Polycystic Kidney Disease

POLYCYSTIC KIDNEY DISEASE

Polycystic kidney disease is a disorder that affects the kidneys as well as other organs. Clusters of fluid-filled sacs, called cysts, develop in the kidneys and thus interfere with their ability to filter waste products from blood. The growth of cysts, if not checked may cause the kidneys to enlarge which can lead to kidney failure. Cysts may also develop in other organs, especially the liver.

The most frequent complications of polycystic kidney disease include blood pressure that can be dangerously high, pain in the back or sides, blood in the urine, recurrent urinary tract infections, kidney stones, and heart valve abnormalities. Additionally, people with polycystic kidney disease have an increased risk of an abnormal bulging (an aneurysm) in a large blood vessel called the aorta or in blood vessels at the base of the brain. If they tear or rupture aneurysms can be life-threatening.

The two major forms of polycystic kidney disease are distinguished by the usual age of onset and the pattern in which it is passed through families.

The autosomal dominant form (otherwise called ADPKD) has signs and symptoms that typically begin in adulthood. This is despite the fact that cysts in the kidney may often be present from birth or childhood. The autosomal dominant polycystic kidney disease can further be divided into type 1 and type 2, depending on the cause.

The autosomal recessive form of polycystic kidney disease (otherwise called ARPKD) is rare and is often lethal and occurs early in life. The signs and symptoms of this condition are usually apparent at birth or in early infancy.

TYPES OF PKD

The three main types of PKD are:

• Autosomal Dominant PKD (also called PKD or ADPKD)

This form of the disease is passed from parent to child by inheritance that is dominant. This means, only one copy of the abnormal gene is needed to cause the disease. The symptoms usually begin between the age 30 and 40, but could begin even in childhood. ADPKD is the most common form of PKD.

• Infantile or Autosomal Recessive PKD (also called ARPKD)

This type is passed from parent to child by inheritance that is recessive. Symptoms can begin in the earliest months of life, even in the womb. It can be very serious, progresses rapidly, and is often fatal in the first few months of life. Suffice to say that this type of ARPKD is extremely rare.

• Acquired Cystic Kidney Disease (also called ACKD)

This type can happen in kidneys with long-term damage and severe scarring. Thus it is often associated with kidney failure and dialysis. About 90 percent of people on dialysis for 5 years develop ACKD. The cysts bleed into the urinary system, which discolors urine this explains why people with ACKD usually seek help, because they notice blood in their urine.

WHAT CAUSES PKD

Generally, PKD is inherited. Although less commonly, it can develop in people who have other serious kidney problems.

The following are three types of PKD.

• Autosomal dominant PKD

Autosomal dominant (ADPKD) is sometimes referred to as adult PKD. It accounts for about 90 percent of all kidney cases. Anyone who has a parent with PKD has a 50 percent chance of developing this condition.

Its symptoms usually develop much later between ages 30 and 40. However, some people still experience symptoms in childhood.

• Autosomal recessive PKD

Much less common than ADPKD, it's also inherited, however both parents must carry the gene for the disease to occur in the offspring.

The people who are carriers of ARPKD would not have symptoms if they have only one gene. It is only if they inherit two genes, one from each parent, that they'll have ARPKD.

There are four types of ARPKD:

1. The perinatal type (present at birth).
2. The Neonatal type (occurs within the first month of life).
3. Infantile type (occurs at age 3 to 12 months old).
4. Juvenile type (occurs after age 1 year old).

• Acquired cystic kidney disease

This type is not inherited, and usually occurs late in life.

ACKD usually develops in people who already have other kidney problems. It's actually more common in people who have kidney failure or are on dialysis.

SYMPTOMS OF PKD?

Many people live with PKD for years without experiencing any symptoms. It is typical for Cysts grow 0.5 inches or larger before a person starts noticing symptoms.

