GAD67抗体;GAD67 Antibody—艾普蒂

The GAD67 antibody targets glutamic acid decarboxylase 67 (GAD67), one of two isoforms (GAD65 and GAD67) of the enzyme responsible for converting glutamate to gamma-aminobutyric acid (GABA), the primary inhibitory neurotransmitter in the central nervous system. GAD67 is predominantly expressed in GABAergic neurons and pancreatic β-cells. Autoantibodies against GAD67 are associated with autoimmune disorders, notably stiff-person syndrome (SPS) and type 1 diabetes. In SPS, these antibodies are thought to impair GABA synthesis, leading to neuromotor hyperexcitability, while in diabetes, they contribute to β-cell destruction. GAD67 antibodies are less common than GAD65 antibodies in these conditions but are occasionally detected in overlapping cases or atypical neurological syndromes. Their presence aids in diagnosis, though clinical correlation is essential, as low titers may occur in healthy individuals. Research also links GAD67 antibodies to rare neurological disorders like cerebellar ataxia and limbic encephalitis. Detection methods include immunohistochemistry, ELISA, and cell-based assays. Therapeutically, immunomodulatory treatments (e.g., IVIG, corticosteroids) may reduce antibody levels and symptoms. Ongoing studies explore the pathogenicity of GAD67 antibodies, particularly their role in disrupting GABAergic signaling and autoimmune cross-reactivity between neuronal and pancreatic tissues.