title: IgG4-related disease of the thyroid glands.
abstract: Recent reports on Hashimoto's thyroiditis (HT) with increased numbers of IgG4-positive plasma cells suggest that this type of HT may have a close relationship to IgG4-related disease (IgG4-RD).  This unique subgroup of HT is termed as IgG4 thyroiditis and reveals distinct clinical, serological, and sonographic features from the non-IgG4 thyroiditis group.  On the basis of immunostaining for IgG4, HT was divided into an IgG4 thyroiditis group and a non-IgG4 thyroiditis group.  Clinically, IgG4 thyroiditis was associated with younger age group, lower female-male ratio, higher levels of thyroid autoantibodies, diffuse low echogenicity, more rapid progress requiring surgical treatment and more subclinical hypothyroidism.  Serum IgG4 concentrations elevated in IgG4 thyroiditis and decreased significantly after a thyroidectomy.  Histopathologically, IgG4 thyroiditis showed a higher grade of stromal fibrosis, lymphoplasmacytic infiltration, and follicular cell degeneration than non-IgG4 thyroiditis.  IgG4 thyroiditis may represent IgG4-RD of thyroid gland, because it shares common histopathological characteristics with IgG4-RD in other organs.  The identification of IgG4-RD of the thyroid gland opens new insights not only for patient's treatment with HT but also for the development of new therapeutic approaches for this rapidly progressive destructive subtype of HT.  This article mainly focuses on reviewing the unique histopathological, clinical, and serological features of IgG4 thyroiditis group of HT.  The etiology and genetic changes of HT are also discussed.
authors: Department of Medical Technology, Faculty of Health Science, Kobe-Tokiwa University, Kobe 653-0838, Japan. k-kakudo@kobe-tokiwa.ac.jp
authors: Kennichi
authors: K
authors: Kakudo
authors: Yaqiong
authors: Y
authors: Li
authors: Emiko
authors: E
authors: Taniguchi
authors: Ichiro
authors: I
authors: Mori
authors: Takashi
authors: T
authors: Ozaki
authors: Eijun
authors: E
authors: Nishihara
authors: Fumio
authors: F
authors: Matsuzuka
authors: Akira
authors: A
authors: Miyauchi
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D050031:Hashimoto Disease / Q000276:immunology / Q000473:pathology*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood* / Q000276:immunology; D008297:Male; D008875:Middle Aged; D013961:Thyroid Gland / Q000473:pathology*; D013965:Thyroidectomy; D013967:Thyroiditis, Autoimmune / Q000000981:diagnostic imaging / Q000276:immunology / Q000473:pathology*; D014463:Ultrasonography
chemical_list: D007074:Immunoglobulin G