AUTOANTIBODIES TO BRAIN GLUTAMIC ACID DECARBOXYLASE IN CHILDREN WITH NEWLY DIAGNOSED IDDM

Abstract

Glutamic asid decarboxylase (GAD) is considered as target antigen in pancreatic beta cell autoimmunity. Two isoforms or GAD (islet and brain GAD) were found recently. Surprisingly, in circulation of app. 80% or recently diagnosed IDDM patients autoantibodies to brain GAD(bGAD) have been demonstrated by others. To define autoantibodies to the bGAD in sera of 37 children (1-14 years old) with newly diagnosed IDDM an indirect immunofluorescent staining of rat cerebellum criosections was performed. Patients sera were examined 1-12 days after from the beginning or the insulin treatment. Autoantibodies to the bGAD were found in 83,3% of these patients. Moreover, bGAD-positivity in different age groups was analysed: 1st group - 1-4 years old; 2nd group - 5-9 years old and 3d group - 10-14 years old and the prevalence of bGAD reactivity in sera of the 3d group of patients was found. Since our data confirmed the high frequency of autoantibodies to bGAD in circulation of children with newly diagnosed IDDM, this immunological marker is rather common for patients of 10-14 years age. The information thus acquiared will then be used for better understanding of the epidemiology of IDDM in children. Futher we intend to study the possible correlation between the character of the onset of the desease and bGAD-positivity.