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Primary sclerosing cholangitis is a disease primarily of the
bile ducts, both inside and outside the liver. The ducts of the
gallbladder and pancreas may also be involved. The walls of the
bile ducts become inflamed (cholangitis). The inflammation causes
scarring and hardening (fibrosis) that narrows the bile ducts.
Because bile cannot drain properly through the ducts, it
accumulates in the liver causing damage to liver cells.
Eventually, so much bile is accumulated, it seeps into the
bloodstream. Finally, with long term cell damage, the liver
develops cirrhosis (hardening or fibrosis) and it can no longer
function properly.
Cause
The exact cause of PSC is unknown.
However, the most likely cause appears to be changes in the
way the immune system works. When the immune system is working
properly, it protects the body from infections caused by foreign
invaders like bacteria and viruses. Sometimes, however, it
recognizes certain body parts or organs as foreign. The body then
goes to war against itself, damaging the body part it thinks is
foreign PSC often starts between the ages of 30 and 50, and it
occurs most often in men. It was once considered a rare disease,
but recent studies show it is more common than previously
thought. About 70% of the patients with PSC also have an
inflammatory bowel disease, especially ulcerative colitis in
which the colon becomes inflamed and ulcerated. Medical experts
believe genetic factors may link PSC and ulcerative colitis.
Symptoms
PSC usually progresses very slowly. Early on there may be no
symptoms. Usually the only findings are abnormal laboratory test
results. For example, a liver enzyme called alkaline phosphatase
may be above normal ranges in the blood. When symptoms do
develop, they may be intermittent or persistent. Gradually, they
may worsen. The symptoms are caused by two things: the bile is
not being drained property through the bile ducts, and the liver
is not doing its job. Bile ducts can become infected, causing
chills, fever and upper abdominal tenderness. Itching may occur
when bile seeps into the bloodstream. As the disease progresses,
chronic fatigue, loss of appetite, weight loss and jaundice
(yellowing of skin and eyes) may occur. Finally, in the advanced
stages of cirrhosis, extensive swelling can occur in the abdomen
and feet. Liver failure may take many years to develop.
Diagnosis
The physician may suspect PSC from the patient's medical
history, especially a history of inflammatory bowel disease, and
from abnormal blood tests. The diagnosis is usually made by
cholangiography, an x-ray called ERCP that involves injecting dye
into the bile ducts. The test is performed under sedation. A
lighted, flexible endoscope is inserted through the mouth,
stomach and then into the small intestine. A thin tube is place
through the scope into the bile ducts, and the dye is injected to
highlight the bile ducts on the x-ray. If there is narrowing of
the bile ducts, the diagnosis of PSC is confirmed.
As the disease progresses, a liver biopsy is usually needed to
determine how much damage has occurred. Under local anesthesia, a
slender needle is inserted through the right lower chest to
extract a small piece of liver for microscopic analysis.
Treatment
At the present time there is no cure for PSC, but effective
treatment is available. There are a number of ways to treat
symptoms and the various stages of the disease. Itching, from too
much bile in the bloodstream, can be controlled with drugs such
as Questran. Bile is usually reabsorbed into the bloodstream from
the large intestine, and goes back to the liver to be reused.
Questran binds up bile in the intestine, allowing it to be
eliminated with the stool instead. This helps to reduce the
build-up of bile in the body. Actigall is a drug that favorably
changes the make-up of bile in the liver. This, in turn, seems to
reduce the amount of liver damage that occurs. Results of early
medical studies seem to indicate that this drug may increase
survival. Sometimes the bile ducts become infected and must be
treated with antibiotics. If ulcerative colitis is also present,
it is treated with the appropriate medicines.
Swelling of the abdomen and feet, due to fluid retention from
cirrhosis, can be treated with a salt-restricted diet and
diuretics (fluid pills). Presently, there are exciting studies
being done to test the effectiveness of other drugs on the
body's immune system, since this seems to be the underlying
problem.
In some cases, endoscopic or surgical procedures may be used
to open major blockages in bile ducts. Through an endoscope, the
physician places a tiny tube with a balloon on the end into the
narrowed bile duct. The balloon is inflated to expand the duct so
bile can flow through it once again. Sometimes stents (plastic
tubing) can be placed in the narrowed ducts to keep them open.
Often PSC progresses to a point where liver transplantation must
be considered.
Liver Transplantation
Liver transplantation is now an accepted form of treatment for
chronic, severe liver disease. Advances in surgical techniques
and the use of new drugs to suppress rejection have improved the
success rate of transplantation. The outcome for PSC patients is
excellent. Because of the disease's slow progress, it is
possible to plan elective transplant surgery. Survival rates at
transplant centers are well over 90 percent, with a good quality
of life after recovery.
Summary
Primary sclerosing cholangitis is a slow, progressive disease.
Once diagnosed, treatment is directed at managing symptoms and
opening narrowed bile ducts. A great deal of research is underway
aimed at preventing damage to the bile ducts, improving symptoms
and prolonging life. By working closely with the physician, there
is good reason to expect a favorable long-term outlook.
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