HbA2 levels in normal, beta-thalassaemia and haemoglobin E carriers by capillary electrophoresis.

OBJECTIVE The capillary electrophoresis (CE) is a new system that utilizes the principle of electrokinetic separation of molecules in eight electrolyte buffer-filled silica capillaries. In this study, we established the normal ranges of haemoglobin A2 (HbA2) and haemoglobin F (HbF) levels for normal individuals using this system and also the HbA2 level in beta thalassaemia and haemoglobin E (HbE) individuals. MATERIALS AND METHODS 154 samples from normal individuals, 218 samples from beta thalassaemia heterozygotes and 91 samples from HbE heterozygotes were subjected to high performance liquid chromatography (HPLC) and CE analysis. RESULTS The normal ranges for HbA2 and HbF by CE were 2.75% (SD 0.26%) and 0.03% (SD 0.24%) respectively, which were significantly lower than that of HPLC 2.88% (SD 0.25%) and 0.58% (SD 0.61%) (p < 0.001). The HbA2 level for HbE heterozygotes was 3.58% (SD 0.44%), which was significantly higher than normal (p < 0.001) but lower than that of beta-thalassaemia heterozygotes (p < 0.001) and the true HbE level was 24.28% (SD 3.38%). CONCLUSION The CE system provided a fully automated and high throughput system for haemoglobin analysis. We established the normal ranges for HbA2 and HbF levels by CE. We also determined the ranges for HbA2 in beta thalassaemia and HbE heterozygotes using this system.