RESUMO
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.
Assuntos
Creatinina , MétodosRESUMO
BACKGROUND: The amount of interference due to hemolysis, bilirubin, and lipemia can be measured on the AU5800 autoanalyzer (Beckman Coulter, USA) by spectrophotometry. This is reported as semi-quantitative indices, specifically H-index, I-index, and L-index, respectively. In this study, we evaluated the impact of interference using chemistry assays and established the concentration of interfering substances and HIL-index above which analytically significant interference exists, according to CLSI guidelines C56-A and EP7-A2. METHODS: Pooled sera including different concentrations of analytes were prepared and mixed with hemoglobin, bilirubin, or Intralipid. These samples were then tested for 35 clinical chemistry analytes by AU5800 and the bias based on interferent concentrations was computed. The interferent concentration above which significant interference exists was calculated from the 50% within-subject biological variation (desirable analytic goal), and the corresponding index was assigned. RESULTS: Among 35 items evaluated, interference was detected for 12 analytes by hemoglobin, 7 analytes by bilirubin, and 12 analytes by Intralipid. We proposed HIL-index₁ and HIL-index₂ for each analyte according to 2 different medical decision levels. HIL-index₁ and HIL-index₂ were considered more reasonable criteria than the HIL-index from the manufacturer's technical document (HIL-index(TD)). This is because HIL-index(TD) was empirically set to 5% or 10%, and had a wide tolerance range, which was not sufficient to reflect the presence of interference, compared to HIL-index₁ and HIL-index₂. CONCLUSIONS: We have demonstrated hemoglobin, bilirubin, and Intralipid interferences according to CLSI guidelines using the desirable analytic goal. Our results provide applicable information for Beckman Coulter automated chemistry analyzers.