EVALUATION OF HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY FOR ROUTINE ESTIMATION OF HEMOGLOBIN-A(2) AND HEMOGLOBIN-F

Aims-To compare high performance liquid chromatography (HPLC) with con ventional methods for the estimation of blood haemoglobin A2 (HbA2) an d haemoglobin F (HbF) concentrations in routine thalassaemia screening . Methods-An HPLC system (the VARIANT Hemoglobin Testing System) was t ested for precision and reproducibility in the measurement of HbA2 and HbF, and reference ranges were obtained for a local healthy adult pop ulation. HPLC was compared with column anion exchange chromatography f or HbA2 measurement, and radial immunodiffusion, or alkaline denaturat ion for HbF measurement. The reliability of HbA2 measurement by HPLC f or the detection of beta thalassaemia and HbE was assessed in 200 cons ecutive samples for routine thalassaemia screening. Results-HPLC was r apid, technically easy, and gave good precision and reproducibility. I n all comparisons linear regression analysis showed good correlation b etween HbA2 or HbF concentrations determined by HPLC and by the respec tive conventional methods. All beta thalassaemia or haemoglobin E carr iers presumptively identified by conventional methods in 200 consecuti ve samples were detected by HbA2 measurement using HPLC, without any f alse positive or false negative results. Conclusions-The measurement o f HbA2 and HbF by HPLC is rapid, reproducible, and precise. It is as r eliable as column chromatography for the measurement of HbA2 and radia l immunodiffusion or alkaline denaturation for the measurement of HbF. HPLC may be an appropriate method for rapid screening in population s urveys for beta thalassaemia and HbE carriers.