The accuracy of haemoglobin A2 measurements in the presence and absence of haemoglobin S.

The quantification of haemoglobin A2 by high-performance liquid chromatography (HPLC) was compared with quantification by capillary electrophoresis for control subjects and patients with sickle cell trait or sickle cell anaemia. Significant differences were found, with estimated values being higher by HPLC for control subjects and higher by capillary electrophoresis for sickle cell trait and sickle cell anaemia patients. There is an ongoing need for improved standardisation and alignment of methods.