The Significance of Trace Proteinuria

Sam, R.
Shaykh, M. S.
Pegoraro, A. A.
Khalili, V.
Hristea, I.
Singh, A. K.
Arruda, J. A.L.
Dunea, G.

^a Division of Nephrology, Cook County Hospital,
^b Section of Nephrology, University of Illinois at Chicago and VAMC, West Side Division,
^c Hektoen Institute for Medical Research, Chicago, Ill., USA

Received: July 14, 2003

Accepted: September 12, 2003

Published online: October 28, 2003

American Journal of Nephrology 23(6):p 438-441, December 2003. | DOI: 10.1159/000074535

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.