Initial symptoms associated with PKD can include:

• Back pain
• Abdominal pain
• Blood in the urine
• Frequent urination
• Pain in the sides
• Urinary tract infection (UTI)
• Kidney stones
• Skin that bruises easily
• Joint pain
• Pale skin
• Constant fatigue

Children with autosomal recessive PKD may have symptoms that include:

• Frequent urination
• Hypertension
• UTI

Symptoms in children may look like that of other disorders. Therefore it's important to get medical attention for a child experiencing any of the symptoms listed above.

COMPLICATIONS

Some complications associated with polycystic kidney disease include:

• Uremia - PKD can interfere with the ability of the kidneys to keep wastes from building up to toxic levels (a condition called uremia). As the disease keeps worsening, end-stage kidney disease may result which will necessitate kidney dialysis or a transplant to prolong life.
• Cysts in the liver - The likelihood of liver cysts for someone with polycystic kidney disease increases with age. While cysts develop in both men and women, female hormones and multiple pregnancies might contribute to the development of larger liver cyst among women.
• High blood pressure - Elevated blood pressure is a common complication of polycystic kidney disease. If left untreated, high blood pressure can cause further damage to the kidneys and increase the risk of heart disease and strokes.
• Complications with Pregnancy - Pregnancy is successful for most women with polycystic kidney disease. However, some women may develop a life-threatening disorder called preeclampsia. Those at risk may have high blood pressure or a decline in kidney function before they become pregnant.
• Loss of kidney function - One of the most serious complications of polycystic kidney disease is progressive loss of kidney function. Nearly half of those with the disease have kidney failure by age 60.
• Chronic pain – The most common symptom for people with polycystic kidney disease is Pain that often occurs at the side or back. That type of pain can also be associated with a urinary tract infection, a kidney stone or a malignancy.
• Development of aneurysm in the brain – The development of a balloon-like bulge in a blood vessel (aneurysm) in the brain can cause bleeding (hemorrhage) should it rupture. Whereas people with polycystic kidney disease have a higher risk of aneurysms. People with a family history of aneurysms seem to be at highest risk. Doctors will always know if screening is needed in any particular case.
• Abnormalities with heart valve - As many as 25% of adults with polycystic kidney disease develops mitral valve prolapse. When this happens, the heart valve no longer closes properly, a situation which allows blood to leak backwards.

• Problems in the Colon - Diverticulosis (weaknesses and pouches or sacs in the wall of the colon) may develop among people with polycystic kidney disease.

INHERITANCE PATTERN

Most cases of PKD have an autosomal dominant pattern of inheritance. People with this condition are born with one mutated copy of the PKD1 or PKD2 gene in each cell. In about 90 percent of these cases, an affected person inherits the mutation from one affected parent. The other 10 percent of cases usually result from a new mutation in one of the genes and this occurs in people without any history of the disorder in their family.

Although a single altered copy of a gene in each cell is sufficient to cause this disorder, an additional mutation in the second copy of the PKD1 or PKD2 gene may make the cysts grow faster and even increase the severity of the disease. The rate at which cysts will enlarge and occasion a loss of kidney function varies widely between persons with the condition, this may be influenced by mutations in other genes that is yet to be identified.

PKD can also can be inherited in an autosomal recessive pattern. People with this type of the condition have two altered copies of the PKHD1 gene in each cell. In this case, the parents of the child are carriers of one copy of the altered gene but are not affected by the condition.

WHEN TO SEE A DOCTOR

It is common for people to be unaware that they have had polycystic kidney disease for years.

If a person develops some of the signs and symptoms of polycystic kidney disease, they should endeavor to see their doctor. If one has a close relative (e.g. a parent, sibling or child) with polycystic kidney disease, they must see their doctors to discuss screening for PKD.

DIAGNOSIS

Ultrasound is undoubtedly the most reliable, inexpensive and non-invasive way to diagnose PKD. Occasionally, a CT scan (computed tomography scan) and MRI (magnetic resonance imaging) may detect smaller cysts that cannot be found by an ultrasound. MRI is used to measure and monitor the volume and growth of kidneys and cysts.

