Glomerulonephritis Flashcards
Definition
Immune mediated disease which affects the glomeruli.
Disruption of the glomerular capillary wall
Which 3 parts of the glomerulus can be affected?
Endothelium
Basement membrane
Podocytes
Causes
Idiopathic Infections Drugs Malignancies Small vessel vasculitis Lupus Goodpastures
Pathology
Depends on site of injury
Depends on type of injury
Proliferative or non proliferative refers to…
Presence or absence of proliferation of mesangial cells
Focal or diffuse refers to…
How much of the glomeruli are affected
- focal = less than 50% affected
- diffuse = more than 50% affected
Global or segmental refers to…
Global - all glomerulus affected
Segmental - parts of glomerulus affected
Cresenteric refers to…
Presence of a crescent of cells
Crescents is a manifestation of mild/severe glomerular damage
Severe
Damage to mesangial cells leads to proliferative/non-proliferative lesion
Proliferative
- mesangial cells proliferate and release angiotensin II
Damage to mesangial cells - urine
Leakage occurs through the glomerular wall resulting in
- haematuria
- proteinuria
Damage to mesangial cells - inflammatory or non inflammatory process?
Inflammatory
Can damage to mesangial cells result in renal failure?
Yes
- gradual progression of renal failure
Damage to endothelial cells - proliferative or non-proliferative lesion?
Proliferative
Damage to endothelial cells - inflammatory or non inflammatory process?
Inflammatory
- inflammation of the endothelium
Which condition does damage to the endothelial cells result in?
Vasculitis
Damage to endothelial cells - urine
Leakage occurs through the glomerular wall resulting in
- haematuria
Can damage to endothelial cells result in renal failure?
Yes
Damage to endothelial cells results in a very rapid decline in the patient. True or false?
True
Damage to podocytes leads to a proliferative or non proliferative lesion?
Non-proliferative
Damage to podocytes involves an inflammatory or non-inflammatory process?
Non-inflammatory process
- podocytes shrink back and they are no longer an effective barrier
Damage to podocytes - urine
Leakage occurs through the exposed glomerular wall resulting in
- haematuria
- proteinuria
What is the range of microalbuminuria
30-300mg albuminuria/day
Asymptomatic proteinuria range
<1g/day
Heavy proteinuria range
1-3g/day
Nephrotic range of proteinuria
> 3g/day
Glomerulonephritis causes a decreased production of urine. True or false?
True
AKI due to glomerulonephritis is most commonly due to
- damage to mesangial cells
- damage to endothelial cells
- damage to podocytes
Damage to endothelial cells
Investigations
Blood tests Urinalysis Urine microscopy Renal biopsy Immunofluoresence Electron microscopy
Investigations - urine microscopy findings
Dysmorphic RBCs
- since they are squeezed through damaged glomerulus
RBC and granular casts
- small tubule shaped prticles which get washed into the urine
What do the presence of granular casts suggest?
There is an active inflammatory process
- damage to mesangial cells
- damage to endothelial cells
If urinalysis reveals proteinuria, what is the next investigation to do?
24 hour urine collection to quantify the proteinuria
Investigations - What is the purpose of immunofluoresence?
Look for circulating immune complexes
Investigations - what is the purpose of electron microscopy?
Shows how cells are affected
Proteinuria impacts on how quickly the disease progresses - true or false?
True
Management - aims
Reduce degree of proteinuria
Preserve long term renal function
Target BP in a patient with proteinuria?
Less than 130/80
Management - medications
ACE inhibitors ARBs Diuretics Statins Anticoagulants/antiplatelets
Management - immunosuppressive therapy
Corticosteroids
Azathioprine
Cyclophosphamides
Is plasmaphoresis of use in GN?
Yes
- rapidly removes the antibody whilst the drugs start to work
Rapidly progressive glomerulonephritis (RPGN) is a treatable cause of AKI. True or false?
True
What is likely to be seen on renal biopsy of RPGN patient?
Granular casts
Management of RPGN
Treat ASAP Strong steroids Cyclophosphamide Plasmapheresis Supportive care
Nephrotic syndrome
Disorder of glomerular filtration allowing protein to appear in filtrate, resulting in proteinuria
Nephrotic syndrome - clinical features
Oedema (everywhere)
Proteinuria
HypoalbuminAEMIA
HypercholesterolAEMIA
Why does oedema occur in nephrotic syndrome
Patients are loosing protein faster than they can make it
Fluid leaks out into the interstitium
Renal function is usually normal in nephrotic syndrome. True or false?
True
- normal creatinine level
Nephrotic syndrome is most likely due to a proliferative or non-proliferative process?
Non proliferative
- affecting the podocytes
Nephrotic syndrome - management
Fluid restriction Salt restriction Diuretics ACE inhibitor or ARBs Anticoagulation
Patients with nephrotic syndrome are more or less susceptible to infection?
More
- peeing out proteins (Ig)
Nephritic syndrome is most likely due to a proliferative or non-proliferative process?
Proliferative
- damage to the mesangial cells
- damage to the endothelial cells
Nephritic syndrome - clinical features
AKI Oliguria Oedema Haematuria Hypertension
What is the commonest cause of nephrotic syndrome in children?
Minimal change nephropathy
Minimal change nephropathy is due to damage of… ?
- mesangial cells
- endothelial cells
- podocytes
Podocytes
Who gets minimal change nephropathy?
Children
Minimal change nephropathy - Renal biopsy appearance?
Looks normal
Electron microcopy is a good way to visualise podocytes?
True
Minimal change nephropathy - management
Oral steroids
Cyclophosphamide
Focal segmental glomerulosclerosis nephropathy (FSGS) is due to damage of ?
- mesangial cells
- endothelial cells
- podocytes
Podocytes
FSGS is more common in adults or children?
Adults
What is the most common cause of nephrotic syndrome in adults?
FSGS
FSGS - pathology
Patches of focal sclerosis
FSGS - causes
HIV
Heroin use
Obesity
Reflux nephropathy
FSGS renal biopsy appearance
Focal segmental glomerulosclerosis
- only some glomeruli are affected
- only some parts are affected
FSGS - management
Prolonged steroids
What is the most common cause of nephrotic syndrome in the UK?
Membranous nephropathy
Membranous nephropathy - definition
Thickening of the glomerular BM
Membranous nephropathy - causes
Infections
CTD (lupus)
Malignancy
Membranous nephropathy - immunology
IgG attaaches to podocytes and causes podocyte damage
Membranous nephropathy renal biopsy appearance
Thickening of the glomerular BM (silver stain)
Immune complex deposition between podocytes
Membranous nephropathy - management
Steroids
Immunosuppression (if steroids don’t work)
MABs
Patients with membranous nephropathy can progress to ESRF?
True
What is the commonest GN in the world?
IgA nephropathy
IgA nephropathy - immunopathogenesis
Wonky IgA
IgA nephropathy - cause
Infection
- More IgA production and therefore more kidney inflammation
Patient develops macroscopic haematuria after a resp infection. What is the most likely diagnosis?
IgA nephropathy
IgA nephropathy - associated condition
HSP (small vessel vasculitis)
IgA nephropathy - renal biopsy appearance
Mesangial cell proliferation and expansion
IgA nephropathy - management
BP control
