Blood Journal
Leading the way in experimental and clinical research in hematology

Circulating clonal lymphocytes in myeloma constitute a minor subpopulation of B cells [see comments]

  1. BJ Chen and
  2. J Epstein
  1. Division of Hematology/Oncology, ArkansasCancer Research Center, University of Arkansas for Medical Sciences, Little Rock, USA.

Abstract

The mononuclear cells in the blood of myeloma patients have been reported to contain a high proportion of phenotypically abnormal myeloma B lymphocytes. These cells have been proposed to constitute the drug-resistant proliferative myeloma cell compartment. To determine the extent of B lymphocyte involvement, the proportion of clonotypic cells among the CD19-expressing cells from myeloma patients was estimated by quantitative polymerase chain reaction analysis of the third complementarity determining region (CDR3). The results indicate that the B lymphocytes constitute, on average, 6% of blood mononuclear cells, and that only a minor fraction of these are clonally related to the myeloma cells. While the small number of circulating clonal cells is not incompatible with their proposed role as a reservoir of proliferating myeloma progenitors, the majority of the B cells appear not to be clonally related to the myeloma cells.