Effect of plasma replacement therapy on determinations of urine protein concentration.

Total protein concentration in urine is currently analyzed in our laboratory by a colorimetric method—Pyrogallol Red (PR)–molybdate complex (1)—adapted to a Cobas Integra analyzer (Cobas Integra Total Protein Urine/CSF 07.5723.3; Roche). We quantify specific urinary proteins by the following immunochemical methods: turbidimetry for urinary albumin (Cobas Integra) and nephelometry for IgG, α1-microglobulin, and light chains of immunoglobulins (BNAII; Behring). We recently observed discrepancies between results obtained for some urine samples, in that the total protein concentration was increased and did …