Influence of hemoglobin E on measurement of hemoglobin A1c by immunoassays.
BACKGROUND
Many assays used for HbA1c measurement can be interfered by hemoglobin variants. Hemoglobin E is one of the most common variant. Effect of HbE on high performance liquid chromatography was widely reported but not on immunoassay.


OBJECTIVE
To determine the effect of hemoglobin E on HbA1c values by immunoassay methods.


METHODS
Two immunoassays were used for measurement of HbA1c in samples with hemoglobin type as A2A (normal controls, n=60), EA (heterozygous hemoglobin E, n=151), and EE (homozygous hemoglobin E, n=43). Results within each assay and each hemoglobin typing group were compared. Mann-Whitney U test, Pearson's correlation and linear regression analysis were used.


RESULTS
There were significant differences of HbA1c values between normal controls and hemoglobin E-contained samples. Correlation between two assays was worse in the presence of hemoglobin E comparing to normal controls.


CONCLUSIONS
Hemoglobin E can affect the immunoassays used for HbA1c measurement. Further studies are needed to understand the mechanism of interference.
Paisooksantivatana
K
K
Kongsomgan
A
A
Banyatsuppasin
W
W
Khupulsup
K
K
D006442:Glycated Hemoglobin / Q000032:analysis*; D006446:Hemoglobin E / Q000032:analysis* / Q000235:genetics; D006720:Homozygote; D006801:Humans; D007118:Immunoassay / Q000379:methods; D015203:Reproducibility of Results
D006442:Glycated Hemoglobin; D006446:Hemoglobin E