Lymphocyte infiltrations of the gastric mucosa in Sjögren's syndrome. An immunoperoxidase study using monoclonal antibodies in the avidin-biotin-peroxidase method.

Biopsy specimens of the gastric mucosa from 7 patients with primary or secondary Sjögren's syndrome were studied using the immunohistochemical avidin-biotin-peroxidase complex (ABC) method. Monoclonal antibodies (OKT series) were used as a primary layer to detect the surface antigens of various lymphocyte subsets in situ. Chronic inflammation with mononuclear cell infiltrates and/or glandular atrophy was seen in all 7 biopsy specimens. Immunohistochemical staining showed that the cell infiltrates consisted mainly of OKT3-positive T lymphocytes. In 1 patient plasma cells predominated at the sites of inflammation. Most of the T cells were OKT4-reactive lymphocytes, the OKT4/OKT8 ratio varying between 3 and 7. These findings from the gastric mucosa are in agreement with those obtained from the salivary glands of patients with Sjögren's syndrome and confirm the view that Sjögren's syndrome is a systemic disease affecting many organs, rather than a local disease restricted only to some exocrine glands.