Determination of glycated hemoglobin in clinically silent hemoglobin variants

Abstract

Our study underscores the need for clinical laboratories and physicians to be aware of the limitations of their HbA1c assay methods as well as the importance of visual inspection of ion-exchange chromatograms to detect abnormalities caused by the hemoglobin variants. Samples with clinically silent Hb variants should be analyzed by a second method with a different assay principle, preferably a boronate affinity HPLC or an enzymatic assay.

Glycemic control indicators in patients with neonatal diabetes mellitus

“…The etiologic diagnosis and treatment of NDM have been making rapid progress; however, there have been few studies on glycemic control indicators useful for is possible to measure all GHb by the affinity method [71] . We measured HbA1c by the HPLC method and the LA method in 26 healthy infants (0 to 8 mo old), calculated HbA1c values corrected by HbF [Adj-HbA1c (HPLC) and Adj-HbA1c (LA), respectively], measured GHb by the affinity method [GHb (Affinity)], and evaluated correlations between these values and plasma glucose and between these values and GA [72] .…”

Hemoglobin Yamagata: Hemoglobin Variant Detected by HbA1c Test

“…In contrast, the methods using immunoassays and affinity chromatography are thought to help measure the HbA1c levels accurately but do not allow the identification of Hb variants [5,11]. Therefore, if HPLC is used for determining HbA1c, the abnormal peaks produced by Hb variants can be detected in the chromatograms.…”

A Rare Case of Variant Hemoglobin (Hb Yahata) Suspected Based on Inconsistent Plasma Glucose and HbA1c Levels

“…This parameter may be determined using several methods, including ion-exchange high-performance liquid chromatography (HPLC), boronate affinity HPLC, immunoassays and enzymatic assays (3)(4)(5)(6). Ion-exchange HPLC methods are most commonly used because they are fast, accurate and reliable.…”

“…With the expansion of ion-exchange HLPC testing, inconsistencies between the plasma glucose and HbA1c levels are sometimes identified (3)(4)(5)(6). These inconsistencies most often result from the effects of an altered blood cell life span and the presence of Hb variants (3)(4)(5)(6). The prevalence of abnormal Hb ranges from 0.04% to 6.06%, with more than 700 Hb variants reported to date, 70% of which are clinically silent (7,8).…”

“…The prevalence of abnormal Hb ranges from 0.04% to 6.06%, with more than 700 Hb variants reported to date, 70% of which are clinically silent (7,8). Measuring the HbA1c level using ion-exchange HPLC methods can be used to detect clinically silent Hb variants (3)(4)(5)(6)(7)(8).…”