title: Lack of association between IL-12B gene polymorphism and autoimmune thyroid disease in Japanese patients.
abstract: Interleukin (IL)-12 is a key factor in cell-mediated immunity that drives the development of Th1 cells and stimulates T lymphocytes and natural killer cells to produce interferon (INF)-gamma. The IL-12B gene, which encodes the p40 subunit of IL-12, is located at chromosome 5q31-33 and a linkage finding for autoimmune thyroid disease (AITD) on 5q31-33 in a Japanese population has been reported. It is also reported that the A/C polymorphism in the 3' untranslated region (UTR) of the IL-12B gene (1188A/C) is associated with IL12B mRNA expression levels. We attempted to determine whether genetic polymorphisms of the IL-12B gene are associated with AITD. One hundred three patients with Hashimoto's thyroiditis, 90 patients with Graves' disease, and 123 healthy control subjects were recruited. We detected the 1188A/C polymorphism using a PCR-RFLP method and the A/T polymorphism in intron 4 of the IL-12B gene using a cycle sequencing method. These IL-12B gene polymorphisms showed strong linkage disequilibrium, and their genotype and allele frequencies in the patients did not differ from those in the control subjects. Our results suggest that IL-12B gene polymorphisms were unlikely to have an effect on the development of Hashimoto's thyroiditis or Graves' disease in Japanese patients.
authors.affiliation: Department of Endocrinology, Metabolism and Nephrology, Kochi Medical School, Kochi University, Nankoku, Kochi 783-8505, Japan.
authors.forename: Yukio
authors.initials: Y
authors.lastname: Ikeda
authors.forename: Wakako
authors.initials: W
authors.lastname: Yoshida
authors.forename: Toru
authors.initials: T
authors.lastname: Noguchi
authors.forename: Koichi
authors.initials: K
authors.lastname: Asaba
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Nishioka
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Takao
authors.forename: Kozo
authors.initials: K
authors.lastname: Hashimoto
mesh_terms: D020413:3' Untranslated Regions / Q000737:chemistry / Q000235:genetics; D015703:Antigens, CD; D000943:Antigens, Differentiation / Q000235:genetics / Q000276:immunology; D060908:CTLA-4 Antigen; D004247:DNA / Q000737:chemistry / Q000235:genetics; D005260:Female; D005838:Genotype; D006111:Graves Disease / Q000235:genetics*; D006801:Humans; D018664:Interleukin-12 / Q000235:genetics* / Q000276:immunology; D053762:Interleukin-12 Subunit p40; D007564:Japan; D015810:Linkage Disequilibrium / Q000235:genetics / Q000276:immunology; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D020641:Polymorphism, Single Nucleotide; D017422:Sequence Analysis, DNA; D013967:Thyroiditis, Autoimmune / Q000235:genetics*
chemical_list: D020413:3' Untranslated Regions; D015703:Antigens, CD; D000943:Antigens, Differentiation; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human; C500879:IL12B protein, human; D053762:Interleukin-12 Subunit p40; D018664:Interleukin-12; D004247:DNA