Glutamic Acid Decarboxylase Antibody (GAD65) Unit Converter

Glutamic acid decarboxylase (GAD) antibody is an autoantibody that targets the GAD65 enzyme. GAD65 is responsible for producing gamma-aminobutyric acid (GABA), the brain's main inhibitory neurotransmitter. It is also found in the insulin-producing beta cells of the pancreas.

When the immune system produces antibodies against GAD65, it can damage pancreatic beta cells (leading to autoimmune diabetes) or impair GABA signaling in the nervous system (causing neurological disorders). The antibody titer often helps distinguish between these two categories: low titers are associated with type 1 diabetes, while very high titers suggest neurological conditions.

GAD antibodies are present in approximately 80% of patients with type 1 diabetes and up to 90% of those with latent autoimmune diabetes in adults (LADA). They are also found in a majority of patients with stiff-person syndrome and related neurological conditions.

GAD antibodies are produced by the immune system and found in the bloodstream. The GAD65 enzyme they target is concentrated in the insulin-producing beta cells of the pancreas and in nerve cells (neurons) throughout the central nervous system.