Sensitivity at diagnosis of combined beta-cell autoantibodies in insulin-dependent diabetic children. French Registry of IDDM in Children Study Group.

The purpose of this study was to test for the presence (alone or in combination) of 4 autoantibodies directed against beta cells in the sera of children at diagnosis of the overt clinical phase of insulin-dependent diabetes mellitus. Children recorded in 1989 in the population-based French Registry of Incidence of Insulin-Dependent Diabetes Mellitus were included in the present study. One hundred and thirty-eight sera were tested for islet cell antibodies (ICA), insulin autoantibodies (IAA) and antibodies against glutamic acid decarboxylase (GAD-Ab) and tyrosine phosphatase (IA2-Ab). IAA showed significantly lower sensitivity (36%) than the other antibodies (ICA: 84%; GAD-Ab: 74%; IA2-Ab: 81%). In the age-range of the registry, the prevalence rates for the 4 antibodies were not significantly affected by age. IAA and GAD-Ab were significantly associated with ICA, whereas GAD-Ab and/or IA2-Ab was(were) associated with 93% sensitivity at diagnosis. Sensitivity was 100% with the 4 antibodies combined. No significant association was found between the antibodies and HLA DR phenotypes. This study shows that a combination of the 4 major autoantibodies allows all children with insulin-dependent diabetes to be identified.