Glomerulonephritis Flashcards
Which parts of the renal parenchyma can be affected in renal disease?
Tubules
Interstitium
Glomeruli
What are some glomerular disease?
Diabetic nephropathy
Glomerulonephritis
Amyloid/light chain nephropathy
Transplant glomerulopathy
How can glomerulonephritis be divided? Which is more common?
Chronic (common)
Acute
What is glomerulonephritis?
Immune mediated disease affecting the glomeruli +/- secondary tubulointerstitial damage
What are the three mediators of glomerulonephritis?
Antibodies (humeral) & immune complexes
Cells (T cells)
Inflammatory cells/mediators/complement
How can antibody induced glomerulonephritis be further subdivided?
Intrinsic
Planted (circulating antigen that has become stuck in glomerulus)
Glomerular capillaries are fenestrated. T/F
True
How is proteinuria and haematuria caused in glomerulonephritis?
Disruption of the basement membrane
Which features must solutes have in order to cross the glomerular membrane?
Small
Positively charged
Describe proliferative and non-proliferative GN and the differences in it’s clinical presentation
Proliferative - endothelial and/or mesangeal cell damage allowing red cells to pass into the urine
Non-proliferative - podocyte damage allowing protein to pass into the urine
What does urine microscopy look for?
Red blood cells, granular casts and lipids
How can urine protein be measured?
Protein creatinine ratio
24 hr urinary collection
In which two ways can haematuria present?
Asymptomatic microscopic
Painless macroscopic
What do dysmorphic red blood cells indicate?
They originated from the kidney (because they passed through glomerular membrane)
How might renal disease present?
Haematuria
Proteinuria
Hypertension
Impaired renal function (AKD/CKD)
How does nephritic syndrome present? What does it indicate?
AKI Oedema Oliguria Hypertension Sediment (RBC, granular casts)
Proliferative process (endothelial)
How does nephrotic syndrome present? What does it indicate?
Proteinuria >3g Hypoalbuminuria Odema Hypercholesterolaemia Normal renal function
Non-proliferative process (epithelial)
What are the complications of nephrotic syndrome? Explain each one
Infection risk (loss of Ig proteins)
Renal vein thrombosis (shift in liver production of pro-thombotic factors)
Pulmonary emboli
Volume depletion (too much diuretic) –> AKI
Vitamin D deficiency
Subclinical hypothyroidism
In which two methods might glomerulonephritis be classified?
Aetiology based
Histologically
What are the causes of glomerulonephritis?
Idiopathic Infection Drugs Malignancies Systemic disease (e.g ANCA associated)
By which methods can glomerulonephritis be histologically classified?
Biopsy
Microscopy
Immunofluroscence
Electron microscopy
What are the histological classifications of GN?
Proliferative/non-proliferative (mesangial/inflamm cells)
Focal/diffuse (>50% affected)
Global/segmental (all or part of glomeruli)
Crescentic (extracapillary proliferation of cells in bowman;s space)
When would you find crescentic injury?
Vasculitic GN (rapidly progressing)
What are the two methods of glomerulonephritis treatment?
Immunosuppressive and non immunosuppressive
What are the non-immunosuppressive means of GN treatment?
Hypertension control
- ACE/ARB
- Diuretic (oedema)
- Statin (hyperlipidaemia)
What is the target blood pressure in someone with GN?
When might anticoagulants be used in GN?
Albumin
What are the immunosuppressive means of GN treatment?
Corticosteroids (prednisolone or IV methoprednisolone)
Azathioprine
Alkylating agents (cyclophosphamide)
Calcineurin inhibitors (cyclosporin, tacrolimus)
Mycophenolate mofetil
Plasmapharesis
Antibodies
How is nephrotic syndrome treated?
Fluid and salt restrict Diuretics ACE/ARB Anticoagulate if profoundly hypoalbumin IV albumin if volume depletion Immunosuppression (steroids & another agent)
Define the remission criteria of nephrotic syndrome
Proteinuria
What are the main types of GN?
Minimal change Focal segmental glomerulosclerosis (FSGS) Membranous Membranoproliferative IgA nephropathy
What is the commonest cause of nephrotic syndrome in under 18s?
Minimal change nephropathy
What is found in histological diagnosis of minimal change nephropathy?
Normal light microscopy
Normal immunofluorescence
Foot process fusion on electron microscopy
How is minimal change nephropathy treated?
