Evaluation of a Dual Hemoglobin A2/A1c Quantitation Kit on the Bio-Rad Variant II Automated Hemoglobin Analyzer

Abstract

Abstract Context.—Quantitation of hemoglobin (Hb) A1c and investigation of hemoglobinopathy on the Bio-Rad Variant analyzers require a switch between 2 separate kits that is time consuming and causes errors. Objective.—Evaluation of a new Variant II HbA2/HbA1c Dual kit capable of both Hb A1c quantitation and hemoglobinopathy investigation on a single kit. Design.—We evaluated Hb A1c, Hb A2, and Hb F quantitation for precision, linearity, and correlation with current methodology. We also evaluated detection of Hb variants and correlation of Hb Barts quantitation. Setting.—Hamilton Regional Laboratory Medicine Program, Provincial Hemoglobinopathy Laboratory, St Joseph's Healthcare Site, Hamilton, Ontario. Patients.—Patient blood samples submitted for Hb A1c quantitation or hemoglobinopathy investigation. Main Outcome Measures.—Precision, linearity, linear regression, and reference interval validation. Results.—We provide tables and figures illustrating precision, linearity, linear regression, and quantitation of Hb variants. We validated reference intervals for Hb A1c, Hb A2, and Hb F. Conclusions.—The dual kit provides precise Hb A1c, Hb A2, and Hb F quantitation. The results show good linearity and correlate well with the results of current methods. We detected all clinically important Hb variants and a wide variety of rare variants. The dual kit has several advantages: it eliminates the need for extensive kit switch over; improves utility for newborn screening because of its quantification of Hb Barts; permits quantification of Hb A1c using the β-Thal method; and eliminates the need for separate Hb A2 reference intervals for patients with Hb S because of its accurate quantitation of Hb A2 in the presence of Hb S.