Autosomal dominant polycystic kidney disease

• The kidney is an organ that filters waste and extra fluid from the blood and produces urine. Individuals have two kidneys, and they are located in the upper part of the abdomen. Autosomal dominant polycystic kidney disease (autosomal dominant PKD) is an inherited genetic condition that affects the function of the kidneys.
• In patients with autosomal dominant PKD, small fluid-filled sacs called cysts form on the kidneys. These cysts replace most of the normal kidney tissue, causing the kidney to become enlarged and leading to loss of kidney function and eventually, kidney failure, which may be life-threatening if not properly treated. About one-half of patients with autosomal dominant PKD develop kidney failure. Some patients may also develop infections of the urinary tract or may have blood in their urine, which is usually caused by bleeding into a cyst following rupture of the cyst.
• When kidneys begin to fail, patients may be treated with dialysis (filtering the blood in a different way, such as with an external filter) or with a kidney transplant.
• A common symptom in patients with autosomal dominant PKD is pain in the back and sides. Pain may be caused by infection of the cysts, bleeding into the cysts, or stretching of the fibrous tissue around the kidney (due to kidney enlargement).
• Patients with autosomal dominant PKD may develop cysts in other areas of the body, especially the liver, pancreas, or blood vessels of the brain and heart. This may lead to complications, such as an aneurysm.
• About one in 1,000 individuals is affected with autosomal dominant PKD.

• Autosomal dominant polycystic kidney disease (autosomal dominant PKD) is a dominant inherited genetic condition. Individuals have two copies of most genes (one inherited from the father and one from the mother). In a dominant genetic condition, only one copy of a certain gene needs to be defective for the condition to develop. It has been shown that mutations in either the PKD1 gene or the PKD2 gene may cause autosomal dominant PKD. Therefore, if an individual has a parent with one mutant copy of either PKD1 or PKD2, that individual has a 50% chance of inheriting the mutant gene. Most individuals who inherit a mutant PKD1 gene or a mutant PKD2 gene will develop autosomal dominant PKD.

• Inheritance: Autosomal dominant polycystic kidney disease (autosomal dominant PKD) is caused by mutations, or errors, in a patient's genes. The genes PKD1 and PKD2 have both been implicated in autosomal dominant PKD. It has been found that a mutation in either of these genes may lead to the disease. Generally, the symptoms patients experience are the same for either mutation, but symptoms may appear earlier in patients with PKD1 mutations.
• PKD1 and PKD2 appear to function in the growth and development of the kidney. PKD2 makes a channel protein that allows calcium ions to enter into a cell. PKD1 makes a protein that associates with PKD2 and may regulate its channel activity. It is currently unclear how mutations in these genes lead to the cyst formation seen in patients with autosomal dominant PKD.
• Random occurrence: Most cases of autosomal dominant PKD are inherited, meaning that a defective gene was transmitted from a parent to the child. However, a small number of cases of autosomal dominant PKD are not inherited, but instead result from a spontaneously arising mutation in the egg or sperm or in early embryonic development.

• Symptoms of autosomal dominant polycystic kidney disease (autosomal dominant PKD) usually develop later in life, between the ages of 30 and 40.
• In patients with autosomal dominant PKD, small fluid-filled sacs called cysts form on the kidneys. These cysts replace most of the normal kidney tissue and cause the kidney to become enlarged, leading to loss of kidney function.
• Patients with autosomal dominant PKD may also develop cysts in other areas of the body, especially the liver, pancreas, or blood vessels of the brain and heart.
• High blood pressure: Hypertension (high blood pressure) is seen in some patients with autosomal dominant PKD.
• Kidney stones: Individuals with autosomal dominant PKD have an increased risk of developing kidney stones. Kidney stones form in the kidney when minerals and other substances in the urine crystallize into a hard mass. They are most likely to form when there is a decrease in urine volume and they may be very painful.
• Pain: The most common symptom in patients with autosomal dominant PKD is pain in the back and sides. Pain may be caused by infection of the cysts, bleeding into the cysts, or stretching of the fibrous tissue around the kidney (due to kidney enlargement). This pain may be temporary or persistent, depending on the patient. Some patients may also experience swelling.
• Urinary tract problems: Because the urinary tract connects to the kidney, urinary tract problems may occur in patients with autosomal dominant PKD. Patients may develop infections of the urinary tract or they may have blood in their urine, which is usually caused by bleeding into a cyst due to rupture of the cyst.

