AUTOIMMUNE DISEASES

Autoimmune pancreatitis is an inflammation in the pancreas. It may be caused by the immune system attacking the pancreas. Autoimmune pancreatitis also is called AIP. Two subtypes of AIP are now recognized, type 1 and type 2.

Type 1 AIP is called IgG4-related disease (IgG4-RD). This type often affects multiple organs, including the pancreas, bile ducts in the liver, salivary glands, kidneys and lymph nodes.

Type 2 AIP seems to affect only the pancreas, although about one-third of people with type 2 AIP have associated inflammatory bowel disease.

Type 1 AIP can be mistakenly diagnosed as pancreatic cancer. The two conditions have overlapping symptoms, but very different treatments, so it is very important to distinguish one from the other.

Symptoms of autoimmune diseases

Autoimmune pancreatitis, also called AIP, is difficult to diagnose. Often, it doesn’t cause any symptoms. Symptoms of type 1 AIP are like those of pancreatic cancer.

Pancreatic cancer symptoms can include:

Dark urine.
Pale stools or stools that float in the toilet.
Yellow skin and eyes, called jaundice.
Pain in your upper belly or middle part of your back.
Nausea and vomiting.
Weakness or extreme tiredness.
Loss of appetite or feelings of fullness.
Weight loss for no known reason.

The most common sign of type 1 AIP is painless jaundice. About 80% of people with type 1 AIP have painless jaundice. This is caused by blocked bile ducts. People with type 2 AIP can have repeat episodes of acute pancreatitis. Pain in the upper abdomen, a common symptom of pancreatic cancer, is often absent in autoimmune pancreatitis.

Differences between type 1 and type 2 AIP are:

In type 1 AIP, the disease may affect other organs in addition to the pancreas. Type 2 AIP affects only the pancreas. Type 2 disease also is associated with another autoimmune condition called inflammatory bowel disease.