Interference of fetal hemoglobin and labile glycosylated hemoglobin with measurements of glycosylated hemoglobin.

We examined the effect of fetal hemoglobin and labile glycosylated hemoglobin on a number of diverse methods used to measure glycosylated hemoglobin. Samples were supplemented with various amounts of cord blood to give proportions of fetal hemoglobin ranging from 1 to 20% of total hemoglobin concentration. Procedures in which the separation of hemoglobin A1 from the major hemoglobin A fraction is based on differences in ionic properties (cation-exchange chromatography and electrophoresis) are subject to interference by fetal hemoglobin, whereas procedures that base the quantitation on other properties (colorimetry and affinity column chromatography) are not. The same procedures that are affected by the presence of fetal hemoglobin are also subject to interference by labile glycosylated hemoglobin. We conclude that the affinity chromatographic and colorimetric methods may give a more nearly accurate determination of glycosylated hemoglobin.