• Autosomal dominant polycystic kidney disease (autosomal dominant PKD) may be difficult to diagnose and may actually go unnoticed in patients for years. This is because the growth of cysts on the kidney may be slow, and it may take many years before any symptoms begin to appear.
• Several types of noninvasive imaging techniques may be used to diagnose autosomal dominant PKD. When cysts have grown to about one-half inch in length, they are large enough to appear upon imaging of the kidney and autosomal dominant PKD can be detected.
• Ultrasound: Ultrasound is a safe, non-invasive imaging method that uses sound waves to take a picture of the kidney. This is the most common imaging method used to check for cysts in patients.
• Other imaging techniques: Other imaging technologies, such as magnetic resonance imaging (MRI) or a computed tomography (CT) scan can be used to provide a more detailed picture of the kidney. MRI is a noninvasive imaging technique that uses magnetic and radio waves to create an image of tissues within the body. A CT scan is a noninvasive imaging technique that uses a series of X-rays to build a picture of the inside of the body. These imaging techniques can offer more detail than ultrasound, and they may be used to make measurements of kidney or cyst volume and growth. They are typically more useful at later stages of the disease.
• Genetic testing: Mutations in the PKD1 or PKD2 gene may lead to autosomal dominant PKD. Genetic tests exist that can detect these mutations in a patient. Genetic testing is recommended for individuals who have a family history of autosomal dominant PKD. Although this test can establish whether any individual is likely to develop the disease, it cannot predict the exact time of onset or how severe the symptoms will be.

• Aneurysm: An aneurysm is a ballooning or a bulge in a blood vessel. In patients with autosomal dominant polycystic kidney disease (autosomal dominant PKD), cysts may begin to grow on blood vessels, leading to aneurysms. Aneurysms can cause blood vessels to burst and may be life-threatening. Individuals with autosomal dominant PKD may develop aneurysms in the blood vessels leading to the brain, which could cause severe headaches or develop into a more severe complication, such as stroke. Also, some patients may experience an aneurysm in the heart.
• Heart valve abnormalities: For unclear reasons, some patients with autosomal dominant PKD may develop problems with their heart valves. The heart valves of patients may not close properly, causing some blood to leak from the bottom of the heart to the top. In some patients, this may lead to palpitations, but in most patients, these heart valve abnormalities do not lead to any serious health problems.
• High blood pressure: Hypertension (high blood pressure) is seen in some patients with autosomal dominant PKD. Hypertension occurs before kidney failure in most patients.
• Kidney failure: About one-half of patients with autosomal dominant PKD develop kidney failure, which may be life-threatening if not properly treated. Kidney failure is due to the growth of a large number of cysts on the kidney.

• Antibiotics: Antibiotics are available that may be used to treat infections of the urinary tract. Urinary tract infections should be treated quickly, to prevent the infection from spreading into the cyst. Infections of the cyst are more difficult to treat because most antibodies can't penetrate the cysts. Some antibiotics that may be used to treat infection in patients with autosomal dominant polycystic kidney disease (autosomal dominant PKD) include ciprofloxacin (Cipro®) or trimethoprim-sulfamethoxazole (Bactrim®).
• Pain medications: Many patients with autosomal dominant PKD experience pain. Pain medications, such as aspirin or acetaminophen, may be used by patients to manage this symptom. Patients with kidney stones may experience more severe pain and may be treated with stronger drugs, such as morphine.
• Surgery: In some patients who experience severe pain, surgery may be performed to reduce the size of the cysts growing on the kidneys. This surgery does not provide a cure for the condition, as the cysts grow back. Additionally, surgery may be used to remove aneurysms in some patients.
• Dialysis: When the kidneys begin to fail, patients can undergo dialysis to restore the filtering function of the kidneys. In hemodialysis, a patient's blood is circulated into an external filter and cleaned. The filtered blood is then returned to the body. In peritoneal dialysis, a fluid containing dextrose is introduced into the abdomen through a tube. This solution absorbs the wastes in the body and is then removed.
• Transplantation: Some patients who experience kidney failure may undergo kidney transplantation. Kidneys that are transplanted into patients with autosomal dominant PKD do not develop cysts. However, transplantation is associated with complications, including infection and the possibility of rejection of the new organ. To reduce the chance of rejection, patients may need to take immunosuppressant drugs.

