title: Commutability of control materials in glycohemoglobin determinations.
abstract: The intermethod variabilities of control materials and patient blood samples for the measurement of glycohemoglobin were compared. Sets of 50 blood samples and 15 control materials were analyzed by HPLC and affinity and immunochemical methods. For each pair of methods, the distances of the materials from the regression line of patient blood results (expressed as normalized residuals) were calculated. Only two of 15 controls had normalized residuals exceeding 3 standard deviations from the regression line. Total hemoglobin (Hb) content, Hb derivatives, and cellulose acetate electrophoresis demonstrated that only a minority of controls could be considered similar to patients' blood samples. We selected Menarini's and our home-prepared controls to simulate calibration of the different techniques by these materials. Intermethod calibration succeeded mostly in harmonizing results obtained by HPLC methods. On the contrary, calibration of the immunochemical techniques (Boehringer and Roche) did not improve intermethod agreement to a clinically useful level.
authors.affiliation: Department of Sciences and Biomedical Technologies, University of Milan, Italy. andrea.mosca@unimi.it
authors.forename: A
authors.initials: A
authors.lastname: Mosca
authors.forename: R
authors.initials: R
authors.lastname: Paleari
authors.forename: A
authors.initials: A
authors.lastname: Madè
authors.forename: C
authors.initials: C
authors.lastname: Ferrero
authors.forename: M
authors.initials: M
authors.lastname: Locatelli
authors.forename: F
authors.initials: F
authors.lastname: Ceriotti
mesh_terms: D002846:Chromatography, Affinity / Q000379:methods; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004588:Electrophoresis, Cellulose Acetate / Q000379:methods; D006442:Glycated Hemoglobin / Q000032:analysis*; D006454:Hemoglobins / Q000032:analysis*; D006801:Humans; D007118:Immunoassay / Q000379:methods; D012016:Reference Values; D015203:Reproducibility of Results
chemical_list: D006442:Glycated Hemoglobin; D006454:Hemoglobins