Polycystic Kidney Disease

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. Palpable, enlarged kidneys may be felt on examination.

There is an autosomal dominant and an autosomal recessive type. The autosomal dominant type of PKD is more common than the autosomal recessive type.

Diagnosis is by kidney ultrasound scan and genetic testing.

 

Autosomal Dominant Type

Autosomal Dominant Genes

  • PKD-1: chromosome 16 (85% of cases)
  • PKD-2: chromosome 4 (15% of cases)

 

Extra-renal Manifestations

  • Cerebral aneurysms
  • Hepatic, splenic, pancreatic, ovarian and prostatic cysts
  • Cardiac valve disease (mitral regurgitation)
  • Colonic diverticula
  • Aortic root dilatation

 

Complications

  • 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

 

Autosomal Recessive Type

Autosomal recessive polycystic kidney disease (ARPKD) is caused by a gene on chromosome 6. It is rarer and more severe. It often presents in pregnancy with oligohydramnios as the fetus does not produce enough urine.

 

Features

The oligohydramnios leads to underdevelopment of the lungs resulting in respiratory failure shortly after birth. Patients may require dialysis within the first few days of life. They can have dysmorphic features such as underdeveloped ear cartilage, low set ears and a flat nasal bridge. They usually have end-stage renal failure before reaching adulthood.

 

Management

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.

 

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

 

Last updated April 2019
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