The application of capillary electrophoresis in HbA1c and HbA2 detection in beta thalassemia patients

Objective To investigate effects of β-thalassemia on 8 HbA1c measurement systems including Capillary electrophoresis and application of HbA2 values of samples with β-thalassemia from Capillary 2 Flex Piercing HbA1c measurement systems. Methods 338 samples without β-thalassemia(include 80 α-thalassemia with --SEA/αα genotype) and 225 samples with β-thalassemia were collected in Peking University Shenzhen hospital from January 2014 to August 2014. Samples with β-thalassemia are all heterozygotes with normal α-globin and abnormal β-globin, and without combining other haemoglobinopathies. 76 normal samples and 76 samples with β-thalassemia were selected from above all samples, HbA1c values of which were given by capillary electrophoresis (Capillary Flex 2 Piercing), enzymatic (Norudia N HbA1c), immune transmission turbidity (oneHbA1c FS), chemiluminescent immunoassay (ARCHITECT HbA1c Reagent Kit), boronate affinity HPLC (Trinity Ultra2)and ion exchange HPLC (HA8160, Variant Ⅱ Turbo and Variant Ⅱ BioRad 2.0), respectively. HbA1c values given by the eight systems were compared. 338 samples without β-thalassemia and 225 samples with β-thalassemia were measured by using Capillarys 2 Flex Piercing HbA1c system and capillary electrophoresis hemoglobin system, the cut-off values of HbA2 from Capillary 2 Flex Piercing HbA1c measurement system for β-thalassemia was assessed by using ROC curve. Data statistics were done by using SPSS 19.0. Results The HbA1c values of normal samples were well correlated with the comparative system. The correlation coefficients for the 7 systems are all greater than 0.98. For samples with β-thalassemia, the correlation coefficients are all greater than 0.98 except for Variant Ⅱ Turbo. The bias between normal samples and samples with β-thalassemia have no significant difference except for Variant Ⅱ Turbo. HbA2 values from Capillary 2 Flex Piercing HbA1c measurement and capillary electrophoresis hemoglobin system were well correlated. The correlation coefficient is 0.993. When cut-off value of HbA2 from Capillary 2 Flex Piercing HbA1c measurement system for β-thalassemia is 3.38, sensitivity is 98.3%, specificity is 100%. Conclusions Samples with β-thalassemia have no significant effects on HbA1c measurement syetems except for Variant Ⅱ Turbo. The Capillary 2 Flex Piercing HbA1c measurement syetem has the advantage of screening β thalassemia by HbA2 while measuring HbA1c.(Chin J Lab Med, 2015, 38: 329-332) Key words: β-thalassemia; Hemoglobin A, glycosylated; Hemoglobin A2; Capillary electrophoresis