An evaluation of glycated haemoglobin eluting in zone 10 on capillary zone electrophoresis

Abstract

This is the first report of glycated haemoglobin (Hb) eluting in zone 10 on capillary zone electrophoresis (CZE). In an index case, the aberrant peak was picked up during routine haemoglobinopathy testing using CZE. Mass spectrometry (MS) revealed this aberrant peak to be glycated Hb. Prompted by this initial case, a study was undertaken and the results showed that there was a strong positive linear relationship (R2 = 0.774; ρ = 0.88) between the level of glycated Hb peak eluting in zone 10 and the HbA1c value. Furthermore, all samples with an HbA1c of 54 mmol/mol or greater had an HbA1c peak eluting in zone 10.

Electrospray triple quadrupole mass spectrometry guides pathologists to suggest appropriate molecular testing in the identification of rare hemoglobin variants

“…Glutathionylation of hemoglobin at βCys93 residue may result from an oxidative imbalance in erythrocytes [31] . Case five was confirmed by molecular sequencing as Hb J Bangkok, with similar CE patterns as observed by Beverley [7] . In the absence of mass information, definitive identification of variants requires molecular sequencing of HBA1, HBA2 and HBB genes.…”

“…1 a, b) were presumed to be α variants based on the presence of minor peaks in zone D or zone D/S. Case one displayed a different migration position on the x-axis (1 0 2) compared to case two (x-axis 80), indicating the presence of two distinct α variants [7] . However, the variant percentage was similar in both cases at 28 %.…”

“…One example of such a variant is the HbJ family, which encompasses around 50 different forms [5] , [6] . Some examples of α variants include HbJ Meerut, HbJ Birmingham, and HbJ Cape Town; while β variants include HbJ Baltimore/Bangkok/Kaohsiung/Cape Town, which are observed in various ethnicities globally [7] .…”

“…The clinical presentation of patients with HbJ variants range from asymptomatic cases to mild effects on hematologic indices [8] , [9] . Presumptive identification of these variants has been reported based on migration zone, migration axis and percentage of the variant using CE [7] . Confirmation is typically performed through molecular sequencing [9] of the α and β genes of Hb.…”

Glycated Hemoglobin and Methods for Its Point of Care Testing

“…Various chromatographic methods, spectrometric methods and their combination are common in the clinical praxis. High-performance liquid chromatography (HPLC) [ 43 , 44 ], cation exchange HPLC [ 45 ], Liquid chromatography (LC) tandem MS [ 46 , 47 , 48 ], matrix-assisted laser desorption ionization time-of-flight MS [ 49 ], capillary electrophoresis [ 50 , 51 ] and capillary zone electrophoresis tandem MS [ 52 , 53 ] can be mentioned as suitable for distinguishing between hemoglobin types. Immunochemical methods like the precipitation–turbidimetric method [ 50 ], fluorometric immunoassays [ 54 ] and the enzyme-linked immunosorbent assay (ELISA) [ 55 , 56 , 57 ] are also suitable for HbA 1c measurement.…”