Abstract
The target antigens of islet cell antibodies (ICA) have not been identified. We tried to modify the antigenic structure of islet cells and to see if there were changes in the immunohistochemical reaction of ICA-positive sera with them.
Human pancreatic tissues were treated with periodate, borohydride, neuraminidase, methanol, chloroform-methanol or protease for modification of their antigens. The treated tissues were subjected to immunohistochemical staining with ICA-positive sera.
Two types of ICAs were observed, one probably reacting with the sialic acid residue of glycolipid and the other with protein. Patients with the latter ICA were found to have a longer duration of diabetes than those with the former type.
The results suggested that there are at least two types of ICAs which recognize different antigens, and that this difference might be related to the duration of diabetes.
