[Limits of chromatographic determination of glycated hemoglobin (Hb A1c) in diabetes mellitus in presence of abnormal hemoglobins].

The content of glycated hemoglobin (Hb A1c) evaluated by high pressure chromatography on a VARIANT analyzer using Hb A1c software correlated with the mean daily blood glucose level in the majority of diabetics with types 1 and 2 disease and helped evaluate the compensation of diabetes mellitus during the latest 2-3 months of observation. Low Hb A1c values in combination with an extra hemoglobin fraction, unidentified by the software we used, were detected in 3 Russian women suffering from type 2 diabetes mellitus, with high blood glucose levels. Application of Hemoglobinopathy software showed an abnormal spectrum of hemoglobin fractions in the blood of all 3 patients: appearance of hemoglobin D paralleled by decrease of Hb A0. The presence of abnormal hemoglobin D in these patients was confirmed by the results of electrophoresis on cellulose acetate films and a negative test for sickle erythrocytes. Abnormal hemoglobins are responsible for discoordination between glucose content and Hb A1c in the blood of diabetics. Measurement of serum fructosamine is recommended for evaluation of diabetes compensation in patients with hemoglobinopathies.