Advances in biology of multiple myeloma: Cell kinetics, molecular biology and immunology

Bone marrow plasma cell proliferative activity has been evaluated in a large series of multiple myeloma (MM) patients. This kinetic parameter has been shown to be a useful tool for patient management, and contributes to a correct diagnosis and a selection of high‐risk patients who can be offered high‐dose chemotherapy. The role of ras oncogenes has been evaluated in the pathogenesis of MM. A point‐mutated and activated H‐ras oncogene, introduced in a human lymphoblastoid cell line, was able to induce neoplastic transformation and differentiation to plasma cell. Indeed, mutated alleles of ras genes have been detected in a high percentage of myeloma patients in relapse phase. Phenotypical and functional studies have been carried out in T‐lymphocyte subsets and an impaired cellular immunity has been detected. Such an impairment was related to the disease status: marked alterations were detected in relapse phase, whereas a partial recovery was observed during remission phase.