Immunohistochemical identification of lymphocyte subsets and macrophages in normal human urothelium using monoclonal antibodies.

Monoclonal antibodies were used to examine the pattern of distribution of lymphocyte subpopulations and macrophages in normal human urothelium. T lymphocytes (T11-positive cells) were demonstrated within the epithelium and within the lamina propria of both the ureter and the urinary bladder. Suppressor/cytotoxic T cells (T8-positive cells) predominated, with the average ratio of suppressor/cytotoxic T cells to the helper/inducer T cells being approximately 8.9 in the epithelium and 1.5 in the lamina propria. Leu M3+ cells (monocytes/macrophages) were detected in both epithelium and lamina propria. The character and distribution of these immunocompetent cells within the urothelium suggest a protective function, especially against infection and in tumour surveillance.