TYPE-1 (INSULIN-DEPENDENT) DIABETIC PATIENT WITH REMARKABLE INFILTRATION OF LYMPHOCYTES TO THE ISLETS

We report the case of a 62-year-old woman who was admitted to our hosp ital with diabetic ketoacidosis. Her urinary C-peptide was 3.5 mug/day , HLA typing was DR9, and serum was positive for islet cell antibodies . There was no significant increase in the major viral titer. Pancreat ic head tumor was suspected, and pancreaticoduodenectomy was performed . The pathology of this tumor was polycystic adenoma. We examined the surgical specimen from around the tumor histologically. The pancreatic islets had decreased in number. The immunohistochemical staining of i slets for insulin, glucagon and somatostatin showed that the number of B cells had decreased remarkably, while A and D cells were preserved, Marked lymphocytic infiltration was observed in the islets. The major ity of lymphocytes were helper/inducer and suppressor/cytotoxic T cell s, which did not express HLA-DR antigen or interleukin-2 receptor. No NK cells were present in the islets. The present case, which was exami ned histologically in detail, is consistent with the previously propos ed hypothesis that autoimmunity might play an important role in the pa thogenesis of insulin-dependent diabetes mellitus.