Evaluation of proteinuria in children
- Olivia Gillion Boyer, MD, PhD
Olivia Gillion Boyer, MD, PhD
- Associate Professor of Pediatrics
- Pediatric Nephrology, Imagine Institute, Paris-Descartes University, Hôpital Necker - Enfants Malades, Paris, France
- Section Editors
- Patrick Niaudet, MD
Patrick Niaudet, MD
- Section Editor — Pediatric Nephrology
- Professor of Pediatrics
- Hôpital Necker-Enfants Malades, Paris, France
- Jan E Drutz, MD
Jan E Drutz, MD
- Section Editor — General Pediatrics
- Professor of Pediatrics
- Baylor College of Medicine
Proteinuria as a marker of renal disease has been well established. The dilemma that faces the primary care clinician is to differentiate the child with transient or other benign forms of proteinuria from the child with proteinuria from renal disease.
An overview of the evaluation of proteinuria in children will be presented here. Some related issues, including the mechanisms of proteinuria, are discussed in more detail elsewhere. (See "Assessment of urinary protein excretion and evaluation of isolated non-nephrotic proteinuria in adults".)
PATHOPHYSIOLOGY AND CLASSIFICATION
Normal protein excretion — Urinary protein excretion in the normal child is less than 100 mg/m2 per day or a total of 150 mg per day. In neonates, normal urinary protein excretion is higher, up to 300 mg/m2, because of reduced reabsorption of filtered proteins.
Approximately one-half of normal protein excretion consists of proteins secreted by tubular epithelium, mostly Tamm-Horsfall protein (uromodulin). The other half consists of plasma proteins including albumin, which accounts for approximately 40 percent of the total urinary protein, and low molecular weight (LMW) proteins, such as beta-2 microglobulin and amino acids.
The normally low rate of urinary protein excretion is due to two factors:
Subscribers log in hereLiterature review current through: Oct 2017. | This topic last updated: Jun 19, 2017.References
- Morcos SK, el-Nahas AM, Brown P, Haylor J. Effect of iodinated water soluble contrast media on urinary protein assays. BMJ 1992; 305:29.
- Hogg RJ, Portman RJ, Milliner D, et al. Evaluation and management of proteinuria and nephrotic syndrome in children: recommendations from a pediatric nephrology panel established at the National Kidney Foundation conference on proteinuria, albuminuria, risk, assessment, detection, and elimination (PARADE). Pediatrics 2000; 105:1242.
- Houser M. Assessment of proteinuria using random urine samples. J Pediatr 1984; 104:845.
- Houser MT, Jahn MF, Kobayashi A, Walburn J. Assessment of urinary protein excretion in the adolescent: effect of body position and exercise. J Pediatr 1986; 109:556.
- Yang CY, Chen FA, Chen CF, et al. Diagnostic Accuracy of Urine Protein/Creatinine Ratio Is Influenced by Urine Concentration. PLoS One 2015; 10:e0137460.
- Vehaskari VM, Rapola J. Isolated proteinuria: analysis of a school-age population. J Pediatr 1982; 101:661.
- Brandt JR, Jacobs A, Raissy HH, et al. Orthostatic proteinuria and the spectrum of diurnal variability of urinary protein excretion in healthy children. Pediatr Nephrol 2010; 25:1131.
- Rytand DA, Spreiter S. Prognosis in postural (orthostatic) proteinuria: forty to fifty-year follow-up of six patients after diagnosis by Thomas Addis. N Engl J Med 1981; 305:618.
- Yoshikawa N, Kitagawa K, Ohta K, et al. Asymptomatic constant isolated proteinuria in children. J Pediatr 1991; 119:375.
- Hama T, Nakanishi K, Shima Y, et al. Renal biopsy criterion in children with asymptomatic constant isolated proteinuria. Nephrol Dial Transplant 2012; 27:3186.
- Lee YM, Baek SY, Kim JH, et al. Analysis of renal biopsies performed in children with abnormal findings in urinary mass screening. Acta Paediatr 2006; 95:849.
- PATHOPHYSIOLOGY AND CLASSIFICATION
- Normal protein excretion
- Abnormal protein excretion
- - Glomerular proteinuria
- - Tubular proteinuria
- - Overflow proteinuria
- MEASUREMENT OF URINARY PROTEIN
- Urine dipstick
- Sulfosalicylic acid test
- Quantitative assessment
- - Spot urine sample
- - Timed 24-hour urine collection
- Qualitative assessment
- APPROACH TO THE CHILD WITH PROTEINURIA
- History and physical examination
- Asymptomatic child
- - Indications for renal biopsy
- Symptomatic child
- SUMMARY AND RECOMMENDATIONS