title: Influence of hemoglobin E on measurement of hemoglobin A1c by immunoassays.
abstract: 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.
authors.forename: K
authors.initials: K
authors.lastname: Paisooksantivatana
authors.forename: A
authors.initials: A
authors.lastname: Kongsomgan
authors.forename: W
authors.initials: W
authors.lastname: Banyatsuppasin
authors.forename: K
authors.initials: K
authors.lastname: Khupulsup
mesh_terms: D006442:Glycated Hemoglobin / Q000032:analysis*; D006446:Hemoglobin E / Q000032:analysis* / Q000235:genetics; D006720:Homozygote; D006801:Humans; D007118:Immunoassay / Q000379:methods; D015203:Reproducibility of Results
chemical_list: D006442:Glycated Hemoglobin; D006446:Hemoglobin E