Simplifed Algorithm for Evaluation of Proteinuria in Clinical Practice: How should A Clinician Approach?

Abstract

Background: Proteinuria is a common laboratory fnding among children and adolescents. It can be identifed as either a transient or a persistent fnding and can represent a benign condition or a serious disease.

Methods: Pertinent medical literature for asymptomatic proteinuria in children and adolescents published in English was searched between January 1980 and May 2017 using PubMed, MEDLINE, EMBASE, and Google Scholar research databases. Of the 64 reviewed articles, 24 studies were eligible for inclusion.

Results: Random spot urine protein‑to‑creatinine (PCR) ratio is widely used to reliably detect proteinuria. The normal value for the spot PCR in children
aged 2 years or older is less than 0.3. In children aged below 2 years, the PCR can be as high as 0.5. Orthostatic proteinuria is defned as urine PCR greater than 0.3 detected in a urine specimen during the daytime activity but less than 0.3 on the frst morning void specimen. PCR above 3.0
signifes heavy proteinuria as seen in nephrotic syndrome. Orthostatic proteinuria is a frequent cause of proteinuria in asymptomatic children and adolescents, which require no specifc therapy except for health maintenance follow‑up. Pediatric nephrologist referral is indicated when the proteinuria is constant and persists over 6 months or is associated with hematuria, hypertension, or renal dysfunction.

Conclusions: We provide a simplifed diagnostic algorithm for evaluation of proteinuria in primary care adolescents who appear well and in whom proteinuria is incidentally discovered during a routine examination.

Keywords: Adolescents, algorithm, asymptomatic proteinuria, children