Nephrotic Syndrome incl. Nephrotic Glomerulonephritis Flashcards
What are the 3 key features of nephrotic syndrome?
1) Proteinuria
2) Hypoalbuminaemia
3) Oedema
What level of hypoalbuminaemia suggests nephrotic syndrome?
< 30
What level of proteinuria suggests nephrotic syndrome?
> 3g/24h
What happens in nephrotic syndrome?
- Renal disease - primary or secondary to systemic disorder
- Proteinuria due to podocyte pathology
- Generalised pitting oedema (rapid, severe) incl. periorbitally
What are the complications of nephrotic syndrome?
- Thromboembolism
- Infection
- Hyperlipidaemia
What is nephrosis?
Proteinuria due to podocyte pathology
What is the most common cause of nephrotic syndrome in children?
Minimal change disease
What are causes of minimal change disease?
- Idiopathic (most common)
- Drugs e.g. lithium, NSAIDs
- Paraneoplastic esp. Hodgkin’s lymphoma
How do you diagnose minimal change disease?
- Electron microscopy - shows effacement of podocyte foot processes
- Light microscopy is normal
How do you treat minimal change disease?
Prednisolone (1mg/kg 4-16 weeks) - give steroids w/o biopsy in children (biopsy only if no response or signs suggestive of other cause)
- If frequent relapses - cyclophosphamide or calcineurin inhibitors (longer term immunosuppression)
What is the most common primary cause of nephrotic syndrome in adults?
FSGS
What are the causes of FSGS?
- Idiopathic (primary)
- HIV
- Heroin
- Lithium
- Lymphoma
- Any cause of decreased kidney mass/nephrons
- Kidney scarring due to other glomerulonephritis
What are the risks of FSGS?
Progressive CKD and kidney failure (more proteinuria worsens prognosis) - disease will recur in 30-50% of kidney transplants
How do you diagnose FSGS?
Renal biopsy - glomeruli scarring of certain segments (focal sclerosis)
How do you treat FSGS?
- ACE-i/ARB and BP control
- Corticosteroids in idiopathic disease - calcineurin inhibitors second line
How do you treat recurrent FSGS in transplants?
- Plasma exchange
- Rituximab
What is the most common glomerulonephritis seen on renal biopsy?
FSGS
What is important to remember about minimal change disease?
It does not cause renal failure - if progressive CKD consider missed FSGS
What are causes of membranous nephropathy?
- Idiopathic (primary)
- Malignancy
- Infection
- Autoimmune disease
- Drugs
How do you diagnose membranous nephropathy?
- Anti phospholipase A2 receptor antibody in 70-80% of idiopathic disease
- Diffusely thickened GBM due to sub epithelial deposits (mainly IgG4 in idiopathic)
- ‘Spikes’ on silver stain
How do you treat membranous nephropathy?
- ACE-i, ARB and BP control
- Corticosteroids + cyclophosphamide if risk of progression
What are the two types of membranoproliferative glomerulonephritis?
1) Immune-complex associated - Increased/abnormal immune complex deposition in kidney activates complement
2) C3 glomerulopathy - genetic or acquired defect in alternative complement pathway
What is membranoproliferative glomerulonephritis?
C3 glomerulopathy - genetic or acquired defect in alternative complement pathway
How do you diagnose membranoproliferative glomerulonephritis?
- Proliferative glomerulonephritis with electron dense deposits
- Ig deposition distinguishes immune complex associated disease from C3 glomerulopathy
How do you treat membranoproliferative glomerulonephritis?
- ACE-i/ARB and BP control
- Immunosuppression
What are underlying cause of immune-complex associated membranoproliferative glomerulonephritis in adults?
- Infection
- Cryoglobulinaemia
- Monoclonal gammopathy
- Autoimmunity
What are secondary causes of nephrotic syndrome?
- Diabetes
- Lupus nephritis
- Myeloma
- Amyloid
- Pre-eclampsia
What is first line investigation for nephrotic syndrome?
Urine dipstick (if oedema)
How do you manage nephrotic syndrome?
- Reduce oedema - fluid and salt restriction, loop diuretics e.g. furosemide (thiazide if resistant to high dose loop)
- Treat underlying cause - adults need renal biopsy, look for underlying condition
- Reduce proteinuria - ACE-i/ARB
