Polycystic kidney disease: pathophysiology and clinical management

Polycystic kidney disease (PKD) is an inherited disorder distinguished by the growth of lots of cysts in the kidneys ("Polycystic Kidney Disease" 1). In the majority of cases, this genetic disease is passed down through families as an autosomal dominant trait. If a parent is the carrier of the gene, there is a fifty percent chance for the children to develop the disorder ("Polycystic Kidney Disease").

The kidneys are two organs. Each kidney is about the size of a fist and is found in a human being's abdomen (upper part) towards the back. Extra fluid and wastes present in the blood are filtered by kidneys forming urine as a result. Kidneys also help in the regulation of amounts of certain essential substances in the body. When cysts are formed in the kidneys, they are full of fluid. The normal structure of the kidneys thus becomes greatly enlarged due to the PKD cysts. As a consequence, kidney function is reduced which ultimately leads to kidney failure ("Polycystic Kidney Disease" 1).

When kidneys fail due to PKD, the need of dialysis or patient kidney transplantation becomes inevitable. Polycystic kidney disease also causes cysts formation in the liver. Other organs in the body (particularly the blood vessels in brain and heart) also get affected with this genetic disease. The doctors distinguish PKD cysts from the harmless cysts after checking and examining the number of cysts and the complications caused by them ("Polycystic Kidney Disease" 1).

Polycystic Kidney Disease exists in two major hereditary forms i.e. Autosomal Dominant PKD and Autosomal Recessive PKD. About ninety percent of all cases of PKD are Autosomal dominant PKD making it the most common form of PKD whereas Autosomal recessive PKD is the rare form of PKD ("Polycystic Kidney Disease" 1). Although it is a rare type but is very grave and gets worse swiftly. It can cause serious lung and liver disease, end-stage kidney disease, and sometimes even death in early life ("Polycystic Kidney Disease").

Method(s) of Diagnosis

Polycystic Kidney Disease is generally identified by kidney imaging studies. Ultrasound is the most common type of diagnostic kidney imaging. Other than this, computerized tomography (CT) scans or magnetic resonance imaging (MRI) are the methods that are used for diagnosing this disease. The beginning of kidney damage and the speed of its progression can vary in Autosomal dominant PKD. Depending on the age of the patient, the findings of kidney imaging can also show a discrepancy in a considerable manner. Fewer and minor cysts are mostly found in the kidneys of younger patients. Therefore, a particular criterion has been developed by the doctors for the diagnosis of the disease keeping in mind the patient's age ("Polycystic Kidney Disease" 2). Genetic tests are also a type of diagnosis by which mutations in the autosomal dominant PKD genes (PKD1 and PKD2) are detected. The genetic test is also helpful in determining whether a young PKD family member can securely give a kidney to a family member with the PKD ("Polycystic Kidney Disease" 3).

Thus, Abdominal CT scan, Abdominal MRI scan, abdominal ultrasound and Intravenous pyelogram (IVP) are the four main methods to detect PKD ("Polycystic Kidney Disease").

Symptoms and Complications

Both children and adults can develop autosomal dominant PKD. However, mostly adults have this kidney disease. It is not until the middle age that the symptoms appear in many cases. Some people even do not have PKD symptoms ("Polycystic Kidney Disease").

The most common symptoms of Polycystic Kidney Disease are headaches, back pains, side pains (between the ribs and hips). The pain can be short-term or constant, mild or severe. Other complications that people with autosomal dominant PKD can experience include "urinary tract infections -- specifically, in the kidney cysts, hematuria -- blood in the urine, liver and pancreatic cysts, abnormal heart valves, high blood pressure, kidney stones, aneurysms -- bulges in the walls of blood vessels in the brain, diverticulosis -- small pouches bulge outward through the colon" ("Polycystic Kidney Disease" 2). Drowsiness, joint pain and nail abnormalities are other symptoms that may happen with PKD ("Polycystic Kidney Disease").

Treatment

Even though autosomal dominant PKD has no cure, proper treatment of this genetic disease can relieve symptoms and make life longer. Cyst infection, bleeding, kidney stone etc. can cause pain in the kidney area. At first, the doctor will assess the causes that are contributing to the pain in order to direct the patient about treatment. If it is evaluated as chronic pain due to the enlargement of cyst, over-the-counter pain medications (aspirin or acetaminophen) may be initially suggested by the doctor. If the pain is severe, it can be relieved by the means of surgery (for shrinking cysts). It must be noted that surgery may only provide an impermanent relief and does not reduce the progression speed of the disease toward kidney failure ("Polycystic Kidney Disease" 4).

The urinary tract infections due to autosomal dominant PKD can be treated with antibiotics. Urinary tract infections can cause cyst infections which are difficult to treat as a lot of antibiotics do not make a way into the cysts for curing them. The effects of autosomal dominant PKD can be slowed down by keeping blood pressure under control. High blood pressure can be kept under control by changing the lifestyle and taking a variety of medications. In many cases, blood pressure can be kept under control just by taking proper diet and doing proper exercise ("Polycystic Kidney Disease" 4).

Thus, the main goal of treatment is controlling PKD symptoms and preventing complications. Although it is not an easy task to control the high blood pressure, controlling it is the most imperative part of PKD cure. There may also be a need of removing one or both kidneys through surgery. Moreover, end-stage kidney disease may be treated by dialysis or a kidney transplant ("Polycystic Kidney Disease").