| Abstract: | Glycosylated hemoglobin (Hgb A1) determinations have been advocated for monitoring the control of diabetes mellitus. The prevalent method today for measuring Hgb A1 for most clinical laboratories has been a "mini-column" utilizing ion exchange chromatography. It has been stated that hemoglobin F (Hgb F) will elute with Hgb A1 and interfere with Hb A1 determinations. This study was designed to determine the quantitative effects of Hgb F upon Hgb A1 determinations. Thirty per cent of the study group had elevated Hgb A1 levels at 2% Hgb F concentration, 66% at 3% Hgb F concentration, and all individuals had elevated Hgb A1 levels at Hgb F concentrations of 4% or greater. The relationship of Hgb F to Hgb A1 concentration was not a simple identity, but could be represented by the equation y = 6.03 + 1.24x. If the ion exchange chromatography methodology is used, Hgb F levels should be determined whenever Hgb A1 levels are elevated, particularly in populations where increased Hgb F levels also might be encountered. The authors determined Hgb F levels whenever the concentration of Hgb A1 was 10% or greater. In their population, they found that approximately 1.5% of samples with elevated Hgb A1 concentrations had increased (greater than 2%) Hgb F levels. |
