Proteinuria in Children

Proteinuria is significant presence of protein in urine. Physiological proteinuria should not be higher than 100 mg/m2/24 hrs.

Proteinuria can be:
 * glomerular proteinuria - usually albuminuria (selective),
 * tubular proteinuria - usually globulins and albumin (nonselective).

Mild Proteinuria
As mild (or intermittent) proteinuria is classified every proteinuria < 0,5 g/m2/24 hrs. Typical causes of mild proteinuria in childhood are:
 * pyelonephritis,
 * renal cystic diseases,
 * obstructive uropathies,
 * mild glomerulonephritis.

Moderate Proteinuria
As moderate proteinuria is clasified proteinurie 0,5 - 1,0 g/m2/24 hrs. Typical causes of moderate proteinuria in children are:
 * PSAGN - it is the most often cause of moderate proteinuria,
 * Henoch Schoenlein nephritis,
 * chronic glomerulonephritis,
 * HUS,
 * severe pyelonephritis.

Nephrotic Proteinuria
Nephrotic proteinuria - typically more than 1 g/m2/24 hrs - is associated with nephrotic syndrome (proteinuria, hypoproteinaemia, hypercholesterolemia and edema). Diseases connected with nephrotic proteinuria are:
 * minimal change nephrotic syndrome
 * focal segmental glomerulosclerosis
 * membranous nepropathy
 * congenital nephrotic syndrome.

Management of child with proteinuria

 * complete history and physical examination (previous pharyngitis → PSAGN, gastroenteritis → HUS, present edema, petechiae, hypertension ...)
 * confirmation of presence proteinuria (is necessary repeat urinalysis)
 * protein/creatinine ratio (from first morning urine sample), if P/C ratio is > 0,5, other evaluation is necessary:
 * serum electrolytes analysis, creatinine clearance, serum levels of cholesterol, total protein, albumin
 * streptozyme, C3, C4, ASLO analysis
 * renal ultrasonography

Related articles

 * Nephrotic Syndrome in Children