The urine microalbumin test is used as a screening test for the diagnosis of renal complications in diseases, such as diabetic nephropathy, cardiovascular disease, and hypertension.

A urine dipstick test that can conveniently and semiquantitatively measure concentrations of urine microalbumin and creatinine as well as the albumin/creatinine ratio (ACR) has been developed and the diagnostic performance of the dipstick evaluated.

Laboratory scientists at the University of Ulsan College of Medicine (Seoul, Republic of Korea) and their colleagues randomly selected 1,040 urine specimens that had been sent for ACR tests from July 1, 2011, to August 31, 2011. Albumin and creatinine tests were performed using random, midstream spot urine samples, and all tests were completed within two hours of urine collection. The results of the dipstick tests were compared with measurements obtained by a quantitative analyzer.

The newly introduced semiquantitative urine dipstick evaluated was the URiSCAN Super cassette ACR (URiSuper-ACR, YD Diagnostics Corp.; Yongin-si, Republic of Korea). Detection of albumin and creatinine in the URiSuper-ACR were performed using the dye-binding and metal complex methods, respectively. The color change made by the reaction was measured by the URiSCAN Super Plus reflectance meter. The Cobas Integra 800 quantitative analyzer (Roche Diagnostics; Rotkreuz Switzerland), which uses immunoturbidometric and the Jaffe-kinetic method, was used as the comparison methodology.

The URiSuper-ACR test showed 88.8% and 86.3% sensitivity and 90.1% and 93.8% specificity for albumin concentration and ACR, respectively and showed 91.1% and 92.6% positive predictive values. The concordance rate between URiSuper-ACR and Cobas Integra quantitative method for albumin and creatinine concentration within the same category were 78.4% and 67.1%, respectively, and for the ±1 category were 98.8% and 99.5%, respectively. For ACR, an 80.0% concordance rate was seen within the same category.

The authors concluded that in their evaluation study on a heterogeneous patient group, the URiSuper-ACR showed good diagnostic performance, such as excellent sensitivity, specificity, concordance rate with quantitative method, linearity, and precision, and this method could be used as an effective screening tool for the detection of microalbuminuria in clinical laboratories. The study was published in the July 2014 issue of the Journal of Clinical Laboratory Analysis.

Related Links:
University of Ulsan College of Medicine
YD Diagnostics Corp. 
Roche Diagnostics