S8) Pathology of the Glomerulus Flashcards
In terms of the pathology of the glomerulus, what does the term focal mean?
Focal – involving less than 50% of the glomeruli on light microscopy
In terms of the pathology of the glomerulus, what does the term diffuse mean?
Diffuse – involving more than 50% of the glomeruli on light microscopy
In terms of the pathology of the glomerulus, what does the term segmental mean?
Segmental – involving part of the glomerular tuft
In terms of the pathology of the glomerulus, what does the term global mean?
Global – involving the entire glomerular tuft
In terms of the pathology of the glomerulus, what does the term membranous mean?
Membranous – thickening of the glomerular capillary wall
In terms of the pathology of the glomerulus, what does the term proliferative mean?
Proliferative – an increased number of cells in the glomerulus (proliferating glomerular cells / infiltrating circulating inflammatory cell)
In terms of the pathology of the glomerulus, what does the term crescent mean?
Crescent – an accumulation of cells within the Bowman’s space; often compress the capillary tuft
In terms of the pathology of the glomerulus, what does the term glomerulosclerosis mean?
Glomerulosclerosis – segmental or global capillary collapse (presumed that there is little/no filtration across sclerotic area)
In terms of the pathology of the glomerulus, what does the term glomerulonephritis mean?
Glomerulonephritis – any condition associated with inflammation in the glomerular tuft
Identify the 4 different renal cortical compartments
Describe two different problems that can occur with the glomerulus
- Glomerulus can block (renal failure, decreased eGFR)
- Glomerulus can leak (proteinuria, haematuria)
What is Nephrotic Syndrome?
- Nephrotic syndrome is a condition that causes the kidneys to leak large amounts of protein into the urine and leads to widespread oedema and increased susceptibility to infections
- It presents with proteinuria, low albumin and high serum lipid levels
What is Nephritic Syndrome?
- Nephritic syndrome is a condition comprising signs of nephritis, which is kidney disease involving inflammation
- It presents with proteinuria, haematuria and hypoalbuminaemia
What factor determines the presentation of glomerular pathology?
The site of glomerular injury determines clinical presentation
What are some likely sites of injury in Nephrotic Syndrome?
- Podocyte/subepithelial damage
- GBM damage
Identify some common primary causes of Nephrotic Syndrome
- Minimal change glomerulonephritis
- Focal segmental glomerulosclerosis (FSGS)
- Membranous glomerulonephritis
What is Focal Segmental Glomerulosclerosis?
FSGS is a type of glomerular disease involving the scarring (sclerosis) of the kidney which only occurs in small sections of each glomerulus and only damages a limited number of glomeruli at first
What is Minimal Change Glomerulonephritis?
- Minimal change glomerulonephritis is a condition affecting the kidneys, commonly occuring in adolescence, which causes nephrotic syndrome
- It presents with proteinuria and podocyte damage rarely progresses to renal failure
Describe the pathogenesis occuring in Minimal Change glomerulonephritis
- Unknown circulating factor damages podocytes
- No immune complex deposition
Which drug can be used to treat minimal change glomerulonephritis?
Steroids
How does FSGS differ from minimal change?
- FSGS occurs in adults
- FSGS is less responsive to steroids
- FSGS involves glomerulosclerosis
- FSGS involves circulating factor which damages podocytes
- FSGS can progress to renal failure
What is membranous glomerulonephritis?
- Membranous glomerulonephritis is a condition affecting the kidneys due to pathology in the glomerular basement membrane involving the build-up of immune complexes within the kidney
- It is the commonest cause of nephrotic syndrome in adults and can occur by itself or in conjunction with other disease e.g. lymphoma
Identify some common secondary causes of Nephrotic Syndrome
- Diabetes Mellitus
- Amyloidosis
Describe 5 clinical presentations of Diabetes Mellitus
- Progressive proteinuria
- Progressive renal failure
- Microvascular
- Mesangial sclerosis → nodules
- Basement membrane thickens
Identify two conditions associated with nephritis
- Goodpasture Syndrome (Anti-GBM disease)
- Vasculitis
Identify three conditions presenting with haematuria
- IgA Nephropathy
- Thin glomerular basement membrane disease
- Hereditary Nephropathy (Alport)
What is IgA nephropathy?
- IgA nephropathy is a kidney disease that occurs when IgA deposits build up in the kidneys, causing inflammation (commonest cause of GN – occurs at any age)
- It presents with visible/invisible haematuria (+/- proteinuria) and a significant proportion progresses to renal failure as there’s no effective treatment
What is thin GBM nephropathy?
Thin GBM Nephropathy is a benign familial nephropathy involving isolated haematuria, a thin basement membrane and a benign course
What is Alport syndrome?
- Alport syndrome is an X-linked recessive disease involving abnormal type IV collagen and an abnormally appearing GBM
- It is associated with deafness and progresses to renal failure
What is Goodpasture’s Syndrome?
- Goodpasture Syndrome is a condition involving the rapid progression of GN due to an autoantibody to collagen IV in the BM, leading to the acute onset of severe nephritic syndrome
- It is associated with pulmonary haemorrhage (smokers) and is treatable by immunosuppression and plasmaphoresis
What is vasculitis?
- Vasculitis is a group of systemic disorder that destroy blood vessels through inflammation.
- There is no immune complex/antibody deposition and presents as GN (treatable if caught early)
