Multicenter Evaluation of Tosoh Glycohemoglobin Analyzer

Background: We describe an Anglo-French evaluation of a new analyzer.

Methods: The Tosoh HLC-723 GHb V, A1c2.2 glycohemoglobin analyzer is an HPLC instrument with primary blood tube sampling, bar-code reading, cap piercing, and the ability to chromatographically separate labile hemoglobin A1c (HbA1c). We evaluated two analytical protocols, 2.2 and 3.0 min, and compared results for blood samples collected from diabetic and nondiabetic subjects with those obtained with Bio-Rad Diamat and Variant analyzers.

Results: Within- and between batch-imprecision (CVs) was <2% with linearity to at least 15.9% HbA1c. Although some hemoglobinopathies were detected in the 2. 2-min chromatography, clearer evidence of abnormality was visible in the 3.0-min version. Comparison with established methods showed good correlation (r = 0.993; n = 316 with Diamat; and r = 0.995; n = 133 with Variant) but highlighted calibration differences.

Conclusions: The problems of manual blood sample preparation, labile HbA1c, and carbamylated hemoglobin interference associated with the older instruments have been eliminated in the new Tosoh analyzer. The 3. 0-min protocol is preferred for routine use.