title: Adaptation of latex-enhanced assay for percent glycohemoglobin to a Dade Dimension analyzer.
abstract: At present no method for glycohemoglobin (%HbA1c) is automated on a main-line analyzer to allow joint measurement with other indicators of diabetic control such as glucose and cholesterol. We describe an adaptation of a latex-enhanced competitive immunoassay for quantifying %HbA1c to the Dade International Dimension analyzer. After a manual hemolysis step, HbA1c and total hemoglobin (Hb) are determined separately. The concentration of glycated beta-subunit is obtained from the immunoassay, whereas Hb is assessed colorimetrically from a derivatized form. Both reactions were fully optimized for accuracy, precision, and specificity on the Dimension; stabilities of reagents and calibration were established; and potential interferences were assessed. The analyzer gave reliable results over the required clinical range of 1-15% HbA1c. Within-run and total assay variation were within 5% of the target CV limits, as determined by ANOVA with three representative sample pools across 20 days. Close agreement with an established HPLC procedure and a commercially available enzyme immunoassay was observed for 140 samples from clinically defined patient groups. Additional samples from patients with hemoglobinopathies (n = 20) demonstrated a more complex relationship between methods. We conclude that adaptation of the method for use with the Dimension analyzer is a valid method for quantifying %HbA1c.
authors.affiliation: Department of Clinical Biochemistry, St. Bartholomew's and the Royal London School of Medicine & Dentistry, UK. p.g.holownia@mds.qmw.ac.uk
authors.forename: P
authors.initials: P
authors.lastname: Holownia
authors.forename: E
authors.initials: E
authors.lastname: Bishop
authors.forename: D J
authors.initials: DJ
authors.lastname: Newman
authors.forename: W G
authors.initials: WG
authors.lastname: John
authors.forename: C P
authors.initials: CP
authors.lastname: Price
mesh_terms: D001322:Autoanalysis; D002138:Calibration; D002851:Chromatography, High Pressure Liquid; D003124:Colorimetry; D003920:Diabetes Mellitus / Q000097:blood; D004355:Drug Stability; D006442:Glycated Hemoglobin / Q000032:analysis*; D006400:Hematocrit; D006453:Hemoglobinopathies / Q000097:blood; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D007118:Immunoassay / Q000379:methods* / Q000706:statistics & numerical data; D007202:Indicators and Reagents; D007840:Latex; D015203:Reproducibility of Results; D012545:Schiff Bases; D012680:Sensitivity and Specificity
chemical_list: D006442:Glycated Hemoglobin; D006454:Hemoglobins; D007202:Indicators and Reagents; D007840:Latex; D012545:Schiff Bases