Autoimmune pancreatitis


Autoimmune pancreatitis (AIP) is characterized by persistent inflammation believed to arise from an immune system malfunction wherein the pancreas becomes the target of attack. This condition has shown positive responses to treatment with steroid therapy.

AIP has two identified types, type 1 and type 2.

  • Type 1 AIP: This is the common type of autoimmune pancreatitis. This type is a pancreatic manifestation of IgG4-related disease (IgG4-RD). The pancreas, bile ducts in the liver, salivary glands, kidneys, and lymph nodes are among the several organs that this disease frequently affects.

Pancreatic cancer may be misdiagnosed as Type 1 AIP. It is crucial to differentiate between the two disorders because they have similar signs and symptoms but totally distinct approaches to treating them.

  • Type 2 AIP: Despite the fact that inflammatory bowel disease affects roughly one-third of persons with type 2 AIP, this type only affects the pancreas. The pancreas and pancreatic ducts are damaged by white blood cells called neutrophils. Inflammatory bowel disease affects many of the younger individuals with this type.


AIP usually do not cause any symptoms. If the symptoms present, a comprehensive investigation is necessary because the symptoms are similar to those with pancreatic cancer.

Signs and symptoms of pancreatic cancer may manifest as follows:

  • Presence of dark urine
  • Pale stools
  • Jaundice, characterized by yellowing of the skin and eyes
  • Upper abdominal or mid-back pain
  • Nausea and vomiting
  • Weakness or excessive fatigue
  • Reduced appetite or feelings of fullness
  • Unexplained weight loss

About 80% of individuals with type 1 AIP have painless jaundice, which is brought on by obstructed bile ducts. Recurrent episodes of acute pancreatitis can be observed in Type 2 AIP. Unlike pancreatic cancer, the presence of upper abdominal pain, which is a typical symptom, is often lacking in cases of autoimmune pancreatitis.

There are some differences between type 1 and type 2 AIP: (1 all)

  • In type 1 AIP, in addition to affecting the pancreas, the condition may also impact other organs. Type 2 AIP primarily targets the pancreas; however, it is commonly linked to another autoimmune disorder known as inflammatory bowel disease.
  • Type 1 AIP primarily affects men in their 60s to 70s.
  • When compared to type 1 AIP, type 2 AIP has a younger age of onset and equally affects men and women.
  • Type 1 AIP is more prone to relapse once treatment is stopped.

The symptoms of autoimmune pancreatitis are frequently undetectable. However, if the patient experiences troublesome signs and symptoms such as unexplained weight loss, stomach pain, or jaundice, they should consult a healthcare provider.


The cause of autoimmune pancreatitis is unknown, but like other autoimmune disorders, it is assumed to be brought on by the body’s immune system attacking healthy bodily tissue.

Risk factors

In certain instances, autoimmune pancreatitis can arise as a result of the immune system’s reaction following a bacterial infection. Moreover, individuals with existing autoimmune disorders are at an increased risk. The frequency of the two types of AIP varies across different regions worldwide. In the United States, approximately 80 percent of individuals diagnosed with autoimmune pancreatitis have type 1.

  • Type 1 autoimmune pancreatitis affects patient that are over the age of 60, and commonly affects male.
  • Type 2 autoimmune pancreatitis patients:
    • Patient who are often over the age of 40.
    • Affects female as male.
    • Have an increased risk of developing inflammatory bowel diseases such as ulcerative colitis.