Analytical performances of a glycated albumin assay that is traceable to standard reference materials and reference range determination.

Background: Glycated albumin (GA) is an intermediate-term marker for monitoring glycemic control (preceding 2-3 weeks) in patients with diabetes mellitus. We evaluated the performance of Lucica Glycated Albumin-L, a new GA assay that is traceable to standard reference materials and determined the reference range in healthy subjects without diabetes.

Methods: The performance and reference range studies were conducted in accordance with Clinical and Laboratory Standards Institute (CLSI) Guidelines. The traceability was established using reference material recommended by the Japan Society of Clinical Chemistry (JSCC).

Results: The coefficient of variation (CV) of overall repeatability, within-laboratory precision, and overall reproducibility values of GA values were not more than 2.6%, 3.3%, and 1.6%, respectively, among laboratories. The GA values showed good linearity from 173 to 979 mmol/mol (9.4%-54.9%) across the assay range. The GA reference range in 262 healthy subjects was between 183 and 259 mmol/mol (9.9%-14.2%) while that of subjects with diabetes was 217-585 mmol/mol (11.8-32.6%). The reagent was stable for 2 months on the bench at room temperature. The limits of blank, detection, and qualification were 6.9, 7.9, and 9.7 μmol/L for GA concentration, and 3.8, 7.0, and 21.8 μmol/L for albumin concentration, respectively. Hemoglobin slightly affected the assay, while other classical interfering substances had no significant impact.

Conclusions: The present GA assay shows comparable performance to current clinical assays and could be used for intermediate-term monitoring of glycemic control in diabetes patients.