Review
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World J Gastroenterol. Jan 7, 2013; 19(1): 35-41
Published online Jan 7, 2013. doi: 10.3748/wjg.v19.i1.35
Retroperitoneal fibrosis associated with immunoglobulin G4-related disease
Nao Fujimori, Tetsuhide Ito, Hisato Igarashi, Takamasa Oono, Taichi Nakamura, Yusuke Niina, Masayuki Hijioka, Lingaku Lee, Masahiko Uchida, Ryoichi Takayanagi
Nao Fujimori, Tetsuhide Ito, Hisato Igarashi, Takamasa Oono, Taichi Nakamura, Yusuke Niina, Masayuki Hijioka, Lingaku Lee, Masahiko Uchida, Ryoichi Takayanagi, Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
Author contributions: Fujimori N, Igarashi H, Ito T, Oono T and Takayanagi R designed research; Fujimori N, Lee L, Nakamura T, Niina Y, Hijioka M and Uchida M performed research and reviewed the literature; Fujimori N, Igarashi H and Ito T analyzed data and wrote the paper.
Supported by The Research Program of Intractable Disease and the Research Committee of Intractable Pancreatic Diseases of the Ministry of Health, Labor and Welfare of Japan
Correspondence to: Tetsuhide Ito, MD, PhD, Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan. itopapa@intmed3.med.kyushu-u.ac.jp
Telephone: +81-92-6425285 Fax: +81-92-6425287
Received: April 30, 2012
Revised: September 18, 2012
Accepted: September 22, 2012
Published online: January 7, 2013
Abstract

Retroperitoneal fibrosis is a rare disease characterized by the development of inflammation and fibrosis in the soft tissues of the retroperitoneum and other abdominal organs. Retroperitoneal fibrosis can be of 2 types: idiopathic and secondary. The recently advocated concept and diagnostic criteria of immunoglobulin G4 (IgG4)-related disease, derived from research on autoimmune pancreatitis (AIP), has led to widespread recognition of retroperitoneal fibrosis as a condition caused by IgG4-related disease. We now know that previously diagnosed idiopathic retroperitoneal fibrosis includes IgG4-related disease; however, the actual prevalence is unclear. Conversely, some reports on AIP suggest that retroperitoneal fibrosis is concurrently found in about 10% of IgG4-related disease. Because retroperitoneal fibrosis has no specific symptoms, diagnosis is primarily based on diagnostic imaging (computed tomography and magnetic resonance imaging), which is also useful in evaluating the effect of therapy. Idiopathic retroperitoneal fibrosis can occur at different times with other lesions of IgG4-related disease including AIP. Thus, the IgG4 assay is recommended to diagnose idiopathic retroperitoneal fibrosis. High serum IgG4 levels should be treated and monitored as a symptom of IgG4-related disease. The first line of treatment for retroperitoneal fibrosis is steroid therapy regardless of its cause. For patients with concurrent AIP, i.e., IgG4-related retroperitoneal fibrosis, the starting dose of steroid is usually 30-40 mg/d. The response to steroid therapy is generally favorable. In most cases, the pancreatic lesion and retroperitoneal fibrosis improve after the initial treatment. However, the epidemiology, treatment for recurring retroperitoneal fibrosis, and long-term prognosis are still largely unknown. Further analysis of such cases and research are necessary.

Keywords: Autoimmune pancreatitis; Extrapancreatic lesion; Immunoglobulin G4; Immunoglobulin G4-related disease; Retroperitoneal fibrosis