Minor salivary gland immunohistology in the diagnosis of primary Sjögren's syndrome

Background: Focal lymphocytic infiltrates of minor salivary glands are considered target‐organ related signs of Sjögren’s syndrome. The percentages of plasma cells expressing IgA, IgG and IgM in minor salivary gland biopsies have also been suggested as useful in establishing a diagnosis of Sjögren’s syndrome, and this study aimed at evaluating this method. Methods: All biopsies from patients under investigation for Sjögren’s syndrome (n = 210) at our department during 4 years were analyzed for IgA, IgG and IgM producing cells by immunohistochemistry, and related to Sjögren classification parameters. Results: A focus score ≥1 was observed in 67/210 patients and the frequency of IgA producing cells was