16) Glomerular Pathology Flashcards
What components of the renal cortex can become diseased?
Glomerulus
Tubules (childhood and rare)
Interstitial
Vascular
Why may the whole nephron be affected by damage to glomerulus?
Vascular structures of glomerulus and nephron are all one complex, so damage to one can cause damage to other
What is nephrotic syndrome?
Loss of protein (>3.5g/day) particularly albumin leading to oedema (low oncotic pressure)
What is nephritic syndrome?
Blockage or inflammation of glomerulus causing glomeruli to burst and haematuria
What are some sites of glomerular injury?
Podocytes
GBM
Sub-endothelial
Mesangial
Why does immune complex deposition causes injury?
Activates complement and causes cell injury
What is minimal change glomerulonephritis?
Loss of podocyte foot processes so wider filtration slits, allowing proteinuria and oedema
Who are more likely to get minimal change glomerulonephritis?
Children or adolescents (mid 20s)
What causes minimal change glomerulonephritis and what treatment does it respond to?
Unknown circulating factor damaging podocytes
Steroids
What is focal segemental glomerulosclerosis?
Unknown circulating factor damaging podocytes and causing glomerulosclerosis
Who does focal segemental glomerulosclerosis affect and what can it progress to?
Affects adults and progresses to renal failure
What is membranous glomerulonephritis?
Immune complex deposits in sub-epithelial space which bind to antigen/receptor on podocytes
What causes membranous glomerulonephritis?
Probably autoimmune
May be secondary to malignancy of immune system e.g. lymphoma
What is seen microscopically in membranous glomerulonephritis?
Capillary loop thick
BM thick and abnormal
What are the outcomes of membranous glomerulonephritis?
1/3 get better
1/3 stay same
1/3 renal failure
What microscopic changes occur to kidney in diabetes?
Microvascular injuries damage glomerulus
Mesangial sclerosis -> nodules
BM thickening
What can diabetes cause, in terms of kidneys?
Progressive proteinuria
Progressive renal failure
What is IgA nephropathy?
Deposition of IgA immune complexes in the mesangium causing local inflammation
How does IgA nephropathy present?
Visible/invisible haematuria
May have proteinuria and progress to renal failure
Why is IgA nephropathy related to mucosal infections?
These infections activate IgA which can then become deposited in the glomerulus
How does IgA nephropathy present microscopically?
Glomerulus becomes cellular due to proliferation of mesangial cells and matrix
May scar
Why does the IgA immune complex deposit in mesangium?
No basement membrane between mesangium and glomerulus
What are two hereditary nephropathies?
Thin GBM nephropathy - thin GBM, isolated haematuria
Alport Syndrome
Describe Alport Syndrome:
X linked, abnormal collagen IV
Associated with deafness
Abnormally split GBM
What is Goodpasture Syndrome?
Acute onset of severe nephritic syndrome due to autoantibody to collagen IV
May affect alveolar membranes as well
How do you treat Goodpasture Syndrome?
Immunosuppression and plasmapheresis
How does Goodpasture Syndrome present microscopically?
IgG deposition and many inflammatory cells
What is vasculitis?
Group of disorders that destroy blood vessels by inflammation. Associated with anti-neutrophil cytoplasmic antibody (ANCA), which activates neutrophils so they attack endothelium
How does vasculitis affect the glomerulus?
Punches holes in glomerulus through endothelium and BM causing segmental necrosis
See crescent of inflammatory cells
