Comparative Analysis of Glycosylated Hemoglobins by Ion-Exchange Column Chromatography and High-Performance Liquid Chromatography in Patients with Hemoglobinopathies

Abstract

Cation-exchange chromatography gives falsely decreased values for glycosylated hemoglobins (GHbs) in patients with abnormal hemoglobins (Hbs) such as S, D, G, C, E, and O. This decrease is thought to be proportional to the percentage of abnormal Hb present. In the authors' study, cation-exchange column chromatographic GHb values on 84 nondiabetic patients heterozygous for Hb S, 28 AS diabetic patients, and 23 nondiabetic patients heterozygous for Hb C were calculated to account for the percentage of abnormal Hb, and the resulting values were compared with the GHb values obtained by high-performance liquid chromatography (HPLC). There existed a good correlation between the calculated GHb and the GHb obtained by HPLC (r = 0.92 for AS and r = 0.94 for AC). In patients with elevated Hb F, chromatographic GHb values are falsely high. In such cases, correction can be made by subtracting the Hb F value from the observed GHb. In laboratories where cation exchange chromatography is used, accurate determination of GHb can be made by adjusting observed values for portion of the abnormal Hb present.

Hemoglobinopathies and Hemoglobin A1c in Diabetes Mellitus

“…38 In this study, HbA1c was measured by ion exchange chromatography, a method that is known for generating falsely decreased levels for glycated hemoglobins in patients with the hemoglobin S variant. 39 The combination of findings in these six studies suggests that in type 2 diabetes elevated HbA1c concentrations out of proportion to mean glycemia, in blacks compared to nHws, could be associated with the presence of the sickle cell hemoglobinopathy variant.…”