A Case of Hemoglobin D-Los Angeles in a Diabetic Patient With Relatively Low HbA1c Compared to Plasma Glucose Levels

Abstract

The percent of hemoglobin A1c (HbA1c) is one of the criteria to diagnose the presence of diabetes or to indicate the need for blood glucose control during treatment. Recently, the method of high performance liquid chromatography (HPLC) has been commonly used to analyze the percent of HbA1c. The glycated Hb of hemoglobinopathy has a different electrical charge and eluates at a different phase from normal HbA1c in the HPLC column. Thus, almost all hemoglobinopathy patients, similar to this case of a mixed Asian-Caucasian American patient have been found to have low HbA1c levels compared to those patients that are indicated to undergo blood glucose control by the HPLC method. The HbA1c levels of this patient were high and so were the average of blood glucose levels according to the latex coagulating method. A genetic analysis showed presence of a heterozygous β-globin miss-sense mutation [121Glu→Gln] which is designated as hemoglobin D (HbD) Los Angeles. In Japan, the number of cases of with abnormal HbD patients have been rare until now. However, they are more commonly observed in Western countries and thus such cases are expected to increase due to the progress of internationalization. We have to evaluate the treatment of abnormal HbD patients not based on the levels of HbA1c, but instead based on the levels of glycoalbumin or the blood glucose.