Epidemiology and immunogenetic background of islet cell antibody - positive nondiabetic schoolchildren : Ulm-Frankfurt population study

Islet cell antibodies (ICAs) were determined in a large cohort of
white nondiabetic schoolchildren (n = 4287) from a homogenous
population in southern Germany. The prevalence of ICA levels
greater than or equal to 5 Juvenile Diabetes Foundation (JDF) U was
1.05% (95% confidence interval 0.8-1.4%). Analysis of HLA-DR beta
and -DQ beta alleles revealed that the specificities found to be
increased in insulin-dependent (type I) diabetic subjects with the
same ethnic background were also associated with ICA positivity in
the nondiabetic schoolchildren. HLA-DR3 (P less than 0.01) and -DR4
(P less than 0.01) phenotypes and absence of Asp residue (P less
than 0.01) at codon 57 of the HLA-DQ beta-chain were significantly
increased in ICA+ compared with control subjects. High levels of
ICAs, which were categorized as either greater than or equal to 17
or greater than or equal to 30 JDF U, were found to be associated
with amino acids other than Asp at position 57 of the HLA-DQ
beta-chain. No association of ICA level was found for HLA-DR
phenotypes.