Polycystic kidney disease(PKD) is a disorder that affects the kidneys and other organs. Clusters of fluid-filled sacs (cysts), develops in the kidneys and interfere with their ability to filter waste products from the blood. The growth of the cysts causes the kidneys to enlarge, leading to kidney failure. Cysts can also develop in other organs, liver in particular.
There are two major types of the Polycystic kidney disease (PKD): the autosomal dominant polycystic kidney disease and the autosomal recessive polycystic kidney disease.
●Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary kidney disease, affecting approximately 1 in every 400 – 1000 people. Autosomal dominant means; each child of the affected parent has a 50 percent chance of inheriting this disease. In addition, autosomal dominant means that it does not skip generations (ie, if a patient with the disease does not pass it along to one of his or her children; the disease disappears from that family and grandchildren cannot inherit the disease). Some patients suffering with ADPKD are not diagnosed during their lifetimes due to very few symptoms. This means that a family member might have the disease but they are unaware of it.
●Autosomal recessive polycystic kidney disease (ARPKD) is uncommon and is typically diagnosed in infancy or utero, although less severe forms may be diagnosed later in childhood or in adolescence. The estimated incidence is somewhat around 1 in 20,000 people. Autosomal recessive means two copies of an abnormal gene must be present in order for the disease to develop. When both parents are carriers ( having one abnormal and one normal gene each), then there is a 25 percent chance that each child will inherit an abnormal gene from both parents and have the disease.
Autosomal dominant polycystic kidney disease (ADPKD) appears to cause abnormal cell growth that leads to cysts on the kidneys. Nephron is the basic unit of the kidney, with each of the kidney containing approximately one million nephrons (figure 1and figure 2). Each nephron consists a glomerulus, a collection of very small arteries intermingled among a series of tubules. The glomeruli and tubules together work to filter waste products from the bloodstream and dispose of them in the urine.
In the Autosomal dominant polycystic kidney disease (ADPKD), the cyst formation begins as an expansion/ ballooning, of a tubule in a small proportion of the nephrons. The cyst subsequently enlarges, usually due to the fluid secretion into the cyst. The cells which make up the cysts multiply, causing the cyst to grow even larger in size. Cysts may grow in other organs, such as the liver, pancreas, thyroid gland and spleen.
EFFECTS ON THE KIDNEY
Autosomal dominant polycystic kidney disease (ADPKD) often leads to progressive kidney or renal failure, primarily due to the continued enlargement of the cysts and replacement of normal kidney tissue. Various other problems involving the kidney can occur, including high blood pressure, blood in the urine (hematuria), kidney infection and kidney stones. Flank and abdominal pain are common.
Kidney stones — Kidney stones occur in up to 25 percent of people with Autosomal dominant polycystic kidney disease (ADPKD). Kidney stones may cause pain, or sometimes they can block the flow of urine without symptoms.
Treating kidney stones that block urine flow is extremely important in the patients with Autosomal dominant polycystic kidney disease (ADPKD). If the blockage is not relieved then the function in that kidney might be lost. Relieving the blockage may require the help of the urologist. The cysts make it difficult to surgically remove the stone or use shock waves to break up the stone (extracorporeal shock-wave lithotripsy [ESWL]).
The goal of treatment is to control symptoms and prevent complications. High blood pressure might be hard to control, but controlling it is a very important part of treatment.
The treatment may include:
• Blood pressure medicines
• Low-salt diet
Any urinary tract infection must be treated quickly with antibiotics.
Cysts that are painful, infected, bleeding, or causing blockage may need to be drained.
Surgery to remove one or both kidneys may be needed. The treatments for end-stage kidney disease may include dialysis or a kidney transplant.