An Automated Hb A2 Analyzer, HLO723G7,for Diagnosis of β-Thalassemia
We investigated the usefulness of an automated analyzer, the HLC-723G7, for determination of Hb Ai in the diagnosis of β-thalassemia. The analyzer was used for 250 Thai subjects who were either normal or were diagnosed with microcytic hypochromia based on hematological findings. An intra-assay precision test of normal subject (Hb A2=2.78%) and that (Hb A2=5.90%) with /?-thalassemia revealed as coefficients of variation (CV%) of 3.2% and 0.95%, respectively. Samples were kept stable at 4ｰC for at least 10 days. The Hb A2 values obtained by the HLO723G7 showed good correlation with those obtained by DEAE-HPLC with the coefficient of correlation (r) being 0.940, the coefficient of determination (R2) 0.884, and the equation of the regression line Yg7=1.057Xdeae-0.248. The subjects with a higher Hb A2 value than about 4% were suspected of having /3-thalassemia based on hematological findings. Most of those with a lower or relatively lower Hb A2 value than the normal range (2.3-3.5%) or 4% and hematological abnormalities were considered to be suffering from of-thalassemia-1, tf-thalassemia-2 or iron deficiency anemia. However, a confirmed diagnosis must be made by the further study of the red cell morphology, clinical manifestations and by the DNA analysis.