In certain situations, genetic testing might also be preferred. This will involve a blood test that checks for abnormal genes that can cause the disease. This kind of testing is not recommended for everyone. Despite the rather expensive cost, it also fails to detect PKD in about a quarter of people who have it.

However, genetic testing can be useful in the following situations:

• The person has an uncertain diagnosis based on imaging tests
• The person has a family history of PKD and wants to donate a kidney
• The person is younger than 30-years old, has a family history of PKD and a negative ultrasound, and is planning to start a family

According to studies, about half of people with PKD will have kidney failure by age 60, and a lot more by age 70. With kidney failure people will need dialysis or a kidney transplant.

Certain people have an increased risk of kidney failure including:

• Patients with protein or blood in their urine
• Hypertensive Patients
• Men
• Hypertensive women who have had more than three pregnancies

TREATMENT

Even among members of the same family, the severity of polycystic kidney disease varies between persons. People with PKD often reach end-stage kidney disease between ages 55 to 65. However, some other people with PKD will only have a mild disease and might never progress to end-stage kidney disease.

Treating polycystic kidney disease involves dealing with the following signs, symptoms and complications in their early stages:

Kidney cyst growth -Tolvaptan therapy may be recommended for adults at risk of rapidly progressive ADPKD. The pill is taken orally (by mouth) and works to slow the rate of kidney cyst growth and the decline in how well the kidneys work.

It is worthy to note that there's a risk of serious liver injury when taking Tolvaptan. It can interact with other medicines one takes. It's advisable to see a Nephrologist (doctor who specializes in kidney health) when taking Tolvaptan, so that proper monitoring can be done for side effects and possible complications.

High blood pressure. Controlling hypertension can delay the progression of the disease and slow down further kidney damage. The combination of

• A low-sodium,
• Low-fat diet that's moderate in protein and calorie content with,
• Not smoking,
• Increasing exercise and
• Reducing stress

May help control high blood pressure.

However, in spite of the above, medications are usually needed to control high blood pressure. Medications called angiotensin-converting enzyme (ACE) inhibitors or angiotensin II receptor blockers (ARBs) are often used to control high blood pressure.

Declining kidney function. To help kidneys stay as healthy as possible for as long as possible, health experts recommend that maintaining a normal body weight drinking water and fluids throughout the day may help slow the growth of kidney cysts, which in turn could slow down a decline in kidney function. People must ensure to follow low-salt diets and eat less protein to allow kidney cysts to respond better to the increase in fluids.

Kidney failure – In the event the kidneys lose their ability to remove waste products and extra fluids from the blood, either dialysis or a kidney transplant will be needed. Consulting the doctor regularly for monitoring of PKD allows for him to determine the best timing of a kidney transplant.

Blood in the urine – One will need to drink lots of fluids, preferably plain water to dilute the urine, as soon as blood is noticed in urine. Dilution might help prevent obstructive clots from forming in the urinary tract. In most of the cases, the bleeding will stop on its own. It's important to contact a doctor if it doesn't.

Bladder or kidney infections – The prompt treatment of infections with antibiotics is always necessary to prevent kidney damage. The doctor may determine whether it is a simple bladder infection or a more complicated cyst or kidney infection. A longer course of antibiotics may be needed for more complicated infections.

Pain - The pain of polycystic kidney disease can be controlled with over-the-counter medications containing acetaminophen. For some people, the pain may be more severe and constant. The doctor might recommend a procedure that uses a needle to draw out cyst fluid and inject a sclerosing agent to shrink kidney cysts. On the other hand, one may need surgery to remove cysts if they're large enough to cause severe pressure and/or pain.

Aneurysms. People with polycystic kidney disease coupled with a family history of ruptured brain (intracranial) aneurysms, the doctor may recommend regular screening for intracranial aneurysms. If an aneurysm is discovered, surgical clipping of the aneurysm may be needed to reduce the risk of bleeding, but this will depend on its size.

