title: Comparison of clinical findings between histologically confirmed type 1 and type 2 autoimmune pancreatitis.
abstract: OBJECTIVE
  Type 2 autoimmune pancreatitis (AIP) has been reported mainly in Western countries and is thought to be very rare in Asia. The aim of this study was to compare the prevalence, clinical profiles, detailed radiological findings, and steroid responsiveness between type 1 and type 2 AIP in Korea.
  
  
  METHODS
  From 120 patients diagnosed with AIP between January 2003 and August 2010, 52 patients with histologically confirmed type 1 (n = 37) or type 2 (n = 15) AIP were included.
  
  
  RESULTS
  The median age of patients with type 2 AIP was significantly lower than that of patients with type 1 AIP (61 vs 34 years, P < 0.05). At initial presentation, severe abdominal pain and presentation with acute pancreatitis were more frequent in patients with type 2 AIP (P < 0.05). On computed tomography scan, the extent of pancreatic enlargement and the frequency of low-density mass did not differ significantly between the two groups. Detailed pancreatographic findings on endoscopic retrograde cholangiopancreatography/magnetic resonance cholangiopancreatography were not significantly different between the two groups. All patients with steroids therapy improved clinically and radiologically in response (25/25 in type 1 AIP and 14/14 in type 2 AIP). During the follow-up period, none of the patients with type 2 AIP experienced relapse.
  
  
  CONCLUSIONS
  Type 2 AIP in all histologically confirmed AIP cases in Korea may not be as rare as originally thought, with an estimated prevalence rate of 28.8% (15/52). The detailed radiological findings of type 1 and type 2 AIP were not significantly different, and both subtypes responded well to steroids.
authors.affiliation: Department of Internal Medicine, Inje University Ilsan Paik Hospital, Koyang, Korea.
authors.forename: Tae Jun
authors.initials: TJ
authors.lastname: Song
authors.forename: Ji Hoon
authors.initials: JH
authors.lastname: Kim
authors.forename: Myung-Hwan
authors.initials: MH
authors.lastname: Kim
authors.forename: Ji Woong
authors.initials: JW
authors.lastname: Jang
authors.forename: Do Hyun
authors.initials: DH
authors.lastname: Park
authors.forename: Sang Soo
authors.initials: SS
authors.lastname: Lee
authors.forename: Dong Wan
authors.initials: DW
authors.lastname: Seo
authors.forename: Sung Koo
authors.initials: SK
authors.lastname: Lee
authors.forename: Eunsil
authors.initials: E
authors.lastname: Yu
mesh_terms: D015746:Abdominal Pain / Q000209:etiology; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D001327:Autoimmune Diseases / Q000150:complications / Q000175:diagnosis* / Q000188:drug therapy*; D001649:Bile Duct Diseases / Q000150:complications; D001706:Biopsy; D016009:Chi-Square Distribution; D002760:Cholangiopancreatography, Endoscopic Retrograde; D049448:Cholangiopancreatography, Magnetic Resonance; D003093:Colitis, Ulcerative / Q000150:complications; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007674:Kidney Diseases / Q000150:complications; D008171:Lung Diseases / Q000150:complications; D008297:Male; D008875:Middle Aged; D010195:Pancreatitis / Q000150:complications / Q000175:diagnosis* / Q000188:drug therapy* / Q000276:immunology; D015995:Prevalence; D056910:Republic of Korea; D012185:Retroperitoneal Fibrosis / Q000150:complications; D012466:Salivary Gland Diseases / Q000150:complications; D018709:Statistics, Nonparametric; D013256:Steroids / Q000627:therapeutic use*; D014057:Tomography, X-Ray Computed; D055815:Young Adult
chemical_list: D007074:Immunoglobulin G; D013256:Steroids