title: Sequential elevation of autoantibodies to thyroglobulin and glutamic acid decarboxylase in type 1 diabetes.
abstract: We have previously reported the high levels of glutamic acid decarboxylase 65 autoantibodies (GAD65A) in patients with type 1 diabetes and autoimmune thyroid disease. Here we describe a 32-year-old Japanese female with a thirteen-year history of type 1 diabetes whose levels of GAD65A were elevated just after the emergence of anti-thyroid autoimmunity. At 19 years of age, she developed diabetic ketoacidosis and was diagnosed with type 1 diabetes. She had GAD65A, insulinoma-associated antigen-2 autoantibodies (IA-2A), and zinc transporter-8 autoantibodies (ZnT8A), but was negative for antibodies to thyroid peroxidase (TPOAb) and thyroglobulin (TGAb) at disease onset. ZnT8A and IA-2A turned negative 2-3 years after the onset, whereas GAD65A were persistently positive at lower level (approximately 40 U/mL). However, just after the emergence of TGAb at disease duration of 12.5 years, GAD65A levels were reelevated up to 5717 U/mL in the absence of ZnT8A and IA-2A. Her thyroid function was normal and TPOAb were consistently negative. She has a HLA-DRB1*03:01/*04:01-DQB1*02:01/*03:02 genotype. Persistent positivity for GAD65A might be associated with increased risk to develop anti-thyroid autoimmunity.
authors.affiliation: Eiji Kawasaki, Toshiyuki Ikeoka, Department of Metabolism/Diabetes and Clinical Nutrition, Nagasaki University Hospital, Nagasaki 852-8501, Japan.
authors.forename: Eiji
authors.initials: E
authors.lastname: Kawasaki
authors.forename: Jun-Ichi
authors.initials: J
authors.lastname: Yasui
authors.forename: Masako
authors.initials: M
authors.lastname: Tsurumaru
authors.forename: Haruko
authors.initials: H
authors.lastname: Takashima
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Ikeoka
authors.forename: Fumi
authors.initials: F
authors.lastname: Mori
authors.forename: Satoru
authors.initials: S
authors.lastname: Akazawa
authors.forename: Ikuko
authors.initials: I
authors.lastname: Ueki
authors.forename: Masakazu
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Hironaga
authors.initials: H
authors.lastname: Kuwahara
authors.forename: Norio
authors.initials: N
authors.lastname: Abiru
authors.forename: Hironori
authors.initials: H
authors.lastname: Yamasaki
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kawakami
keywords: Autoimmune thyroid disease; Case report; Glutamic acid decarboxylase autoantibodies; Type 1 diabetes