title: Effects of hemoglobin variants on hemoglobin a1c values measured using a high-performance liquid chromatography method.
abstract: Hemoglobin A1c (HbA1c) is routinely used to monitor long-term glycemic control and for diagnosing diabetes mellitus. However, hemoglobin (Hb) gene variants/modifications can affect the accuracy of some methods. The potential effect of Hb variants on HbA1c measurements was investigated using a high-performance liquid chromatography (HPLC) method compared with an immunoturbimetric assay. Fasting plasma glucose (FPG) and HbA1c levels were measured in 42 371 blood samples. Samples producing abnormal chromatograms were further analyzed to characterize any Hb variants. Fructosamine levels were determined in place of HbA1c levels when unstable Hb variants were identified. Abnormal HPLC chromatograms were obtained for 160 of 42 371 samples. In 26 samples HbS was identified and HbA1c results correlated with FPG. In the remaining 134 samples HbD, Hb Louisville, Hb Las Palmas, Hb N-Baltimore, or Hb Porto Alegre were identified and HbA1c did not correlate with FPG. These samples were retested using an immunoturbidimetric assay and the majority of results were accurate; only 3 (with the unstable Hb Louisville trait) gave aberrant HbA1c results. Hb variants can affect determination of HbA1c levels with some methods. Laboratories should be aware of Hb variants occurring locally and choose an appropriate HbA1c testing method.
authors.affiliation: Department of Clinical Chemistry, Hospital Universitario de Gran Canaria Doctor Negrin, Las Palmas de Gran Canaria, Spain mlormed@gmail.com.
authors.forename: Mercedes
authors.initials: M
authors.lastname: Lorenzo-Medina
authors.affiliation: Department of Hematology, Hospital Universitario de Gran Canaria Doctor Negrin, Las Palmas de Gran Canaria, Spain.
authors.forename: Silvia
authors.initials: S
authors.lastname: De-La-Iglesia
authors.affiliation: Department of Hematology, Hospital Clinico San Carlos, Madrid, Spain.
authors.forename: Paloma
authors.initials: P
authors.lastname: Ropero
authors.affiliation: Department of Clinical Chemistry, Hospital Universitario de Gran Canaria Doctor Negrin, Las Palmas de Gran Canaria, Spain.
authors.forename: Patricia
authors.initials: P
authors.lastname: Nogueira-Salgueiro
authors.affiliation: Department of Clinical Chemistry, Hospital Universitario de Gran Canaria Doctor Negrin, Las Palmas de Gran Canaria, Spain.
authors.forename: Jesus
authors.initials: J
authors.lastname: Santana-Benitez
mesh_terms: D001786:Blood Glucose / Q000032:analysis; D002851:Chromatography, High Pressure Liquid; D003920:Diabetes Mellitus / Q000097:blood*; D006442:Glycated Hemoglobin / Q000032:analysis*; D006455:Hemoglobins, Abnormal / Q000032:analysis*; D006801:Humans
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin; D006455:Hemoglobins, Abnormal; C517652:hemoglobin A1c protein, human
keywords: HbA1c; diabetes; diagnosis; glycated hemoglobin