Silent haemoglobin variants and determination of HbA1c with the HPLC Bio-Rad Variant II

Abstract

Aims: To evaluate the determination of HbA_1c with an automated high performance liquid chromatography (HPLC) method in patients with clinically silent haemoglobin variants. Methods: HbA_1c values were determined with the ion exchange HPL Bio-Rad Variant II using the high resolution β thalassaemia programme in patients with silent haemoglobin variants, namely: Hb Graz, Hb Sherwood Forest, Hb O Padova, and Hb D. Results: All of these haemoglobin variants caused additional peaks in the chromatograms. No clinically useful HbA_1c results were produced for patients with Hb Graz and Hb Sherwood Forest, the results for the patient with Hb D were too low, but the results for patients with Hb O Padova were acceptable. Conclusions: The development of this automated HPLC method modification with high resolution mode aids the identification of interference caused by the described clinically silent haemoglobin variants in HbA_1c determination.