Context Autoimmune pancreatitis is increasingly diagnosed in the everyday gastroenterology practice. It is considered as a subclass of chronic pancreatitis. Steroid treatment results in a quick recovery and long-term prognosis is good. Objective To evaluate experiences in the diagnosis, classification and late outcome of autoimmune pancreatitis in two tertiary centers in Chile. Methods Retrospective analysis of clinical files and follow-up of our patients with diagnosis of autoimmune pancreatitis between 1997 and 2017. Results Autoimmune pancreatitis was diagnosed in 83 patients in the study period. Nine of them were excluded for incomplete data (n=1) or lost to followup (n=8). Autoimmune pancreatitis was classified as type 1 by increased serum IgG4 level, other organ involvement and/or pancreatic histology (n=44; age: 52.95 ± 17.00, males: 33). Type 2 was assumed if IgG4 was normal and ulcerative colitis associated (n=10 age: 28.9 ± 16.83, males: 5). In 20 cases autoimmune pancreatitis was classified as not otherwise specified (age: 37.05 ± 17.40, males: 11). Steroid treatment resulted in a complete recovery in all cases. Recurrence was observed in 11 type 1 and in 3 not otherwise specified but in none of type 2 patients, with good response to a second course of steroids. Azathioprine maintenance therapy was used in 5 patients and micofenolate in 1 patient. One patient developed chronic pancreatitis, exocrine insufficiency was detected in 2 and diabetes in 11 cases. Conclusions Autoimmune pancreatitis is increasingly recognized in Chile. The diagnosis is feasible by imaging, serology and response to steroids, classification without histology is difficult. Several cases remain undetermined. The prognosis is good, and progression to calcified chronic pancreatitis is an exception in our experience.
Zoltán Berger, Andrea Jiménez, Carla Mancilla, Gonzalo Araneda, Rocío Sedano