S8) Pathology of the Glomerulus

Question 1

In terms of the pathology of the glomerulus, what does the term focal mean?

Answer 1

Focal – involving less than 50% of the glomeruli on light microscopy

Question 2

In terms of the pathology of the glomerulus, what does the term diffuse mean?

Answer 2

Diffuse – involving more than 50% of the glomeruli on light microscopy

Question 3

In terms of the pathology of the glomerulus, what does the term segmental mean?

Answer 3

Segmental – involving part of the glomerular tuft

Question 4

In terms of the pathology of the glomerulus, what does the term global mean?

Answer 4

Global – involving the entire glomerular tuft

Question 5

In terms of the pathology of the glomerulus, what does the term membranous mean?

Answer 5

Membranous – thickening of the glomerular capillary wall

Question 6

In terms of the pathology of the glomerulus, what does the term proliferative mean?

Answer 6

Proliferative – an increased number of cells in the glomerulus (proliferating glomerular cells / infiltrating circulating inflammatory cell)

Question 7

In terms of the pathology of the glomerulus, what does the term crescent mean?

Answer 7

Crescent – an accumulation of cells within the Bowman’s space; often compress the capillary tuft

Question 8

In terms of the pathology of the glomerulus, what does the term glomerulosclerosis mean?

Answer 8

Glomerulosclerosis – segmental or global capillary collapse (presumed that there is little/no filtration across sclerotic area)

Question 9

In terms of the pathology of the glomerulus, what does the term glomerulonephritis mean?

Answer 9

Glomerulonephritis – any condition associated with inflammation in the glomerular tuft

Question 10

Identify the 4 different renal cortical compartments

Answer 10

Question 11

Describe two different problems that can occur with the glomerulus

Answer 11

• Glomerulus can block (renal failure, decreased eGFR)
• Glomerulus can leak (proteinuria, haematuria)

Question 12

What is Nephrotic Syndrome?

Answer 12

- 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

Question 13

What is Nephritic Syndrome?

Answer 13

• ​Nephritic syndrome is a condition comprising signs of nephritis, which is kidney disease involving inflammation
• It presents with proteinuria, haematuria and hypoalbuminaemia

Question 14

What factor determines the presentation of glomerular pathology?

Answer 14

The site of glomerular injury determines clinical presentation

Question 15

What are some likely sites of injury in Nephrotic Syndrome?

Answer 15

• Podocyte/subepithelial damage
• GBM damage

Question 16

Identify some common primary causes of Nephrotic Syndrome

Answer 16

• Minimal change glomerulonephritis
• Focal segmental glomerulosclerosis (FSGS)
• Membranous glomerulonephritis

Question 17

What is Focal Segmental Glomerulosclerosis?

Answer 17

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

Question 18

What is Minimal Change Glomerulonephritis?

Answer 18

- 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

Question 19

Describe the pathogenesis occuring in Minimal Change glomerulonephritis

Answer 19

• Unknown circulating factor damages podocytes
• No immune complex deposition

Question 20

Which drug can be used to treat minimal change glomerulonephritis?

Answer 20

Steroids

Question 21

How does FSGS differ from minimal change?

Answer 21

• 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

Question 22

What is membranous glomerulonephritis?

Answer 22

• 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

Question 23

Identify some common secondary causes of Nephrotic Syndrome

Answer 23

• Diabetes Mellitus
• Amyloidosis

Question 24

Describe 5 clinical presentations of Diabetes Mellitus

Answer 24

• Progressive proteinuria
• Progressive renal failure
• Microvascular
• Mesangial sclerosis → nodules
• Basement membrane thickens

Question 25

Identify two conditions associated with nephritis

Answer 25

- Goodpasture Syndrome (Anti-GBM disease) - Vasculitis

Question 26

Identify three conditions presenting with haematuria

Answer 26

- IgA Nephropathy - Thin glomerular basement membrane disease - Hereditary Nephropathy (Alport)

Question 27

What is IgA nephropathy?

Answer 27

- **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

Question 28

What is thin GBM nephropathy?

Answer 28

Thin **GBM Nephropathy** is a benign familial nephropathy involving isolated haematuria, a thin basement membrane and a benign course

Question 29

What is Alport syndrome?

Answer 29

**- 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

Question 30

What is Goodpasture's Syndrome?

Answer 30

- **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

Question 31

What is vasculitis?

Answer 31

- 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)