Urinary 10 - Glomerular disease Flashcards
What is the main problem in the kidney causing nephrotic syndrome?
Damaged glomerulus = increased permeability = LEAKS PROTEIN
Give 2 major symptoms in nephrotic syndrome:
1) Proteinuria > 3.5g/24hrs (+ oedema)
2) Foamy/frothy urine
Where is the most likely site of injury in the glomerulus causing glomerular disease?
Subepithelial layer (podocytes)
Name 3 common primary causes of Nephrotic syndromw:
1) Minimal change glomerulonephritis
2) Focal segmental glomerulosclerosis
3) Membranous glomerulonephritis
What is glomerulonephritis?
Any condition associated with inflammation of the glomerular tuft
At what age does Minimal Change Glomerulonephritis typically present?
Childhood/Adolescence
What is the main treatment for Minimal Change Gloerulonephritis?
Steroids
Does Minimal Change Glomerulonephritis typically progress to renal failure?
No
Describe the pathogenesis causing Minimal Change Glomerulonephritis:
Unknown circulating factor damaging podocytes, causing increased permeability of glomerulus
What is the name given to any condition associated with inflammation of the glomerular tuft?
Glomerulonephritis
What is the meaning of ‘focal’ when describing glomerular pathology?
Involving <50% of glomeruli on light microscopy
What is the meaning of ‘segmental’ when describing glomerular pathology?
Involving part of the glomerular tuft
What is the meaning of ‘glomerulosclerosis’ when describing glomerular pathology?
Segmental/global capillary collapse, presumed little/no filtration in hardened/sclerotic areas
At what age does Focal Segmental Glomerulosclerosis typically present?
~ 40-60 yrs
Does Focal Segmental Glomerulosclerosis typically progress to renal failure?
Yes
Describe the pathogenesis causing Focal Segmental Glomerulosclerosis:
Unknown circulating factor damaging podocytes
Name the 2 glomerular pathologies caused by unknown circulating factors damaging podocytes:
1) Minimal Change Glomerulonephritis
2) Focal Segmental Glomerulosclerosis
What is the meaning of ‘membranous’ when describing glomerular pathology?
Thickening of the glomerular capillary wall
Name the commonest cause of Nephrotic syndrome in adults:
Membranous glomerulonephritis
What age does membranous glomerulonephritis typically present?
Adulthood
Describe the outlook of a patient with membranous glomerulonephritis:
Rule of thirds:
1/3 = will get better
1/3 = will stay the same
1/3 = will progress to renal failure
Describe the pathogenesis of membranous glomerulonephritis:
Deposition of immune complexes in the basement membrane under the podocyte layer
= Complement cascade activated
= Cellular injury to podocytes
(Often secondary to malignancies like Lymphoma)
Name the antigen and antibody which forms the immune complexes deposited in membranous glomerulonephritis:
Antigen = Phospholipase A2 receptor on podocyte Antibody = IgG
How does proteinuria in nephrotic syndrome lead to oedema?
Increased protein in urine
= decreased protein in blood
= water moves from blood into interstitial space
= oedema
What is the most likely cause of persistently foamy urine?
Proteinuria
Name 2 common secondary causes of nephrotic syndrome:
1) Diabetes mellitus
2) Amyloidosis
Describe the pathogenesis of diabetes mellitus causing nephrotic syndrome:
Persistent high blood glucose injures all parts of the glomerulus:
- Basement membrane thickens and becomes abnormal
- Sclerotic nodules form in mesangium
What is the main problem in the kidney causing nephritic syndrome?
Blocked glomerulus
List the main features of nephritic syndrome:
- Renal failure = oedema, oliguria, SOB
- Haematuria (microscopic/macroscopic)
- Decreased eGFR
- Red cell casts in urine
Where is the most likely site of injury of nephritic syndrome?
Endothelium
Which glomerular syndrome describes the blocking of the glomerulus?
Nephritic syndrome
Which glomerular syndrome describes protein leaking through the glomerulus?
Nephrotic syndrome
Give 5 diseases associated with Nephritic syndrome:
1) IgA nephropathy
2) Thin GBM nephropathy
3) Alport syndrome
4) Goodpasture syndrome
5) Vasculitis
Which glomerular syndrome is IgA nephropathy associated with?
Nephritic syndrome
Which glomerular syndrome is Thin GBM nephropathy associated with?
Nephritic syndrome
Which glomerular syndrome is Alport syndrome associated with?
Nephritic syndrome
Which glomerular syndrome is Goodpasture syndrome associated with?
Nephritic syndrome
Which glomerular syndrome is Vasculitis associated with?
Nephritic syndrome
Which disease is the most common primary cause of glomerulonephritis?
IgA nephropathy
Describe the presentation of IgA nephropathy:
Any age
Haematuria
Proteinuria (foamy urine)
Activated by URTI
Describe the pathogenesis of IgA nephropathy:
IgA deposited anywhere in glomerulus
= Blocked filter (irreversible)
Which nephropathy is typically activated by a URTI?
IgA nephropathy = Nephritic syndrome
What is the treatment of IgA nephropathy?
No cure
- IgA deposition = irreversible
- Treat hypertension, dialysis, transplant
What is the inheritance pattern of Thin GBM nephropathy?
Autosomal dominant
What is the typical inheritance pattern of Alport syndrome?
X-linked recessive
Why is Goodpasture’s syndrome called a ‘cresentic’ glomerulonephritis?
Causes accumulation of cells in Bowman’s capsule, which compresses the glomerulus forming a crescent shape
Describe the pathogenesis of Goodpasture’s syndrome:
Autoimmune:
= IgG (anti-GBM autoantibody) attacks collagen IV in basement membrane
= Glomerulus becomes ball of inflammatory cells
= Heals by scarring therefore reduces filtration
Why does Goodpasture’s syndrome sometimes present with haemoptysis?
Autoantibodies attack collagen IV, which is also present in alveoli membranes.
= More common when lungs are already damaged, ie in smokers
What is the treatment of Goodpasture’s syndrome?
No cure, can prevent worsening via immunosuppresants and plasmaphoresis
Name 2 crescentic glomerulonephritis’, and their associated glomerular syndromes:
1) Goodpasture’s syndrome
2) Vasculitis (ANCA)
Both cause nephritic syndrome
Describe the pathogenesis of Vasculitis (nephropathy):
ANCA (Anti-Neutrophil Cytoplasmic Antibody) causes inflammation of blood vessels
