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: Karina Rodríguez-Capote, Mathew P Estey, Vilte E Barakauskas, Teralee Burton, Deborah Holmes, Richard Krause, Trefor N Higgins
• Journal: Clinical biochemistry (Clin Biochem) Vol. 48 Issue 16-17 Pg. 1144-50 (Nov 2015) ISSN: 1873-2933 [Electronic] United States
• PMID: 26247176 (Publication Type: Journal Article)
• Copyright: Copyright © 2015 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Chemical References

• Glycated Hemoglobin A
• Hemoglobins, Abnormal
• hemoglobin A1c protein, human
• hemoglobin Wayne

Topics

• Algorithms
• Chromatography, High Pressure Liquid (methods)
• Diabetes Mellitus, Type 2 (metabolism)
• Electrophoresis, Capillary (methods)
• Glycated Hemoglobin (metabolism)
• Hemoglobinopathies (diagnosis, metabolism)
• Hemoglobins, Abnormal (metabolism)
• Humans
• Sequence Analysis, DNA (methods)