The significance of trace proteinuria

Am J Nephrol. Nov-Dec 2003;23(6):438-41. doi: 10.1159/000074535. Epub 2003 Oct 28.

Abstract

Background: The clinical significance of a trace protein reading on urinalysis is unclear, and such a result is often ignored by the clinician.

Methods: We examined 185 samples of urine with trace proteinuria by both Chemstrips and sulfosalicylic acid testing, and compared the results with those of urinary albumin and total protein concentrations.

Results: Taking for the purposes of this study an arbitrary upper limit of normal of 20 mg/l for albumin and 100 mg/l for total protein concentration, we found abnormal albumin excretion in 87% and abnormal total protein excretion in 88% of trace samples. In this study, a negative urinalysis for protein excluded microalbuminuria in 87% and proteinuria in 78% of cases.

Conclusion: Qualitative testing for protein by urinalysis has a high sensitivity and specificity for diagnosing or ruling out microalbuminuria. Trace proteinuria usually means microalbuminuria; negative proteinuria tends to rule it out.

Publication types

  • Comparative Study

MeSH terms

  • Albuminuria / diagnosis*
  • Benzenesulfonates
  • Humans
  • Kidney Diseases / diagnosis*
  • Proteinuria / diagnosis
  • Reagent Strips
  • Salicylates
  • Sensitivity and Specificity
  • Urinalysis / methods

Substances

  • Benzenesulfonates
  • Reagent Strips
  • Salicylates
  • sulfosalicylic acid