Outcome of patients with type 1 or 2 autoimmune pancreatitis.
OBJECTIVE
Autoimmune pancreatitis (AIP) is better described than before, but there is still no international consensus for definition, diagnosis, and treatment. Our aims were to analyze the short- and long-term outcome of patients with focus on pancreatic endocrine and exocrine functions, to search for predictive factors of relapse and pancreatic insufficiency, and to compare patients with type 1 and type 2 AIP.


METHODS
All consecutive patients followed up for AIP in our center between 1999 and 2008 were included. Two groups were defined: (a) patients with type 1 AIP meeting HISORt (Histology, Imaging, Serology, Other organ involvement, and Response to steroids) criteria; (b) patients with definitive/probable type 2 AIP including those with histologically confirmed idiopathic duct-centric pancreatitis ("definitive") or suggestive imaging, normal serum IgG4, and response to steroids ("probable"). AIP-related events and pancreatic exocrine/endocrine insufficiency were looked for during follow-up. Predictive factors of relapse and pancreatic insufficiency were analyzed.


RESULTS
A total of 44 patients (22 males), median age 37.5 (19-73) years, were included: 28 patients (64%) with type 1 AIP and 16 patients (36%) with type 2 AIP. First-line treatment consisted of steroids or pancreatic resection in 59 and 27% of the patients, respectively. Median follow-up was 41 (5-130) months. Steroids were effective in all treated patients. Relapse was observed in 12 patients (27%), after a median delay of 6 months (1-70). Four patients received azathioprine because of steroid resistance/dependence. High serum IgG4 level, pain at time of diagnosis, and other organ involvement were associated with relapse (P<0.05). At the end point, pancreatic atrophy was observed in 35% of patients. Exocrine and endocrine insufficiencies were present in 34 and 39% of the patients, respectively. At univariate analysis, no factor was associated with exocrine insufficiency, although female gender (P=0.04), increasing age (P=0.006), and type 1 AIP (P=0.001) were associated with the occurrence of diabetes. Steroid/azathioprine treatment did not prevent pancreatic insufficiency. Type 2 AIP was more frequently associated with inflammatory bowel disease than type 1 AIP (31 and 3%, respectively), but relapse rates were similar in both groups.


CONCLUSIONS
Relapse occurs in 27% of AIP patients and is more frequent in patients with high serum IgG4 levels at the time of diagnosis. Pancreatic atrophy and functional insufficiency occur in more than one-third of the patients within 3 years of diagnosis. The outcome of patients with type 2 AIP, a condition often associated with inflammatory bowel disease, is not different from that of patients with type 1 AIP, except for diabetes.
Maire
Frédérique
F
Department of Gastroenterology and Pancreatology, Beaujon Hospital, AP-HP, Diderot-Paris VII University, Clichy, France. frederique.maire@bjn.aphp.fr
Le Baleur
Yann
Y
Rebours
Vinciane
V
Vullierme
Marie Pierre
MP
Couvelard
Anne
A
Voitot
Hélène
H
Sauvanet
Alain
A
Hentic
Olivia
O
Lévy
Philippe
P
Ruszniewski
Philippe
P
Hammel
Pascal
P
D000328:Adult; D000368:Aged; D001327:Autoimmune Diseases / Q000276:immunology* / Q000473:pathology / Q000628:therapy*; D001707:Biopsy, Needle; D015331:Cohort Studies; D003131:Combined Modality Therapy; D010188:Exocrine Pancreatic Insufficiency / Q000276:immunology* / Q000473:pathology / Q000628:therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis / Q000276:immunology; D007150:Immunohistochemistry; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D010180:Pancreatectomy / Q000379:methods; D010183:Pancreatic Ducts / Q000473:pathology; D010186:Pancreatic Function Tests; D010195:Pancreatitis / Q000276:immunology* / Q000473:pathology / Q000628:therapy*; D011239:Prednisolone / Q000627:therapeutic use; D012008:Recurrence; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D016896:Treatment Outcome; D055815:Young Adult
D007074:Immunoglobulin G; D011239:Prednisolone