Performance Evaluation of the Afinion AS100 Analyzer for Its Use in the Albumin Creatinine Ratio Test

Lee, Yong Wha; Kim, Jeong Gwon

Abstract

BACKGROUND
Early detection of moderately increased albuminuria using the albumin-creatinine ratio (ACR) test is very important for preventing renal insufficiency and cardiovascular disease in patients with diabetes. The purpose of this study was to analyse the clinical usefulness of the Afinion AS100 Analyzer (Alere Technologies AS, Norway) for determining the ACR by evaluating its precision and linearity and comparing it with another conventional device.
METHODS
Urine samples of patients and quality control materials were used for evaluation. The Afinion AS100 was used to measure albumin and creatinine, and the ACR was automatically calculated. The Cobas Integra 800 (Roche Diagnostics, Germany) was used as a reference instrument for correlation analysis. In accordance with the Clinical and Laboratory Standards Institute guidelines, precision, linearity, and turnaround time were evaluated, and the Afinion AS100 was compared with another device.
RESULTS
The total coefficients of variation of albumin and creatinine were 2.8% and 2.9% for high concentration and 2.9% and 2.5% for low concentration, respectively. Both albumin and creatinine showed coefficients of determination of 0.999 or higher in linearity. Correlation coefficients of albumin, creatinine, and ACR were higher than the Clinical and Laboratory Standards Institute recommended value of 0.975, suggesting a high correlation as well as showing significant correlation with a 24-hour urinary albumin level obtained using the Cobas Integra 800. Mean turnaround time was 5 minute 35 seconds.
CONCLUSIONS
The albumin, creatinine, and ACR tests performed with the Afinion AS100 showed satisfactory performance in terms of precision and linearity and showed good correlation with the central laboratory instrument and a 24-hour urine albumin quantitative test using a conventional instrument.