title: Haemoglobin J-Baltimore can be detected by HbA1c electropherogram but with underestimated HbA1c value.
abstract: Glycated haemoglobin (HbA(1c)) 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 HbA(1c) 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 HbA(1c). 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 HbA(1c) 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 HbA(1c).  Capillary electrophoresis is a good method for detecting HbJ but does not seem suitable for evaluation of HbA(1C) value in patients in presence of HbJ variant.
authors.affiliation: Department of Medical Biochemistry, Rouen University Hospital, Rouen, France.
authors.forename: Valéry
authors.initials: V
authors.lastname: Brunel
authors.affiliation: Department of Haematology, Rouen University Hospital, Rouen, France.
authors.forename: Agnčs
authors.initials: A
authors.lastname: Lahary
authors.affiliation: Department of Medical Biochemistry, Rouen University Hospital, Rouen, France.
authors.forename: Abdeslam
authors.initials: A
authors.lastname: Chagraoui
authors.affiliation: Department of Medical Biochemistry, Rouen University Hospital, Rouen, France; Department of Pharmacology, Rouen University Hospital, Rouen, France.
authors.forename: Christian
authors.initials: C
authors.lastname: Thuillez
mesh_terms: D000328:Adult; D016640:Diabetes, Gestational / Q000097:blood*; D019075:Electrophoresis, Capillary; D005260:Female; D006442:Glycated Hemoglobin / Q000302:isolation & purification* / Q000378:metabolism; D006448:Hemoglobin J / Q000302:isolation & purification* / Q000378:metabolism; D006801:Humans; D011247:Pregnancy
chemical_list: D006442:Glycated Hemoglobin; D006448:Hemoglobin J; C517652:hemoglobin A1c protein, human; C030639:hemoglobin J Baltimore
keywords: capillary electrophoresis; glycated haemoglobin; haemoglobin J-Baltimore