scholarly journals State of the Art for Measurement of Urine Albumin: Comparison of Routine Measurement Procedures to Isotope Dilution Tandem Mass Spectrometry

2014 ◽  
Vol 60 (3) ◽  
pp. 471-480 ◽  
Author(s):  
Lorin M Bachmann ◽  
Goran Nilsson ◽  
David E Bruns ◽  
Matthew J McQueen ◽  
John C Lieske ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Isotope Dilution ◽  
State Of The Art ◽  
Total Error ◽  
Isotope Dilution Mass Spectrometry ◽  
Urine Albumin ◽  
Routine Measurement ◽  
Concentration Interval ◽  
High Concentrations ◽  
Instructions For Use

Abstract BACKGROUND Urine albumin is the primary biomarker for detection and monitoring of kidney damage. Because fixed decision criteria are used to identify patients with increased values, we investigated if commonly used routine measurement procedures gave comparable results. METHODS Results from 17 commercially available urine albumin measurement procedures were investigated vs an isotope dilution mass spectrometry (IDMS) procedure. Nonfrozen aliquots of freshly collected urine from 332 patients with chronic kidney disease, diabetes, cardiovascular disease, and hypertension were distributed to manufacturers to perform urine albumin measurements according to the respective instructions for use for each procedure. Frozen aliquots were used for measurements by the IDMS procedure. An error model was used to determine imprecision and bias components. RESULTS Median differences between the largest positive and negative biases vs IDMS were 45%, 37%, and 42% in the concentration intervals of 12–30 mg/L, 31–200 mg/L, and 201–1064 mg/L, respectively. Biases varied with concentration for most procedures and exceeded ±10% over the concentration interval for 14 of 16 quantitative procedures. Mean biases ranged from −35% to 34% at 15 mg/L. Dilution of samples with high concentrations introduced bias for 4 procedures. The combined CV was >10% for 5 procedures. It was not possible to estimate total error due to dependence of bias on concentration. CVs for sample-specific influences were 0% to 15.2%. CONCLUSIONS Bias was the dominant source of disagreement among routine measurement procedures. Consequently, standardization efforts will improve agreement among results. Variation of bias with concentration needs to be addressed by manufacturers.

A new commercial method for the enzymatic determination of creatinine in serum and urine evaluated: comparison with a kinetic Jaffé method and isotope dilution-mass spectrometry.

1989 ◽  
Vol 35 (5) ◽  
pp. 835-837 ◽  
Author(s):  
B Lindbäck ◽  
A Bergman
Keyword(s):  
Mass Spectrometry ◽  
Isotope Dilution ◽  
Isotope Dilution Mass Spectrometry ◽  
Kinetic Method ◽  
Reference Method ◽  
Enzymatic Method ◽  
Routine Work ◽  
Enzymatic Determination ◽  
Commercial Method ◽  
High Concentrations

Abstract We evaluated a new, simple, enzymatic kinetic method from Wako Chemicals GmbH in comparison with a kinetic Jaffé method by using isotope dilution-mass spectrometry (ID-MS) as a reference method. An ID-MS-calibrated serum standard was used. Both the enzymatic and the Jaffé method correlated well with ID-MS, except for sera with high concentrations of bilirubin. Ethyl acetoacetate, acetone, and glucose in serum interfered somewhat with the Jaffé method but not with the enzymatic method. We conclude that the present enzymatic method has merit as compared with a Jaffé method for routine work, but is more expensive.

Accuracy of some routine method used in clinical chemistry as judged by isotope dilution-mass spectrometry.

1981 ◽  
Vol 27 (5) ◽  
pp. 733-735 ◽  
Author(s):  
I Björkhem ◽  
A Bergman ◽  
O Falk ◽  
A Kallner ◽  
O Lantto ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Isotope Dilution ◽  
State Of The Art ◽  
Clinical Chemistry ◽  
Isotope Dilution Mass Spectrometry ◽  
Routine Method ◽  
Accuracy Control ◽  
Mean Values ◽  
Reference Methods

Abstract Serum from patients was pooled, filtered, dispensed, and frozen. This pooled specimen was used for accuracy control in 64 participating laboratories in Sweden. Mean values ("state-of-the-art" values) were obtained for creatinine, cholesterol, glucose, urea, uric acid, and cortisol. These values were compared with values obtained with highly accurate reference methods based on isotope dilution-mass spectrometry. Differences were marked in the case of determination of creatinine and cortisol. Concerning the other components, the differences between the state-of-the-art value and the values obtained with the reference methods were negligible. Moreover, the glucose oxidase and the oxime methods for determination of glucose and urea were found to give significantly lower values than the hexokinase and urease methods, respectively. We conclude that methods with a higher degree of accuracy are required for routine determination of creatinine and cortisol.

Results of the recalibration of creatinine measurement with the modular Beckman Coulter® Jaffe creatinine method

2011 ◽  
Vol 49 (12) ◽  
Author(s):  
Catherine Fillée ◽  
Guido Vranken ◽  
Myriam Othmane ◽  
Marianne Philippe ◽  
Jean-Michel Allaeys ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Isotope Dilution ◽  
Total Error ◽  
Isotope Dilution Mass Spectrometry ◽  
Reference Method ◽  
Biological Variability ◽  
Acceptance Criteria ◽  
The Impact ◽  
Creatinine Measurement ◽  
Enzymatic Methods

AbstractSerum creatinine is important for detecting the beginning of a decline in kidney function. The Beckman Coulter Jaffe reagents for measuring creatinine have been standardized to the internationally accepted reference method: isotope dilution mass spectrometry (IDMS). The impact of this recalibration on the Beckman CoulterRecalibrated Jaffe (calibrator set points IDMS traceable) and classic National Institute of Standards and Technology (NIST) creatinine methods (traceable to NIST 914a) were compared with an enzymatic method (Sentinel, traceable to NIST SRM 967). All measurements were performed on Synchron DxC 800 systems. Imprecision of the routine methods was studied using the Clinical and Laboratory Standards Institute (CLSI) protocols and laboratory quality survey. Thirteen plasma pools, with concentrations <354 μmol/L, were analyzed with a gas chromatography isotope dilution mass spectrometry (GC-IDMS) method and routine methods. Total error of 8.2% based on biological variability, set on the GC-IDMS values and acceptance criteria (bias <5%, imprecision <8% at concentrations ≥88.4 μmol/L and a maximum 10% increase in the relative error of estimated glomerular filtration rate (eGFR) of the National Kidney Disease Educational Program (NKDEP) were used for evaluating analytical performance of the routine methods studied.After recalibration of the Jaffe method, median bias (μmol/L) decreased from 12.4 (95% CI: 9.1–21.2) to 7.3 (95% CI: 1.5–10.5). Imprecision of the Jaffe method is in agreement with the claim of the manufacturer, namely <9 μmol/L or <3% below or above 292 μmol/L. Below creatinine of 88.4 μmol/L, imprecision of the recalibrated Jaffe and enzymatic methods is between 4.1% and 6.9%, and 5.0% and 7.1%, respectively, and significantly different (p=0.02 for both the Jaffe and enzymatic methods) from the goal, based on biological variability, of 2.7%. For the adult pools, all recalibrated Jaffe and enzymatic results fall within the total error of 8.2%. In the pediatric samples, one-third of the recalibrated Jaffe and three of the six enzymatic results fall within this total error goal.Recalibration significantly reduced bias of the Jaffe method. For pediatric samples, recalibrated Jaffe results do not comply with either the imprecision goal or the total error based on biological variability. Adult recalibrated Jaffe results are in compliance with the goals based on biological variability and with the acceptance criteria from the NKDEP.

Development of a primary reference material of natural C-reactive protein: verification of its natural pentameric structure and certification by two isotope dilution mass spectrometry

2021 ◽  
Vol 13 (5) ◽  
pp. 626-635
Author(s):  
Jianyi Liu ◽  
Wen Zhu ◽  
Haofeng Sun ◽  
Dewei Song ◽  
Peng Xiao ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Reference Material ◽  
Isotope Dilution ◽  
Isotope Dilution Mass Spectrometry ◽  
C Reactive Protein ◽  
Reactive Protein ◽  
Primary Reference

Development of a primary reference material of natural C-reactive protein: verification of its natural pentameric structure and certification by two isotope dilution mass spectrometry.

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