Glycosal TM : The First Rapid,Point-of-Care Test for the Determination of Hemoglobin A 1c in Patients with Diabetes

Abstract

Background: Glycosal^TM is a rapid, point-of-care test using the established method of affinity chromatography for the quantitative determination of hemoglobin A_1c (HbA_1c). Glycosal enables the measurement of HbA_1c to be performed in the diabetic clinic or doctor's office during a normal consultation, within minutes. The Glycosal test cartridge integrates with HaemaQuar^TM, a compact spectrophotometric analyser equipped with a light emitting diode (LED) photo-optic detection system. An interactive liquid crystal display (LCD) provides the operator with an intuitive guide through the test procedure with the final result being expressed as HbA_1c. Glycosal has a linear working range of at least 3%-18% HbA_1c, requires approximately 10 mu L of whole blood and generates a result in approximately 4 minutes. Glycosal has a mean coefficient of variation of less than 5% across its linear range. Methods: Glycosal was evaluated in the clinical environment by means of comparison to two routine HbA_1c autoanalyser methods used in the Clinical Chemistry Department of the Malmo University Hospital, Sweden. The Variant (BioRad) and the Mono-S (Pharmacia) systems are both cation exchange high-performance liquid chromatography (HPLC) systems specifically measuring HbA_1c. Fresh (<2 days) EDTA anticoagulated blood samples were randomly selected from the routine diabetic clinic (n = 54) along with nondiabetic samples from consenting volunteers (n = 8). Results: The Variant and Mono-S HPLC methods showed excellent agreement compared to each other (correlation coefficient [r] > 0.99). The agreement between Glycosal and Variant (r = 0.98) and Glycosal and Mono-S (r > 0.98) HPLC methods were almost equally as significant. A further final evaluation of a 10 sample series(4%-10% HbA_1c) of the hospital's HbA_1c reference materials by Glycosal produced very strong agreement (r > 0.99) against the Mono-S HPLC. Conclusions: The Glycosal rapid test is proven to be comparable to two high-precision cation exchange HPLC autoanalyzers and constitutes a low-cost, HbA_1c measurement system for the management of individuals suffering from diabetes mellitus at the point-of-care.