Histopathological and immunohistochemical features of the labial salivary glands in children with type I diabetes.

The aim of this study was to investigate the morphological alterations of labial salivary glands in children with type I diabetes. For this purpose labial salivary glands under local anesthesia were excised from the lower lip of ten diabetic children at the onset of diabetes (mean age, 10 years). Additionally ten similar biopsies were obtained from ten healthy children (mean age, 9 years). The tissues were conventionally processed and embedded in paraffin wax. The first section was stained with hematoxylin/eosin, while two additional sections were stained immunohistochemically using the indirect immunoperoxidase avidin-biotin method to detect T and B lymphocytes. The results showed that a mononuclear infiltration was apparent in all diabetic children. Lymphocytes were particularly seen around various ducts. In contrast, the salivary glands of healthy controls were free of infiltrates. The immunohistochemical analysis showed that the majority of these cells were T cells. B cells were found to a lesser extent. These findings indicate that a destruction of labial salivary glands takes place in type I diabetes. This phenomenon is T-cell mediated. The similarity of this condition with the insulitis suggests that labial salivary glands and pancreas may share a common antigen that might be the target of the autoimmune process in type I diabetes.