title: Recurrent attacks of autoimmune pancreatitis result in pancreatic stone formation.
abstract: OBJECTIVE
  Autoimmune pancreatitis has been characterized by irregular narrowing of the main pancreatic duct and sonolucent swelling of the parenchyma, both of which are due to lymphoplasmacytic inflammation at the active stage of the disease, and by the absence of pancreatic stone formation. The aim of the present study was to confirm or deny whether or not this disease is progressive with recurrent attacks, resulting in pancreatic stone formation like ordinary chronic pancreatitis.
  
  
  METHODS
  Forty-two patients, 36 of whom were treated with prednisolone, were followed up for periods longer than 12 months (median follow-up period: 54.5 months, range: 13-111 months) by regular interview and examination of their medical records for laboratory tests and image tests.
  
  
  RESULTS
  Eleven patients (26.2%) who were treated with prednisolone showed recurrent attacks during median follow-up periods of 22 months. Eight patients (19%) showed the formation of pancreatic stones during the follow-up periods. Because 6 of 11 patients (54.5%) who suffered relapse showed pancreatic stone formation, it is significantly associated with relapse in comparison with nonrelapse (p= 0.0019).
  
  
  CONCLUSIONS
  Contrary to previous reports, we observed both relapse and pancreatic stone formation in some patients with autoimmune pancreatitis, which suggests that autoimmune pancreatitis has the potential to be a progressive disease with pancreatic stones.
authors.affiliation: Department of Medicine, Gastroenterology, Shinshu University School of Medicine, Matsumoto, Japan.
authors.forename: Mari
authors.initials: M
authors.lastname: Takayama
authors.forename: Hideaki
authors.initials: H
authors.lastname: Hamano
authors.forename: Yasuhide
authors.initials: Y
authors.lastname: Ochi
authors.forename: Hisanobu
authors.initials: H
authors.lastname: Saegusa
authors.forename: Kenichi
authors.initials: K
authors.lastname: Komatsu
authors.forename: Takashi
authors.initials: T
authors.lastname: Muraki
authors.forename: Norikazu
authors.initials: N
authors.lastname: Arakura
authors.forename: Yasuharu
authors.initials: Y
authors.lastname: Imai
authors.forename: Osamu
authors.initials: O
authors.lastname: Hasebe
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Kawa
mesh_terms: D000368:Aged; D001327:Autoimmune Diseases; D002137:Calculi / Q000000981:diagnostic imaging / Q000209:etiology* / Q000601:surgery; D002760:Cholangiopancreatography, Endoscopic Retrograde / Q000379:methods; D002908:Chronic Disease; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010183:Pancreatic Ducts / Q000000981:diagnostic imaging / Q000473:pathology*; D010195:Pancreatitis / Q000150:complications* / Q000000981:diagnostic imaging / Q000276:immunology*; D011446:Prospective Studies; D012008:Recurrence; D018570:Risk Assessment; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed