Guideline sources The following summarized guidelines for the evaluation and management of autoimmune pancreatitis (AIP) are prepared by our editorial team based on guidelines from the European Pancreatic Club (EPC/IAP 2017). 1 2 3 4 5 Definition AIP is an IgG4 systemic disease characterized by obstructive jaundice, abdominal pain, and acute pancreatitis. 2 Epidemiology The exact cause of AIP is unknown; however, autoimmune cause (association with HLA haplotype) is postulated. 3 Disease course Th1 type of immune response is predominantly involved in the development of AIP, which presents as type 1 and type 2 subtypes with symptoms of obstructive jaundice, acute pancreatitis, abdominal pain, and IBD. Manifestations of other organ involvement include biliary disease, symptoms of Sjogren's disease (due to salivary gland involvement), lung nodules, interstitial nephritis, and retroperitoneal fibrosis. 4 Prognosis and risk of recurrence The risk of mortality increased with OR 2.07 (p = 0.02; 95% CI 1.07-3.55) in type 1 AIP. 5 https://web.pathway.md/diseases/recoLth7ikLnTajJ8 1/3 6/23/23, 3:16 AM Autoimmune pancreatitis Pathway Pathway Autoimmune pancreatitis Management Guidelines 1. Classification and risk stratification Predictors of relapse: Predictors of relapse include: remarkably high serum IgG4 levels such as > 4 times the ULN before treatment persistently high serum IgG4 levels after steroid treatment diffuse enlargement of the pancreas proximal type of IgG4-related sclerosing cholangitis extensive multi-organ involvement ( 2 other organs involved). B 2. Medical management Indications for treatment (symptomatic patients): treat patients with AIP who are symptomatic due to pancreatic involvement (e.g., obstructive jaundice, abdominal pain, back pain), or other organ involvement (e.g., jaundice due to bile duct stricture). B Indications for treatment (asymptomatic patients): Treat patients with AIP who are asymptomatic but have a persistent pancreatic mass on imaging. B Treat patients with AIP and associated IgG4-related sclerosing cholangitis who are asymptomatic but have persistent liver test abnormalities. B Induction of remission: Initiate corticosteroids as first-line therapy for active AIP in patients who do not have contraindications to their use. A Consider initiating rituximab as first-line therapy for active AIP in patients with contraindications to the use of corticosteroids. C Corticosteroid dosing: Initiate prednisone at a dose of 0.6-1.0 mg/kg/day. A Consider tapering prednisone by 5-10 mg/day every 1-2 weeks until a daily dosage of 20 mg, followed by tapering by 5 mg every 2 weeks. C Maintainance therapy (type 1 AIP): https://web.pathway.md/diseases/recoLth7ikLnTajJ8 2/3 6/23/23, 3:16 AM Autoimmune pancreatitis Pathway Consider maintenance therapy with low-dose corticosteroids or steroid-sparing agents in high- risk patients with type 1 AIP. C Avoid maintenance therapy in patients with type 1 AIP and low disease activity before treatment (focal involvement of the pancreas alone and rapid, complete radiological and biochemical remission in response to steroids). D Maintainance therapy (type 2 AIP): avoid maintenance therapy in patients with with type 2 AIP. D Management of relapse: Consider steroid and steroid-sparing agents (such as immune-modulators or rituximab) for treatment of relapsing AIP. C Consider surgical treatment in selected patients who are refractory to medical therapy. C 3. Specific circumstances Patients with obstructive jaundice: Consider performing biliary drainage in patients with obstructive jaundice in order to prevent biliary infection, obtain endoscopic brushings and cytology to differentiate IgG4-related sclerosing cholangitis from biliary malignancy. C Consider not performing biliary stenting, and attempting steroid treatment alone, in patients with mild jaundice and no signs of infection. D References 1. Okazaki K, Chari ST, Frulloni L et al. International consensus for the treatment of autoimmune pancreatitis. Pancreatology. 2017 Jan Feb;17 1 1 6. Open 2. Kamraan Madhani, James J Farrell. Autoimmune Pancreatitis: An Update on Diagnosis and Management. 2016 Mar;45 1 29 43.2016 Mar;45 1 29 43. Open 3. Iman Zandieh, Michael-F Byrne. Autoimmune pancreatitis: a review. 2007 Dec 21;13 47 6327 32.2007 Dec 21;13 47 6327 32. Open 4. Gyanprakash A Ketwaroo, Sunil Sheth. Autoimmune pancreatitis. 2013 Jul;1 1 27 32.2013 Jul;1 1 27 32. Open 5. Matthew T Huggett, E L Culver, M Kumar et al. Type 1 autoimmune pancreatitis and IgG4-related sclerosing cholangitis is associated with extrapancreatic organ failure, malignancy, and mortality in a prospective UK cohort. 2014 Oct;109 10 1675 1683.2014 Oct;109 10 1675 1683. Open 6. Isabelle Scheers, Joseph J Palermo, Steven Freedman et al. Recommendations for Diagnosis and Management of Autoimmune Pancreatitis in Childhood: Consensus From INSPPIRE. J Pediatr Gastroenterol Nutr. 2018 Aug;67 2 232 236. Open https://web.pathway.md/diseases/recoLth7ikLnTajJ8 3/3