Republished: Recent advances in autoimmune pancreatitis: type 1 and type 2

Abstract

Autoimmune pancreatitis (AIP) is a form of chronic pancreatitis characterised clinically by frequent presentation with obstructive jaundice, histologically by a lymphoplasmacytic infiltrate with fibrosis, and therapeutically by a dramatic response to steroids. When so defined, AIP can be sub-classified into two subtypes, 1 and 2. Recent international consensus diagnostic criteria for AIP have been developed for diagnosis of both forms of AIP. Type 1 AIP is the pancreatic manifestation of a multiorgan disease, recently named IgG4-related disease. Little is known about the pathogenesis of either form of AIP. Despite frequent association of type 1 AIP with elevated serum IgG4 levels and infiltration with IgG4-positive plasma cells, it is unlikely that IgG4 plays a pathogenic role in AIP. Type 1 AIP responds to steroids, but there needs to be consensus on treatment regimens for induction and therapeutic end points. Relapses are common, but can be reduced by long-term use of low-dose steroids. Recent reports suggest that immunomodulators (azathioprine, 6-mercaptopurine and mycophenolate mofetil), as well biological agents (the antibody to CD20, rituximab) may have a role in maintaining remission in relapsing type 1 AIP. Future studies should clarify the best management options for treatment of relapses and maintenance of remission. Type 2 AIP is a pancreas-specific disorder not associated with IgG4. It presents in younger individuals equally with obstructive jaundice and pancreatitis. The inflammatory process responds to steroid therapy; relapses are uncommon. The clinical spectrum and long-term outcomes of medically treated type 2 AIP are still being evaluated.

Pancreatic tumor in type 1 autoimmune pancreatitis: a diagnostic challenge

“…Other imaging characteristics suggestive of PaT include MPD dilatation, pancreatic parenchymal atrophy and peripancreatic vessel stricture. However, these characteristics were also noted in pure AIP cases, which was in accordance with previous studies [3, 14, 25]. These imaging features in AIP may be attributed to the longstanding intra- and peri-pancreatic inflammation and fibrosis in AIP.…”

Clinical profile and treatment outcomes in autoimmune pancreatitis: a report from North India

“…Type 1 AIP is a systemic IgG4-positive disease in which the pancreas also becomes affected. It typically presents with obstructive jaundice, diffuse pancreatic enlargement, diabetes and steatorrhea in the active phase, and with calcifications, parenchymal atrophy and persistent pancreatic insufficiency in the late phase [ 5 ]. In contrast, type 2 AIP is a pancreas-specific disorder, in which almost 50% of patients present with acute pancreatitis and almost half have coexisting inflammatory bowel disease (IBD) [ 2 , 6 ].…”

Diagnosis and Treatment of Autoimmune Pancreatitis. (Review)

“…В Соединенных Штатах и Соединенном Королевстве, где поддерживающую терапию не назначают, частота рецидива составила 38-60% [29,42,51,53]. По данным корейских ученых, при полном прекращении приема поддерживающей терапии через 6 мес частота рецидива АИП составила 33% (13/40) [22].…”

“…В Соединенных Штатах и Соединенном Королевстве пациентам с АИП для поддержания ремиссии также назначают иммуносупрессивные препараты, несмотря на побочные эффекты, такие как аллергические реакции, подавление функции костного мозга и повышение риска инфекционных осложнений [42,51,53]. Пациентов с АИП, рефрактерным к ГКС, успешно лечили 6-меркаптопурином с ритуксимабом, монокло-нальными АТ к антигену CD20 В-лимфоцитов [29,54,55].…”

“…При обследовании больных чаще определяются нормальные показатели IgG и IgG4, аутоАТ не выявляются. При АИП 2-го типа выявляется также неспецифический язвенный колит, синдром Эванса, тиреоидит Хашимото [8,18,[28][29][30][31].…”