Polycystic Kidney Disease

Question 1

What is PKD?

Answer 1

development of multiple renal cysts that gradually expand + replace normal kidney substance, variably associated with extra-renal (liver + cardiovascular) abnormalities

Question 2

Describe the aetiology of PKD

Answer 2

85%: mutations in PKD1 on chr 16

15%: mutations of PKD2 on chr 4

Question 3

Describe the pathogenesis of PKD

Answer 3

Proliferative abnormality of tubular epithelium
Initially cysts are connected to tubules from which they arise + fluid content is glomerular filtrate
When cyst diameter >2 mm, they detach from the tubule + fluid content is derived from secretion of the lining epithelium
With time, the cysts enlarge + cause progressive damage to adjacent functioning nephrons

Question 4

Describe the epidemiology of PKD

Answer 4

MOST COMMON inherited kidney disorder (AD)
Responsible for 10% of end-stage renal failure
Presents at 30-40 yrs
20% have no FH

Question 5

List 3 symptoms of PKD

Answer 5

Flank Pain: from cyst enlargement/ bleeding, stone, blood clot migration, infection
Headaches
Dysuria, urgency, suprapubic pain

Question 6

List 8 signs of PKD

Answer 6

Abdominal distension 
Enlarged cystic kidneys  
Hepatomegaly
Cardiac murmur 
HTN
Haematuria 
Signs of chronic renal failure (at late stage) 
Signs of associated AAA or aortic valve disease

Question 7

What investigations should be performed in PKD? What is seen?

Answer 7

US or CT
Multiple cysts bilaterally in enlarged kidneys
Liver cysts may also be seen

Question 8

What is PKD associated with? Thus how may it present?

Answer 8

Berry aneurysms

May present with subarachnoid haemorrhage

Question 9

How may PKD present?

Answer 9

May be asymptomatic