Type 1 Autoimmune Pancreatitis in Europe: Clinical Profile and Response to Treatment
Authors: Kasper A. Overbeek, Jakob L. Poulsen, Marco Lanzillotta, Olof Vinge-Holmquist, Peter Macinga, A. Fatih Demirci, Daniko P. Sindhunata, Johanna Backhus, Hana Algül, Jorie Buijs, Philippe Levy, Mariia Kiriukova, Elisabetta Goni, Marcus Hollenbach, Rainer C. Miksch, Lumir Kunovsky, Miroslav Vujasinovic, Sara Nikolic, Luke Dickerson, Michael Hirth, Markus F. Neurath, Malte Zumblick, Josephine Vila, Mustafa Jalal, Georg Beyer, Fabian Frost, Silvia Carrara, Zdenek Kala, Petr Jabandziev, Gurhan Sisman, Filiz Akyuz, Gabriele Capurso, Massimo Falconi, Alexander Arlt, Frank P. Vleggaar, Luca Barresi, Bill Greenhalf, László Czakó, Peter Hegyi, Andrew Hopper, Manu K. Nayar, Thomas M. Gress, Francesco Vitali, Alexander Schneider, Chris M. Halloran, Jan Trna, Alexey V. Okhlobystin, Lorenzo Dagna, Djuna L. Cahen, Dmitry Bordin, Vinciane Rebours, Julia Mayerle, Alisan Kahraman, Sebastian Rasch, Emma Culver, Alexander Kleger, Emma Martínez-Moneo, Ola Røkke, Tomas Hucl, Søren S. Olesen, Marco J. Bruno, Emanuel Della-Torre, Ulrich Beuers, J.-Matthias Löhr, Jonas Rosendahl, A. Mohr Drewes, S.L. Haas, B.F. Hoyer, J. Hampe, C. Noreen Hinrichs, M.M. Lerch, A.A. Aghdassi, T. Grote, D.J. Heuser, P. Ignatavicius, E. Malecka-Panas, J.E. Domínguez-Muñoz, A. López-Serrano, F. Auriemma, G. Oracz, D. Duman, N. Gubergrits
Journal: Clinical Gastroenterology and Hepatology (2024)

Background and aims Autoimmune pancreatitis (AIP) is an immune-mediated disease of the pancreas with distinct pathophysiology and manifestations. Our aims were to characterize type 1 AIP in a large pan-European cohort and study the effectiveness of current treatment regimens. Methods We retrospectively analyzed adults diagnosed since 2005 with type 1 or not-otherwise-specified AIP in 42 European university hospitals. Type 1 AIP was uniformly diagnosed using specific diagnostic criteria. Patients with type 2 AIP and those who had undergone pancreatic surgery were excluded. The primary endpoint was complete remission, defined as the absence of clinical symptoms and resolution of the index radiological pancreatic abnormalities attributed to AIP. Results We included 735 individuals with AIP (69% male; median age 57 years; 85% White). Steroid treatment was started in 634 patients, of whom 9 (1%) were lost to follow-up. The remaining 625 had a 79% (496/625) complete, 18% (111/625) partial, and 97% (607/625) cumulative remission rate, while 3% (18/625) did not achieve remission. No treatment was given in 95 patients, who had a 61% complete (58/95), 19% partial (18/95), and 80% cumulative (76/95) spontaneous remission rate. Higher (≥0.4 mg/kg/day) corticosteroid doses were no more effective than lower (<0.4 mg/kg/day) doses (OR 0.428; 95%CI 0.054-3.387) and neither was a starting dose duration > 2 weeks (OR 0.908; 95%CI 0.818-1.009). Elevated IgG4 levels were independently associated with a decreased chance of complete remission (OR 0.639; 95%CI 0.427-0.955). Relapse occurred in 30% of patients. Relapses within 6 months of remission induction were independent of the steroid tapering duration, induction treatment duration, and total cumulative dose. Conclusion Patients with type 1 AIP and elevated IgG4 level may need closer monitoring. For remission induction, a starting dose of 0.4 mg/kg/day for 2 weeks followed by a short taper period seems effective. This study provides no evidence to support more aggressive regimens.