Oral steroids
Cyclophosphomide
CSA
Minimal change nephropathy can rarely cause renal failure but only in under 5s. T/F
False - never causes renal failure
Minimal change nephropathy is often steroid resistant. T/F
False - the minority are steroid resistant/have multiple relapses
What is the suggested cause of minimal change nephropathy?
IL-13
What is the commonest cause of GN in adults?
Focal segmental glomerulosclerosis
List causes of secondary FSGS
HIV
Heroin
Obesity
Reflux nephropathy
What is found on histological diagnosis of FSGS?
Characteristic appearance on light microscopy
Minimal Ig & complement deposition on immunofluorescence
How is FSGS treated?
Steroids (prolonged)
Calcineurin inhibitors
What percentage of patients with FSGS progress to renal failure?
50% over 10 years
Describe the pathogenesis of FSGS
Increased soluble urokinase plasminogen activator receptors (suPAR) up-regulate integrins (cell signalling molecules) causing changes in podocytes
Membraneous nephropathy can be primary or secondary. List some secondary causes
Infections (hep B, parasites)
Connective tissue diseases (lupus)
First manifestation of malignancy (lymphoma)
Drugs (gold, penicillamine i.e rheumatoid drugs)
Most older adults with membraneous nephropathy have underlying malignancy. T/F
False - around 25%
What is seen on renal biopsy of a patient with membraneous nephropathy?
Subepithelial immune complex deposition in the basement membrane
How is membraneous nephropathy treated?
Steroids
Alkylating agents (cyclophosphamide)
B cell monoclonal antibodies (rituximab)
Can membraneous nephropathy progress to end stage renal failure?
Yes - 30% do
What is the cause of the majority of primary membraneous nephropathies?
Anti PLA2r antibody (on surface of podocytes)
What is characteristically seen histologically in membranous nephropathy?
Thickened basement membrane (silver stain)
What is the commonest nephropathy world wide?
IgA nephropathy
How does IgA nephropathy present?
- Asymptomatic haematuria +/- non nephrotic range proteinuria
- Macroscopic haematuria post resp/GI infection
- AKI
- CKD
What conditions are associated with IgA nephropathy?
Henoch-Schonlein purpura (arthritis, colitis, purpuric rash)
How does IgA appear on renal biopsy?
Mesangeal cell proliferation and expansion on light microscopy
IgA deposits in mesangium on immunofluorescence
Can IgA nephropathy progress to end stage renal failure?
Yes - 25% do (10-30 years timescale)
How is IgA nephropathy treated?
ACE/ARB (i.e BP control)
How does IgA nephropathy look histologically?
Increased mesangeal cells (increased purple dots!)
How does rapidly progressive glomerulonephritis (RPGN) present?
Rapid deterioration in renal function over days/weeks Urinary sediment (RBC, granular casts) \+/- systemic disease
What is found on biopsy of someone with RPGN?
Crescents
What does ANCA stand for?
Anti neutrophil cytoplasmic antibody
How can RPGN be classified?
ANCA positive
ANCA negative
What are some causes of ANCA positive RPGN?
GPA
Microscopic polyangitis
What are some causes of ANCA negative RPGN?
Goodpastures disease
Henloch scholein purpura (systemic IgA nephropathy)
Lupus
Which antibody is present in goodpastures disease?
Anti glomerular basement membrane (anti-GBM)
How is ANCA tested?
Indirect immunofluorescence
What happens to blood vessels at end stage vasculitis? What does this result in within the kidney?
Endothelial rupture
Crescent formation on histology
By which processes are acellular fibrous crescents formed with respect to RPGN?
Vasculitic inflammation causes endothelial rupture allowing blood and inflammatory cells to leak out –>
Leakage gradually compresses glomerulus until it becomes ischaemic –>
Develops into fibrous remanent
How does vasculitis manifest dermatologically?
Vasculitic skin rash aka purpura
Give another name for Goodpasture’s syndrome
Pulmonary-renal syndrome
How does goodpasture’s syndrome present?
Pulmonary haemorrhage (i.e coughing up blood) + renal failure
How is RPGN treated?
Strong immunosuppression +/- renal support (i.e dialysis)
Which immunosuppresants can be used in RPGN?
Steroids (IV methypred 3 days –> oral pred) +
Cyclophosphamide OR rituximab
Plasmapharesis (advanced renal failure)