Analysis and function of T and B cell subpopulations in sarcoidosis

Studies carried out in vitro with purified T cells from patients with sarcoidosis demonstrate that: 1. There is an important loss in peripheral blood T cells in active sarcoidosis. 2. These T cells seem to be functionally normal (PHA response, lymphokine production). 3. Memory cells to previously encountered antigens are still present in anergic sarcoidosis. 4. Stimulation of memory cells need the presence of sensitized macrophages from healthy individuals. 5. The stimulation of lymphokine producing T cells also need the presence of healthy macrophages. It is suggested that the development of anergy in sarcoidosis may result at least partly, from an abnormal function of macrophages.