Glomerular Diseases: Glomerulonephritis And Diabetes Mellitus

Question 1

What is Glomerulonephritis?

Answer 1

Inflammation of glomeruli.

Question 2

What 4 structures in the glomerulus can be damaged?

Answer 2

1. Capillary endothelium.
2. Glomerular basement membrane.
3. Mesangial cells.
4. Podocytes.

Question 3

What are the features of Nephrotic Syndrome?

Answer 3

Proteinuria, 
Hypoalbuminaemia, 
Oedema, 
High cholesterol, 
BP normal, 
creatinine normal.

Question 4

How do we Manage Nephrotic Syndrome?

Answer 4

1. Manage the oedema using diuretics and salt and fluid restriction.
2. ACE-Inhibitor: to reduce protein loss in urine.
3. Treat the hypercholesterolaemia with atherogenic medication if long term.
4. Treat the underlying condition.

Question 5

What are the features of nephritic syndrome?

Answer 5

Haematuria,
Reduced GFR.
Hypertension.
Proteinuria (less than nephrotic syndrome).
Disruption of endothelium results in inflammatory response and damage to glomerulus.
Onset may be acute or rapidly progressive.

Question 6

What are the commonest cause of nephritic syndrome?

Answer 6

1. Anti-GBM disease.
2. ANCA associated vasculitis.
3. IgA.
4. Post-infection.
5. Systemic Lupus Erythematosus.

Question 7

What is the commonest cause of end stage renal disease?

Answer 7

Diabetic nephropathy.

Question 8

What pathological changes occur in diabetic nephropathy?

Answer 8

1. Hyperfiltration/capillary hypertension.
2. Glomerular basement membrane thickening.
3. Mesangial expansion.
4. Podocyte injury.
5. Glomerular sclerosis/areteriolosclerosis.

Question 9

Describe hyperfiltration.

Answer 9

The first stage of diabetic nephropathy. Hypertrophy occurs due to hyperglycaemia and glomerular hypertension and there is an increased GFR to try and compensate.

Question 10

Describe microalbuminuria.

Answer 10

The first clinical sign usually if GFR not measured.
GBM thickens and mesangial cells expand.
Albuminuria occurs but only a small amount not picked up on dipstick.
0-3.5mg/mmol Cr in women and 0-2.5mg/mmol Cr in men.

Question 11

Describe overt proteinuria.

Answer 11

When protein appears in dipstick.
There is worsening systemic hypertension and microvascular changes of hyalinosis of the arterioles, causing tissue ischaemia.

Question 12

What are the risk factors of diabetic nephropathy?

Answer 12

1. Genetics.
2. Race.
3. Hypertension.
4. Hyperglycaemia.
5. High level of hyperfiltration.
6. Increasing age.
7. Duration of diabetes.
8. Smoking.

Question 13

What are the stages of diabetic nephropathy?

Answer 13

1. Hyperfiltration and hypertrophy (Increased GFR).
2. Latent stage: normal albuminuria and GBM thickening and mesangial expansion.
3. Microalbuminuria: variable mesangial expansion, sclerosis, increased GBM thickening, podocyte changes and normal GFR.
4. Overt proteinuria: diffuse glomerular histopatholgoical changes, systemic hypertension and decreased GFR.
5. ESRD.

Question 14

What is the primary prevention of diabetic nephropathy?

Answer 14

1. Tight Blood Glucose Control at less than 48mmol/mol. Multiple injections or insulin pump can reverse.
2. Tight blood pressure control.
3. SGLT2 inhibitors.
4. Stop smoking.
5. Statin therapy.

Question 15

How do you manage microalbuminuria and proteinuria?

Answer 15

1. Inhibit the RAAS to tightly control the BP at 130/80 max.
2. Statin therapy to reduce CV risk.
3. Moderate Protein intake.
4. Tight blood glucose control to stop progression once overt proteinuria develops.

Question 16

What does the RAAS blockade do to help diabetic nephropathy?

Answer 16

Reduces glomerular hyperfiltration and has an anti-proteinuric effect.

Question 17

What does Angiotensin II do if left unchecked?

Answer 17

It is released following renin release.

1. It lead to increased glomerular permeability to proteins.
2. Mesangial cell proliferation.
3. Increased mesangial matrix.
4. Efferent glomerular constriction to increase the glomerular pressure.