Evaluation of enzymatic BM Test HbA1c on the JCA-BM6010/C and comparison with Bio-Rad Variant II Turbo, Tosoh HLC 723 G8, and AutoLab immunoturbidimetry assay

Background: A novel enzymatic HbA(1c) assay was introduced for use in an automated chemistry analyzer. With this unique method, HbA(1c) and plasma glucose can be measured from the same EDTA tube. We evaluated the analytical performance of this enzymatic HbA(1c) assay in a JCA-BM6010/C analyzer and compared the HbA(1c) values with the results from other widely used methodological instruments. Methods: The imprecision, linearity, carry-over and concordance rate of the enzymatic HbA(1c) test (BM Test HbA(1c)) using the JCA-BM6010/C analyzer were evaluated. Three hundred and seventy-seven specimens with HbA 1c concentrations from 16 to 133 mmol/mol were used for a comparison study with two high performance liquid chromatography methods: Variant II Turbo and Tosoh HLC 723 G8 and the AutoLab Hemoglobin A(1c) immunoturbidimetry reagent using a Hitachi 7600-110. Forty specimens were used for the glucose method comparison. Results: The HbA(1c) coefficients of variation of the within-run imprecision for low and high levels were 0.6% and 0.4%, respectively. The linearity of the BM Test HbA(1c) using the JCA-BM6010/C analyzer was excellent in the range between 31 mmol/mol and 143 mmol/mol. The carry-over rate was 0.2%. The relationships between the BM test and the other three methods were 0.916 x Tosoh G8+ 3.644, r = 0.986; 0.887 x Bio-Rad Variant II+ 1.896, r = 0.972; and 0.941 x AutoLab+ 4.532, r = 0.977. The concordance rates using a cut-off of 48 mmol/mol were 91.5% with Tosoh G8, 82.8% with Bio-Rad Variant II, and 91.0% with AutoLab. The simultaneously assayed plasma glucose with HbA(1c) was 1.002 x Routine plasma glucose+ 0.625, r = 1.000 Conclusions: The enzymatic BM Test HbA 1c in the JCA-BM6010/C analyzer showed excellent precision and linearity, and a minimal carry-over rate. The simultaneously assayed plasma glucose analysis showed good performance.