[Interference of hemoglobin variants on glycated hemoglobin measurement using Architect ci8200 immunoassay (Abbott...

The objective of this study was to compare haemoglobin A(1c) (HbA(1c)) levels measured by the immunoturbidimetric assay on ci8200 Architect (Abbott Diagnostics) to those obtained by the high pressure liquid chromatography (HPLC) assay from Tosoh Bioscience. Firstly, we verified correlation between the two methods in 47 subjects without hemoglobin variants: the coefficient of correlation was 0.968 and the regression equation was as follows: y(Abbott) = 0.928x(Tosoh) - 0.081. We then measured HbA(1c) levels by both methods in blood samples of 23 patients with a structural hemoglobin variant (A/S, A/C or S/C). Analysis of these samples revealed significant discrepancies between results of both methods, as indicated by the higher mean value obtained by immunoturbidimetric assay when compared to HPLC assay (7.17 +/- 2.68% vs. 5.86 +/- 1.41%). Classification of patients according to the HAS (French Haute Autorité de Santé) recommendations HbA(1c) was not modified for 68% of patients with abnormal hemoglobin. However, in 32% of cases, discrepancies between the two methods may have clinical importance, which justifies the occurrence of an abnormal hemoglobin when the HbA(1c) assay is performed by the method immunoturbidimetry Abbott Diagnostics.