GLYCATED HEMOGLOBIN (HBA(1C)) MEASUREMENTS IN SUBJECTS WITH HEMOGLOBIN-VARIANTS, USING THE DCA-2000

Measurement of glycated haemoglobin (HbA(1c)) has become an establishe d procedure in the long-term assessment of glycaemic control in diabet ic patients.(1) The availability of current results at the time of con sultation is important, and real time within-clinic measurements of Hb A(1c) meets this need. A novel, portable, cartridge-based immunoassay system (the DCA 2000, Bayer Diagnostics, Basingstoke, UK) has been fou nd to give reliable analytical results(2) and to be useful in a variet y of in-clinic settings.(3) In the measurement of HbA(1c) by immuno-as say, glycated variants of haemoglobin may be included,(4) or excluded, (5) depending on the region of the N-terminal beta chain recognized by the antibody used. Exclusion gives rise to falsely low values and mis interpretation of results is likely in patients whose variant status i s unrecognized. This is most likely to occur in subjects who are heter ozygotes for HbAS or HbAC, since only relatively minor pathology is as sociated with these conditions and recognition of variant status is fr equently fortuitous. In patients with sickle cell disease (HbSS, HbSC, HbSDPunjab, HbSOArab and HbS beta(0)thalassaemia) measurement of HbA( 1c) is of doubtful value, because of the reduced variable red cell lif e span in such patients. In this study we compared the DCA 2000 immuno assay system with two automated highperformance liquid chromatography (HPLC) systems, the Diamat and the Glycomat in monitoring patients wit h haemoglobin variants.