Autoimmune pancreatitis - diagnosis, management and longterm follow-up.

Background & Aims: Autoimmune pancreatitis (AIP) is a fibroinflammatory condition affecting the pancreas and could present as a multisystem disorder. Diagnosis and management can pose a diagnostic challenge in certain groups of patients. We report our experience of managing this condition in a tertiary pancreaticobiliary centre in the North East of England.

Methods: Patients were identified from a prospectively maintained database of patients diagnosed with AIP between 2005 and 2013. Diagnosis of definite/probable AIP was based on the revised HISORt criteria. When indicated, patients were treated with steroids and relapses were treated with azathioprine. All patients have been followed up to date.

Results: Twenty-two patients were diagnosed with AIP during this period. All patients had pancreatic protocol CT performed while some patients had either MR or EUS as part of the work up. Fourteen out of 22 (64%) had an elevated IgG4 level (mean: 10.9 g/L; range 3.4 - 31 g/L). Four (18%) patients underwent surgery. Extrapancreatic involvement was seen in 15 (68%) patients, with biliary involvement being the commonest. Nineteen (86%) were treated with steroids and five (23%) required further immunosuppression for treatment of relapses. The mean follow up period was 36.94 months (range 7 - 94).

Conclusion: Autoimmune pancreatitis is being increasingly recognized in the British population. Extrapancreatic involvement, particularly extrahepatic biliary involvement seems to be a frequent feature. Diagnosis should be based on accepted criteria as this significantly reduces the chances of overlooking malignancy. Awareness of this relatively rare condition and a multi-disciplinary team approach will help us to diagnose and treat this condition more effectively thereby reducing unnecessary interventions.