Treatment

There's currently no cure for autosomal recessive polycystic kidney disease (ARPKD).

However, treatments are available to manage the condition's associated symptoms and any complications that may occur, such as:

• breathing difficulties caused by underdeveloped lungs (pulmonary hypoplasia)
• high blood pressure (hypertension)
• liver problems
• chronic kidney disease (CKD) and kidney failure

Treatments for these common problems are described below.

Breathing difficulties

If there's a significant risk your baby will be born with underdeveloped lungs (pulmonary hypoplasia), particularly ifyour baby ispremature, treatment can begin before they're born.

You may be injected with a medication called betamethasone during your pregnancy. This stimulates the development of your baby's lungs and helps them work more efficiently if they're born prematurely.

After birth, it's likely your baby will be immediately admitted to an intensive care unit (ICU) , where they'll be placed on a ventilator (an artificial breathing machine) to assist their breathing.

They may also be given a type of medication called a surfactant, which helps prevent tiny air sacs inside the lungs known as alveoli collapsing. The more working alveoli your baby has, the better their ability to breathe.

Breathing difficulties can be made worse if your baby's enlarged kidneys press on their diaphragm (the sheet of muscle in the abdomen that helps with breathing). In a few cases, the doctor treating your baby may recommend removing one of their kidneys to relieve the pressure.

Despite advances in treatment, pulmonary hypoplasia is a very difficult condition to manage in babies with ARPKD. In some cases, your baby may need to stay in hospital for weeks or months. Even with thebest efforts of the medical team, around one in every threebabies will die as a result of the condition.

High blood pressure

An angiotensin-converting enzyme (ACE) inhibitor is the most widely used treatment for babies and children with high blood pressure.

ACE inhibitors reduce blood pressure by reducing the pressure across the filtering units of the kidney (glomeruli).

Possibleside effects of ACE inhibitors caninclude:

• dizziness
• tiredness or weakness
• headaches
• a persistent dry cough
• high potassium levels or worsening kidney function ( blood tests are needed to monitor this)

Most of these side effects should pass in a few days, although some people have a dry cough for longer.

A similar group of blood pressure medicines are angiotensin 2 receptor blockers (ARBs), which work in a similar way to ACE inhibitors, but don't cause a cough.

As well as ACE inhibitors and ARBs, there are lots of other medications that may also be used to control blood pressure in children with ARPKD, such as calcium channel blockers, beta-blockers and diuretics.

These blood vessels, known as varices, are smaller and more fragile than the blood vessels in the liver and can burst under high blood pressure.

If your child has bleeding from these varices, urgent treatment will be needed to stop the bleeding. This will usually involve passing a thin, flexible tube called an endoscope down their mouth and gullet (oesophagus), and either placing a small band around the base of the varices or injecting a special medication "superglue" to make the blood clot.

If your child has particularly severe liver problems, they may need a liver transplant . If they also need a kidney transplant, both procedures may be combined into a single operation.

Chronic kidney disease

If your child's condition progresses to a stage where their kidney function is significantly affected, they'll usually need a number of different treatments to manage the various problems this can cause.

For example, your child may need treatment for the following problems:

• anaemia (a lack of iron in the body, which leads to a decreasing numberof red blood cells) this can be treated with iron supplements, injections of erythropoietin (the hormone the kidneys produce to stimulate red blood cell production), or blood transfusions in severe cases
• high phosphate levels, which can affect bone health this can be treated with a medication called a phosphate binder,which istaken with meals
• growth problems which can be treated with injections ofhuman growth hormone (HGH), a synthetic version of the hormones used by the body to stimulate growth

You could alsoask your relatives if they would consider having themselves tested to see if they could donate one of their kidneys.