Evaluation of the performance of an immunoturbidimetric HbA1c reagent applied to the Siemens ADVIA 2400 automatic analyzer

Abstract

ObjectivesA new immunochemical reagent based on latex particles and antibodies against HbA1c (Axis-Shield), using Siemens ADVIA 2400 Instrument was evaluated. Design and methodsIntra-assay and total imprecision, interferences studies (bilirubin ~850μmol/L, triglycerides ~16.9mmol/L, total protein ~140g/L, sodium cyanate ~50mg/dL, ascorbic acid ~50mg/dL, urea ~24.99mmol/L, glucose ~105.46mmol/L, rheumatoid factor ~600U/mL), method comparison vs Capillary Electrophoresis (Sebia), Lot to Lot reproducibility, linearity and carry over were conducted on ADVIA 2400 according to CLSI protocols. Additionally, 40 samples were measured by the two methods and also by a NGSP reference lab. ResultsCVs % obtained by intra-assay imprecision, on 3 human HbA1c specimens at different concentrations (48, 48–64 and >64mmol/mol) in 20 replicates, were <4%. CVs % by total imprecision, performed over 20days with 4 calibrations on 3 human HbA1c samples (48, 48–64 and >64mmol/mol), resulted <4%. Interferences were studied on two human samples (42–53 and>64mmol/mol) without obtaining significant biases (<10%). Methods comparison vs Capillary Electrophoresis, performed on 120 samples ranging 23–137mmol/mol, obtaining r=0.974 as regression coefficient and a mean bias at decision level (48mmol/mol) <3%. The results obtained with the NGSP samples have allowed the certification of the new reagent. ConclusionsThe ASD reagent met the needs of clinical laboratories, fulfilling both NGSP and IFCC requirements and it is robust to endogenous interferences.