Sialoadenitis in experimental graft-versus-host disease. An animal model of Sjögren's syndrome.

Using light microscopic, immunohistochemical, and ultrastructural techniques, we studied sialoadenitis in mice with chronic graft-versus-host disease (GVHD). To induce chronic GVHD, DBA/2 spleen cells were injected into nonirradiated (C57BL/6 x DBA/2)F1 mice. By light and electron microscopy, the submandibular gland lesion was characterized by mononuclear cell infiltration around the interlobular ducts, often with parenchymal destruction. Immunohistochemically, T cells predominated. The ratio of CD4+ to CD8+ T cells ranged from 1.9:1 to 6:1, with an average of 3.6:1. Lesser numbers of B cells, plasma cells, and macrophages were also present. Histologically, lymphocytic sialoadenitis in chronic GVHD mice was very similar to that reported in patients with chronic GVHD and Sjögren's syndrome.