Sequential elevation of autoantibodies to thyroglobulin and glutamic acid decarboxylase in type 1 diabetes

摘要

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 to5717 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.