Kurtoğlu Ayşegül Uğur, Eren Esin, Aslan Vedat, Erkal Özgür, Kurtoğlu Erdal, Yilmaz Necat
Department of Biochemistry, Sağlık Bilimleri Universiy Antalya Education and Research Hospital, Antalya, Turkey.
Department of Hematology, Sağlık Bilimleri University Antalya Education and Research Hospital, Antalya, Turkey.
J Med Biochem. 2017 Jul 14;36(3):270-273. doi: 10.1515/jomb-2017-0016. eCollection 2017 Sep.
Glycated hemoglobin (HbA1c) is used for the assessment of glycemic control in patients with diabetes. The presence of genetic variants of hemoglobin can profoundly affect the accuracy of HbA1c measurement. Here, we report two cases of Hemoglobin G-Coushatta (HBB:c.68A>C) variant that interferes in the measurement of HbA1c by a cation-exchange HPLC (CE-HPLC) method. HbA1c was measured by a CE-HPLC method in a Tosoh HLC-723 G7 instrument. The HbA1c levels were 2.9% and 4%. These results alerted us to a possible presence of hemoglobinopathy. In the hemoglobin variant analysis, HbA2 levels were detected as 78.3% and 40.7% by HPLC using the short program for the Biorad Variant II. HbA1c levels were measured by an immunoturbidimetric assay in a Siemens Dimension instrument. HbA1c levels were reported as 5.5% and 5.3%. DNA mutation analysis was performed to detect the abnormal hemoglobin variant. Presence of Hemoglobin G-Coushatta variant was detected in the patients. The Hb G-Coushatta variants have an impact on the determination of glycated hemoglobin levels using CEHPLC resulting in a false low value. Therefore, it is necessary to use another measurement method.