Note
: Currently, there is insufficient evidence available on the safety and effectiveness of integrative therapies for the prevention or treatment of autosomal dominant polycystic kidney disease (autosomal dominant PKD). The integrative therapies listed below should be used only under the supervision of a qualified healthcare provider, and should not be used in replacement of other proven therapies or preventive measures.

B

Good scientific evidence

• Cranberry juice
  : Because the urinary tract connects to the kidney, urinary tract problems may occur in patients with autosomal dominant PKD. There are multiple studies of cranberry (juice or capsules) for the prevention of urinary tract infections (UTIs) in healthy women and nursing home residents. While no single study convincingly demonstrates the ability of cranberry to prevent UTIs, the sum total of favorable evidence combined with laboratory research tends to support this use. Cranberry seems to work by preventing bacteria from sticking to cells that line the bladder. Contrary to prior belief, urine acidification does not appear to play a role. Notably, many studies have been sponsored by the cranberry product manufacturer Ocean Spray®. Additional research is needed in this area before a strong recommendation can be made. It is not clear what dose is best.
• Avoid if allergic to cranberries, blueberries, or other plants of the Vaccinium genus. Sweetened cranberry juice can affect blood sugar levels. Use cautiously with a history of kidney stones. Avoid more than the amount usually found in foods if pregnant or breastfeeding.

