[Evaluation of a strip test (Micral test) for the semi-quantitative assessment of microalbuminuria in clinical practice].

Microalbuminuria (AER 20-200 micrograms/min) is the earliest clinical sign of incipient diabetic nephropathy. Current methods for measuring urinary albumin are not suitable for use in an office setting. A test strip (Micral-Test, Boehringer Mannheim [D]) based on immunochemical principles has recently been developed which allows semiquantitative detection of urinary albumin concentrations. In this study Micral-Test results were compared with conventional immunoturbidimetric laboratory measurement. 65 single-void urine samples of diabetic patients were analyzed (38 type 1, 27 type 2). Urinary albumin values as obtained from Micral-Test and laboratory measurement showed a significant correlation (r = 0.85, p less than 0.001). An interclass correlation was performed for normal urinary albumin values (less than 20 micrograms/ml) and for microalbuminuric values (20-200 micrograms/ml) and resulted in correlation coefficients of 0.56 and 0.81 respectively. Interindividual variation was checked by three observers reading the same 13 urine samples. The values obtained from the three observers correlated significantly (r greater than 0.95, p less than 0.001). The test strip must be evaluated after precisely 5 minutes in order to avoid false pathological results. In conclusion, the Micral-Test is a good screening method for easy and quick detection of microalbuminuria in an office setting.