Glomerulonephritis

Question 1

Define glomerulonephritis.

Answer 1

Inflammation of the glomeruli

Question 2

Briefly describe the pathophysiology of glomerulonephritis. (2)

Answer 2

1. Inflammation causes damage to the glomerulus, e.g. by
   a. Extrinsic mechanisms
   b. Intrinsic mechanisms
2. Glomerulonephritis may progress to CKD, even if primary insult resolves
   a. Due to hyperfiltration theory

Question 3

List 6 extrinsic mechanisms of glomerular damage in glomerulonephritis.

Answer 3

Antibodies
Immune complexes
Complement
Cytokines
Lymphocyte infiltration
Other infiltrating cells

Question 4

List 3 intrinsic mechanisms of glomerular damage in GN.

Answer 4

Cytokines
Growth factors (e.g. PDGF, TGF beta, IFN gamma)
Proteinuria

Question 5

What is the hyperfiltration theory? (RE. progression of GN to CKD). (3)

Answer 5

Damaged nephrons cannot carry out normal filtration, therefore remaining (undamaged) nephrons work more to compensate

Overworking the undamaged nephrons will eventually cause them to fail prematurely too

Therefore CKD may occur even if initial insult resolves

Question 6

List 6 ways in which glomerulonephritis may present.

Answer 6

Hypertension
Haematuria
Renal impairment
Nephrotic syndrome
Nephritic syndrome
RPGN (rapidly progressing glomerulonephritis)

Question 7

What is the nephrotic syndrome? (4)

Answer 7

Proteinuria (3+ g/day)
Hypoalbuminaemia
Oedema
Hyperlipidaemia

Question 8

What is the nephritic syndrome? (3)

Answer 8

Haematuria
Oliguria
Hypertension

Question 9

Define oliguria.

Define anuria.

Answer 9

Oliguria: <400ml urine/day

Anuria: <100ml urine/day

Question 10

Which 3 methods would you use to diagnose GN?

Answer 10

Light microscopy
Fluorescent microscopy
Electron microscopy

Question 11

To diagnose GN, which features would you see on light microscopy? (5)

Answer 11

From a biopsy:

• Loss of renal tubules
• Glomerulosclerosis
• Leukocyte infiltration

From a urine sample:

• Fragmented RBCs
• RBC casts

Question 12

To diagnose GN, which features would you see on fluorescent microscopy? (1)

Answer 12

Antibodies in the glomeruli

Question 13

To diagnose GN, which features would you see on electron microscopy? (1)

Answer 13

Damage to the basement membrane

Question 14

Which tests would you do to investigate GN? (i.e. a GN screen). Consider:

a) Blood tests (6)
b) Urine tests (6)
c) Antibodies (5)
d) Other tests (2)

Answer 14

Blood tests:

• FBC
• U&Es
• LFTs
• Glucose
• CRP/ESR
• Blood cultures

Urine tests:

• Dipstick
• Microscopy
• Protein PCR
• Electrophoresis (for Ig)
• Complement proteins (C3)
• Urine cultures

Antibodies:

• Antinuclear factor (ANF)
• Rheumatoid factor (RF)
• Anti-GBM
• Anti-neutrophilic cytoplasmic antibody (ANCA)
• Immunoglobin (A, M, G)

Other tests:

• Coagulation tests
• Virology (HIV, hep B/C)

Question 15

What are the 6 main types of glomerulonephritis?

Answer 15

Post-infectious GN
IgA nephropathy
Membranous GN
Minimal change disease
RPGN/crescentic GN/vasculitis
Diabetic nephropathy