title: Serum levels of IgG and IgG4 in Hashimoto thyroiditis.
abstract: Although IgG4-related disease is characterized by extensive infiltration of IgG4-positive plasma cells and lymphocytes of various organs, the details of this systemic disease are still unclear. We screened serum total IgG levels in the patients with Hashimoto thyroiditis (HT) to illustrate the prevalence of IgG4-related thyroiditis in HT. Twenty-four of 94 patients with HT (25.5%) had elevated serum IgG levels and their serum IgG4 was measured. Five of the 24 cases had more than 135 mg/dL of IgG4, which is the serum criterion of IgG4-related disease. One was a female patient who was initially treated as Graves' disease and rapidly developed a firm goiter and hypothyroidism. The biopsy of her thyroid gland revealed that follicular cells were atrophic with squamous metaplasia, replaced with fibrosis, which was compatible with the fibrous variant of HT. Immunohistochemical examination revealed diffuse infiltration of IgG4-positive plasma cells, and the serum IgG4 level was 179 mg/dL. The levels of IgG and IgG4 were positively correlated with the titers of anti-thyroglobulin antibody or anti-thyroid peroxidase antibody. In conclusion, at least a small portion of patients with HT with high titers of anti-thyroid antibodies may overlap the IgG4-related thyroiditis.
authors.affiliation: Division of Endocrinology and Metabolism, National Hospital Organization Kyoto Medical Center, Mukaihata-cho 1-1, Fukakusa, Fushimi-ku, Kyoto, 612-8555, Japan.
authors.forename: Sachiko-Tsukamoto
authors.initials: ST
authors.lastname: Kawashima
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Tagami
authors.forename: Kanako
authors.initials: K
authors.lastname: Nakao
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Nanba
authors.forename: Tamiko
authors.initials: T
authors.lastname: Tamanaha
authors.forename: Takeshi
authors.initials: T
authors.lastname: Usui
authors.forename: Mitsuhide
authors.initials: M
authors.lastname: Naruse
authors.forename: Sachiko
authors.initials: S
authors.lastname: Minamiguchi
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Mori
authors.forename: Jun
authors.initials: J
authors.lastname: Tsuji
authors.forename: Issei
authors.initials: I
authors.lastname: Tanaka
authors.forename: Akira
authors.initials: A
authors.lastname: Shimatsu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D002648:Child; D005260:Female; D050031:Hashimoto Disease / Q000097:blood* / Q000473:pathology; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D008297:Male; D008875:Middle Aged; D010950:Plasma Cells / Q000473:pathology; D012720:Severity of Illness Index; D013961:Thyroid Gland / Q000473:pathology; D055815:Young Adult
chemical_list: D015415:Biomarkers; D007074:Immunoglobulin G