Metodos para el diagnostico de diabetes y de estados prediabeticos

A method for detecting autoantibodies to glutamic acid decarboxylase (GAD) in the serum of a patient as diagnostic of a diabetic or prediabetic condition in the patient, comprises contacting a serum sample from the patient with a GAD antigen and detecting binding of autoantibodies to GAD in the sample by the GAD antigen, wherein the GAD antigen comprises a GAD preparation containing an enhanced amount of dimer(s) or oligomer(s) of the 65 kD or 67 kD isoforms, or both, of GAD. A diagnostic kit is also inclosed.