Case Report
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Sep 7, 2015; 21(33): 9808-9816
Published online Sep 7, 2015. doi: 10.3748/wjg.v21.i33.9808
IgG4-unrelated type 1 autoimmune pancreatitis
Eriko Nakano, Atsushi Kanno, Atsushi Masamune, Naoki Yoshida, Seiji Hongo, Shin Miura, Tetsuya Takikawa, Shin Hamada, Kiyoshi Kume, Kazuhiro Kikuta, Morihisa Hirota, Keisuke Nakayama, Fumiyoshi Fujishima, Tooru Shimosegawa
Eriko Nakano, Atsushi Kanno, Atsushi Masamune, Naoki Yoshida, Seiji Hongo, Shin Miura, Tetsuya Takikawa, Shin Hamada, Kiyoshi Kume, Kazuhiro Kikuta, Morihisa Hirota, Tooru Shimosegawa, Division of Gastroenterology, Tohoku University Graduate School of Medicine, Sendai 980-8574, Japan
Keisuke Nakayama, Division of Nephrology, Endocrinology and Vascular Medicine, Tohoku University Graduate School of Medicine, Sendai 980-8574, Japan
Fumiyoshi Fujishima, Department of Pathology, Tohoku University Graduate School of Medicine, Sendai 980-8574, Japan
Author contributions: Nakano E, Kanno A and Masamune A designed the study and wrote the manuscript; Yoshida N, Hongo S, Miura S, Takikawa T, Hamada S, Kume K, Kikuta K, Hirota M and Nakayama K contributed to attending physicians for the patient; Fujishima F performed pathological examination; and Shimosegawa T critically reviewed the manuscript and gave final approval for submission.
Supported by (in part) Grant-in-Aid from the Japan Society for the Promotion of Science, No. 25461020 (to Kanno A) and by the Ministry of Health, Labor, and Welfare of Japan (to Chiba T and Takeyama Y).
Institutional review board statement: This study was approved by the Institutional Review Board.
Informed consent statement: This patient provided written informed consent.
Conflict-of-interest statement: There is no conflict of interest regard to this case report.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Atsushi Kanno, MD, PhD, Division of Gastroenterology, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan. atsushih@med.tohoku.ac.jp
Telephone: +81-22-7177171 Fax: +81-22-7177177
Received: February 14, 2015
Peer-review started: February 22, 2015
First decision: March 26, 2015
Revised: April 14, 2015
Accepted: June 26, 2015
Article in press: June 26, 2015
Published online: September 7, 2015
Core Tip

Core tip: Type 1 autoimmune pancreatitis (AIP) is regarded as a pancreatic lesion of IgG4-related disease (IgG4-RD). However, the role of IgG4 in AIP or IgG4-RD phenotypes has not been established. This patient was diagnosed with compatible type 1 AIP according to the International Consensus Diagnostic Criteria without an elevation of serum IgG4 levels or IgG4-positive plasma cells. This case suggests that type 1 AIP phenotypes do not require IgG4 elevation.