DEFINITION

SIGNIFICANT PROTEINURIA

• >4- 40 mg/ m2 /hr of protein/ 24 hr urine

Or

• Spot urine protein creatinine ratio  >0.2- 2 mg/mg.

NEPHROTIC range proteinuria

• >40 mg/ m2 /hr of protein/ 24 hr urine

Or

• Spot urine protein creatinine ratio  > 2 mg/mg

If proteinuria persists on > 3 occasions then its persistent proteinuria.

Nephrotic syndrome is proteinuria(nephrotic range) with hypoalbuminuria and oedema.

CAUSES OF PROTEINURIA

TRANSIENT

• Fever.
• Exercise.
• Stress.
• Dehydration.

ORTHOSTATIC( significant proteinuria on standing up, but not on lying down)

GLOMERULAR CAUSES-

• Minimal change disease.
• Focal/ segmental glomerulosclerosis.
• Glomerulonephritis.
• Membranous nephropathy.
• Amyloidosis.
• Diabetic nephropathy.
• Post infectious.
• Acute tubular necrosis.
• IgA nephropathy.
• Polycystic kidneys.
• Wilsons/ Cystinosis.

CAUSES OF PERSISTENT PROTEINURIA

DIAGNOSIS

History-

• Headache.
• Oliguria/ haematuria.
• Joint pains/ rashes.
• Hypertension/ repeated UTI.
• Symptoms of tumour-weight loss.
• Medications.

Family history (cystic kidney disease/ deafness/ renal disease/ dialysis)

Physical Examination.

• Growth retardation.
• Blood pressure.
• Flank pain/ oedema.
• Anaemia.

Laboratory Testing

• Urinary dipsticks (screening method )
  • Trace (<20 mg/dl)
  • 1+ (30 mg/dl)
  • 2+ (100 mg/dl)
  • 3+ (300 mg/dl)
  • 4+ (>2000 mg/dl)
• Random urine protein creatinine ratio (mg/dl) –
  • Normal  <0.2
  • Nephrotic range is >2
• 24 hr urinary protein excretion- Gold standard test
  • Normal  <4 mg/m2/hr
  • Nephrotic range is 4-40 mg/m2/hr
  • Nephrotic range is > 40 mg/m2/hr.

Laboratory Workup In asymptomatic patient( No other complications)

• Repeat urine dipstick needs to be repeated weekly
• Make sure proteinuria is transient.
• Follow up with 6 monthly dip sticks

In persistent proteinuria

Orthostatic proteinuria( benign condition)-

• Test with split a 24 hr urine collection( morning sample)
• Urine is collected separately in lying/supine or upright position
• Early morning urine protein creatinine ratio <0.2mg/mg
• Protein excretion from lying/supine position  <60/m2/day

OTHER INVESTIGATIONS-

• Blood tests
• Renal function tests (BUN and creatinine) with Phosphorus
• Anti nuclear antibiotic/ Anti double stranded DNA
• Ant neutrophil antibodies( C and p-ANCA)
• Serum albumin
• Lipid profile
• Renal and Bladder ultrasound
• Complement levels( C3 and C4)
• Infection workup( Hepatitis B and C/ HIV)

Referral to a paediatric nephrologist.