GLYCOLIPIDS AS THE MAJOR AUTOANTIGENS OF CYTOPLASMATIC ISLET-CELL ANTIBODIES

It has been recently suggested that pancreatic glycolipidic extracts a nd acidic glycolipid fractions are able to block the binding of ICA to frozen sections of human pancreas. We study the prevalence of blockin g effect by the upper-phase from human pancreatic glycolipid extracts (PGE) in thirty-eight sera ICA positive from seventeen IDDM patients a nd twenty-one first relatives of type 1 diabetics. Total inhibition wa s found in 82% and 76% insulin dependent diabetes mellitus patients an d first relatives of type 1 diabetics respectively. Partial and no inh ibition of ICA + sera was seen in 6%, 12% of type 1 diabetics and 19%, 5% of the first degree relatives of type 1 diabetics respectively. Ou r study suggests that there is heterogeneity of cytoplasmatic islet ce ll antibodies and that glycolipids are the major autoantigen of ICA.