MICRAL-TEST (R) - A QUALITATIVE DIPSTICK TEST FOR MICROALBUMINURIA

Micro-albuminuria is a very sensitive predictor of the development of renal disease in insulin- and non-insulin-dependent diabetes mellitus. A reliable dipstick test for routine screening for micro-albuminuria is, therefore, desirable. Such a test has been developed by Boehringer Mannheim, Germany, and marketed as Micral-Test(R). It is an immunological slide-test with semi-quantitative properties. To evaluate its performance as a screening test we compared it with a turbidimetric immuno-assay. In 396 urine specimens from 132 patients, sensitivity was 91 % and specificity 96 % for a discriminating albumin level of 20 mg/l. Correlation with quantitative values was reasonable (r = 0.73). We also tested for micro-albuminuria, defined as mean albumin excretion rate of greater-than-or-equal-to 20 mug/min, determined with the turbidimetric immuno-assay in timed ovenight urines on three consecutive days, whereas Micral-Test was considered to be positive for micro-albuminuria if the albumin concentration in one of the three urine samples was greater-than-or-equal-to 20 mg/ml. In 132 patients, the sensitivity of Micral-Test was 82 % and the specificity 86 %. Albumin excretion rate in all false-negative results was < 50 mug/min. We therefore concluded that Micral-Test is a useful qualitative screening test for micro-albuminuria in diabetic patients.