BACKGROUND: HbA1c is a key biomarker for the monitoring of glycemic balance in diabetic patients. It may be measured by various methods, including HPLC and immunoassays. Here we report the results of the first evaluation of Capillarys 2 Flex Piercing®, a new analyzer using capillary electrophoresis for the separation and the quantification of HbA1c. METHODS: We have evaluated the analytical performances of the method as well as the influence of the most frequent analytical interferences regarding HbA1c assays (i.e., labile HbA1c, carbamylated hemoglobin, high HbF and hemoglobin variants). RESULTS: Intra-assay and between-assays CVs were respectively lower than 1.98% and 2.68% on the pre-market version of the instrument, and lower than 1.62% and 1.45% on the commercial version. The linearity was excellent for HbA1c values ranging from 19 mmol/mol (3.9%) to 161 mmol/mol (16.9%) (r=0.999). The results were well correlated with those obtained by the HPLC method routinely used in the laboratory (Variant II® NU Kit - Bio-Rad): HbA1c[Capillarys 2]=0.9452×HbA1c[Variant II]+1.7279 (r=0.994, n=500). The use of titrated quality control samples indicated a good accuracy of the method. Neither the presence of HbF (until 15%), labile HbA1c or carbamylated hemoglobin, nor that of some typical hemoglobin variants, such as hemoglobin S, D, C and E, affected HbA1c measurement. CONCLUSIONS: This evaluation showed that the analytical performances of Capillarys 2 Flex Piercing® analyzer for HbA1c assay fulfilled quality criteria requested for clinical use, and allowed to recommend its implementation in clinical chemistry laboratories for routine practice.
BACKGROUND: HbA1c is a key biomarker for the monitoring of glycemic balance in diabeticpatients. It may be measured by various methods, including HPLC and immunoassays. Here we report the results of the first evaluation of Capillarys 2 Flex Piercing®, a new analyzer using capillary electrophoresis for the separation and the quantification of HbA1c. METHODS: We have evaluated the analytical performances of the method as well as the influence of the most frequent analytical interferences regarding HbA1c assays (i.e., labile HbA1c, carbamylated hemoglobin, high HbF and hemoglobin variants). RESULTS: Intra-assay and between-assays CVs were respectively lower than 1.98% and 2.68% on the pre-market version of the instrument, and lower than 1.62% and 1.45% on the commercial version. The linearity was excellent for HbA1c values ranging from 19 mmol/mol (3.9%) to 161 mmol/mol (16.9%) (r=0.999). The results were well correlated with those obtained by the HPLC method routinely used in the laboratory (Variant II® NU Kit - Bio-Rad): HbA1c[Capillarys 2]=0.9452×HbA1c[Variant II]+1.7279 (r=0.994, n=500). The use of titrated quality control samples indicated a good accuracy of the method. Neither the presence of HbF (until 15%), labile HbA1c or carbamylated hemoglobin, nor that of some typical hemoglobin variants, such as hemoglobin S, D, C and E, affected HbA1c measurement. CONCLUSIONS: This evaluation showed that the analytical performances of Capillarys 2 Flex Piercing® analyzer for HbA1c assay fulfilled quality criteria requested for clinical use, and allowed to recommend its implementation in clinical chemistry laboratories for routine practice.
Authors: Zhen Zhao; Jeffrey Basilio; Steven Hanson; Randie R Little; Anne E Sumner; David B Sacks Journal: Clin Chim Acta Date: 2015-04-08 Impact factor: 3.786