Polycystic Kidney Disease

Question 1

What is the prevalence of PCKD?

Answer 1

1:1000

Question 2

What is the inheritance pattern of PCKD?

Answer 2

autosomal dominant

Question 3

What is the most common gene responsible for PCKD?

Answer 3

PKD1 (polycystin-1) - 78%

Question 4

What percentage of PCKD patients don’t have a family history?

Answer 4

10-15%

Question 5

Which type of mutation results in a milder phenotype?

Answer 5

non truncating

Question 6

Which is more severe PKD1 or PKD2?

Answer 6

PKD1

Question 7

By what age to 50% of PCKD reach ESRF?

Answer 7

60

Question 8

What are the risk factors for more progressive renal disease in PCKD?

Answer 8

PKD1, truncating mutation, male, early onset sx, family hx of early ESKD, kidney size, hypertension, proteinuria

Question 9

Is there an increased risk of RCC in PCKD?

Answer 9

no

Question 10

What are the renal manifestations of PCKD?

Answer 10

hypertension, haematuria, proteinuria (less common), renal failure, flank pain, chronic pain, UTI, calculi

Question 11

What are the extra renal manifestations of PCKD?

Answer 11

cerebral aneurysms, hepatic cysts, pancreatic cysts, seminal vesicle cysts, cardiac valve disease, aortic dissection/aneurysms, cardiomyopathy, LVH, AF, coronary aneurysms, pericardial effusions, colonic/duodenal diverticulae, abdominal wall and inguinal hernia

Question 12

What risk factor modification is important for cerebral aneurysms in PCKD?

Answer 12

BP, lipid control, smoking cessation

Question 13

Which patients should be screened for cerebral aneurysms?

Answer 13

phx ruptured aneurysm, fhx, neurological sx, high risk job (e.g. pilot), prior to major surgery

Question 14

Which artery is usually involved in cerebral aneurysms?

Answer 14

MCA

Question 15

What percentage of patients with PCKD have cerebral aneurysms?

Answer 15

5% in young adults, up to 20% in patients > 60

Question 16

What percentage of patients with PCKD have severe polycystic liver disease?

Answer 16

15%

Question 17

What symptoms to patients get from polycystic liver disease?

Answer 17

early satiety, reflux, abdominal pain, bloating, dyspnoea, back pain, ascites, oedema

Question 18

Which type of cardiac valve disease is more common?

Answer 18

mitral valve prolapse and aortic regurgitation

Question 19

What is required for diagnosis of PCKD?

Answer 19

FHx + > 3 cysts if age 15-39 or > 2 cysts in each kidney age 40-49

OR

> 10 cysts in each kidney

Question 20

When should you consider a differential diagnosis?

Answer 20

If eGFR doesn’t match with degree of renal cyst burden

Question 21

What are some differential diagnoses for PCKD?

Answer 21

benign cysts, cysts secondary to dialysis, cysts secondary to lithium, ADTKD, autosomal recessive PKD, tuberous sclerosis

Question 22

Which gene is affected in autosomal recessive PKD?

Answer 22

PKHD1

Question 23

Which is more severe - autosomal recessive or autosomal dominant PKD?

Answer 23

autosomal recessive

Question 24

Why does tuberous sclerosis sometimes occur concurrently with PCKD?

Answer 24

because the genes are proximal

Question 25

What are the key features for a diagnosis of ADPKD?

Answer 25

diffuse cysts, enlarged kidneys and positive family hx

Question 26

What are the benefits of BP control in PCKD?

Answer 26

reduces the increase in TKV, reduces eGFR decline, improves CV mortality

Question 27

What are the conservative management strategies for PCKD?

Answer 27

ACE/ARB, reduce sodium intake, increase fluid intake, lipid control, ?caloric restriction

Question 28

What is the mechanism of action of tolvaptan?

Answer 28

vasopression V2 receptor antagonist

Question 29

What criteria are required to prescribe tolvaptan on the PBS?

Answer 29

eGFR < 90mL/min and eGFR decline >5mL/min/year or > 2.5mL/min/year for 5 years or more

Question 30

What is the dose for tolvaptan?

Answer 30

start: 45mg mane then 15mg eight hours later | increase every 1-4 weeks up to max 90mg mane, 30mg afternoon

Question 31

What is the aim of using tolvaptan?

Answer 31

to decrease urine osmolality to < 280 (hypotonic)

Question 32

What are the side effects in tolvaptan?

Answer 32

small decline in eGFR (6-8%) polydipsia, polyuria, nocturia deranged LFTs (measure LFTs monthly for 18 months) hypernatraemia (need to increase hydration or reduce dose)

Question 33

What are the contraindications for tolvaptan?

Answer 33

baseline hypernatraemia, inability to sense or respond to thirst, frailty, hypovolaemic, concurrent diuretic usage

Question 34

What drugs to tolvaptan interact with?

Answer 34

CYP3A4 inhibitors

Question 35

What is the most common cause of death in PCKD?

Answer 35

cardiac cause