Immunoprofile of focal lymphocytic infiltration in minor salivary glands of healthy individuals

Aim: To characterize the immunohistochemical profile of the inflammatory cells included in the focal lymphocytic infiltration in the minor salivary glands of healthy individuals. Methods: Tissue samples of the labial and palatal salivary glands from 46 postmortem subjects, demonstrating the presence of focal lymphocytic infiltration were quantitatively evaluated for the presence of T- and B-cell lymphocytes, plasma cells and macrophages by immunohistochemical and morphometric methods. Results: B-cell lymphocytes, the predominant cell population in labial (67.5%) and palatal salivary glands (60.8%), were more frequent than T-cell lymphocytes in both glands (P < 0.001). Among the T-cell lymphocytes, CD4-positive cells were significantly more prevalent than the CD8-positive cells (P < 0.001). Plasma cells were almost absent, comprising only 0.01% of the focal lymphocytic infiltration cells of the labial and palatal salivary glands. Conclusions: Focal lymphocytic infiltration in the samples of the salivary glands obtained from healthy individuals is devoid of plasma cells. This can serve as an additional means to differentiate between focal lymphocytic infiltration in patients with Sjogren's syndrome, in which plasma cells are abundant, and focal lymphocytic infiltration in individuals with other causes of focal sialadenitis.