Circulating peripheral blood plasma cells in multiple myeloma

Area of Science:

• Hematology
• Oncology
• Immunology

Background:

• Monoclonal plasma cells are key indicators in multiple myeloma (MM).
• Routine white blood cell (WBC) differentials may not detect these cells in peripheral blood.
• Distinguishing MM from monoclonal gammopathy of undetermined significance (MGUS) and smoldering multiple myeloma (SMM) is crucial.

Purpose of the Study:

• To investigate the presence and significance of monoclonal plasma cells in peripheral blood of multiple myeloma patients.
• To determine the correlation between peripheral blood monoclonal plasma cells and disease status (active, relapsed, refractory).
• To assess the impact of treatment on peripheral blood monoclonal plasma cell levels.

Main Methods:

• Detection of monoclonal plasma cells in peripheral blood using sensitive techniques beyond routine WBC differentials.
• Monitoring cell levels in patients with active, relapsed, or refractory multiple myeloma.
• Observing changes in cell counts in response to therapy.

Main Results:

• Monoclonal plasma cells are detectable in the peripheral blood of patients with active multiple myeloma, particularly in relapsed/refractory cases (over 90%).
• These cells are typically absent in MGUS and true SMM.
• Therapeutic effectiveness is associated with a decrease or disappearance of these cells from circulation.

Conclusions:

• Peripheral blood monoclonal plasma cells are valuable biomarkers for active multiple myeloma.
• Their presence influences results of immunological, molecular, or cytogenetic studies on peripheral blood.
• Further research is needed to determine if these circulating cells represent the myeloma stem cell, necessitating studies on precursor cells.