Autoimmune Pancreatitis

A persistent inflammatory condition known as autoimmune pancreatitis (AIP) that responds to steroid medication is considered to be brought on by the body's immune system attacking the pancreas. Type 1 and type 2 AIP subtypes are now recognized.

IgG4-related illness, which has a pancreatic presentation as type1 AIP (IgG4-RD). The pancreas, liver's bile ducts, salivary glands, kidneys, and lymph nodes are among the many organs that are frequently affected by this illness.

Even though roughly one-third of type2 AIP sufferers also have inflammatory bowel illness, type2 AIP appears to solely impact the pancreas.

Pancreatic cancer may be misdiagnosed as Type1 AIP. It is crucial to differentiate between the two disorders since they have similar indications and symptoms but distinct approaches to treating them.

Autoimmune Pancreatitis: Causes

Although autoimmune pancreatitis is assumed to be brought on by the body's immune system attacking healthy human tissue, its exact etiology is unknown to medical professionals.

Autoimmune Pancreatitis: Symptoms

The diagnosis of autoimmune pancreatitis (AIP) is challenging. It frequently has no symptoms. Type 1 AIP symptoms and indications are comparable to those of pancreatic cancer.

Signs and symptoms of pancreatic cancer might include −

• Dark faeces

• Stools that are pale or float on the toilet

• Yellow eyes and skin (jaundice)

• Discomfort in your middle back or upper abdomen

• Nausea and diarrhea

• Deficiency or severe exhaustion

• Appetite loss or a sensation of fullness

• Loss of weight with no apparent cause

The most prevalent indication of type1 AIP is painless jaundice, which is brought on by blocked bile ducts and is present in roughly 80% of individuals. Acute pancreatitis episodes may reoccur in type2 AIP patients. In autoimmune pancreatitis, upper abdominal pain, a prominent sign of pancreatic malignancy, is usually absent.

There are several differences between type1 and type2 AIP.

• Along with the pancreatic, type1 AIP can affect other organs as well. Inflammatory bowel disease is a condition that is also an autoimmune disorder, however, type2 AIP only affects the pancreas.

• In their sixth to seventh decade of life, men are most commonly affected by type1 AIP.

• In comparison to type1 AIP, type2 AIP has a younger age of onset and equally affects men and women.

• Type1 AIP has a higher risk of relapse if therapy is stopped.

Numerous consequences can result from autoimmune pancreatitis.

• Inadequate pancreatic exocrine function − Your pancreas' capacity to produce adequate enzymes might be impacted by AIP. Diarrhea, weight loss, metabolic bone disease, and a vitamin or mineral shortage are just a few possible signs and symptoms.

• Diabetes − Since the pancreas is the organ that creates insulin, diabetes may result from injury to it, necessitating either oral medicine or insulin therapy.

• Bile duct and pancreatic stricture.

• Stones or calcifications in the pancreas.

Autoimmune Pancreatitis: Risk Factors

The two forms of AIP occur in various regions of the world at various rates. About 80% of those have type1 autoimmune pancreatitis in the United States.

Type1 autoimmune pancreatitis patients frequently are older than 60.

Those who have type2 autoimmune pancreatitis who are male

• Often above 40 (one or two decades younger than those with type1)

• Equally likely to be male or female

• Have an increased risk of developing inflammatory bowel diseases like ulcerative colitis

Autoimmune Pancreatitis: Diagnosis

Due to the similarities between its signs and symptoms and those of pancreatic cancer, autoimmune pancreatitis is challenging to diagnose. On the other hand, a precise diagnosis is crucial. Cancer that has not been identified may cause therapy to be postponed or not provided at all.

A mass in the pancreas is also possible in AIP patients, who typically have a generalized enlargement of the pancreas. Blood and imaging tests are required to provide a precise diagnosis and identify the kind of AIP you have.

Autoimmune pancreatitis cannot be diagnosed by a single test or distinguishing trait. Consensus diagnostic criteria include the results of imaging, blood testing, and biopsy findings.

Specific testing might consist of −

Imaging Exams

Endoscopic ultrasound (EUS), endoscopic retrograde cholangiopancreatography, CT, and MRI scans of your pancreas and other organs may be performed (ERCP).

A Blood Test

Your immune system produces an immunoglobulin called IgG4 that will be examined for high amounts in you. IgG4 levels in the blood will be extremely raised in those with type 1 AIP but not typically in those with type 2 AIP.

A positive test result does not, however, guarantee that you have the illness. Some persons with pancreatic cancer and a small percentage of those without autoimmune pancreatitis also have elevated levels of IgG4 in their blood.

Core Biopsy via Endoscopy

In this examination, a sample of pancreatic tissue is examined by pathologists in a lab setting. An experienced pathologist can quickly identify AIP under a microscope due to its unusual look. An endoscope is a tiny tube that medical professionals place via the mouth into the stomach to remove pancreatic tissue under ultrasound guidance.

The difficulty is in collecting a tissue sample that is big enough to be examined, rather than just a few cells. Results from this method might not be definitive because it is not frequently used.

Test of Steroids

Steroids often work to treat autoimmune pancreatitis; occasionally, a trial course of this medication is used to confirm a diagnosis.

Autoimmune Pancreatitis: Treatment

Autoimmune pancreatitis can be treated in the following ways −

Bile Duct Stenting

In patients with obstructive jaundice symptoms, doctors may implant a catheter to empty the bile ducts (biliary stenting) before beginning treatment. But frequently, steroid therapy is all that is needed to improve jaundice. If the diagnosis is questionable, drainage may occasionally be advised. At the moment of stent implantation, tissue samples and cells from the bile duct may be collected.

Steroids

A brief treatment of prednisolone or prednisone usually helps the symptoms of autoimmune pancreatitis. Numerous people react fast, sometimes drastically. Without any medical intervention, some patients can recover.

Immunomodulators and immunosuppressants

The condition relapses around 30% to 50% of the time in type1 AIP and less than 10% of the time in type2 AIP, necessitating further therapy, occasionally long-term.

Doctors frequently add immunosuppressants or altering medicines, sometimes known as steroid-sparing pharmaceuticals, to the treatment to assist lessen the severe adverse effects linked to prolonged steroid usage. Depending on how you react to steroid-sparing therapy, you might be able to completely stop using steroids.

Among the immunosuppressants and immunomodulators are rituximab, azathioprine, mercaptopurine, and mycophenolate. They have often been tested on limited sample sizes, and the long-term advantages are still being investigated.

Monitoring the Participation of Other Organs

Other organ involvements, such as swollen lymph nodes and salivary glands, bile duct scarring, liver inflammation, and renal illness are frequently linked to type 1 AIP. With steroid medication, these symptoms could get better or perhaps go away entirely, but your doctor will still keep an eye on you.

Conclusion

Autoimmune pancreatitis is a medical disorder that is getting more and more attention. Understanding the clinical profile of AIP has advanced significantly, however, the pathophysiology of AIP is still unknown. You cannot stop autoimmune pancreatitis from occurring.

Even though the condition has been linked to several reports of elevated blood IgG4 levels and IgG4-positive cells in bile duct biopsy specimens, the disease's full range is not captured by the accepted diagnostic criteria for autoimmune pancreatitis. Steroids can treat autoimmune pancreatitis, but it's still difficult to keep it in remission.