Absolute Monocyte Count Ratio at Diagnosis in Patients with Multiple Myeloma

Background: Absolute lymphocyte count (ALC) in peripheral blood has recently been reported to be an independent prognostic factor in multiple myeloma (MM). Previous studies indicated that the absolute monocyte count (AMC) in peripheral blood reflects the state of the tumor microenvironment in lymphomas. Neither the utility of the AMC nor its relationship with ALC has been studied in MM. Methods: The prognostic value of ALC, AMC, and the ALC/AMC ratio at the time of diagnosis was retrospectively examined in 189 patients with MM. Results: On univariate analysis, low ALC (???1,400 cells/μL), high AMC (≥490 cells/μL), and low ALC/AMC ratio (???2.9) were correlated with worse overall survival (OS) (p=.002, p=.038, and p=.001, respectively). On multivariate analysis, the ALC/AMC ratio was an independent prognostic factor (p=.047), whereas ALC and AMC were no longer statistical significant. Low ALC, high AMC, and low ALC/AMC ratio were associated with poor prognostic factors such as high International Staging System stage, plasmablastic morphology, hypoalbuminemia, and high β2-microglobulin. Conclusions: Univariate analysis demonstrated that changes in ALC, AMC, and the ALC/AMC ratio are associated with patient survival in MM. Multivariate analysis showed that, of these factors, the ALC/AMC ratio was an independent prognostic factor for OS