Insulitis (Lymphocytic Infiltration of Pancreatic Islets) in Late-onset Diabetes

Two examples of “insulitis” (infiltration of pancreatic islets by mononuclear cells, apparently chiefly lymphocytes) are reported in adults with late-onset diabetes. Attempts to demonstrate cell-bound antibodies by immunofluorescent methods and to isolate a virus in one case were inconclusive. Possible implications with regard to auto-immune processes and virus infection in the etiology of diabetes are discussed.