[The monocyte-macrophage system in Hodgkin's disease]

Hodgkin's disease (HD) is considered as a tumor of the lymph nodes histologically characterized by a variety of cell types, resembling a nonspecific inflammatory reaction. The Reed-Sternberg cells present in the granuloma are considered neoplastic due to cytogenetic alterations, tissue culture properties and heterotransplantability. They originate from a macrophage-derived interdigitating reticulum cell. The lymph node is an immunologic organ and its alterations reveal qualitative and/or quantitative defects of the immune system. These are observed in HD at very early stages even with a minimum of lymph node involvement. Considering HD as a neoplasm of the monocyte-macrophage system, our objective was to investigate the functional capability of peripheral blood monocytes transformed into macrophages in vitro. The phagocytic and lytic activities were evaluated by the generation of toxic oxygen metabolites as due to an excessive production of PGE-2. This defect could be corrected by cyclo-oxygenase inhibitors. The defect was present at very early stages of HD and persisted even during prolonged continuous complete remissions. We also found a defect in the ingestion of candida which could not be modified by drug treatment, indicating the existence of a global dysfunction of the phagocyte. Presently, more than 90% of HD patients respond to specific therapy and remain in prolonged remission, being considered "cured". This fact may contribute to the diminished number of reports in relation to the biology of the monocyte-macrophage system in this disease.