Diagnosis

Autoimmune pancreatitis is hard to diagnose, because its symptoms are a lot like those of pancreatic cancer. However, an accurate diagnosis is extremely important. Undiagnosed cancer may result in delaying or not receiving necessary treatment.

People with AIP tend to have a general enlargement of the pancreas, but they also may have a mass in the pancreas. To pinpoint the diagnosis and determine the type of AIP, blood and imaging tests are necessary.

Tests

No single test or characteristic feature identifies autoimmune pancreatitis. Recommended guidelines for diagnosis use a combination of imaging, blood tests and biopsy results.

Specific tests may include:

  • Imaging tests. Tests of your pancreas and other organs may include CT, MRI, endoscopic ultrasound (EUS) and endoscopic retrograde cholangiopancreatography (ERCP).

  • Blood tests. You may have a test to check for elevated levels of an immunoglobulin called IgG4. IgG4 is produced by your immune system. People with type 1 AIP often have high levels of IgG4 in their blood. People with type 2 AIP usually do not.

    However, a positive test doesn't necessarily mean that you have the disease. A small number of people who don't have autoimmune pancreatitis, including some with pancreatic cancer, also have high levels of IgG4 in their blood.

  • Endoscopic core biopsy. In this test, a medical professional called a pathologist studies a sample of pancreatic tissue in the laboratory. AIP has a distinctive appearance that can be easily recognized under a microscope by an expert pathologist. A small tube called an endoscope is inserted through the mouth into the stomach, guided by ultrasound. A sample of tissue is then removed from the pancreas using a special needle.

    The challenge is getting a sample of tissue large enough to study, rather than just a few cells. This procedure is not widely available, and results may not be conclusive.

  • Steroid trial. Autoimmune pancreatitis generally responds to steroids; healthcare professionals sometimes use a trial course of this drug to confirm a diagnosis. However, this strategy should ideally happen under expert guidance. It should be used sparingly and only be done when there is strong evidence to support a diagnosis of autoimmune pancreatitis. Response to corticosteroids is measured by CT and improvement in serum IgG4 levels.

Treatment

  • Biliary stenting. Before starting medicine, sometimes doctors or other healthcare professionals will insert a tube to drain the biliary ducts. This is called biliary stenting and is done in people with symptoms of obstructive jaundice. Often, though, jaundice improves with steroid treatment alone. Sometimes drainage is recommended if the diagnosis is not certain. Tissue samples and cells from the bile duct may be taken at the time of stent placement.
  • Steroids. Symptoms of autoimmune pancreatitis often improve after a short course of prednisolone or prednisone. Many people respond quickly, even dramatically. Sometimes people get better without any treatment.

  • Immunosuppressants and immunomodulators. The disease can relapse. For type 1 AIP, the disease relapses about 30% to 50% of the time. For type 2 AIP, it relapses less than 10% of the time. Cases of relapse require additional treatment, sometimes long term.

    To help reduce the serious side effects associated with extended steroid use, medicines that suppress or modify the immune system may be added to the treatment. These are sometimes called steroid-sparing medicines. You may be able to stop taking steroids altogether depending on your response to steroid-sparing medicine.

    Immunosuppressants and immunomodulators include mycophenolate (CellCept), mercaptopurine (Purinethol, Purixan), azathioprine (Imuran, Azasan) and rituximab (Rituxan). In general, they have been used in small sample groups and long-term benefits are still being studied.

  • Monitoring of other organ involvement. Type 1 AIP often is associated with other organ involvement, including enlarged lymph nodes and salivary glands, scarring of the bile ducts, liver inflammation, and kidney disease. Although these signs may lessen or disappear completely with steroid therapy, your care team will continue to monitor you.

Preparing for your appointment

Start by seeing your healthcare team if you have symptoms that worry you. If your care team suspects you may have autoimmune pancreatitis, you may be referred to a health professional who specializes in digestive issues, called a gastroenterologist, or a health professional who specializes in issues related to the pancreas, called a pancreatologist.

What you can do

  • Be aware of any pre-appointment restrictions. When you make your appointment, be sure to ask if there's anything you need to do in advance, such as restrict your diet.
  • Write down any symptoms you're experiencing, including any that may seem unrelated to the reason for which you scheduled the appointment.
  • Write down key personal information, including any major stresses or recent life changes.
  • Make a list of all medications and any vitamins or supplements that you're taking.
  • Consider taking along a family member or friend. Sometimes it can be difficult to remember all the information provided during an appointment. Someone who accompanies you may remember something that you missed or forgot.
  • Write down questions to ask your doctor or other healthcare professional.

Your time with the health professional is limited. To make the most of the time, bring a list of questions you have to the appointment. Here are some possible questions about autoimmune pancreatitis:

  • Can you explain my test results to me?
  • How can you be sure that I do not have pancreatic cancer?
  • Will I need more tests?
  • How far has my disease progressed?
  • Will it come back after initial treatment?
  • Do I need lifelong treatment to prevent relapse?
  • What do I need to do if it comes back?
  • How severe is the damage to my pancreas?
  • What treatments can relieve symptoms?
  • What are the potential side effects of each treatment?
  • What symptoms signal that my condition is worsening and that I need to make another appointment?
  • What symptoms of complications should I watch for?
  • I have other health conditions. How can I best manage them together?
  • Are there any restrictions that I need to follow?
  • Are there any brochures or other printed material that I can take with me? What websites do you recommend?

In addition to the questions that you've prepared to ask your healthcare professional, don't hesitate to ask questions that come up during your appointment.

What to expect from your doctor

Your healthcare professional is likely to ask you several questions. Being ready to answer them may allow more time later to cover points you want to address. Your care professional may ask:

  • When did you begin experiencing symptoms?
  • Do you have abdominal pain, dark urine, pale stools, itching or weight loss?
  • Have your symptoms been continuous or occasional?
  • How severe are your symptoms?
  • What, if anything, seems to improve your symptoms?
  • What, if anything, appears to worsen your symptoms?
  • Have you had these symptoms before?
  • Have you ever been diagnosed with pancreatitis?
  • Did you start any new medicines before your symptoms began?
By Mayo Clinic Staff