Polycystic Kidney Disease Flashcards
What is polycystic Kidney Disease?
An autosomal dominant disease causing multiple cysts to develop, gradually and progressively, throughout the kidney eventually resulting in renal enlargement and kidney tissue destruction.
Briefly describe the pathophysiology of polycystic kidney disease?
Mutations in PKD1 (85%) gene on chromosome 16 or in PKD2 (15%) gene on chromosome 4 which causes disruption of the polycystin pathway resulting in reduced cytoplasmic Ca2+, which, in principal cells of the collecting duct, causes defective ciliary signalling and disorientated cell division resulting in cyst formation.
What is the rate of renal decline dependent on?
Size and growth rate of the cysts. - Patients with rapidly growing cysts will loose kidney function more rapidly.
What are the three risk factors for PKD?
- Family history of Autosomal Dominant Kidney Disease
- End Stage RF
- Hypertension
What age does PKD usually present?
20-30
Why is family screening in PKD essential?
Because it can be clinically silent for many years. Symptoms tend to start to present from 20 yrs onwards.
What are the signs of PKD?
- Bilateral kidney enlargement
- Hypertension
- Renal stones (calculi) - mainly uric acid stones
- Progressive renal failure
What extra renal involvement do you get in PKD?
- Subarachnoid haemorrhage associated with berry aneurysm rupture
- Polycystic liver disease (70%)
- Pancreatitis
- Male infertility (rare)
- Mitral valve prolapse
- Ovarian cysts
- Diverticular disease
What ultrasound criteria can you use to exclude a diagnosis of PKD?
≥ 40yrs < 2 cysts
What is the diagnosis criteria for PKD?
- 5-39yrs ≥ 3 cysts (uni/bilateral)
- 40-59yrs ≥ 2 cysts (each kidney)
- > 60yrs ≥ 4 cysts (each kidney)
Is there a treatment for PKD?
No as the disease progression is very slow
What can you do to help with the pain in PKD?
Laparoscopic removal of the cysts and analgesia.
How would you monitor the disease progression in PKD?
Serial progression of serum creatinine
What is autosomal recessive polycystic kidney disease?
Rarer than Autosomal dominant Polycystic kidney disease, it’s a disease of infancy and is Autosomal recessive PKHD1 mutation on long arm (q) of chromosome 6.
What is the presentation of ARPKD?
- Variable
- Many present in infancy with multiple renal cysts and
congenital hepatic fibrosis - Enlarged polycystic kidneys
- 30% develop kidney failure
