Quantitative analysis of HbA_2 with high-performance liquid chromatography in thalassemia screening

Objecitve To evaluate the application of quantitative analysis of HbA2 with high-performance liquid chromatography (HPLC) in thalassemia screening.Methods Seventy-five couples randomly selected and 140 couples at high risk of thalassemia were studied.Gene analysis of thalassemia was adopted as“gold standard”. The precision and stability were evaluated by comparing the coefficient of variation intra-assay and inter-assay of HbA2 value measured with HPLC.The genotypes of positive samples were determined to assess the accuracy of HPLC-measured HbA2 for diagnosis of thalamessia.Results The distribution range of 95% frequency of HbA2 measured by HPLC in the local healthy adults was from 2.28% to 3.42%.The cutoff value of HbA2 for diagnosing heterozygous β thalassemia was greater than or equal to 4.35%.Among 94 patients (65 cases of heterozygous β thalassemia,19 cases of β thalassemia,2 cases of HbE and 8 cases of HbH) only 1 case was lost,and no one was misdiagnosed.Conclusion HPLC is a fast,highly stable and accurate method for measuring HbA2 so it can be adopted in screening β thalassemia.