Nephrology Flashcards
What is the pathophysiology of minimal change disease?
T cell and cytokine mediated damage to glomerular basement membrane, causing polyanion loss and reduction in electrostatic charge, leading to increased glomerular permeability to serum albumin.
What are the features of minimal change disease?
- Nephrotic syndrome
- Normotension
- High selective proteinuria (intermediate proteins loss only)
What are the findings on renal biopsy in minimal change disease?
- Normal glomeruli on light microscopy
- Fused podocytes and effacement of foot processes on electron microscopy.
What are the causes of minimal change disease?
- Usually idiopathic
- NSAIDs, rifampicin
- Infectious mononucleosis
- Hodgkin’s lymphoma, thymoma
What is the management of minimal change disease?
1st line: oral corticosteroids
2nd line: cyclophosphamide
What are the causes of membranous glomerulonephritis?
- Idiopathic: anti-phospholipase A2 antibodies
- Infections: Hep B, malaria, syphilis
- Malignancy: prostate, lung, leukaemia, lymphoma
- Drugs: gold, penicillamine, NSAIDs
- Autoimmune: SLE class V, thyroiditis, rheumatoid
What are the renal biopsy findings of membranous glomerulonephritis?
Thickened basement membrane with sub epithelial electron dense deposits
‘spike and dome’ appearance
What is the management for membranous glomerulonephritis?
- ACEIs or ARBs
- Immunosuppression in severe/progressive disease (not corticosteroids on their own)
- Anticoagulation in high risk patients
What are good prognostic factors of membranous glomerulonephritis?
- female
- early age at presentation
- asymptomatic proteinuria of modest degree at presentation
What are the features of type 1 membranoproliferative glomerulonephritis?
- 90% cases
- causes by cryglobulinaemia or hep C
- electron microscopy = sub endothelial and mesangium immune deposits of electron dense material resulting in ‘Tram-track’ appearance.
What are the features of type 2 membranoproliferative glomerulonephritis?
- ‘dense deposit disease’
- caused by partial lipodystrophy (loss of submit tissue from face) or factor H deficiency
- persistent activation of alternative complement pathway
- low circulating C3
- C3b nephritic factor in 70% (antibody to alternative pathway C3 convertase C3bBb, stabilises C3 convertase).
- electron microscopy = intramembranous immune complex deposits ‘dense deposits’
What are the causes of Type 3 membranoproliferative glomerulonephritis?
Hep B and C
What are the causes of focal segmental glomerulosclerosis?
Generally presents in young adults
- Idiopathic
- Secondary to other renal pathology e.g. IgA nephropathy, reflux nephropathy
- HIV
- Heroin
- Alport’s syndrome
- Sickle cell
What are the renal biopsy findings in focal segmental glomerulosclerosis?
Light microscopy = focal and segmental sclerosis and hyalinosis
Electron microscopy = effacement of foot processes
What is the management of focal segmental glomerulosclerosis?
Steroids +/- immunosuppressants
What is the prognosis of focal segmental glomerulosclerosis?
If untreated <10% have a chance of spontaneous remission.
What is IgA neuropathy?
- Commonest cause of glomerulonephritis worldwide
- Mesangial deposition of IgA immune complexes
- Presents with macroscopic haematuria usually in young people following a recent respiratory infection.
- Associated with alcoholic cirrhosis, Henoch-Schonlein purpura and coeliac disease/dermatitis herpetiformis
What are the histology findings in IgA nephropathy?
mesangial hypercellularity, positive immunofluorescence for IgA and C3
What are the features of IgA nephropathy?
- Typically young males
- Recurrent episodes of macroscopic haematuria
- Recent upper Respiratory tract infection
- Nephrotic range proteinuria is rare
- renal failure is unusual and only seen in minority
What is the management for IgA nephropathy?
Isolated haematuria with no or minimal proteinuria and normal GFR = no treatment.
Persistent proteinuria, normal or slightly reduced GFR = ACEIs
If active disease e.g. falling GFR or failure to respond to ACEIs then immunosuppression with corticosteroids
What are poor prognostic factors in IgA Nephropathy?
- Male
- Proteinuria
- HTN
- Smoking
- Hyperlipidaemia
- ACE genotype DD
What is a good prognostic factor in IgA Nephropathy?
Frank haematuria
What are the features of Henoch-Schonlein Purpura?
- palpable purpuric rash with localised oedema over buttocks and extensor surfaces of arms/legs
- Abdominal pain
- Polyarthritis
- Features of IgA nephropathy may occur
What is Henoch-Schonlein Purpura?
- IgA mediated small vessel vasculitis
- Overlaps with IgA nephropathy
- Usually seen in children following infection
