[Autoantibodies to glutamate decarboxylase in children with newly detected insulin-dependent diabetes mellitus].

Glutamic acid decarboxylase (GAD) is considered as target antigen in pancreatic beta cell autoimmunity. Two isoforms of GAD (islet and brain GAD) were detected recently. In circulation of approximately 80% of recently detected patients with insulin-dependent diabetes mellitus (IDDM) autoantibodies to brain GAD (bGAD) have been demonstrated. To detect autoantibodies to bGAD blood sera of 48 children aged 1 to 14, 36 of these with newly diagnosed IDDM, 2 with impaired glucose tolerance (IGT), 10 healthy controls, were tested. Indirect immunofluorescent staining of rat cerebellum cryoslices was carried out. The results were assessed using fluorescent microscopy and processed by statistical methods. Autoantibodies to bGAD were found in 30 out of 36 patients with IDDM: 83.3 +/- 12.4% (p = 95%), in 1 with IGT, and in none of controls. The fact that all controls were antibody-negative proves a high specificity of this immunological marker of IDDM. Family history or a younger age by the moment of diabetes onset were conductive to a higher prevalence of autoantibodies to GAD, each of these factors being unrelated to the other.