Performance evaluation of immunoassay for infectious diseases on the Alinity i system

Although a diagnosis of infectious diseases is essential for timely treatment, the performance of diagnostic tests has been hardly evaluated due to variable results that are influenced by multiple factors in different conditions. In the present study, the performance of the Alinity i system, which is a newly developed immunoassay to diagnose infectious diseases, was evaluated.

We evaluated the precision, linearity, correlation, and carryover of 16 analytes (HAV Ab IgG, HBsAg, HBeAg, anti-HBc, anti-HBe, anti-HBs, anti-HCV, HIV Ag/Ab, EBV VCA IgM, EBV VCA IgG, EBV EBNA IgG, CMV IgM, CMV IgG, Toxoplasma IgG, Rubella IgG, and Syphilis TP) of Alinity i by comparison with ARCHITECT i2000_SR system following the rationale of the Clinical and Laboratory Standards Institute (CLSI).

For quantitative tests, the coefficients of variation (CV) % of repeatability and intermediate precision were between 0% and 4.18%. The coefficients of the linearity (r² ) over a widely tested analytical range were ≥ 0.990 and the correlation between Alinity i and the ARCHITECT i2000_SR system was strong (r ≥ 0.994). For qualitative tests, the agreement between Alinity i and the ARCHITECT i2000_SR system was excellent (kappa coefficient 1) with 100% sensitivity and specificity. Carryover rates for all analytes were less than 1.0% (-0.11% ~ 0.21%).

The Alinity i system showed good analytical performance and favorable comparability with the ARCHITECT i2000_SR. It could be suitable as a routine immunoassay analyzer for screening and diagnosis of infectious disease.