1: Br J Haematol 1999 Apr;105(1):265-7

High numbers of clonal CD19+ cells in the peripheral blood of a patient with
multiple myeloma.

Rasmussen T, Kastrup J, Knudsen LM, Johnsen HE

Department of Haematology L, Herlev Hospital, University of Copenhagen, Herlev,
Denmark. thomas.r@inet.uni2.dk

Recent studies concerning the numbers of circulating clonal B cells in patients
with multiple myeloma (MM) have reported conflicting data regarding the exact
levels of clonal B cells and the existence of clonal cells in the CD34
compartment. In this report we show that high numbers of clonal cells with a
phenotype of late-stage B cells or pre-plasma cells were present in the
peripheral blood (PB) of a patient with MM. During treatment the initial high
level of PB clonal cells was markedly reduced and remained low (<1%) post
transplant, even after disease progression. In addition, we found that the MM
clone did not include a B-progenitor population defined by CD34.

PMID: 10233390, UI: 99250530