Primary sclerosing cholangitis is a rare disease that mainly affects bile ducts inside and outside the liver. It can also occur in the ducts of the gallbladder and pancreas.
In cases of primary sclerosing cholangitis (PSC), the walls of the bile ducts become inflamed, leading to scarring and hardening. These changes cause the ducts to narrow, making it difficult for bile to drain through them.
As a result, bile accumulates in the liver, where it damages liver cells. Eventually, bile seeps into the bloodstream.
After sustaining long-term damage, the liver develops cirrhosis, which is a hardening, or fibrosis. It can no longer function properly.
The disease is more likely to develop in males, who make up 70 percent of people with PSC. Symptoms appear, on average, at the age of 40 in males and 45 in females.
The liver produces bile, a greenish-brown fluid that is necessary for digestion.
Liver cells excrete bile into tiny tubes within the liver called bile ducts. These tubes come together like the veins of a leaf.
These small tubes drain bile into a common duct, a larger tube that leads into the intestine. There, the bile assists digestion and gives stool its brown color.
In a person with PSC, inflammation and scarring cause the bile ducts to become blocked.
As a result, bile collects in the liver. Over time, it damages liver cells and causes fibrosis, or cirrhosis, which is scarring of the liver.
As cirrhosis progresses, more scar tissue builds up, and the liver gradually becomes unable to function. The scar tissue may prevent the bile ducts from draining, which can lead to infection in the ducts.
Most people with early-stage PSC have no symptoms. A doctor may only detect the disease during a routine test. A blood test can indicate high levels of liver enzymes, particularly alkaline phosphatase.
Symptoms occur for the following reasons:
- Bile is not draining properly through the ducts.
- The liver is damaged.
- The liver is starting to fail.
If the bile ducts become infected, it can cause chills, fever, and upper abdominal tenderness.
Itching may occur when bile seeps into the bloodstream.
As the disease progresses, a person may develop:
Jaundice causes the skin and the whites of the eyes to become yellowish. It results when a compound called bilirubin accumulates in the body.
A person in the advanced stages of cirrhosis may experience extensive swelling in the abdomen and feet.
Liver failure may occur 10–15 years after a person receives a PSC diagnosis, or it may take longer, depending on the individual.
People with PSC have a high risk of:
Scientists do not know exactly what causes PSC. According to Genetics Home Reference, a combination of environmental and genetic factors likely play a role.
Some researchers have suggested that PSC could be an autoimmune condition. These conditions arise when the functioning of the immune system changes.
Usually, the immune system protects the body from infections caused by foreign invaders such as bacteria and viruses.
Sometimes, however, the immune system mistakenly recognizes organs or other body parts as invaders, causing the body to attack and damage these areas.
Exactly how an autoimmune disorder could result in PSC, however, remains unclear.
In addition, most autoimmune conditions affect females more often than males, but PSC is more common among males.
Scientists also report that — unlike autoimmune conditions — PSC does not respond well to a treatment known as immunosuppression.
These issues suggest that if PSC is an autoimmune disease, it acts differently from other autoimmune diseases.
PSC often occurs in people with a type of inflammatory bowel disease, such as Crohn’s disease or, especially, ulcerative colitis. It is also common in people with sarcoidosis, chronic pancreatitis, or other autoimmune-related disorders.
Genetic factors may also play a role. According to Genetics Home Reference, the disease tends to develop in clusters of family members.
Researchers have not linked PSC to the viruses that cause hepatitis.
If a person has a history of inflammatory bowel disease or blood tests show certain unusual results, a doctor may suspect PSC.
Endoscopic retrograde cholangiopancreatography (ERCP)
While the individual is under anesthesia, the doctor inserts a lighted, flexible endoscope through the mouth, down the esophagus, through the stomach, and into the small intestine. They then insert a thin tube through the scope and into the bile ducts. The doctor uses this to inject a dye, which will make the condition of the bile ducts show clearly on an X-ray.
In a person with PSC, the bile ducts appear narrower than usual, and they have a beaded appearance, with multiple narrowed and widened segments.
As the disease progresses, the person may need a biopsy to determine how much damage has occurred.
The doctor will apply a local anesthetic and insert a slender needle through the right lower area of the chest to extract a small piece of the liver for microscopic analysis.
People with PSC have a high chance of developing ulcerative colitis, and those with both PSC and ulcerative colitis have a higher risk of developing colon cancer.
For this reason, having colonoscopies is important. They can help the doctor diagnose ulcerative colitis and detect cancer or precancerous conditions early.
Treatment includes ursodiol, or ursodeoxycholic acid, a bile acid naturally produced by the liver.
Research shows that it can lower elevated liver enzyme levels in people with PSC. However, it does not improve the liver’s condition or overall survival rates.
A study updated in 2011 suggests that the medical community needs more evidence about the benefits and harms of this treatment.
A doctor may also prescribe:
- medications to relieve itching, called antipruritics
- bile acid sequestrants, such as cholestyramine, to reduce cholesterol
- antibiotics to treat infections
- vitamin supplements
If a person also has ulcerative colitis, the doctor will recommend appropriate treatment.
If fluid retention from cirrhosis results in swelling in the abdomen and feet, a low-salt diet and diuretics may help.
Researchers have tried using various immunosuppressants and antibiotics to manage PSC, but these have had no effects on mortality rates. Examples of these medications include cyclosporine, tacrolimus, methotrexate, budesonide, and metronidazole.
In some cases, a surgeon may use an endoscopic or surgical procedure to open major blockages in bile ducts.
Using an endoscope, the physician can place a tiny tube with a balloon on one end into the narrowed bile duct. Inflating the balloon expands the duct so that bile can flow through it again.
Also, placing stents of plastic tubing in the narrowed ducts can help keep them open.
The American Liver Foundation note that many people with PSC eventually need liver transplants, usually around 10 years after diagnosis.
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 after a liver transplant. Survival rates at transplant centers are high, and people tend to experience a good quality of life after recovery.