Biochemistry

Question 1

What is nephrotic syndrome?

Answer 1

• Podocytes recede/breakdown so protein cannot be kept in the glomerulus, leak across GBM
• Frothy urine - protein >3g/24hr
• Oedema
• Decreased blood albumin - <30g/L
• Increased lipids
• Decreased AT-3

Question 2

What is nephritic syndrome?

Answer 2

• Antibody complex lodges in the capillary and elicit an immune response. WBCs are recruited so inflammation occurs allowing RBCs to leak out the openings along with WBCs + proteins
• Blood, protein + WC in urine
• Haematuria
• Oliguria
• Increased BP

Question 3

What are the causes of nephrotic syndrome?

Answer 3

Primary/idiopathic
Secondary:
- Autoimmune e.g. SLE
- Infections e.g. malaria, hepB+C, HIV
- Drugs e.g. NSAIDs, penicillin
- Heavy metals e.g. good, Mercury
- Tumours e.g. lung, colon, multiple myeloma

Question 4

What are the types of rapidly progressive glomerulonephritis?

Answer 4

• Idiopathic
• Type 1: anti-GBM antibody (Goodpasture)
• Type 2: immune complexes (poststreptococal glomerulonephritis, lupus, IgA nephropathy, HSP)
• Type 3: pauci-immune (no anti-GBM, no immune complexes - ANCA in blood) - cANCA = Wegner granulomatosis, pANCA = microscopic polyangitis

Question 5

What cells are involved in the scarring of rapidly progressive glomerulonephritis?

Answer 5

Crescent moon scarring of glomeruli - monocytes + macrophages, plasma proteins (C3b), fibrin, parietal epithelial cells

Question 6

What are the autosomal dominant causes of cystic kidney diseases?

Answer 6

• ADPKD
• Tuberous sclerosis
• Von Hippel Lindau disease
• Medullary cystic disease

Question 7

What are the non-genetic causes of cystic kidney disease?

Answer 7

Development cysts:
- Medullary sponge kidney
- Multicystic dysplastic kidneys
- Pyelocalyceal cysts
Acquired cysts:
- Simple cysts
- Acquired renal cystic disease
- Hypokalaemia related cysts

Question 8

What is ADPKD?

Answer 8

• 1:800 births
• Approx 50% reach ESRD by age 60 (PKD1) - PKD2 has a slower course
• Extrarenak cysts - liver, pancreas, spleen, berry anueurysms, SAH, mitral valve prolapse

Question 9

What is Von Hippel-Lindau disease (VHL)?

Answer 9

• Autosomal dominant
• Usually 2nd-3rd decade onset with an array of tumours - CNS hemangioblastoma, retinal angioma, renal lesions
• Screening for asymptomatic patients (annual US and CT every 3yrs) and at risk relatives (CT every 3yrs age 20-65yrs)