RECENT PROGRESS IN THE BIOLOGY OF MULTIPLE-MYELOMA AND FUTURE-DIRECTIONS IN THE TREATMENT

A great amount of scientific information, accumulated over recent year s on the biology of Multiple Myeloma (MM), has fuelled speculation abo ut the origin of malignant plasma cells, about a purported critical ro le played by the bone marrow stroma, and further still, on cytokine in teractions and in particular that of IL-6 and its relationship with th e immune system. Among the growth factors secreted by stroma cells, IL -6 is a potent stimulator of myeloma cells in vitro but does not induc e a malignant phenotype in normal plasma cells. Many efforts have been produced to identify the stem cell in MM and probably memory B lympho cytes are the best candidates. The demonstration of a Graft vs Myeloma effect in the allogeneic setting strongly supports the immunotherapy in MM. Recent data also suggest that a virus (Kaposi-associated herpes virus, HHV-8) may be significantly associated with the development of MM. In parallel, progress has been achieved in the treatment of this incurable disease with well defined prognostic factors, more efficient supportive care and its corollary, improved quality of life and dose- intensified chemo-radiotherapy followed by autologous hematopoietic st em cell support. Improving the quality of grafts with the selection of CD34 positive cells is another approach aimed at reducing plasma cell contamination without impairing haematological recovery. An EBMT rand omised study assessing the role of CD34 selection has been initiated b y our group. Increasingly efficient first-line therapy, better quality autografts and improved post-remission treatment with, for exemple, a nti-idiopatic vaccination are the most promising future directions.