Analytical Performances of an Enzymatic Assay for the Measurement of Glycated Albumin

Abstract

Background: Short to intermediate integrated glycemic control is best determined by glycated albumin (GA). This assay is appropriate when interpretation of glycated hemoglobin (HbA 1c) is critical because of hemoglobinopathies, severe anemias, or other factors that affect red blood lifespan as hemodialysis. We evaluated a new assay based on the enzymatic quantification of GA by ketoamine oxidase and an albumin-specific protease. Methods: Limits of blank, detection, and quantification; precision; linearity; accuracy; interferences; correlation with HbA 1c ; and serum vs plasma study have been evaluated on ILab ® systems. Results: Limit of blank, detection, and quantification for GA (g/L) were, respectively, 0.26, 0.36, and 1.15. Repeatability and within-device precision CVs were lower than 2.11%, 1.61%, and 1.56% for GA (g/L), albumin (g/L), and GA%, respectively. Linearity for GA (g/L) and GA% was 1.2-36.8 and 5.5-92.2, respectively. Highest deviation from linearity was <11% and recovery was higher than 90%. Accuracy against the certified ReCCS Japan Clinical Chemistry Reference Material (JCCRM) 611 was <1%. Classical interfering substances had no significant impact. Correlation of GA% between ILab ® Taurus and ADVIA system was y = 1.02[GA%]+0.25; R 2 = 0.994. No difference was found in the determination of GA% in serum vs plasma. Conclusions: GA enzymatic assay is a reliable, fully automated method allowing accurate and precise determination of GA in a routine laboratory. IMPACT STATEMENT This article will benefit both diabetic patients with hemoglobinopathies or reduced red blood cell lifespan that need an alternative marker for glycemic control and people at risk of developing diabetes. Data show glycated albumin (GA) assay reliability. Moreover, it is easy to use, being a clinical chemistry assay: it can be run on standard clinical chemistry automated systems. This article summarizes almost a full proof of performance report of a GA assay investigating most of the performance aspects as precision, accuracy, linearity, and interference study.

Update on biomarkers of glycemic control

“…However, these methods are complicated and expensive and require dedicated equipment and expertise, and this has limited their routine use. Consequently, simpler and more affordable colorimetric and enzymatic methods, applicable on various automated analytical platforms, were developed for use in clinical laboratories[69]. Enzymatic methods showed a better analytical performance and were free of colorimetric interferences ( e.g ., bilirubin)[70-72].…”

A selective LSPR biosensor for molecular-level glycated albumin detection

“…A research group [ 50 ] was able to detect 0.47 mg/ml in an enzymatic test and 50 g/ml in a graphene-based aptasensor, which performs better in terms of limit of detection but in the consideration of quick and cost-effective detection platform this LSPR based sensor performed well [ 51 ]. For GA detection various methods were applied to achieve the LD, some of them are electrochemiluminescence sensor (0.1 μM (6.6 μg ml −1 )) [ 52 ], Enzymatic assay sensor (0.36 mg/ml) [ 53 ], Electrochemical (3 μg ml −1 ) [ 54 ], Raman spectroscopy sensor (13.7 μM) [ 55 ], colorimetric sensor based on Hydrazine (0.7 μM) [ 56 ], immunoturbimetric sensor focused on chromatography (0.81 mg l −1 ) [ 57 ]. GA content in HS was also discovered to be 3–105.3 μM (0.2–7.0 mg/ml) [ 50 , 51 ].…”

Monitoring gestational diabetes at the point-of-care via dual glycated albumin lateral flow assays in conjunction with a handheld reader

“…The use of bare gold nanoparticles for colorimetric signal generation is a sensitive and cost-effective optical transduction technique since it does not require any dye and uses less sophisticated equipment for signal generation and measurement. [37][38][39][40] Ikeda et al, 41 Testa et al, 42 and Ko et al 43 have published assays for glycated albumin detection using various enzymatic methodologies. Inoue et al, 44 and Bohli et al 45 have published enzyme and antibody-based sensors using electrochemical detection methods.…”

“…Ikeda et al , 41 Testa et al , 42 and Ko et al 43 have published assays for glycated albumin detection using various enzymatic methodologies. Inoue et al , 44 and Bohli et al 45 have published enzyme and antibody-based sensors using electrochemical detection methods.…”