RESUMO
BACKGROUND: The AU3000i thyroid assay panel (TSH, fT4, T4, fT3, T3) was evaluated at four sites in a European multicenter study. The study was designed to assess the basic analytical performance characteristics of the Olympus thyroid assays. In addition, a comprehensive assessment of the TSH functional sensitivity was undertaken to challenge the manufacturer's claim of 4th generation assay performance. RESULTS: Repeatability (within-run precision) of TSH, ff4 and T4 was better than 3% across the measurable range, T3 and fT3 repeatability was better than 6%. Within-laboratory (total) precision was better than 10% for all assays, for fT4, it was better than 3%. Method comparisons were undertaken against the Roche Elecsys 2010, the Siemens Advia Centaur and the Abbott Architect. Overall, good to excellent correlations were seen, however in some cases there were systematic differences which can be attributed to the lack of an appropriate standard or reference method and/or heterogeneity of the analyte. The functional sensitivity of the Olympus TSH assay was confirmed to be 4th generation, giving a mean functional sensitivity (at 20% CV) of 0.0011 mIU/L with no sites exceeding 0.002 mIU/L. Plasma (Li-heparinate) was shown to be an acceptable sample type for use in these assays. CONCLUSION: The results generated in this study indicate that the assays of the Olympus AU3000i routine thyroid panel are precise, correlate well with other established assays, and are suitable for use in the routine clinical laboratory.