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The Barricor tube (Becton Dickinson [BD], Sunnyvale, CA, USA) was recently developed to mechanically separate plasma by increasing the centrifugation rate. We compared the Barricor tube with existing serum- and plasma-based tubes based on 35 biochemical analytes and preanalytical turnaround time (TAT). Blood samples were collected from 30 healthy volunteers in a Barricor tube, serum separating tube (SST, Vacutainer SST II Tube 8.5 mL, #368972; BD), or plasma separating tube (PST, Vacutainer PST Tube 8.0 mL, #367964; BD) in random order. Next, 27 chemistry analytes, six immunochemistry analytes, and two cardiac markers were compared using Passing-Bablok regression and the Bland-Altman method. Preanalytical TAT was measured for each tube.The Barricor tube exhibited bias exceeding the desirable limit for nine and four analytes compared with the SST and PST, respectively. The Barricor tube lactate dehydrogenase value showed a bias of -10.29% and -9.86% compared with that of the SST and PST, respectively. The preanalytical TAT of Barricor tube was 8.8 minutes, which was the shortest among the three tubes. The clinical performance of the Barricor tube was equivalent to that of the SST and PST for most analytes, with an apparent advantage in preanalytical TAT. When using the Barricor tube, the reference range needs to be changed for some analytes that exceed the desirable bias limit.
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0.99, slope: 0.965 and 0.955). When Modular D and Cobas 8000c 702 were compared, the slope and y-intercept were 0.9928 (95% confidence interval [CI]: 0.9802 to 1.000) and -0.0156 (95% CI: −0.0200 to −0.0054), respectively. The slope and y-intercept were 0.9811 (95% CI: 0.9570 to 0.9951) and -0.0484 (95% CI: −0.0638 to −0.0297) when Modular D and Au5800 were compared. Serum Cr measured by Cobas 8000 c702 and AU5800 using the Jaffe method were 3.2% and 6.9% lower than the values measured by Modular D, respectively. Both Modular D and Cobas 8000 c702 showed acceptable accuracies.CONCLUSIONS: Serum Cr measurements using Cobas 8000 c702 and AU5800 were comparable to those measured by Modular D, and showed satisfactory precision and linearity; thus, these techniques could be useful for clinical laboratories.
Subject(s)
Creatinine , MethodsABSTRACT
Background@#Therapeutic drug monitoring (TDM) is clinically recommended for vancomycin and aminoglycoside antibiotics owing to their narrow therapeutic range and nephrotoxicity at high concentrations in the blood. This study was conducted to investigate the current status of TDM of vancomycin and aminoglycosides in Korean clinical laboratories. @*Methods@#Ten organizations participated in this survey. Vancomycin, amikacin, gentamicin, and tobramycin were prepared in three samples of five or six different concentrations. Data from each institution were calculated for the mean, standard deviation, within-day, between-day, and within-laboratory precision. The results from each institution were compared in various ways. @*Results@#Six instruments from three manufacturers were used. Samples with the lowest drug concentration were reported as below the lower limit of quantitation in most laboratories. Coefficients of variation for within-laboratory values ranged from 1.1% to 10.9% for vancomycin, 0.8% to 18.2% for amikacin, 1.2% to 7.8% for gentamicin, and 1.3% to 6.1% for tobramycin. Based on the overall results of the participants, only one institution’s vancomycin samples standard deviation index exceeded 3, with all other values below 2. The College of American Pathologist criteria were met by all institutions; however, measurement of vancomycin in one laboratory and of gentamycin in three laboratories failed to meet the Royal College of Pathologists of Australasia acceptance criteria. @*Conclusions@#Although the precision of the antibiotic test in individual institutions was excellent, there was a difference in the measured values between laboratories. Harmonization of antibiotic TDM is needed to reduce inconsistencies in results.
