[Evaluation of Variant II analyzer equipped with the new 270-2101 NU kit (Bio-Rad) for HbA 1c assay]

Abstract

HbA(1c) represents a key parameter in the follow-up of glycemic balance in diabetic patients. It may be assayed by different methods, among which high-pressure liquid chromatography (HPLC). We have evaluated a new method available on HPLC Variant II analyzer (BioRad) equipped with the new kit 270-2101 NU. Chromatographic separation is improved, allowing a better identification of peaks. Intra- and inter-assay coefficients of variation are respectively lower than 1.1% and 1.8%. Linearity is excellent from 3.2% to more than 18%. The correlation with the previous method (kit 270-2101) is good: y (% HbA(1c) new kit) = 0.944x (% HbA(1c) previous kit) + 0.299, r(2) = 0.995. There is no inter-sample contamination. This method is less sensitive to interferences frequently found in practice (labile glycated hemoglobin, carbamylated haemoglobin) than the previous one. Validation is possible in more circumstances when an abnormal hemoglobin is present (especially in case of hemoglobin D or E). As the control of analytic quality is a major element for validation and clinical use of HbA(1c) results, the characteristics of this new method make it a well-suited tool for daily laboratory practice.