Islet cell autoimmunity in white and black children and adolescents with IDDM

OBJECTIVE - To compare the frequency of islet cell antibodies (ICA) and antibodies to GAD65 and IA-2 (ICA512) between black and white children and adolescents at the diagnosis of IDDM in a large consecutive series of cases from Children's Hospital of Pittsburgh. RESEARCH DESIGN AND METHODS - ICA and antibodies to GAD65 and IA-2 were measured in 437 white and black children and adolescents who were diagnosed with IDDM at <19 years of age at Children's Hospital of Pittsburgh from January 1983 to December 1985, from January to December 1989, and from January 1996 to December 1997. RESULTS - The prevalence of ICA(H), GAD65, and IA-2 antibodies was significantly lower in blacks than whites at onset of the disease. In contrast, the prevalence of ICA(R) alone was higher in blacks. None of the antibodies were present in 12% of the blacks compared with 4% in whites. The same pattern was seen in both sexes. The prevalence of antibodies in white patients with onset of IDDM at <11 years of age was no different than in those who developed IDDM during adolescence. In contrast, black patients showed a significantly lower prevalence of almost all antibodies in the adolescent group. CONCLUSIONS - Black adolescents were more likely to not have antibodies, suggesting either that they have a nonautoimmune type of diabetes or that antibodies are not being detected by these assays.