Macrophage function in leprosy.

The macrophage function in patients with leprosy was assessed by estimating histochemically the acid phosphatase activity in skin biopsies and by assessment of phagocytic and lytic capability of in vitro cultured macrophages derived from peripheral blood monocytes, challenged with live M. leprae. Acid phosphatase was demonstrated in skin biopsies of different groups of leprosy patients classified according to the Ridley and Jopling scale. The degree of acid phosphatase positivity was correlated with clinical spectrum, Bacterial and Morphologic Indices and treatment status. Peripheral blood monocytes from patients with leprosy, either tuberculoid or lepromatous, were cultured in monolayers and challenged with M. leprae. The phagocytosis and lysis of mycobacteria by macrophages was observed at different time intervals from the 1st to the 28th day. The morphology of the macrophages in different types of leprosy was also studied. The results suggest that macrophages from patients with either tuberculoid or lepromatous leprosy are not by themselves capable of lysing live M. leprae. Live M. leprae injected into the foot pad of Wistar strain of rats evoked similar responses on the tenth day, in normal and protein deficient animals.