Antibodies to IA-2 and GAD65 in type 1 and type 2 diabetes: isotype restriction and polyclonality

Antibodies to IA-2 and GAD65 in type 1 and type 2 diabetes: isotype restriction and polyclonality. M I Hawa , D Fava , F Medici , Y J Deng , A L Notkins , G De Mattia and R D Leslie Department of Diabetes and Metabolism, St. Bartholomew's Hospital, London, UK. m.i.hawa@mds.gmw.ac.uk Abstract OBJECTIVE: To determine the isotypes and clonality of antibodies to GAD (GADA) and IA-2 (IA-2A) in patients with type 1 and type 2 diabetes. RESEARCH DESIGN AND METHODS: We studied the following consecutive series of patients who attended a diabetes center for antibodies to GADA and IA-2A: 52 newly diagnosed type 1 diabetic patients, 199 type 2 diabetic patients, 200 control patients, and a cohort of 34 nondiabetic identical twins of patients with type 1 diabetes (15 of whom developed diabetes) who were followed prospectively. RESULTS: GADA or IA-2A were detected in 37 (71%) type 1 diabetic patients compared with only 10 (5%) type 2 diabetic patients (P