C

Unclear or conflicting scientific evidence

• Acupuncture
  : Early study in women suggests a reduced recurrence of UTIs over six months and reduced residual urine (urine retained in the bladder after voiding) with acupuncture treatment. Better-designed studies are needed to determine recommendations for this use.
• Needles must be sterile in order to avoid disease transmission. Avoid with valvular heart disease, infections, bleeding disorders, or with drugs that increase the risk of bleeding (anticoagulants), medical conditions of unknown origin, or neurological disorders. Avoid on areas that have received radiation therapy and during pregnancy. Use cautiously with pulmonary disease (like asthma or emphysema). Use cautiously in elderly or medically compromised patients, patients with diabetes, or people with a history of seizures. Avoid electroacupuncture with arrhythmia (irregular heartbeat) and in patients with pacemakers.
• Bromelain
  : There is not enough information to recommend for or against the use of bromelain in UTIs.
• Avoid if allergic to bromelain, pineapple, honeybee, venom, latex, birch pollen, carrots, celery, fennel, cypress pollen, grass pollen, papain, rye flour, wheat flour, or other members of the Bromeliaceae
  family. Use cautiously with a history of bleeding disorders, stomach ulcers, heart disease, liver disease, or kidney disease. Use caution before dental or surgical procedures or while driving or operating machinery. Avoid if pregnant or breastfeeding.
• Cranberry juice
  : There are no well-designed human studies of cranberry for the treatment of UTIs. Laboratory research suggests that cranberry may not be an effective treatment when used alone, although it may be helpful as an adjunct to other therapies such as antibiotics.
• Avoid if allergic to cranberries, blueberries, or other plants of the Vaccinium genus. Sweetened cranberry juice can affect blood sugar levels. Use cautiously with a history of kidney stones. Avoid more than the amount usually found in foods if pregnant or breastfeeding.
• Horseradish
  : Horseradish may have antibiotic activity and has been used in combination with other herbs to treat UTIs. However, additional studies are needed that use horseradish as a single therapy, before a strong recommendation can be made.
• Avoid if allergic or hypersensitive to horseradish (Armoracia rusticana), its constituents, or members of the Brassicaceae family. Large oral doses may provoke allergic reactions. Use cautiously with clotting disorders, hypotension (low blood pressure), thyroid disorders, kidney disorders, kidney inflammation, gastrointestinal conditions, ulcers, and stomach ulcers. Use cautiously if taking anticoagulants or antiplatelets (blood thinning agents), antihypertensives (blood pressure-lowering agents), anti-inflammatory agents, or thyroid hormones. Use cautiously if undergoing treatment for cancer. Avoid medicinal amounts of horseradish if pregnant or breastfeeding, as glucosinolates from horseradish are considered a toxin that can be excreted through breast milk and may pose a toxicity hazard. Also, based on herbal textbooks and folkloric precedent, horseradish has been used to induce abortion.
• Lingonberry
  : Cranberry juice is commonly used to prevent and treat UTIs. One clinical trial using a combination of cranberry and lingonberry juice found that this was more effective. Higher quality research comparing lingonberry juice or cranberry-lingonberry juice to cranberry juice alone is needed before a recommendation can be made.
• Avoid if allergic or hypersensitive to lingonberry (Vaccinium vitis-idaea), its constituents, or members of the Ericaceae family. Use cautiously in male patients, or in couples who are trying to become pregnant. Avoid if pregnant or breastfeeding.
• Peppermint
  : Peppermint tea added to other therapies has been used in the treatment of UTIs. It is not clear if this is an effective treatment, and it is not recommended to rely on peppermint tea alone to treat this condition.
• Avoid if allergic or hypersensitive to peppermint or menthol. Peppermint is generally considered safe in non-allergic adults when taken in small doses. Use cautiously with G6PD deficiency or gallbladder disease. Menthol, a component of peppermint oil, is generally considered safe in non-allergic adults. But, doses of menthol greater than 1 gram per kilogram of body weight may be deadly in humans. Avoid if pregnant or breastfeeding.
• Probiotics
  : Studies of Lactobacillus preparations for UTIs have had mixed results. Evidence suggests a combination of Lactobacillus rhamnosus GR-1 and L. fermentum RC-14 may reduce potentially harmful vaginal bacteria and yeast in healthy women. Other studies have found no benefit for women or pre-term infants. More studies are needed to determine the effectiveness of probiotics in urinary and urogenital tract infections.
• Probiotics are generally considered safe and well-tolerated. Avoid if allergic or hypersensitive to probiotics. Use cautiously if lactose-intolerant.
• Thymus extract
  : Early evidence from a controlled trial suggests that thymus extract reduces re-infection frequency and infection persistence of UTIs. Further evidence is required before recommendations can be made.
• Avoid if allergic or hypersensitive to thymus extracts. Use bovine thymus extract supplements cautiously due to the potential for exposure to the virus that causes "mad cow disease." Avoid use with an organ transplant or with other forms of allografts or xenografts. Avoid if receiving immunosuppressive therapy, with thymic tumors, myasthenia gravis (a neuromuscular disorder), untreated hypothyroidism, or if taking hormonal therapy. Avoid if pregnant or breastfeeding. Thymic extract increases human sperm motility and progression.
• Uva ursi
  : Uva ursi (Arctostaphylos uva-ursi) has long been used as a folk remedy to treat UTIs. The active ingredients in uva ursi are believed to be ursolic acid and isoquercitrin. Additional study is needed to make a strong recommendation.
• Avoid if allergic or hypersensitive to Arctostaphylos uva-ursi or to other members of the Ericaceae family. Use cautiously with kidney or liver dysfunction, gastrointestinal distress, and gallstones. Use cautiously if taking diuretics. Avoid with anxiety, high blood pressure, glaucoma, impaired cerebral circulation, benign prostate tumors (with residual urine accumulation), pheochromocytoma (adrenal medulla or sympathetic paraganglia tumor), Grave's disease, and kidney disease. Avoid if pregnant or breastfeeding.

• There are currently no known ways to prevent autosomal dominant PKD. However, genetic counseling is available to help prospective parents understand the risks of having a child with autosomal dominant PKD.