title: T helper subsets in Sjögren's syndrome and IgG4-related dacryoadenitis and sialoadenitis: a critical review.
abstract: IgG4-related disease (IgG4-RD) is a systemic disease characterized by the elevation of serum IgG4 and infiltration of IgG4-positive plasma cells in multiple target organs, including the pancreas, kidney, biliary tract and salivary glands. In contrast, Mikulicz's disease (MD) has been considered a subtype of Sjögren's syndrome (SS) based on histopathological similarities. However, it is now recognized that MD is an IgG4-RD distinguishable from SS and called as IgG4-related dacryoadenitis and sialoadenitis (IgG4-DS). Regarding immunological aspects, it is generally accepted that CD4+ T helper (Th) cells play a crucial role in the pathogenesis of SS. Since it is well known that IgG4 is induced by Th2 cytokines such as interleukin (IL)-4 and IL-13, IgG4-DS is speculated to be a unique inflammatory disorder characterized by Th2 immune reactions. However, the involvement of Th cells in the pathogenesis of IgG4-DS remains to be clarified. Exploring the role of Th cell subsets in IgG4-DS is a highly promising field of investigation. In this review, we focus on the selective localization and respective functions of Th cell subsets and discuss the differences between SS and IgG4-DS to clarify the pathogenic mechanisms of these diseases.
authors.affiliation: Section of Oral and Maxillofacial Oncology, Division of Maxillofacial Diagnostic and Surgical Sciences, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Moriyama
authors.affiliation: Section of Oral and Maxillofacial Oncology, Division of Maxillofacial Diagnostic and Surgical Sciences, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Tanaka
authors.affiliation: Section of Oral and Maxillofacial Oncology, Division of Maxillofacial Diagnostic and Surgical Sciences, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Maehara
authors.affiliation: Section of Oral and Maxillofacial Oncology, Division of Maxillofacial Diagnostic and Surgical Sciences, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Sachiko
authors.initials: S
authors.lastname: Furukawa
authors.affiliation: Division of Nephrology and Rheumatology, Department of Internal Medicine, Faculty of Medicine, Fukuoka University, Fukuoka, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Nakashima
authors.affiliation: Section of Oral and Maxillofacial Oncology, Division of Maxillofacial Diagnostic and Surgical Sciences, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan. Electronic address: seiji@dent.kyushu-u.ac.jp.
authors.forename: Seiji
authors.initials: S
authors.lastname: Nakamura
mesh_terms: D000818:Animals; D016207:Cytokines / Q000378:metabolism; D003607:Dacryocystitis / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology*; D007378:Interleukins / Q000378:metabolism; D012793:Sialadenitis / Q000276:immunology* / Q000378:metabolism; D012859:Sjogren's Syndrome / Q000175:diagnosis / Q000276:immunology*; D016176:T-Lymphocyte Subsets / Q000276:immunology* / Q000378:metabolism; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology* / Q000378:metabolism; D000098546:Interleukin-21
chemical_list: D016207:Cytokines; D007074:Immunoglobulin G; D007378:Interleukins; D000098546:Interleukin-21
keywords: Cytokine; IgG4-related dacryoadenitis and sialoadenitis; IgG4-related disease; Sjögren's syndrome; T helper subset