[4 varieties of islet cell antibodies in 74 insulin-dependent diabetics and their families as a function of the HLA genotype].

The sera of 74 diabetic patients and of their first degree relatives were studied for 4 different types of islet cell antibodies (ICA, CFICA, ICSA, ICACT) and the results were compared according to the HLA genotype. Seventy two percent of the patients' sera were positive for at least one type of auto-antibody. Two types of auto-antibodies were observed: anticytoplasmic antibodies (ICA and CFICA), and surface antibodies (ICSA and ICACT). The different types of antibodies were not associated with any HLA-DR. These antibodies were also present in 15% of the healthy relatives. The fact that they were detected in the sera of siblings sharing no haplotype with the proband, some of them bearing neither DR3 nor DR4 antigens, suggests that non HLA linked genes and/or environmental factors partly control their secretion.