Silent hemoglobin variants and determination of HbA1c with the high-resolution program of the HPLC HA-8160 hemoglobin analyzer

Objectives: Evaluation of HbA1c determination with an automated ion-exchange high-performance liquid chromatography (HPLC) method in patients with clinically silent hemoglobin (Hb) variants. Design and methods: HbA1c values were determined with the Arkray HA-8160 ion-exchange HPLC using the high-resolution, 4.2-min β-thalassemia screening mode in patients with silent hemoglobin (Hb) variants, namely, Hb Graz, Hb Sherwood Forest, Hb O Padova, and HbD. Results: All of these hemoglobin variants caused additional peaks in the chromatograms, without HbA1c results in patients with Hb Graz and Hb Sherwood Forest, and demonstrated extra peaks with HbA1c results that were clinically too low for patients with Hb O Padova and in the patient with HbD. Conclusions: The development of this automated HPLC method modification with high-resolution β-thalassemia screening mode aids identification of interference due to some clinically silent Hb variants in HbA1c determination.