Performance Evaluation of the ARCHITECT i2000 for the Determination of Whole Blood Cyclosporin A and Tacrolimus / 임상검사와정도관리

Maintaining immunosuppressant concentrations within the therapeutic range in organ recipients requires regular monitoring. The blood concentrations of immunosuppressants are routinely measured using one of several automated immunoassays, such as chemiluminescence immunoassays (CLIAs) and liquid chromatography-tandem mass spectrometry (LC-TMS). The ARCHITECT i2000 immunoassay analyzer (Abbott Diagnostics, USA) was developed as an automated CLIA analyzer for the measurement of cyclosporin A and tacrolimus in whole blood. Here, the precision and linearity of the ARCHITECT i2000 analyzer for the detection of cyclosporin A and tacrolimus in whole blood were evaluated according to Clinical and Laboratory Standards Institute guidelines and were compared with those of an LC-TMS detection method. The total coefficient of variation for the two drugs was less than 10%, and they showed linearity values of 0.97 or more, which was within the manufacturer's range. The measurements of both immunosuppressants by the ARCHITECT i2000 were closely correlated with measurements determined by LC-TMS. However, most measurements were lower with LC-TMS than with the ARCHITECT i2000. Measurement of cyclosporin A and tacrolimus in whole blood using the ARCHITECT i2000 showed very satisfactory performance in terms of precision and linearity as well as good correlation with the comparative method.

Comparison of Four Automated Carcinoembryonic Antigen Immunoassays: ADVIA Centaur XP, ARCHITECT I2000sr, Elecsys E170, and Unicel Dxi800

BACKGROUND: Carcinoembryonic antigen (CEA) is one of the tumor markers available for evaluating disease progression status after initial therapy and monitoring subsequent treatment modalities in colorectal, gastrointestinal, lung, and breast carcinoma. We evaluated the correlations and differences between widely used, automated CEA immunoassays at four different medical laboratories. METHODS: In total, 393 serum samples with CEA ranging from 3.0 to 1,000 ng/mL were analyzed on ADVIA Centaur XP (Siemens Diagnostics, Tarrytown, NY, USA), ARCHITECT i2000sr (Abbott Diagnostics, Abbott Park, IL, USA), Elecsys E170 (Roche Diagnostics, Indianapolis, IN, USA), and Unicel DxI800 (Beckman Coulter, Fullerton, CA, USA), and the results were compared. Deming regression, Passing-Bablok regression, and Bland-Altman analyses were performed to evaluate the data correlation and % differences among these assays. RESULTS: Deming regression analysis of data from Elecsys E170 and UniCel DxI800 showed good correlation (y=3.1615+0.8970x). According to Bland-Altman plot, no statistically significant bias (−1.78 ng/mL [95% confidence interval: −4.02 to 0.46]) was observed between Elecsys E170 and UniCel DxI800. However, the relative differences of CEA concentrations between assays exceeded the acceptable limit of 30%. Regarding the agreement of positivity with cut-off value 5.0 ng/mL, ARCHITECT i2000sr and Elecsys E170 showed the highest agreement (95.2%), whereas ADVIA Centaur XP and ARCHITECT i2000sr showed the lowest agreement (70.7%). CONCLUSIONS: Agreements between automated CEA immunoassays are variable, and individual CEA concentrations may differ significantly between assays. Standardization of serum CEA concentrations and further harmonization are needed.

Evaluation of Serologic Marker Tests for Hepatitis B Viral Infection Using the Automated Immunoassay System ARCHITECT i2000 / 대한임상병리학회지

BACKGROUND: The prevalence of Hepatitis B virus (HBV) in Korea is still higher than that of devel-oped countries. Recently, the automated chemiluminescent microparticle immunoassay analyzer ARCHITECT i2000 (Abbott Laboratories, Abbott Park, IL USA) was introduced in Korea and we evaluated performance of the tests for serological markers for HBV infection. METHODS: We analyzed precision, agreement, sensitivity, specificity and throughput of the HBs antigen, anti-HBs and anti-HBc as well as linearity and compared with the AxSYM (Abbott Labora-tories, Abbott Park, IL USA) for anti-HBs. Precision, linearity and comparison were performed on the basis of the National Committee for Clinical Laboratory Standards guidelines. Random patients 'sera were used for this study. RESULTS: The coefficients of variations of precision were below 5% for anti-HBs and anti-HBc (total) except for the HBs antigen. The agreements, sensitivities and specificities for serologic mark-ers were more than 90%. The linearity and comparison for anti-HBs were statistically significant (P < 0.001). The throughput of ARCHITECT i2000 was 110 tests/hours and that was 2.8 times faster than that of the AxSYM. CONCLUSIONS: These results suggest that ARCHITECT i2000 can provide rapid and effective results for serologic markers for HBV infection. However, each laboratory should decide the utiliza-tion of this analyzer on the basis of volume of samples, other items tested concurrently, and the inter-face of existing facilities etc.