Evaluation of Micro-Bumintest reagent tablets for screening of microalbuminuria

The presence of significant microalbuminuria is an important predictor of early diabetic nephropathy. Currently methods available to detect microalbuminuria are not suitable for routine screening. This study assessed the performance of Micro-Bumintest reagent tablets (Ames Laboratory) as a visual screening test for qualitative measurement of urinary albumin. 150 urine specimens from type 1 diabetic patients with a disease duration of less than 1-19 years were assayed over 15 runs using quantitative albumin (radioimmunoassay) and total protein assays. In parallel, 600 determinants were made with the tablets. Each sample was assessed by two readers using a color chart with patterns illustrating typical negative and positive color reactions with a grading from 1 to 7. Urinary protein was determined with an Ames Clinitek 10 urine chemistry analyzer and the Multistix 10 SG reagent strips. The results revealed that as the albumin concentration increased, the percentage of specimens detected visually as presumptive positive (grading = 3) reactions and positive reactions (grading greater than 3) increased. A positive Micro-Bumintest reaction was obtained with an albumin concentration of greater than 40 micrograms/ml. Presumptive positive reactions occur more than 50% of the time at protein concentrations greater than 14 mg/dl. The tablet test is more sensitive than the Clinitek 10/Multistix 10 SG strip system. These data show that the Micro-Bumintest reagent tablets are a sensitive and convenient screening test for detection of microalbuminuria.