Nonsurgical treatment of small aneurysms may involve the control of hypertension and high blood cholesterol, as well as quitting smoking.

PREVENTION

There is no known way to prevent PKD of any form. With PKD, one may be able to keep their kidneys working longer by following a healthy lifestyle.

Some tips for living healthy will include:

• Taking all prescription medicines as the doctor recommends.
• Exercising for at least 30 minutes a day.
• Keeping a healthy blood pressure.
• Keeping a healthy blood sugar level.
• Keeping a healthy weight.
• Following a low-salt, low-fat diet.
• Limiting alcohol.
• Not smoking or using any tobacco product.
• Not taking more than the recommended dose of over-the-counter medicines.

LIFESTYLE CHANGES

Be active for 30 minutes or more on most days. Regular physical activity can help an individual reduce stress, manage weight, and control blood pressure. People who engage in contact sports, such as football or hockey, health care providers should do a magnetic resonance imaging (MRI) test to see whether these sports are safe because trauma to especially the back and sides, may cause kidney cysts to burst.

Lose weight. Being overweight stresses the kidneys to work harder. Thus losing weight helps protect the kidneys.

Aim for at least 7 hours of sleep each night. Getting enough sleep is important for overall physical and mental health, and can help one manage their blood pressure, blood glucose, or blood sugar.

Reduce stress. Long-term stress can raise blood pressure and even lead to depression. Some of the steps taken to manage PKD are also healthy ways to cope with stress. For example, getting enough physical activity and sleep helps reduce stress.

Refrain from smoking. Cigarette smoking and the use of tobacco products generally can raise blood pressure and make the kidney damage worse. Refraining from smoking may help meet blood pressure commitments, which will be good for the kidneys and can lower the chances of a heart attack or stroke. Quitting smoking is even more critical for people with PKD who have aneurysms.

Change of diet and drink

People may need to change what they eat and drink to help control blood pressure and protect the kidneys. Patients, including those with PKD, should talk with a dietitian about which foods and drinks to include in their healthy eating plans. Drinking the right amount of fluid and generally staying hydrated by may help slow PKD's progress toward kidney failure.

Take blood pressure medicines

Just in case lifestyle and diet changes fail to control the blood pressure, a doctor may prescribe one or more blood pressure medicines. Two types of blood pressure medicines, angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs), may slow kidney disease and delay kidney failure.

Reproductive support

Because PKD can be an inherited condition, the doctor may recommend consulting a genetic counselor in order to help trace out a map of the family's medical history with respect to PKD.

Genetic counseling can help one to make important decisions on the best way forward, especially for offspring in relation to PKD.

Kidney failure and transplant options

Arguably, the most serious complications of PKD is kidney failure. This is when the kidneys are no longer able to:

• Maintain blood pressure
• Filter waste products
• Maintain fluid balance

At this stage, the doctor will discuss options that may include a kidney transplant or perhaps dialysis treatments to act as artificial kidneys.

If the doctor recommends a kidney transplant, it would have been considered after several factors may have been weighed including the patient's overall health, expected survival, and how long he/she has been on dialysis.

It's also possible to have a donor to donate a kidney, this is because people can live with only one kidney with relatively few complications, and this can be an option for families who have a willing donor.

The decision to undergo a kidney transplant or donate a kidney to a person with kidney disease is not one to be made lightly. Speaking to the nephrologist can help weigh the options.

OUTLOOK FOR PEOPLE WITH PKD

For most people, PKD slowly gets worse over time, and because the kidneys are such important organs, their failure usually affects other organs, including the liver.

Proper medical care can help with the management of PKD symptoms for years. If there are no other medical conditions, the patient may be a good candidate for a kidney transplant.

Also, it will be good to consider speaking with a genetic counselor if there is a family history of PKD and the patient is planning to have children