Effect of hemoglobin F and A2 on hemoglobin A1c determined by cation exchange high-performance liquid chromatography

Abstract

Background: The potential effect of increase in hemoglobin (Hb) A2 and HbF on glycated hemoglobin (HbA1c) measurements were investigated using a high-performance liquid chromatography (HPLC) method compared with an immunoturbimetric assay. Methods: Samples producing abnormal chromatograms during the measurement of routine HbA1c testing with HPLC were further analyzed to characterize abnormal Hb variants. Patients were divided into three groups that had only high HbF (group 1), only high HbA2 (group 2), and both high HbA2 and HbF (group 3). HbA1c values of patients were re-assayed using the immunoturbidimetric method (Advia, Siemens Healthcare, Germany). Results: HbA1c levels were significantly higher in all groups measured by immunoassay than in HPLC. We found a positive correlation between HPLC and immunoturbidimetry in the group 2 and a slight correlation in the group 1. There was no correlation between the two methods in group 3. Conclusions: HbA1c measurement by HPLC method interfering with elevated HbA2 and HbF, especially HbF, should be verified by an immunoturbidimetric method.