High Fluorescent Lymphoid Cell Levels Assessed on Initial Blood Count in Newly Diagnosed Multiple Myeloma Carry Prognostic Significance

Abstract

The outcome of multiple myeloma (MM) has tremendously improved over the past decade, due to the development of efficient chemotherapy and mostly immunotherapy. Yet, some patients still display poor responses and outcome. This could be in part related to the presence of peripheral plasma cells, at levels not compatible with a diagnosis of plasma-cell leukaemia. Some recent publications have highlighted the prognostic influence of low levels of such cells which is around 0.1%. Automated blood cell analysers now include fluorescent staining, allowing to identify cells with higher levels or nucleic acids such as activated B-lymphocytes/plasma cells with highly active ribosomal activity related to antibody production. Here, a prospective evaluation of peripheral high fluorescent lymphoid cell (HFLC) levels was carried out on samples from patients with newly diagnosed MM, and data computed with regard to patient evolution. HFLC above a 0.1% threshold were identified as strongly correlated with poorer response in a cohort of 127 patients. The 74 patients with low HFLC had a significantly better PFS both in univariate (p = 0.0017) and multivariate (p = 0.0007) analyses. This simple test provides a significant prognostic value for patients with MM and could eventually lead clinicians to consider more aggressive strategies for patients with peripheral HFLC above 0.1%. Trial Registration: The authors have confirmed clinical trial registration is not needed for this submission.

Keywords: circulating plasma; cytology; myeloma; prognostic factors.

FIGURE 1

Scattergram from the WDF channel showing a population of cells (purple) to the right above lymphocytes, corresponding to HFLC.

FIGURE 2

Relationships between HFLC levels and ISS scores. Higher levels of HFLC are associated with more pejorative scores.

FIGURE 3

HFLC levels discriminate PFS but not OS.

FIGURE 4

Combining HFLC, cytogenetic PI and ISS‐R discriminates prognostic groups for PFS.