Autoimmune Pancreatitis

What is autoimmune pancreatitis?

Autoimmune pancreatitis occurs when your immune system triggers swelling and inflammation in your pancreas. It happens when your body confuses healthy cells for germs and attacks them.

How common is autoimmune pancreatitis?

Autoimmune pancreatitis is rare, occurring in less than 1 in 100,000 people. It accounts for only 2% of all cases of long-lasting (chronic) pancreatitis.

Are there different types of autoimmune pancreatitis?

There are two types of autoimmune pancreatitis:

Type 1 autoimmune pancreatitis is more common. It’s associated with high levels of a protein called immunoglobulin G4 (IgG4). High levels of IgG4 antibodies occur when there's inflammation. IgG4 protein is an antibody that produces immune cells.

Type 1 doesn't only affects your pancreas. It can cause inflammation and damage in other organs, including your:

• Bile ducts (tiny tubes that transport bile from your liver to your small intestine).
• Kidney ducts (renal tubes).
• Liver.
• Lungs.
• Gallbladder.
• Salivary glands.
• Thyroid.

Type 2 autoimmune pancreatitis only affects your pancreas. It occurs when white blood cells called neutrophils damage your pancreas and pancreas ducts. People with this condition are often younger and have inflammatory bowel disease.

What causes autoimmune pancreatitis?

Researchers are still determining the precise cause of autoimmune pancreatitis. The condition often develops in people between the ages of 50 and 60, but it can occur sooner. It affects men and people assigned male at birth twice as often as women and people assigned female at birth.

What are common autoimmune pancreatitis risk factors?

In some cases, autoimmune pancreatitis may develop due to your body’s immune response after a bacterial infection. In addition, people with other autoimmune disorders face a higher risk, such as:

• Hashimoto’s thyroiditis (which causes low thyroid levels or hypothyroidism).
• Inflammatory bowel disease (especially ulcerative colitis).
• Primary biliary cholangitis.
• Retroperitoneal fibrosis (a condition where scar-like tissue forms in the lining at the back of your abdomen).
• Rheumatoid arthritis.
• Sarcoidosis.
• Sjögren's syndrome.

Symptoms of autoimmune pancreatitis

In its early stages, autoimmune pancreatitis doesn’t always cause symptoms. As it progresses, your pancreas ducts may narrow, preventing the release of enzymes.

Blockage of the pancreas duct can result in:

• Upper abdominal pain.
• Middle back pain.
• Diarrhea.
• Nausea/vomiting.
• Weight loss.

Autoimmune pancreatitis can also cause swelling and non-cancerous growths in your pancreas and fluid collections (cysts) in or around your pancreas. If the swelling, growths or cysts occur in the head of your pancreas, they can block the portion of the bile duct (tube) that runs through your pancreas, preventing passage of bile into your small intestine. Bile contains a pigment called bilirubin. Buildup of bilirubin in your bloodstream can lead to jaundice (yellowing of the skin and whites of your eyes) and fatigue. Excessive bilirubin in your urine can cause dark urine (pee). Less bilirubin going into your intestines can lead to pale-colored stools (poop).

Many of these symptoms also occur in pancreatic cancer, but It’s important to realize that having this condition doesn’t mean you have cancer.

What are the complications of autoimmune pancreatitis?

Chronic (long-term) inflammation of your pancreas can result in nausea, weight loss and chronic upper abdominal and back pain. Damage to the insulin-producing cells of the pancreas can lead to diabetes. IgG4 antibodies can also attack other organs, including your:

• Bile ducts.
• Salivary (spit) glands.
• Lacrimal (tear) glands.
• Thyroid.
• Kidneys.
• Heart.
• Lungs and pleura (lung lining).

How is autoimmune pancreatitis diagnosed?

Many tests are necessary to diagnose autoimmune pancreatitis and rule out pancreatic cancer. Your evaluation may include:

• Blood tests. These tests detect abnormal levels of IgG4. They may also check liver function and the levels of certain types of blood cells.
• Imaging tests. These tests check the size of your pancreas and detect signs of scarring and narrowed ducts. Imaging tests may include CT scans and MRIs.
• Biopsy. This involves taking a sample of pancreas tissue and examining it under a microscope. A biopsy is usually obtained via a minimally invasive endoscopic procedure called endoscopic ultrasound (EUS). During this procedure, a provider advances a long flexible tube with a light ultrasound at the end into your stomach and intestine to visualize your pancreas. They then get a biopsy through your stomach or intestine. Sometimes, surgeons may need to perform a procedure through a small incision in your skin (laparoscopy) to obtain a biopsy specimen.
• Corticosteroid trial. This can help confirm a diagnosis. You take a short-term dose of steroids and undergo lab tests to see if it lowers IgG4 levels and improves imaging findings.

How do you treat autoimmune pancreatitis?

In a small number of people, autoimmune pancreatitis goes away on its own. But most people need treatment.

Autoimmune pancreatitis treatment includes corticosteroids like prednisone or prednisolone. These medications reduce inflammation and calm an overactive immune system. Care usually begins with a high dose of steroids that's gradually lowered (tapered).

Additional treatments are typically not necessary unless you experience complications. The therapies you may need depend on the type of complication. If duct narrowing occurs, you may need a procedure to open and reinforce the duct with a hollow mesh device (stent).

Can I prevent autoimmune pancreatitis?

There’s nothing you can do to prevent autoimmune pancreatitis.

What is the prognosis for people with autoimmune pancreatitis?

Many people feel better after corticosteroids and experience no complications. A bout of autoimmune pancreatitis doesn't affect your life expectancy.

Autoimmune pancreatitis often comes back (relapses). This is more common in people with Type 1. Relapses are likely in the first three years after diagnosis. A person with relapsing autoimmune pancreatitis is more likely to experience complications.

What happens if I experience a relapse?

With successful management, people with relapsing autoimmune pancreatitis can live active, healthy lives.

You may need to go back on corticosteroids. Some people continue steroid therapy for several years to keep symptoms from returning. Healthcare providers may also try other drugs that treat an overactive immune system. These include immunomodulating and immunosuppressive drugs.

How will I feel during treatment?

You may experience steroid side effects. These include stomach irritation, increased appetite, nervousness and difficulty sleeping. Side effects can complicate daily life, but they’re temporary. To get the most out of autoimmune pancreatitis treatment, it’s essential to continue taking steroids as prescribed.

If side effects become bothersome, contact your healthcare provider before stopping treatment. They may recommend additional therapies to help you get relief or change your treatment plan.

When can I return to my regular activities after autoimmune pancreatitis treatment?

Steroid therapy usually relieves autoimmune pancreatitis symptoms within a few weeks. Most people go back to their usual activities once their symptoms are gone.

A note from Cleveland Clinic

Autoimmune pancreatitis is an uncommon disorder causing inflammation that can affect pancreas functioning. Seeing healthcare providers who are familiar with pancreatic disease can help you receive the best care for your needs. Most people make a full recovery after taking steroids. Some people need additional autoimmune pancreatitis treatment to achieve lasting relief.