[Immune defects in multiple myeloma].

Multiple myeloma derives from the precursor cells of B lymphocytes, and it alters the host's immunity. It suppresses polyclonal antibody production, reduces CD4/8 ratio, and suppresses NK cells and dendritic cells. Myeloma cells and bone marrow stromal cells produce IL-6 and VEGF, which also alters the immunological microenvironment. While most anti-cancer agents suppress the host's immunity deeply, immunomodulatory drugs (IMiDs) activate T and NK cells, which induce anti-myeloma effects. Currently several bisphosphonates and anti-RANKL antibody are used to prevent skeletal-related events in myeloma, and these agents also have some impacts to the immune system. To enhance therapeutic strategies of myeloma, it is crucial to uncover the interactions of the immunological microenvironment and these agents in myeloma patients.