What is Polycystic Kidney Disease
Polycystic kidney disease (PKD or PCKD, also known as polycystic kidney
syndrome) is a cystic genetic disorder of the kidneys. There are two types of
PKD: autosomal dominant polycystic kidney disease (ADPKD) and the less-common
autosomal recessive polycystic kidney disease (ARPKD).
It occurs in humans and some other animals. PKD is characterized by the
presence of multiple cysts (hence, "polycystic") typically in both kidneys;
however 17% of cases initially present with observable disease in one kidney,
with most cases progressing to bilateral disease in adulthood. The cysts are
numerous and are fluid-filled, resulting in massive enlargement of the kidneys.
The disease can also damage the liver, pancreas and, in some rare cases, the
heart and brain. The two major forms of polycystic kidney disease are
distinguished by their patterns of inheritance.
Polycystic kidney disease is one of the most common life-threatening genetic
diseases, affecting an estimated 12.5 million people worldwide.
Types
Autosomal dominant
CT scan showing autosomal dominant polycystic kidney disease
Autosomal dominant polycystic kidney disease (ADPKD) is the most common of
all the hereditary cystic kidney diseases with an incidence of 1 to 2:1,000 live
births. Studies show that 10% of end-stage renal disease (UREMIA) patients being
treated with hemodialysis in Europe and the U.S. were initially diagnosed and
treated for ADPKD. ADPKD does not appear to demonstrate a preference for any
particular ethnicity.
ADPKD is characterized by progressive cyst development and bilaterally
enlarged kidneys with multiple cysts. There are three genetic mutations in the
PKD-1, PKD-2, and PKD3 gene with similar phenotypical presentations. Gene PKD-1
is located on chromosome 16 and codes for a protein involved in regulation of
cell cycle and intracellular calcium transport in epithelial cells, and is
responsible for 85% of the cases of ADPKD. A group of voltage-linked calcium
channels are coded for by PKD-2 on chromosome 4. PKD3 recently appeared in
research papers as a postulated 3rd gene. At this time, PKD3 has not been
proven. Fewer than 10% of cases of ADPKD appear in non-ADPKD families.
Cyst formation begins in utero from any point along the nephron, although
fewer than 5% of nephrons are thought to be involved. As the cysts accumulate
fluid, they enlarge, separate entirely from the nephron, compress the
neighboring renal parenchyma, and progressively compromise renal function.
Under the function of gene defect, epithelial cells of renal tubule turn into
epithelial cells of cyst wall after phenotype change, and begin to have the
function of secreting cyst fluid, which leads to continuous cysts
enlargement.
Autosomal recessive
Studies show that the incidence of ARPKD is 1:20,000 live births and is
typically identified in the first few weeks after birth. Unfortunately,
resulting hypoplasia results in a 30% death rate in neonates with ARPKD. In
ARPKD kidneys retain their shape but are larger than the normal anatomical range
with dilated collecting ducts from the medulla to the cortex.
Symptoms
Abdominal pain or tenderness
Blood in the urine
Excessive urination at night
Flank pain on one or both sides
Other symptoms that may occur with this disease include:
Drowsiness
Joint pain
Nail abnormalities
Preventions
1. Prevent catching cold. PKD is a hereditary disease which will accompany
the patients for lifelong time. Cold and infections will speed up the illness
progression.
2. Prevent physical traumas. The multiple cysts in the kidneys will
experience progressive enlargement and increase the capsule internal pressure.
In such case, any light trauma like bump, sprain will further increase the
pressure and have impact on large cysts which will cause the cysts to rupture
and bleed.
3. Well control of hypertension. High blood pressure will speed up renal
damages and cause cerebrovascular damages, therefore it is crucial to bring the
blood pressure well under control for slowing down the deterioration of renal
function.
Possible Complications
Anemia
Bleeding or rupture of cysts
Chronic kidney disease
End-stage kidney disease
High blood pressure
Infection of liver cysts
Kidney stones
Liver failure (mild to severe)
Repeated urinary tract infections
Treatment
Since PKD is a congenital and hereditary disease and it is related to gene
mutation, there is at present no instant cure for it. What can be done is to
deal with the symptoms and complications and slow down the development of the
illness condition. These symptoms and discomforts can be alleviated in a short
time, however the renal damage can’t be reversed and the kidney function will be
gradually lost and in the end patients will have no choice but dialysis and
kidney transplant.
1. Surgeries
Operations such as aspiration and decortication can help remove the cysts in
a short time, however they are more suitable for single and large cysts and the
recurrent rate is high and they can’t reverse the continuous deterioration of
renal functions. They are especially not suitable for PKD patients because their
kidneys are full of varying sizes cysts. PKD will progress gradually into end
stage renal failure and at that time patients will have no choice but dialysis
and kidney transplant.
2. Traditional Chinese Medicines (TCM)
As we know the continuous deterioration of renal function is caused by the
progressive enlargement and increase of the cysts, therefore the key point is to
slow down their growth rate and try to shrink them to smaller size. In this
regard, Tradition Chinese Medicines have particularly good effects on shrinking
these multiple cysts and at the same time regulating disorders and repairing
kidney damages. Though it take relatively longer time to take effect compared
with western therapies, its curative effects can last for a long time since it
deal with the disease from the root. And what is more it has far fewer side
effects and injuries to the body. Even though, many patients are reluctant to
take TCM due to its bitterness, inconvenience and slow effects.
Diet
PKD patients should take foods in a balance amount, not too much or too
little. As for PKD patients, they can have less food at one time but more times
in one day to keep energetic and nutritious.
1. PKD patients should have more water (4000ml) and the urine output should
be maintained at about 2000-2500ml.
2. Polluted foods which can cause gastrointestinal diseases or even poisoning
symptoms should be forbidden.
3. PKD patients should have a diet with low salt, low fat and low protein.
They should avoid beef and mutton, animal innards as well as spicy and excitant
foods. Uncooked and cold foods which may injure spleen and stomach should be
limited in a certain amount which should depend on patients' specific illness
and physical conditions.
4. More fruit and vegetables with rich vitamins are suggested especially
those that have the functions of dissolving stones and diuresis. Alkaline foods
should also be eaten more.
5. PKD patients should avoid alcohol, tobacco, strong tea and foods and
drinks containing caffeine.
