Detection of hemophagocytic extremely multinucleated giant plasma cells after rituximab/low-dose lenalidomide treatment in CD20+ multiple myeloma

摘要

CD20 positive Multiple myeloma (MM) cells occur in 13- 22% of patients [1] at the time of diagnosis and is associated with higher overall survival (OS) and progression free survival (PFS) rates [2]. For this sub-group of patients, anti-CD20 antibody rituximab alone or in combination with standard therapy could be a treatment option, however, its effect on myeloma cells is uncertain, with limited objective responses observed in a few small studies [1]. Rituximab-induced killing of lymphoid cells could be enhanced by the addition of lenalidomide, an immunomodulatory drug approved for MM treatment. Authors have described improved function of natural killer cells and monocyte-mediated antibody-dependent cellular cytotoxicity (ADCC) targeting rituximab-treated CD20?tumor cells [3], however data regarding the changes in morphology and function of MM cells under combined immunomodulatory therapy are lacking.