This research paper is to discuss the horrific inherited disease of polycystic kidneys. Polycystic kidney disease or PKD is a very serious disease that affects many individuals all over the world. PKD equally affects men and women regardless of race, age, ethnic origin, or sex. It can be either a recessive or dominant gene but the dominant case is much more prevalent. In addition, 10% of the reported cases are via spontaneous mutation in the gene. There are at least 3 genes that scientists have found PKD to be located. About 80 percent of the people with PKD have the PKD1 gene, located on chromosome 16. Most of the rest of the PKD population has the PKD2 gene located on chromosome 4. The location of the PKD3 gene has not yet been determined.
An individual affected with PKD is diagnosed by a physician when someone reports that there is a family history of it or when the patient shows signs and symptoms that commonly occur. The physician can perform one of three main clinical tests: Ultrasound, Computed Tomography (CT), or magnetic resonance imaging (MRI).
CT is usually done first because it is the safest and least expensive. However there are limitations to the size of cyst that CT can detect and in this case MRI would be better.
The symptoms of PKD usually show up later in life and are not obvious early on. Therefore, an individual may not even be aware that they are affected until in their late 40’s. Most often the first sign of ADPKD is high blood pressure or hypertension. Hypertension affects 60-70 percent of people with PKD. The high blood pressure is caused by blood vessel constriction or an increase in total peripheral resistence (TPR). As we learned in lab, an increase in TPR leads to increase in mean arterial pressure. As a result of this increased blood pressure, the hypertension can damage the kidneys and enlarge the heart and cause a stroke. So, in addition to having kidney problems, PKD also wreaks havoc with the cardiovascular system as well.
Other common symptoms of PKD are hematuria, diverticulitis, mitral valve prolapse, urinary tract infection (UTI), kidney stones, and chronic pain. The pain is usually in the back or the side where the infected kidneys are located. Kidney stones form when cysts blocking the tubules prevent normal drainage. Another reason that stones may form is that there is a decrease in urine citrate.
People with PKD have a 5-10 percent risk of developing intracranial aneruysms. An aneurysm is a outpoutching in a blood vessel. Intracranial aneurysms occur in the blood vessels of the brain and can cause sudden severe headache, pain in moving the neck, nausea, and vomiting, and even loss of conciousness. This is a very severe symptom that requires immediate medical attention if noticed.
As you can see, PKD is a very serious disease that affects many different organ systems not just the kidney. In fact, 60-70 percent of people with PKD have cysts in the liver as well. Liver cysts form later in life and with equal frequency in males and females.
Is there any treatment for people with polycystic kidney disease? There is treatment for various symptoms and varies depending on the stage of the disease. Analgesics such as codeine can help control the pain. Non-steroidal anti-inflammatory agents can also help the pain. However these drugs also decrease blood flow to the kidney and exacerbate the high blood pressure problem thus are not recommended for all.
There is no cure for PKD but a patient may slow the progression of the disease by watching his or her diet. A diet low in protein and salt will slow the progression and symptoms. There has also been some debate over caffine and its effect on the kidney. The general consensus is that if the patient has high blood pressure than caffine should be watched but if not then it should not matter.
More than 60 percent of individuals with PKD eventually develop kidney failure. When this happens the kidneys must be transplanted or else dialysis is done to replace the lost function. With a transplantation, patients may live another 5-10 years if they survive the rejection phase of transplantation. This is when the immune system fights the foreign tissue and can result in death. Drug cocktails have been developed to prevent this and each year the drugs become more improved. However, there is still some chance that organ rejection will occur and the patient will have to wait for a new organ. Kidney transplant wait lists are fairly long. A patient may end up waiting several years to get an organ that matches close to his or her tissue type. This could be a wait that takes too long and a patient may die of end stage renal failure before an organ is found. Therefore, most patients choose kidney dialysis as an immediate treatment for renal failure. Dialysis can perform the physiological functions of the kidney and buys time for the patient while they wait for an organ for transplantation.
There are two types of dialysis for a patient to choose. These are hemodialysis and peritoneal dialysis. Hemodialysis is a procedure that removes extra fluid and waste using a machine that dialyzes the blood. Usually a patient must go to a dialysis center 3-4 times a week for several hours to have this done. If they do not, they will start to feel very crappy within 24 hours. They feel bad because waste is accumulating in their blood. It is the kidney’s job to get rid of this waste. Within only 48 hours of a missed dialysis session, creatinin, a measure of waste in the blood, can go from a normal 1.5 to a deathly 7. One can see what an inconvienience hemodialysis can be to a patient. However it is an absolute must.
Peritoneal dialysis, the other form of dialysis, has it’s advantages and disadvantages to hemodialysis. An advantage is that it can be performed at home by the patient him/herself. It is more natural than hemodialysis. It removes waste and extra fluid by using the lining of the abdominal cavity, the peritoneum. It works by simple osmosis.
The blood of the patient has a low osmolarity compared to the fluids placed in the peritoneum during the dialysis session. Thus excess fluid leaves the blood and enters the hypertonic medium in the peritoneum where it can then be drained from a cannula permanently placed within the abdomen. The disadvantage to this method is that it does not remove the toxic waste as well as hemodialysis. Thus after one session, the blood is not cleaned as well as a hemodialyzer may clean it.
For a patient that has undergone years of either type of dialysis, a transplant can seem like a dream come true. A patient no longer suffers from fatigue, no longer is tied to a dialysis machine or bag every 14-24 hours, no longer has to deal with complication from indwelling catheters used by dialysis. He or she now has a working functional kidney that can clean the blood of excess water and waste every second of the day.
This is why it is so important for people to become organ donners. Currently, only 2% of the population is considered an organ donner. Of this 2%, less than 1% will actually die in a way that allows their organs to be harvested and donated. This explains the long 2 year waiting list that exists for an organ. It is very important that the public be educated about organ donation. With education and understanding comes tolerance and acceptance. People need to realize that organs save lives. With a death can come a life.
My aunt died of polycystic kidney disease just a few years ago. She had added a good 4 years to her life by receiving a kidney transplant after having gone for years of troublesome hemodialysis. The dialysis tired her, it made traveling and vacationing out of the question. It took away so much from her life. After the transplant she was not perfect but her quality of life was certainly better than before. My family is grateful to the man who had donated his organ at his death to my aunt. He provided four more years of life to a woman and four more years of happiness to my whole family who knew and loved this woman. Organ donation should be a requirement of everyone. But since it is not, it is our job as educated science students to inform our friends, family, and the general public of its importance.
Reference:
PKD Patient Information: http://www.pkdcure.org/pkd/patientinfo.html
P215 lab book: Osmosis and Blood pressure labs.