Infusion of plasma expanders may lead to unexpected results in urinary protein assays

de Keijzer, MH Klasen, IS Branten, AJW Hordijk, W Wetzels, JFM

Mh. De Keijzer et al., Infusion of plasma expanders may lead to unexpected results in urinary protein assays, SC J CL INV, 59(2), 1999, pp. 133-137

14

INGLESE

Article

Research/Laboratory Medicine & Medical Tecnology","Medical Research General Topics

SCANDINAVIAN JOURNAL OF CLINICAL & LABORATORY INVESTIGATION

0036-5513 → ACNP

59

2

1999

133 - 137

ISI

0036-5513(199904)59:2<133:IOPEML>2.0.ZU;2-V

Overt proteinuria was detected in the urine of a potential kidney donor, ul timately leading to the refusal of the kidneys for transplantation purposes . Histological examination of the kidneys did not reveal any abnormalities. Searching for substances that could have interfered with the urinary total protein assay, the role of infused, modified gelatin plasma expanders was investigated. We therefore measured the concentration of protein before and after the addition of various artificial plasma expanders to urine. Only w hen Biuret reagent or Pyrogallol Red dye were used did we find elevated con centrations of protein. Other methods, including the turbidimetric assays, did not detect additional amounts of protein in the spiked urine. We conclu de that the infusion of modified gelatin solutions may cause apparent prote inuria. This effect is not observed with starch-based plasma expanders. Cli nical chemists and clinicians should be aware of this phenomenon and possib ly repeat the analysis with a different technique.