Peripheral Blood Monocyte Count Is a Strong, Dynamic Prognostic Biomarker for Risk Stratification in Multiple Myeloma

Introduction: Multiple myeloma (MM) is a heterogeneous disease with diverse clinical outcomes. Although survival in MM has improved, high risk patients still experience early relapses and shorter survival. Current methods for risk stratification in MM are useful at diagnosis but need to be refined as our knowledge of disease pathobiology evolves. Tumor-associated macrophages, derived from peripheral blood monocytes, support malignant plasma cell proliferation in the bone marrow (BM) microenvironment. Since peripheral blood absolute monocyte count (AMC) could reflect the BM microenvironment, we evaluated the prognostic significance of AMC in MM at diagnosis and during the disease course.