Comparison of hemoglobin A1C results by two different methods on patients with structural hemoglobin variants

Objectives: The objective was to compare hemoglobin A1C (HbA1C) results obtained by two methods based on different analytical principles for individuals with a structural hemoglobin variant. Design and methods: Hemoglobin A1C results were obtained using the Bio-Rad Variant (based on cation exchange chromatography) and the Bayer DCA 2000 (based on an immunological reaction) on individuals with a structural hemoglobin variant. The identity of the hemoglobin variant was confirmed by high pressure liquid chromatography (HPLC) and electrophoresis. Results: Hemoglobin A1C results obtained by the two methods on individuals with S, C, D, and E trait were in close agreement. Conclusion: The Bio-Rad Variant and Bayer DCA 2000 produce equivalent hemoglobin A1C results on patients with S, C, and E trait. With appropriate correction, correlation of hemoglobin A1C results from the Bio-Rad Variant for individuals with D trait was good (r = 0.927). Glycohemoglobin results obtained by the two methods for some unusual structural hemoglobin variants were in close agreement.