Abstract
The analytical performance of “Nanopia LRG” (Sekisui Medical Co., Ltd.), which can be mounted on a multi-test biochemical analyzer, was evaluated for the measurement of leucine-rich alpha-2 glycoprotein (LRG), a novel biomarker for inflammatory bowel disease (IBD). Serum levels of LRG were quantified using a Nanopia LRG on the cobas 8000 modular analyzer with c702 module (Roche Diagnostics). Repeatability and intermediate precision were less than 5% coefficient of variation. In the on-board stability testing, serum LRG declined by less than 5% from the average value measured on the first day over thirty days at any of the three concentrations. Dilution analysis yielded linear results up to a concentration of 100 μg/mL. The limit of quantification was 1.37 μg/mL. The prozone effect occurred with LRG concentrations higher than 200 μg/mL, resulting in a reported value lower than 100 μg/mL. This suggests that dilution testing of LRG samples is required when the values are near the upper limit of quantification. The effects of interferents, including hemoglobin, bilirubin F, bilirubin C, chyle and rheumatoid factor on assay results were negligible and non-significant. Deming regression analysis yielded y = 1.02x − 0.16. The correlation coefficient (r) was 0.998. This study demonstrated that “Nanopia LRG” for use on the cobas c702 module has acceptable performance for routine testing. Therefore, the results of a blood test performed just before a physical examination may be helpful for the clinicians to evaluate disease activity of IBD.
