Polycystic kidney disease

What is it?

In polycystic kidney disease, many small sacs filled with fluid (cysts) form in the kidneys.¹ A fault in a gene, most often PKD1 or PKD2, upsets how kidney cells grow.¹ You are born with it, but it usually causes no problems until the cysts are big enough to affect the kidneys, most often between 30 and 40.¹

It is the most common inherited kidney condition, though still relatively uncommon: it is estimated that up to 1 in every 1,000 to 2,500 people in the UK has it.¹ If one parent has the faulty gene, each child has a 1 in 2 chance of getting it.¹ In about 1 in 10 people the gene fault is new, and they can pass it on.¹ A rarer form, autosomal recessive PKD, needs a faulty gene from both parents and usually starts in childhood.¹

The first signs

When signs appear, they can include:

• pain in the tummy;¹
• high blood pressure;¹
• blood in the pee, which you may not be able to see;¹
• upper urinary tract infections, which can be serious;¹
• kidney stones.¹

How doctors find out

Your family doctor asks about your symptoms and family, checks your blood pressure and urine, and does a blood test to see how well your kidneys filter.³ A painless ultrasound scan looks for cysts in the kidneys and other organs such as the liver; sometimes a CT or MRI scan is needed.³ Genetic blood tests are used only in special cases.³ Very small cysts can be missed in young people, so a scan may need repeating later.³ Testing children or relatives without signs has pros and cons.³ If brain aneurysms run in your family, an MRI scan of the brain is recommended.³

Current treatment

Blood pressure medicines (ACE inhibitors or ARBs) and less salt; tolvaptan to slow cyst growth in some adults whose kidney disease is getting worse quickly; dialysis or a transplant if the kidneys fail.Source: NHS

Will it get worse?

It differs a lot between people.¹ Kidney function may slowly get worse over time.¹ Some people reach kidney failure soon after finding out, while others keep fairly good kidneys all their life; on average about half of people need treatment for kidney failure by age 60.¹ High blood pressure raises the risk of heart attack and stroke, and a bulging blood vessel in the brain (aneurysm) can bleed.¹

Medicines: what helps, and what to watch for

High blood pressure is usually treated with medicines, most often ACE inhibitors or ARBs.² Tolvaptan is a tablet taken twice a day that slows cyst growth and helps keep the kidneys working for longer; it can only be used in adults who have chronic kidney disease (stage 2 or 3) at the start of treatment and signs that the kidney disease is getting worse quickly.² Antibiotics treat urine infections, though infections in the cysts are harder to cure, and painkillers can ease the pain.²

Good to know:

• paracetamol is the first choice for pain; painkillers such as ibuprofen (NSAIDs) are usually avoided, because they can harm the kidneys and work against blood pressure medicines;²
• tolvaptan often makes you thirsty and need to pee more, also at night;²
• tolvaptan has caused liver damage in some people, so at first you are monitored often through hospital clinics;²

Dialysis or a transplant, for some people

Large kidney stones can be broken up with shock waves or removed with a thin tube, and large cysts can sometimes be drained.² When the kidneys fail, dialysis (a machine does some of their work) or a kidney transplant are the main options.² You only need one kidney to survive, so a living person can donate a kidney; close relatives usually make the best match.² Some people choose care focused on comfort instead.²

Is there a cure?

No, there is currently no cure.² The cysts cannot be prevented, but treatment can slow their growth and manage the problems they cause.²

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Sources

Written in plain words by Frontlight from these pages:

1. NHS: Autosomal dominant polycystic kidney disease (ADPKD)
2. NHS: ADPKD – Treatment
3. NHS: ADPKD – Diagnosis