The purpose of this study was to evaluate the utility of the semiquantitative colonmetric bromophenol-blue test in the diagnosis of microalbuminemia in 82 insulin-dependent diabetes mellitus patients, compared with radioimmunoanalysis (RIA) quantitative measurement.

In all cases, the first morning urine was analyzed twice by bromophenol blue test (Microbumintest, Bayer), maximum 30 minutes after voiding, and then freezed (-35oC) until the RIA quantitative determination. Urines with positive reaction for ketones and/or pH equal or higher than 7.0 (Bililabstix, Ames) were excluded from the study.

Since the bromophenol-blue test is positive for albumin urine concentration higher than 40 μg/mL, a similar value was considered positive in the quantitative assay. RIA was realized once for each sample, using only one kit for all urines, with intraassay variability coefficient of 0.012 to 0.069μg/dL.

The significancy test is presented: Table

Table 1
Full size table

The conciusion was that bromophenol-blue semiquantitative test is useful as screening method in order to exclude microalbuminuria, but not to diagnose it, and a positive test mus be confirmed with radioimmunoanalysis before establishing the diagnosis of nepnropathy.