Paeds: Proteinuria Flashcards
Transient versus persistant proteinuria
May occur during febrile illnesses or after exercise and does not require investigation.
Does nto exceed 0.15g/24hr
If persistent next step?
Should be quantified by measuring the urine protein/creatinine ratio in an early morning sample (protein should not exceed 20mg/mmol of creatinine)
Causes – non-pathological proteinuria
Transient Fever Exercise UTI Orthostatic proteinuria
Causes: pathological
Glomerular abnormalities - Minimal change disease - Glomerulonephritis - Abnormal glomerular BM (familial nephritides) Increased glomerular filtration pressure Reduced renal mass Hypertension Tubular proteinuria – tubular interstitial nephritis CKD
Orthostatic proteinuria
Protein only found when child is upright e.g. during the day
Diagnosed: measuring the urine protein/creatinine ratio in a series of early morning urine specimens
Prognosis: excellent and further investigations are not necessary.
Nephrotic Syndrome:
Description
Heavy proteinuria results in a low plasma albumin and oedema.
Nephrotic Syndrome:
Cause
Unknown, but a few cases are a secondary to systemic diseases such as henoch-Schonlein purpura and other vasculitides e.g. SLE, infections (e.g. malaria) or allergens (e.g. bee sting)
Nephrotic Syndrome:
Clinical signs of the nephrotic syndrome are:
- Periorbital oedema (particularly on waking), the earliest sign
- Scrotal or vulval, leg and ankle oedema
- Ascites
Breathlessness due to pleural effusions and abdominal distension
Nephrotic Syndrome:
Initial investigations
- Urine protein – dipstick
- FBC and ESR
- U+E, creatinine and albumin
- Complement levels – C3, C4
- Antistreptolysin O or anti-DNase B titres and throat swab
- Urine microscopy and culture
- Urinary sodium concentration
- Hepatitis B and C screen
Malaria screen if travel abroad
Nephrotic Syndrome: Diagnosis
Heavy proteinuria and low plasma albumin
Nephrotic Syndrome: Types
- Steroid-nephrotic syndrome
Steroid-resistant syndrome
Steroid-sensitive nephrotic syndrome Description
In 85-90% of children with nephrotic syndrome, the proteinuria resolves with corticosteroid therapy (steroid-sensitive nephrotic syndrome). These children do not progress to renal failurev
Epi
Steroid-sensitive nephrotic syndrome
Commoner in boys vs. girls
Asian children than in Caucasians
Weak association with atopy
Precipitated sometime
Steroid-sensitive nephrotic syndrome
Resp infections
Features suggesting steroid-sensitive nephrotic syndrome
Steroid-sensitive nephrotic syndrome
- Age between 1 and 10 years
- No macroscopic haematuria
- Normal blood pressure
- Normal complement levels
Normal renal function
Management
Steroid-sensitive nephrotic syndrome
- Oral corticosteroids (60mg/m2 per day of prednisolone), unless atypical features.
After 4 weeks dose reduced to 40mg/m2 on alternate days for 4 weeks and then stopped
Median time for urine to be free of protein
Steroid-sensitive nephrotic syndrome
11 days
New evidence shows
Steroid-sensitive nephrotic syndrome
Extending the initial course of steroids, by gradually tapering the alternate day part of the course, leads to a marked reduction in the proportion of children who develop relapsing or steroid-dependeant course.
Renal histology in steroid-
Steroid-sensitive nephrotic syndrome
Normal on light microscopy but fusion of the specialised epithelial cells that invest the glomerular capillaries (podocytes) is seen on electron microscopy—MINIMAL CHANGE DISEASE
With nephrotic syndrome is susceptible to several serious complications at presentation or relapse:
Steroid-sensitive nephrotic syndrome
- Hypovolaemia
- Thrombosis
- Infection
Hypercholesterolaemia
Prognosis
Steroid-sensitive nephrotic syndrome
- Relapses are identified by parents on urine testing
- Side-effects of corticosteroid therapy may be reduced by an alternate-day regimen
- Potentially steroid sparing agents
1/3 resolves directly, 1/3 infreqeunt relapses, 1/3 freqeunt relapses – steroid-dependant
Steroid sparing agents
Steroid-sensitive nephrotic syndrome
immunomodulator levamisole, alkylating agents (e,g, cyclophosphamide), calcineurin inhibitors such as tacrolimus and ciclosporin A and the ummunosuppressant mycophenolate mofetil
Hypovolaemia
Steroid-sensitive nephrotic syndrome
- Initial phase of oedema formation the intravascular compartment may become volume depleted
Hypovolaemia symptoms
Steroid-sensitive nephrotic syndrome
Abdominal pain and may feel faint
Indications of hypovolaemia
Steroid-sensitive nephrotic syndrome
Low urinary sodium (
Management if indications present
Steroid-sensitive nephrotic syndrome
Urgent reatment with intravenous albumin as the child is at risk of vascular thrombosis and shock.
Thrombosis:
Processes
Steroid-sensitive nephrotic syndrome
Urinary losses of antithrombin, thrombocytosis which may be exacerbated by steroid therapy, increased synthesis of clotting factors and increased blood viscosity from the raised haematocrit, predisposes to thrombosis.
Steroid-sensitive nephrotic syndrome: thombosis complications
May affect the brain, limbs and splanchnic circulation
Steroid-sensitive nephrotic syndrome: Hypercholesterolemia:
description
Correlates inversely with the serum albumin, but the cause of the hyperlipidaemia is not fully understood.
Steroid-resistant nephrotic syndrome:
Management of the oedema is by
- Referral to a paediatric nephrologist.
- - diuretic therapy, salt restriction, ACE inhibitors and sometimes NSAIDS, which may reduce proteinuria
Steroid-resistant nephrotic syndrome:
Cause
Focal segmental glomerulosclerosis
Mesangiocapillary glomerulonephritis (membranoproliferative glomerulonephritis
Membranous nephropathy
Focal segmental glomerulosclerosis
Specific features
Prognosis
Most common
30% progress to end-stage renal failure in 5 years
Respond to cyclophosphamide, ciclosporin, tacrolimus or rituximab
Recurrence post-transplant is common
Mesangiocapillary glomerulonephritis (membranoproliferative glomerulonephritis
Specific features
Prognosis
- More common in older children
Haematuria and low complement level present - Decline in renal function over many years
Membranous nephropathy
Specific features
Prognosis
Associated with hepatitis B
May precede SLE
Most remit spontaneously within 5 years
Congenital Nephrotic syndrome: Presence
- First 3 months of life.
It is rare
Congenital Nephrotic syndrome: Aetiology
- Commonest kind is recessively inherited and the gene frequency is particularly high in Finns
UK more common in consanguineous families.
Congenital Nephrotic syndrome: Associated with
High mortality due to complication of hypoalbuminaemia rather than renal failure
Congenital Nephrotic syndrome:
Outcome
Hypoalbuminaemia may be so severe that a unilateral nephrectomy may be necessary for its control, followed by dialysis for renal failure, which is continued until the child is large and fit enough for renal transplantation.
