Glomerular Disease

Question 1

What is nephrotic syndrome?

Answer 1

• oedema
• proteinuria (+3-4g/day)
• hyopalbuminaeima
• hyperlipidaemia

Question 2

What are the common causes of proteinuria/nephrotic syndrome?

Answer 2

• diabetes mellitus
• some forms of glomerulonephritis
  
  • minimal change disease
  • membranous GN
• amyloid deposition
• inherited abnormalities
  
  • Alport syndrome - abnormal collagen IV of BM
  • Finnish NS - nephrin, proteins between podocytes (slit membranes)

Question 3

What does acute renal failure refer to?

Answer 3

• acute reduction in GFR reflected as reduced creatinine clearance (increased serum urea and creatinine)

Question 4

What causes acute renal failure?

Answer 4

• pre-renal eg hypoperfusion of kidney (shunting)
• renal eg damage to the machinery (glomeruli, tubules)
• post-renal eg downstream obstructions (prostate)

Question 5

What are the renal causes of ARF?

Answer 5

• acute tubular necrosis (ATN) - most common
• acute GN
• acute interstitial nephritis
• others, eg vascular disease

Question 6

What is glomerulonephritis?

Answer 6

• acute or chronic/protracted injury
• almost always immune-mediated
  
  • glomerular capillary bed is susceptible to deposition which attracts inflammatory cells, complement activation, MAC etc. and eventual tissue damage

Question 7

What are some specific forms of GN?

Answer 7

• post-strep or post-infectious GN - due to the immune response, not the infection
  
  • common in rurual and aboriginal Aus
• IgA nephropathy - most common
• memranous nephropathy

Question 8

How do glomeruli react in acute GN?

Answer 8

• cells (mesangial, endothelial, epithelial/podocytes) proliferate
• inflammatory cells may arrive - neutrophils (complement activation), lymphocytes and monocytes
• BM proliferates - new layers, spikes or protrusions on the epithelial surface

Question 9

How is glomerular disease diagnosed?

Answer 9

• clinical (complement, urine)
• LM
• immunostains for complex deposition (stain against human immunoglobulins)
• EM to see immune complexes

Question 10

IgA nephropathy results in deposition in

Answer 10

mesangial cells

Question 11

Membranous nephropathy causes deposition of ICs in

Answer 11

the outer aspect of the BM

Question 12

What does a crescent response in GN indicate?

Answer 12

• crescent consists of exuded fibrin, monocytes, neutrophils, and proliferating podocytes
  
  • sit in the urinary space
• caused by necrosis of a glomerular segment
  
  • seen generally in clinically severe cases of ARF
  • can scar over time - sclerotic glomeruli, contract; capillaries not perfused tf non-functional

Question 13

What is diabetic nephropathy?

Answer 13

• not immune-mediated
• due to chronic hyperglycaemia affecting glomerular structure and function
• most common cause of ESRF in Australia
• early on, major cause of protein leakage and nephrotic syndrome
  
  • BM gets thick and abnormal, proteins get glycosylated –> leaks proteins
  • as damage accumulates, major cause of renal failure