title: Identification of Hb Wayne and its effects on HbA1c measurement by 5 methods.
abstract: BACKGROUND
  The World Health Organization and the American and Canadian Diabetes Associations approved HbA1c >6.5% as diagnostic for type 2 diabetes mellitus (T2DM). Hb variants and/or their chemically modified species can interfere with HbA1c measurements. We recently described a patient with Hb Wayne trait who was misdiagnosed with T2DM based on falsely elevated HbA1c. Hb Wayne is a clinically silent variant that exists as two isoforms: Hb Wayne I (Asn 139) and Hb Wayne II (Asp 139).
  
  
  METHODS
  Hemoglobinopathy investigation was performed by HPLC (Bio-Rad VARIANT-II), alkaline and acid electrophoresis (Sebia Hydrasis2), capillary zone electrophoresis (Sebia CAPILLARYS2™) and DNA sequencing. HbA1c was measured by five methods.
  
  
  RESULTS
  Hb Wayne eluted as two small fractions with retention times of 1.0 and 1.46min on the HPLC (Bio-Rad VARIANT-II). Alkaline gel and capillary electrophoresis showed two small bands migrating faster than HbA. Hb Wayne generated spuriously high results on the Bio-Rad VARIANT-II Turbo 2.0, no results on the Tosoh G8, and did not interfere with either the Sebia CAPILLARYS2™ or immunoassays from Roche (tinaquant) and Siemens (Bayer DCA2000+). Based on the Hb Wayne HPLC profile of 3 patients, an algorithm was developed to facilitate its detection, which identified 9 additional patients with Hb Wayne trait.
  
  
  CONCLUSIONS
  We characterize Hb Wayne by chromatographic and electrophoretic techniques and show the effect of Hb Wayne on five common HbA1c methodologies. We developed a quality assurance tool to assist in detecting Hb Wayne trait during HbA1c analysis on the Bio-Rad VARIANT-II™ Turbo 2.0.
authors.affiliation: DynaLIFE(DX) Diagnostic Laboratory Services, Edmonton, AB, Canada; Dept Laboratory Medicine and Pathology, University of Alberta, Edmonton, AB, Canada. Electronic address: karina.capote@dynalifedx.com.
authors.forename: Karina
authors.initials: K
authors.lastname: Rodríguez-Capote
authors.affiliation: DynaLIFE(DX) Diagnostic Laboratory Services, Edmonton, AB, Canada; Dept Laboratory Medicine and Pathology, University of Alberta, Edmonton, AB, Canada.
authors.forename: Mathew P
authors.initials: MP
authors.lastname: Estey
authors.affiliation: DynaLIFE(DX) Diagnostic Laboratory Services, Edmonton, AB, Canada; Dept Laboratory Medicine and Pathology, University of Alberta, Edmonton, AB, Canada.
authors.forename: Vilte E
authors.initials: VE
authors.lastname: Barakauskas
authors.affiliation: Regina Qu'Appelle Health Region, Regina, SK, Canada.
authors.forename: Teralee
authors.initials: T
authors.lastname: Burton
authors.affiliation: DynaLIFE(DX) Diagnostic Laboratory Services, Edmonton, AB, Canada.
authors.forename: Deborah
authors.initials: D
authors.lastname: Holmes
authors.affiliation: Calgary Laboratory Services, Calgary, AB, Canada.
authors.forename: Richard
authors.initials: R
authors.lastname: Krause
authors.affiliation: DynaLIFE(DX) Diagnostic Laboratory Services, Edmonton, AB, Canada; Dept Laboratory Medicine and Pathology, University of Alberta, Edmonton, AB, Canada.
authors.forename: Trefor N
authors.initials: TN
authors.lastname: Higgins
mesh_terms: D000465:Algorithms; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism; D019075:Electrophoresis, Capillary / Q000379:methods; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006453:Hemoglobinopathies / Q000175:diagnosis / Q000378:metabolism; D006455:Hemoglobins, Abnormal / Q000378:metabolism*; D006801:Humans; D017422:Sequence Analysis, DNA / Q000379:methods
chemical_list: D006442:Glycated Hemoglobin; D006455:Hemoglobins, Abnormal; C517652:hemoglobin A1c protein, human; C041280:hemoglobin Wayne
keywords: Diabetes; HPLC; HbA1c; Hemoglobinopathy; Interference; Quality assurance