Stimulation of Macrophage Phagocytosis by Clofazimine

Macrophages were cultured from peripheral blood of 5 healthy donors. In the presence of 10-6 M clofazimine their capacity to ingest yeast cells in vitro was enhanced in all cases. Clofazimine also stimulated the in vitro phagocytosis by macrophages in pleural exudates from 2 patients and peripheral blood monocytes from 1 patient with acute monocytic leukaemia. In the pleural exudate from 1 patient with a mediastinal lymphosarcoma the ingestion of cell debris and whole lymphocytic cells by macrophages was increased in vitro. The results suggest that clofazimine may stimulate the activity of various reticuloendothelial phagocytic cells.