Clinicopathological Features of Type 2 Autoimmune Pancreatitis in Japan: Results of a Multicenter Survey.
OBJECTIVE
The aim of the study was to clarify clinicopathological features of type 2 autoimmune pancreatitis (AIP) in Japan; a multicenter survey was carried out.


METHODS
The first screening collected patients with pancreatitis whose pancreatic tissue samples were available and who fulfilled at least 1 of the following 3 criteria as possible type 2 AIP: (1) histological presence of granulocytic epithelial lesion, (2) age of 50 years or younger, and (3) association of ulcerative colitis, Sjogren syndrome, and/or primary biliary cirrhosis. Patients with histologically confirmed type 1 AIP were also collected as a control. Clinical information was gathered by questionnaire.


RESULTS
A histological re-evaluation identified 8 patients with type 2 AIP and 20 with type 1 AIP. Three of the latter had intralobular neutrophilic infiltration. Factors more frequent in type 2 included age younger than 40 years, abdominal pain, and elevation of serum amylase and lipase, whereas patients with type 1 more frequently showed jaundice, elevated serum IgG and IgG4, presence of autoantibodies, association of IgG4-related disease, sclerosing cholangitis and diabetes mellitus, and imaging findings of intrapancreatic biliary stenosis and extrapancreatic biliary dilatation.


CONCLUSIONS
The clinical features of type 2 AIP in Japan were similar to those of western countries. Intralobular neutrophilic infiltration in type 1 is a potential pitfall, especially in the biopsy-based diagnosis.
From the *Department of Anatomic Pathology, Kurashiki Central Hospital, Kurashiki; †Nishimori Clinic, Sakawa, Kochi; ‡Department of Gastroenterology, Aichi Cancer Center Hospital, Nagoya; §Department of Gastroenterology and Hepatology, Kansai Medical University, Hirakata, Osaka; ∥Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka; ¶Center for Health, Safety, and Environmental Management, Shinshu University, Matsumoto; #Division of Hepato-Biliary-Pancreatic Surgery, Tohoku University Graduate School of Medicine, Sendai; **Department of Gastroenterology, Kitakyushu General Hospital, Kitakyushu; and †† Division of Gastroenterology, Tohoku University Graduate School of Medicine, Sendai, Japan.
Kenji
K
Notohara
Isao
I
Nishimori
Nobumasa
N
Mizuno
Kazuichi
K
Okazaki
Tetsuhide
T
Ito
Shigeyuki
S
Kawa
Shinichi
S
Egawa
Yasuyuki
Y
Kihara
Atsushi
A
Kanno
Atsushi
A
Masamune
Tooru
T
Shimosegawa
D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D000328:Adult; D000368:Aged; D000681:Amylases / Q000097:blood; D044466:Asian People; D001323:Autoantibodies / Q000097:blood; D001327:Autoimmune Diseases / Q000145:classification / Q000175:diagnosis* / Q000208:ethnology; D015209:Cholangitis, Sclerosing / Q000473:pathology; D005260:Female; D006306:Health Surveys / Q000379:methods* / Q000706:statistics & numerical data; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007564:Japan; D008049:Lipase / Q000097:blood; D008297:Male; D008875:Middle Aged; D010179:Pancreas / Q000187:drug effects / Q000473:pathology* / Q000601:surgery; D010195:Pancreatitis / Q000145:classification / Q000175:diagnosis* / Q000208:ethnology; D011795:Surveys and Questionnaires; D016896:Treatment Outcome; D055815:Young Adult
D000305:Adrenal Cortex Hormones; D001323:Autoantibodies; D007074:Immunoglobulin G; D008049:Lipase; D000681:Amylases