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Background@#Therapeutic drug monitoring (TDM) is clinically recommended for vancomycin and aminoglycoside antibiotics owing to their narrow therapeutic range and nephrotoxicity at high concentrations in the blood. This study was conducted to investigate the current status of TDM of vancomycin and aminoglycosides in Korean clinical laboratories. @*Methods@#Ten organizations participated in this survey. Vancomycin, amikacin, gentamicin, and tobramycin were prepared in three samples of five or six different concentrations. Data from each institution were calculated for the mean, standard deviation, within-day, between-day, and within-laboratory precision. The results from each institution were compared in various ways. @*Results@#Six instruments from three manufacturers were used. Samples with the lowest drug concentration were reported as below the lower limit of quantitation in most laboratories. Coefficients of variation for within-laboratory values ranged from 1.1% to 10.9% for vancomycin, 0.8% to 18.2% for amikacin, 1.2% to 7.8% for gentamicin, and 1.3% to 6.1% for tobramycin. Based on the overall results of the participants, only one institution’s vancomycin samples standard deviation index exceeded 3, with all other values below 2. The College of American Pathologist criteria were met by all institutions; however, measurement of vancomycin in one laboratory and of gentamycin in three laboratories failed to meet the Royal College of Pathologists of Australasia acceptance criteria. @*Conclusions@#Although the precision of the antibiotic test in individual institutions was excellent, there was a difference in the measured values between laboratories. Harmonization of antibiotic TDM is needed to reduce inconsistencies in results.
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BACKGROUND: Rheumatoid factor (RF) is used as one of the diagnostic criteria for rheumatoid arthritis. The purpose of this study was to evaluate qualitative RF reagents used in clinical laboratories in Korea, and to provide basic data that can be used as a reference to improve the quality of RF testing. METHODS: We reviewed the proficiency testing results for RF from the Korean Association of External Quality Assessment Service (KEQAS) and College of American Pathologists. Moreover, we evaluated five commercially available RF qualitative reagents, including LabSlide RF (IVD Lab Co., Korea), ASAN RA Latex Reagents (Asan Pharmaceuticals Co., Korea), RaPET RF (Stanbio Laboratory, USA), RF Latex Test (Pulse Scientific Inc., Canada), and RF-100 (Teco Diagnostics, USA). Commercially available quality control materials, calibrators, and pooled sera were used in this study. The consistency of qualitative reagents and Kappa statistics were calculated based on the quantitative values of the quality control materials and the mixed sera. RESULTS: Up to 51.5% of high concentration samples were reported as negative in KEQAS. RF qualitative reagent test results were not consistent among reagent types. The consistency of the qualitative and quantitative test results was between 51% and 100%, and the kappa statistics varied depending on the reagent manufacturer. CONCLUSIONS: Measurement of RF qualitative reagents used in domestic clinical laboratories was not consistent with the quantitative values, and hence it is necessary to improve the consistency and verify the adequacy of the cut-off value.
Subject(s)
Arthritis, Rheumatoid , Indicators and Reagents , Korea , Latex , Quality Control , Rheumatoid FactorABSTRACT
BACKGROUND: Measurement of insulin and C-peptide concentrations is important for deciding whether insulin treatment is required in diabetic patients. We aimed to investigate the analytical performance of insulin and C-peptide assays using the Lumipulse G1200 system (Fujirebio Inc., Tokyo, Japan). METHODS: We examined the precision, linearity, and cross-reactivity of insulin and C-peptide using five insulin analogues and purified proinsulin. A method comparison was conducted between the Lumipulse G1200 and Roche E170 (Roche Diagnostics, Mannheim, Germany) systems in 200 diabetic patients on insulin treatment. Reference intervals for insulin and C-peptide concentrations were determined in 279 healthy individuals. RESULTS: For insulin and C-peptide assays, within-laboratory precision (% CV) was 3.78–4.14 and 2.89–3.35%, respectively. The linearity of the insulin assay in the range of 0–2,778 pmol/L was R2=0.9997, and that of the C-peptide assay in the range of 0–10 nmol/L was R2=0.9996. The correlation coefficient (r) between the Roche E170 and Lumipulse G1200 results was 0.943 (P < 0.001) for insulin and 0.996 (P < 0.001) for C-peptide. The mean differences in insulin and C-peptide between Lumipulse G1200 and the Roche E170 were 19.4 pmol/L and 0.2 nmol/L, respectively. None of the insulin analogues or proinsulin showed significant cross-reactivity with the Lumipulse G1200. Reference intervals of insulin and C-peptide were 7.64–70.14 pmol/L and 0.17–0.85 nmol/L, respectively. CONCLUSIONS: Insulin and C-peptide tests on the Lumipulse G1200 show adequate analytical performance and are expected to be acceptable for use in clinical areas.