glomerulonephritis (nephritic vs nephrotic syndrome) Flashcards
What is glomerulonephritis?
Immune-mediated disease of the kidney affecting glomerulus with secondary tubulointerstitial damage
What are the different pathophysiologies of glomerulonephritis?
Humoral (Ab) mediated: intrinsic/planted Ag, deposition circulating immune complexes
Cell mediated: T cells
Inflammatory cell mediated and complement
What is nephrotic syndrome? What is the treatment in general?
Damage to podocytes = non-proliferative lesion
- proteinuria >3g/day
- hypoalbuminaemia <30
- oedema (periorbital)
- hypercholesterolaemia
- usual normal renal function
Treatment:
- fluid and salt restrict
- diuretics
- ACEI/ARBs
- anticoag?
- IV albumin if volume deplete
What are the complications of nephrotic syndrome?
- infections
- renal vein thrombosis
- pulmonary emboli
- volume depletion (may lead to pre-renal ARF)
- vit D deficiency
- subclinical hypothyroid
What different forms of nephrotic syndrome exist?
Primary glomerular disease:
- minimal change nephropathy
- focal segmental glomerulosclerosis
- membranous nephropathy
Secondary glomerular disease:
- amyloidosis
- diabetic nephropathy
What is minimal change nephropathy?
What is the management?
Does it cause renal failure?
This is the commonest cause of nephrotic syndrome in children
- see abnormality on electron microscopy (not light microscopy or immunofluorescence)
- see foot process fusion
Management:
- oral steroid (94% complete remission), give this first to see if works
- if steroid resistant cyclophosphamide or cyclosporin A
Doesn’t cause renal failure
What is focal segmental glomerulosclerosis?
What is the management?
How is this different to minimal change nephropathy?
Commonest cause nephrotic syndrome in adults
- primary or secondary to HIV/Heroine/Obesity/Reflux nephropathy
- see glomerulosclerosis on light microscopy
Management:
- prolonged steroids (60% in remission)
- 50% progress to renal failure after 10yrs
This causes more progressive damage and sclerosis and is more steroid resistant than minimal change nephropathy
What is membranous nephropathy?
caused by?
On biopsy what is seen?
Management?
Second commonest cause nephrotic syndrome in adults
Causes:
- primary (due to Ab causing immunecomplexes)
- secondary to infection (hep B or parasites), malignancies (paraneoplastic syndrome), connective tissue diseases (e.g.SLE), Drugs (gold/penicillamine)
Biopsy:
-subepithelial immune complex deposits in the glomerular basement membrane = thickened GBM
Management:
-steroids
-alkylating agents
-B cell Ab’s
(no immunosuppression if secondary to malignancy or infection)
(treat with non-immunosuppressants for first 3mths as it tends to self limit)
30% progress to ESRD in 10years
What is nephritic syndrome?
This is damage to endothelial/mesangial cells = proliferative lesion
- Haematuria, RBC casts in urine, dysmorphic RBCs as they are squeezing through glomerulus
- small proteinuria <3.5g/day
- hypertension
- uraemia
- acute renal failure - variable renal insufficiency
- oedema/fluid retention
what are the different forms of nephritic syndrome?
- IgA nephropathy
- Rapidly progressive glomerular nephritis (good pastures/henoch schonlein purpura/SLE/ANCA +ve vasculitides)
How is nephritic syndrome classified?
Primary: idiopathic (majority)
Secondary: caused by infection/drugs
- assoc. with malignancy
- as part of a systemic illness
What is IgA nephropathy? what are the different presentations of this?
IgA nephropathy:
-commonest glomerulonephritis in the world
-IgA deposits in the kidney’s mesangium = mesangial proliferation and expansion
(IgA is made ‘funny’ due to genetics and then deposits in the mesangium)
Presentations:
- asymptomatic microhaematuria +/- non-nephrotic proteinuria
- macroscopic haematuria after resp./GI infection
- AKI/CKD
- assoc. with henoch-schonlein purpura
Management:
- BP control
- ACEI/ARBs
- Fish oil
25% progress to ESRD in 10-30years
What is rapidly progressive glomerulonephritis? What different types exist?
This is a rapid deterioration in renal function over days/weeks due to:
ANCA +ve (majority):
- granulomatosis with polyangiitis
- microscopic polyangiitis
ANCA -ve:
- good pastures (anti-GBM Ab)
- henoch schonlein purpura (IgA)
- SLE
What is the pathophysiology of ANCA +ve rapidly progressive glomerulonephritis?
ANCA +ve blows a hole in the endothelium, WBCs and RBCs burts into bowmans capsule, squeezing glomerulus = ischaemia
What is the pathophysiology of goodpastures disease?
Ab attack basement membrane of lungs and kidney
