Immunophenotyping of Plasma Cells and Immune Effector Cells in Peripheral Whole Blood and Bone Marrow Samples From Multiple Myeloma (MM) Patients

The objective of this study is to evaluate the immune profile of plasma cells and immune effector cells in paired peripheral whole blood and bone marrow samples from MM patients by standardized flow cytometry. The quantitative and/or qualitative variation of these immune effectors according to the different status of myeloma pathology (diagnosis, relapse or refractory). It is interesting to assess the extent to which a particular immune profile is associated with a better therapeutic response for a given treatment. In addition, the study will validate the stability of the samples between T0 (\< 4 hours after sampling) and T0 + 72 hours.