Polycystic Kidney Disease

Question 1

What is the problem in PKD?

Associated issues?

Answer 1

Polycystic kidney disease is a genetic condition where the kidneys develop MULTIPLE FLUID FILLED CYSTS

Kidney function is also significantly impaired.

There are a number of associated findings outside the kidneys such as HEPATIC CYSTS and CEREBRAL ANEURYSMS.

Question 2

Autosomal Dominant Type

Genes

Answer 2

PKD-1: chromosome 16 (85% of cases)

PKD-2: chromosome 4 (15% of cases)

Question 3

Autosomal Dominant Type

Extra-renal manifestations

Answer 3

CEREBRAL ANEURYSMS
HEPATIC, splenic, pancreatic, ovarian and prostatic CYSTS
Cardiac valve disease (mitral regurgitation, aortic regurgitation)
Colonic diverticula
Aortic root dilatation

Question 4

Complications of PKD

Answer 4

Gross haematuria can occur with cyst rupture. This usually resolves within a few days.

Renal stones are more common in patients with PKD

End stage renal failure occurs at a mean age of 50 years

Question 5

Autosomal Recessive Type

Gene

Compare it to dominant type

How does it present

Management

Answer 5

Autosomal recessive polycystic kidney disease (ARPKD) is caused by a gene on chromosome 6.

It is more rare and more severe than dominant type

PRESENTATION

• It often presents in pregnancy with oligohydramnios as the fetus does not produce enough urine.
• The oligohydramnios leads to underdevelopment of the lungs resulting in respiratory failure shortly after birth.
• They can have dysmorphic features such as underdeveloped ear cartilage, low set ears and a flat nasal bridge.

MANAGEMENT
Patients may require dialysis within the first few days of life.

Question 6

Polycystic Kidney Disease

Answer 6

TOLVAPTAN (a vasopressin receptor antagonist) can slow the development of cysts and the progression of renal failure in autosomal DOMINANT polycystic kidney disease.

(It is recommended by NICE in certain situations although it should be initiated and monitored by a specialist.)

Management of polycystic kidney disease is mainly supportive of the complications:

• Antihypertensives for hypertension.
• Analgesia for renal colic related to stones or cysts.
• Antibiotics for infection. Drainage of infected cysts may be required.
• Dialysis for end stage renal failure.
• Renal transplant for end stage renal failure.
• Genetic counselling
• Avoid contact sports due to the risk of cyst rupture
• Avoid anti-inflammatory medications and anticoagulants
• Regular ultrasound to monitor the cysts
• Regular bloods to monitor renal function
• Regular blood pressure to monitor for hypertension
• MR angiogram can be used to diagnose intracranial aneurysms in symptomatic patients or those with a family history