title: Identification of the Presence of Variant Hemoglobin Using a Measurement of the Labile HbA1c (#C) Fraction.
abstract: Labile HbA1c migrates in the #C fraction together with modified hemoglobin (such as carbamylated hemoglobin, acetaldehyde hemoglobin, and acetylated hemoglobin) when HbA1c is measured by Arkray's high-performance liquid chromatography (HPLC). It is assumed that most of the labile glycation products of variant hemoglobin do not migrate in #C fraction; in addition, a part of the stable glycation products of variant hemoglobin migrates in #C fraction. We hypothesized that subjects with variant hemoglobin are likely to show abnormally low or high values of #C fraction. In this study, we investigated this hypothesis. Twenty-one non-diabetic subjects with nine types of variant hemoglobin, and 103 non-diabetic subjects without variant hemoglobin were used. HbA1c and #C fraction were measured by Arkray's HPLC (HA-8180) using standard mode. The values of #C fraction in the control group were 1.75 ± 0.15% (range: 1.5-2.1%). The variant hemoglobin group reported #C fraction values of ≤1.3% in twelve subjects, ≥2.3% in five subjects, and within the reference range (1.4-2.2%) in three subjects. When the cutoff values of #C fraction were set at ≤1.3% and ≥2.3%, sensitivity and specificity were 86% and 100%, respectively. Most non-diabetic subjects with variant hemoglobin showed abnormal values of #C fraction. Measurement of #C fraction is a useful screening test for variant hemoglobin in non-diabetic subjects.
authors.affiliation: Department of Internal Medicine, Kawanishi City Hospital, Kawanishi, Japan m-koga@kawanishi-city-hospital.com.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Koga
authors.affiliation: Department of Internal Medicine, Kawanishi City Hospital, Kawanishi, Japan.
authors.forename: Shinya
authors.initials: S
authors.lastname: Inada
authors.affiliation: Department of Clinical Laboratory Medicine, Hyogo Medical College, Nishinomiya, Japan.
authors.forename: Ayako
authors.initials: A
authors.lastname: Miyazaki
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002851:Chromatography, High Pressure Liquid; D003920:Diabetes Mellitus / Q000097:blood; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006455:Hemoglobins, Abnormal / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged
chemical_list: D006442:Glycated Hemoglobin; D006455:Hemoglobins, Abnormal
keywords: HPLC; HbA1c; labile HbA1c; variant hemoglobin