MULTICENTER EVALUATION OF THE MICRAL-TEST-II TEST STRIP, AN IMMUNOLOGICAL RAPID TEST FOR THE DETECTION OF MICROALBUMINURIA

OBJECTIVE - To assess the performance of the Micral-Test II immunologi c test strip for the detection of microalbuminuria, a multicenter eval uation in eight European study sites was performed. RESEARCH DESIGN AN D METHODS - Using both the Micral-Test II test strip and the routine m ethod for the determination of albumin concentration, we investigated 2,228 urine samples from diabetic patients. Additionally, interperson variability color stability, and possible interfering factors (tempera ture, pH, leucocyturia, erythrocyturia, and drugs) were tested. RESULT S - For a cutoff concentration of 20 mg/l with respect to the routine methods, a sensitivity of 96.7% and a specificity of 71% were calculat ed for the Micral-Test TI test strip. The negative predictive value wa s 0.95, and the positive predictive value was 0.78, with a prevalence of positive samples (laboratory method) of 52%. The interperson variab ility of color interpretation showed 93% concordant readings. The inte rference study showed an influence of oxytetracycline, leading to high er readings. There was no interference from pH. A sample temperature o f < 10 degrees C led to lower readings. In the case of samples with ma ssive leucocyturia and erythrocyturia that may delete the chromatograp hic process, waiting an additional 1-2 min is needed before reading. C ONCLUSIONS - The results of the multicenter evaluation show that the M icral-Test II test strip permits an immediate and reliable semiquantit ative determination of low albumin concentrations in urine samples wit h an almost user-independent color interpretation.