognition of kidney dysfunction more difficult. Hence, this study was designed to determine the extent of misclassification of the patients who have significantly reduced GFR as calculated by reexpressed four variable modification of diet in renal disease (MDRD) equation but, normal range of SCr. The study included 1040 in and out patients referred by physicians for serum creatinine measurement. When an exclusion criterion was applied 928 patients were qualified for the study. SCr was measured in 928 patients by a Roche kinetic compensated Jaffe's assay. GFR was calculated using reexpressed four variable MDRD study equation. Of the 928 patients 270 (29.1%) had renal dysfunction on the basis of eGFR (\60 ml/min/1.73 m 2 ). However, with SCr only 162 (17.5%) patients had abnormal renal function ([1.5 mg/dl) and SCr values misrepresented (108) 11.6% patients with impaired kidney function. In addition, more females, about 15% were failed to detect by SCr method in contrast to males of 9%. This study documented that, a large proportion of patients with impaired renal function are not diagnosed if clinicians rely solely on normal SCr as evidence of normal renal function. Inclusion of eGFR calculated by re-expressed 4 variable MDRD equation may facilitates the early identification and intervention of patients with renal impairment.

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“…Underestimation of higher GFR levels with overestimation of CKD has been observed [3]. Underestimation of iGFR has been attributed to inaccuracies of measurement, and greater variability in creatinine concentration due to non-renal factors in patients without CKD [4][5][6].…”

Section: Discussionmentioning

confidence: 99%

“…Serum creatinine is a critical variable for MDRD-calculated eGFR. Currently great interlaboratory variability exists in the measurement and calibration of creatinine [4,5]. This variability introduces error into GFR estimates, which has greatest impact at creatinine concentrations within the normal range; this is particularly important when attempting to detect early decline in GFR [4].…”

Section: Introductionmentioning

confidence: 99%

Performance of the revised ‘175’ Modification of Diet in Renal Disease equation in patients with type 2 diabetes

et al. 2008

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Aims/hypothesis Estimation of GFR (eGFR) is recommended for the assessment of kidney function in all patients with diabetes. We studied performance of the traditional '186' Modification of Diet in Renal Disease (MDRD) equation, and the 2005 revised '175' MDRD equation in patients with type 2 diabetes. Methods Two hundred and ninety-three mainly normoalbuminuric (267/293) patients were recruited. Patients were classified as having mild renal impairment (group 1, GFR <90 ml min −1 1.73 m −2 ) or normal renal function (group 2, GFR ≥90 ml min −1 1.73 m −2 ). eGFR was calculated by the traditional 186 MDRD equation using traditional creatinine values and the revised 175 MDRD equation using isotope dilution mass spectrometry-standardised creatinine values. Isotopic GFR was measured by the four-sample plasma clearance of 51 Cr-EDTA. Results For patients in group 1, mean±SD isotopic 51 Cr-EDTA GFR (iGFR) was 83.8±4.3 ml min −1 1.73 m −2 , and eGFR was 73.2±11.9 and 75.8±13.7 ml min −1 1.73 m −2 using the 186 and 175 MDRD equations, respectively. Method bias was −10.6 with the 186 MDRD and −7.9 ml min −1 1.73 m −2 (p<0.05) with the 175 MDRD equation. In group 2, iGFR was 119.4±20.2 ml min −1 1.73 m −2 , and eGFR was 92.3±18.6 and 97.5±21.6 ml min −1 1.73 m −2 using the 186 and 175 MDRD equations, respectively. Method bias was −27.1 with the 186 MDRD equation and −21.9 ml min −1 1.73 m −2 (p<0.05) with the 175 MDRD equation. Conclusions/interpretation In patients newly diagnosed with type 2 diabetes, the revised 175 MDRD equation was less biased than the traditional 186 MDRD equation. Despite a continued tendency to underestimate isotopically measured GFR, use of standardised creatinine values is a positive step towards improved estimation of GFR.

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Variation in the serum creatinine assay calibration: A practical application to glomerular filtration rate estimation

Cited by 129 publications

References 14 publications

A multicentric evaluation of IDMS-traceable creatinine enzymatic assays

A multicentric evaluation of IDMS-traceable creatinine enzymatic assays

Underestimation of Impaired Kidney Function with Serum Creatinine

Performance of the revised ‘175’ Modification of Diet in Renal Disease equation in patients with type 2 diabetes

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