Ultrastructural characteristics of macrophages in dermal leprosy granulomas: macrophages in leprosy granulomas

Abstract

The characteristics of the cells of mononuclear phagocyte series (MPS) in the dermal granulomas of tuberculoid and lepromatous leprosy were studied by elereron microscopy. In the tuberculoid granulomas, majority of the cells of MPS (epithelioid cells) showed a distinct appearance. They were seen in close association with a large number of activated lymphocytes. The cells of MPS had a prominent nucleus. Their cytoplasm contained mainly rough endoplasmic reticulum, developed golgi and was free of M. leprae or its products. In contrast, the cells of MPS (macrophages) in lepromatous leprosy had a large nucleus. Their cytoplasm contained mainly whole M. leprae organisms/its phagocytosed products and rough endoplasmic reticulum. There was paucity of lymphocytes in these granulomas. These observations support the view that the cells of MPS in the tuberculoid granulomas may be secretory while those in the lepromatous granulomas were phagocytic.