Glutamic acid decarboxylase 65 or GAD-65, IgG (antibody) test is useful in detecting autoimmune diseases in people. The antibodies start to attack their body cells, thinking they are potential “foreign” cells and cause autoimmune diseases. A blood test is carried out to confirm the presence of such antibodies and autoimmunity. A needle is pricked in the arm to take the blood sample from the vein. Slight pain in the arm is normal for one or two days.
GAD-65 antibodies level of below 5 units/mL is considered normal. Unusually high levels of serum antibodies can indicate problems like type 1 diabetes, cerebellar ataxia (brain disorder), stiff person syndrome (neurological), rheumatoid arthritis, or thyroid diseases. In case of a positive result, consult a doctor immediately for the treatment plan.