The silent hemoglobin α chain variant Hb Riccarton [α51(CE9)Gly→Ser] may affect HbA1c determination on the HLC-723 G7 analyzer
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Johannes M.W. van den Ouweland
Abstract
Background: Structural hemoglobin variants can affect the accuracy of hemoglobin A1c (HbA1c) testing and represent the most common pitfall in the determination of HbA1c. We here describe the characterization of an α chain variant in diabetic patients as the cause of an abnormal presentation of the HbA1c fraction on the HLC-723 G7 analyzer.
Methods: HbA1c analysis was performed using various HPLC-based HbA1c analyzers and by immunoassay. α-Globin mutation analysis was performed by GAP-PCR and DNA sequencing.
Results: The peak partially overlapping HbA1c in the chromatogram represents the glycated fraction of the silent α chain variant Hb Riccarton [α51(CE9)Gly→Ser]. This aberrant peak is uniquely identified by the HLC-723 instrument, as it is not observed on other HPLC-based HbA1c analyzers. Occasionally, the HLC-723 may fail to properly integrate both glycated Hb fractions, resulting in a falsely low HbA1c result. The variant was confirmed in samples from other diabetic patients with identical chromatographic patterns.
Conclusions: The silent α chain variant Hb Riccarton [α51(CE9)Gly→Ser] leads to an abnormal chromatographic presentation on the HLC-723 analyzer with a risk of erroneous HbA1c determination. Manual validation of chromatograms to detect abnormalities caused by Hb variants is important to prevent incorrectly produced HbA1c results from being reported.
Clin Chem Lab Med 2008;46:827–30.
©2008 by Walter de Gruyter Berlin New York
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- Cardiovascular biomarkers: increasing impact of laboratory medicine in cardiology practice
- Haemolysis: an overview of the leading cause of unsuitable specimens in clinical laboratories
- Cardiovascular Diseases
- APOA5 Ala315>Val, identified in patients with severe hypertriglyceridemia, is a common mutation with no major effects on plasma lipid levels
- Gender-modulated impact of apolipoprotein A5 gene (APOA5) −1131T>C and c.56C>G polymorphisms on lipids, dyslipidemia and metabolic syndrome in Turkish adults
- Oxidative stress markers, C-reactive protein and heat shock protein 70 levels in subjects with metabolic syndrome
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