Performance Evaluation of Thyroid Function Tests on a Novel Chemiluminescent Microparticle Immunoassay System

Background: The Alinity i system (Abbott), a recently developed automated immunoassay analyzer, has a compact footprint and a throughput of 200 tests per hour. Here, we present the first performance evaluation of thyroid function test (TFT) on the Alinity i system. Methods: We performed precision, linearity, comparison, functional sensitivity, carryover, and reference interval verification of 4 hormones (Thyroid Stimulation Hormone; TSH, total T3, free T4, and total T4) using the reagents provided by the manufacturer following the guidelines of the Clinical Laboratory Standards Institute. The performance of Alinity i was compared to that of the Architect i2000 immunoassay analyzer (Abbott, US). Results: The within-laboratory coefficients of variation for all the hormones were 1.6-3.6%. Linearity was observed for all the hormones over the entire tested analytical range (R-2 >= 0.99). The results for all the evaluated hormones using Alinity i system strongly correlated (r >= 0.978) with those from Architect i2000. Functional sensitivity was lower than the lower limit of the analytical measurement range. Sample carryover was less than 1.0%. Conclusions: TFTs on the Alinity i system showed acceptable performance in terms of precision, linearity, comparison, functional sensitivity, and carryover. Therefore, this system could be a useful laboratory tool for performing TFTs.