Polycystic Kidney Disease

Question 1

PKWhat is polycystic kidney disease?

Answer 1

Autosomal dominant polycystic kidney disease is a common genetic disorder characterised by multiple renal cysts.

Can be atuosomal recessive but very rare

Question 2

Which gene are associated with POLYCYSTIC KIDNEY DISEASE?

Answer 2

MC: PKD1 (Chr16)
Encodes for protein polycystin-1: Involved in cell adhesion via regulation of calcium influx
Severe and early onset impairment

PKD2 Chr4
Encodes the protein polycystin-2: a calcium-permeable channel transmembrane proteins

Question 3

describe the pathophysiology of polycystic kidney disease

Answer 3

All cells have genetic mutation but damage is only expressed on 1% of nephrons

Further genetic alteration (somatic mutation) leads to cysts; most commonly on distal region.

Cyst can grow with fluid from the glomerular filtration.
Overtime
Cysts separate from nephron -> isolated sacs that continue to grow
=Continued epithelial hyperplasia, fluid secretion, membrane alterations and fibrosis of the interstitium
= massive cystic disease and impaired renal function

Progressive renal impairment
ESRD\

Question 4

What are the extra renal manifestation of PKD

Answer 4

The proteins polycystin-1 and polycystin-2 can be found in a variety of other tissues including hepatic ducts and pancreatic ducts

Circle of willis cysts - berrys aneurysm
Polycystic liver disease
Pancreatic cysts
Cardiac valve disease: seen in 25-30%. Most commonly mitral valve prolapse and aortic regurgitation
Gastrointestinal abnormalities: diverticulosis and hernias (abdominal/inguinal) occur at higher frequency

Question 5

ADPKD Sx

Answer 5

NB may be Asx for decades

Bilateral flank pain(back or abdo pain)
haematuria (rupture)
Hypertension

Question 6

Cyst complication

Answer 6

Ruptured cyst: common cause of loin pain, usually self-limiting
Haemorrhagic cyst: describes a ruptured cyst with haemorrhage.
Infected cyst: many occur in relation to rupture.
Typical features include fever, pain, dysuria.

Question 7

PKD diagnosis

Answer 7

KUB USS
Screening those w/FHX

Other investigations:
CKD function tests and complications

Question 8

PKD TX

Answer 8

No curative - manage complications:
Hydration
HTN - Acei/ARB
pain - Analgesia
Infection - Ab