Recurrent and Autoimmune Pancreatitis

Pancreatitis

The Most common cause of Acute pancreatitis is Gallstones, and the second most common cause is Alcohol consumption. 

The TIGAR-O classification gives the Proposed classification of risk factors or causes of chronic pancreatitis.   

T- Toxins

“T” stands for toxins. It includes causes such as alcohol, Calcium (which can cause symptoms like Hyperparathyroidism), and Hypertriglyceridemia (TGL > 1000 mg/dL ), which are associated with the exponential rise in the risk of developing acute and chronic pancreatitis).                  

I- Idiopathic

“I” is the idiopathic causes/risk factors. Chronic calcific pancreatitis/ Tapioca Pancreatitis (because tapioca is believed to increase the risk of this disease) is common in South India, especially in Kerala and Tamil Nadu. Also known as Tropical pancreatitis, it is common in Tropical countries where the consumption of tapioca is high. 

G- Genetics

“G” stands for genetic causes/risk factors. Mutations of genes such as   

• PRSS1                            
• SPINK1
• CFTR (Cystic fibrosis is an important risk factor)

A- Autoimmune pancreatitis 

“A” stands for Autoimmune pancreatitis, which mainly includes IgG4-related diseases. It is a set of disorders characterized by lymphocytic infiltration, and lymphocytes are positive for IgG4. Lymphocytic infiltration makes the organ look like a mass, so it might appear like a pancreatic mass. Hence, generally, it has a tumor-like presentation. The head of the pancreas is most commonly affected by autoimmune pancreatitis. Hence, there is a chance of obstruction that can lead to obstructive jaundice. 

In ultrasound, a mass-like appearance at the head of the pancreas due to extensive infiltration of lymphocytes is visible. Patients with autoimmune pancreatitis show excellent responses to steroids. For example, Ormond’s disease, Riedl’s thyroiditis, and IgG4-related hypophysitis.

R- Recurrent pancreatitis 

“R” stands for Recurrent Pancreatitis. It includes certain risk factors that can lead to necrotic Pancreatitis. Recurrent acute pancreatitis is the recurrent episode of pancreatitis, but the pancreas appears morphologically normal between the two episodes. Thus, the diagnosis is a little blurry). 

O- Obstructive Pancreatitis 

“O” stands for Obstructive Pancreatitis, which includes anything that obstructs the pancreas and causes obstructive pancreatitis.    

Recurrent Acute Pancreatitis          

Definition

More than or equal to 2 episodes of acute pancreatitis with morphologically normal pancreas and no ongoing inflammation between episodes of acute pancreatitis.              

Causes                                                         

The most common cause of recurrent acute pancreatitis is Occult gallstone disease, and the second most common cause is Sphincter of Oddi dysfunction. Studies have shown that removing the gallbladder and sphincter of Oddi reduced the incidence of recurrent acute pancreatitis in those patients. 

Management 

Cholecystectomy / Sphincterotomy

Autoimmune Pancreatitis 

Autoimmune pancreatitis is also known as lymphocyte-predominant sclerosing pancreatitis (LPSP). It is a condition where there is a development of some degree of pancreatitis and lymphocytic infiltration of the pancreas. Another name for autoimmune pancreatitis is Non-alcoholic destructive pancreatitis.

Classification of Autoimmune Pancreatitis

Type 1

• Type 1 comes under IgG4-related disease.
• The most common manifestation of IgG4-related diseases.
• Often, there will be other organ involvement.
• Type 1 is the most common, which accounts for 85% of autoimmune pancreatitis.

Type 2

• Type 2 is also known as idiopathic duct-centric pancreatitis (IDCP). 
• There is Granulomatous inflammation around the pancreatic duct.
• No other organ is involved in this variant of autoimmune pancreatitis.

Characteristic features of IgG4-related diseases 

There is increased serum IgG4 levels (>140 mg/dL) and Lymphocytic and plasma cell infiltration of the affected organs. Plasma cells are usually IgG4 positive, but the number of plasma cells that need to be positive is organ-specific. For example, if the pancreas is>10/hpf, which is IgG4 positive, then it can be said there is sufficient IgG4 plasma infiltration. There are characteristic tumefactive lesions (tumor-like lesions). Storiform fibrosis is the cartwheel arrangement of fibrotic tissues, which can also be seen in IgG4-related diseases.

For Example, Mikulicz disease and Ormond’s disease

Clinical features of autoimmune pancreatitis

• Recurrent episodes of obstructive jaundice, which are usually painless. 
• Long-run patients can develop chronic pancreatic insufficiency.

Diagnosis of autoimmune pancreatitis

Criteria known as HISORt criteria proposed by an Indian doctor known as S.T. Chari followed. HISORt is the short form for:

• H- Histopathology
• I- Imaging
• S- Serology
• O- Other organ involvement
• Rt- Response to treatment (especially response to steroids)

Components of HISORt criteria

Management of Autoimmune Pancreatitis

• First-line management- oral corticosteroids
• Both type 1 and type 2 show responses to steroids, but the best response is shown by type 1 autoimmune pancreatitis.
• More than 50% of cases relapse require repeat dosing or long-term steroid therapy. 
• For patients requiring long steroid therapy, azathioprine, or other immunosuppressants.

Frequently Asked Questions

Q: Which of the following is m/c cause for recurrent pancreatitis?

A. Recurrent acute pancreatitis

B. Occult gallstone disease

C. Alcohol

D. Pancreatic divisum

Answer: Occult Acute Pancreatitis

Q: Which Indian doctor proposed the HISORt criteria?

Answer: S.T.Chari

Q: Which type of infiltration makes the organ look like a mass?

Answer: Lymphocytic Infiltration

Q: What is the Cartwheel arrangement of fibrotic tissues known as?

Answer: Storiform fibrosis

Also Read: Mesenteric Ischemia: Causes, Symptoms, and Treatments

Hope you found this blog helpful for your NEET SS Gastroenterology and Hepatobiliary preparation. For more informative and interesting posts like these, keep reading PrepLadder’s blogs.