Polycystic Kidney Disease

Question 1

What is PKD (general)

Answer 1

Genetic condition - where kidneys develop multiple fluid-filled cysts

Kidney function is also significantly impaired.

Kidneys may be enlarged and palpable on examination

Question 2

Common associated findings in PDK (general)

Answer 2

Hepatic cysts

Cerebral aneurysms

Question 3

Diagnosis of PKD:

Answer 3

Kidney ultrasound

Genetic testing

Question 4

2 types of PKD

Answer 4

Autosomal dominant  (more common)
Autosomal recessive

Question 5

Autosomal dominant PKD genes:

Answer 5

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

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

Question 6

Extra-renal manifestations of autosomal dominant PKD

Answer 6

Cerebral aneurysms

Hepatic, splenic, pancreatic, ovarian and prostatic cysts

Cardiac valve disease (mitral regurgitation)

Colonic diverticula

Aortic root dilatation

Question 7

Complications of autosomal dominant PKD

Answer 7

Chronic loin pain

Hypertension

Cardiovascular disease

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 8

Autosomal recessive type PKD - gene on which chromosome?

Answer 8

chromosome 6

Question 9

ARPKD: Features

Answer 9

Often presents in pregnancy with oligohydramnios - as foetus doesnt produce enough urine

• oligohydramnios - leads to underdevelopment of lungs (respiratory failure shortly after birth)
• Patient may require dialysis within first few days of life

Dysmorphic features such as:

• underdeveloped ear cartilages
• low set ears
• flat nasal bridge
• Usually have end-stage renal failure before reaching adulthood

Question 10

Management of PKD:

Answer 10

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

Management mainly supportive of 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.

Other management steps:

• 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