Haemoglobin J-Baltimore can be detected by HbA1c electropherogram but with underestimated HbA1c value.

Valéry Brunel,Christian Thuillez,Abdeslam Chagraoui,Agnès Lahary

doi:10.11613/bm.2016.026

Abstract

Glycated haemoglobin (HbA1c) is considered the gold standard for assessing diabetes compensation and treatment. In addition, fortuitous detection of haemoglobin variants during HbA1c measurement is not rare. Recently, two publications reported different conclusions on accuracy of HbA1c value using capillary electrophoresis method in presence of haemoglobin J-Baltimore (HbJ). Here we describe the fortuitous detection of unknown HbJ using capillary electrophoresis for measurement of HbA1c. A patient followed for gestational diabetes in our laboratory presented unknown haemoglobin on Capillarys 2 Flex Piercing analyser which was identified as HbJ. HbJ is not associated with haematological abnormalities. High Performance Liquid Chromatography methods are known to possibly underestimate HbA1c value in the presence of this variant. This variant and its glycated form are clearly distinguished on electropherogram but HbJ was responsible for underestimating the true area of HbA1c. Capillary electrophoresis is a good method for detecting HbJ but does not seem suitable for evaluation of HbA1C value in patients in presence of HbJ variant.

Highlights

Glycated haemoglobin (HbA1c) is considered the gold standard for assessing diabetes compensation and treatment
We report a case of haemoglobin J-Baltimore detected by electropherogram and discuss the consequences of the presence of this haemoglobin variant on accurate interpretation of HbA1c result obtained by C2FP analyser
HbA1c was measured at 4.6% (27 mmol/mol) with the presence of an unknown peak in P3 window, the window on Variant’s chromatogram where haemoglobin variant could be detected, quantified at 44.3%

Summary

Introduction

Glycated haemoglobin (HbA1c) is considered the gold standard for assessing diabetes compensation and treatment. Fortuitous detection of haemoglobin variants during HbA1c measurement is not rare. An analytical evaluation of Capillarys 2 Flex Piercing (C2FP, Sebia, Lisses, France) has been published, assessing the possible interference of the most common haemoglobin variants in African immigrants to the United States [1]. The authors concluded that those common African haemoglobin variants, notably heterozygous for haemoglobin S (HbS) or haemoglobin C (HbC), could be detected, and do not interfere with HbA1c results and do not impair the ability of HbA1c to detect abnormal glucose tolerance on C2FP analyser. We report a case of haemoglobin J-Baltimore detected by electropherogram and discuss the consequences of the presence of this haemoglobin variant on accurate interpretation of HbA1c result obtained by C2FP analyser

Methods

Results

Conclusion