Tuesday, June 24, 2008

some information on PKD

Polycystic kidney disease (PKD) is a genetic disorder characterized by the growth of numerous cysts in the kidneys. The kidneys are two organs, each about the size of a fist, located in the upper part of a person’s abdomen, toward the back. The kidneys filter wastes and extra fluid from the blood to form urine. They also regulate amounts of certain vital substances in the body. When cysts form in the kidneys, they are filled with fluid. PKD cysts can profoundly enlarge the kidneys while replacing much of the normal structure, resulting in reduced kidney function and leading to kidney failure.


When PKD causes kidneys to fail—which usually happens after many years—the patient requires dialysis or kidney transplantation. About one-half of people with the most common type of PKD progress to kidney failure, also called end-stage renal disease (ESRD).
PKD can also cause cysts in the liver and problems in other organs, such as blood vessels in the brain and heart. The number of cysts as well as the complications they cause help doctors distinguish PKD from the usually harmless “simple” cysts that often form in the kidneys in later years of life.


In the United States, about 600,0001 people have PKD, and cystic disease is the fourth leading cause of kidney failure.

Autosomal dominant PKD is the most common inherited disorder of the kidneys. The phrase “autosomal dominant” means that if one parent has the disease, there is a 50 percent chance that the disease gene will pass to a child. In some cases—perhaps 10 percent—autosomal dominant PKD occurs spontaneously in patients. In these cases, neither of the parents carries a copy of the disease gene.

Many people with autosomal dominant PKD live for several decades without developing symptoms. For this reason, autosomal dominant PKD is often called “adult polycystic kidney disease.” Yet, in some cases, cysts may form earlier in life and grow quickly, causing symptoms in childhood.

The cysts grow out of nephrons, the tiny filtering units inside the kidneys. The cysts eventually separate from the nephrons and continue to enlarge. The kidneys enlarge along with the cysts—which can number in the thousands—while roughly retaining their kidney shape. In fully developed autosomal dominant PKD, a cyst-filled kidney can weigh as much as 20 to 30 pounds. High blood pressure is common and develops in most patients by age 20 or 30.



The two forms of polycystic kidney disease (PKD) are


  • autosomal dominant PKD, a form that usually causes symptoms in adulthood

  • autosomal recessive PKD, a rare form that usually causes symptoms in infancy and early childhood

The symptoms and signs of PKD include


  • pain in the back and lower sides

  • headaches

  • urinary tract infections

  • blood in the urine

  • cysts in the kidneys and other organs
Diagnosis of PKD is obtained by


  • ultrasound imaging of kidney cysts

  • ultrasound imaging of cysts in other organs

  • family medical history, including genetic testing

  • PKD has no cure

Treatments include:


  • medicine to control high blood pressure

  • medicine and surgery to reduce pain

  • antibiotics to resolve infections

  • dialysis to replace functions of failed kidneys

  • kidney transplantation

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