EVALUATION OF GLYCEMIC CONTROL LIMITS USING THE AMES-DCA-2000 HBA(1C) ANALYZER

The Ames DCA 2000 is a benchtop analyser that measures HbA(1c) by an agglutination inhibition immunoassay using a monoclonal antibody. Laboratory and nursing staff measured HbA(1c) on-site in 78 patients with Type 1 diabetes at the outpatient clinic. Significant correlations were noted with both the Coming Glytrac total HbA(1) assay (r = 0.89) and the Novoclone assay for HbA(1c) (r = 0.95). Mean within-assay CV was 1.6 % and 3.0 % at HbA(1c) of 5.4 % and 13.0 %, respectively, while between-assay CVs were 4.2 % and 3.8 %. These results are as good as our routine laboratory method based on the Corning HbA(1) assay. Locally derived reference population data for HbA(1c) were produced and patients were assigned to categories of good, acceptable, and poor glycaemic control using conventional recommendations for Type 2 diabetes. There was poor agreement between the methods, with only 22 % of patients achieving good/acceptable control using the DCA 2000, while 46 % of patients had an HbA(1) in this range. It appears that the convention for derivation of control limits for HbA(1) does not hold for this HbA(1c) assay.