Pre-B cells in peripheral blood of multiple myeloma patients
LM Pilarski, MJ Mant and BA Ruether
Although multiple myeloma is a disease of plasma cells, abnormalities have
been detected in both B and T lymphocytes in peripheral blood. Although
multiple myeloma patients are deficient in surface Ig (sIg)- positive B
lymphocytes, analysis of lymphocytes present in blood indicates an
abnormally large pool of circulating pre-B cells. These pre-B cells express
BA-1, do not bear sIg, and contain cytoplasmic mu chains. High numbers of
pre-B cells occur in 88% of individuals with frank myeloma and in 44% of
individuals with monoclonal gammopathy of undetermined significance. Pre-B
cells bearing BA-1 differ between patients in their expression of HLA-DR
and receptors for peanut agglutinin (PNA). Those pre-B cells in myeloma
patients are either BA- 1+ PNA- HLA-DR+ (54% of patients) or BA-1+ PNA+
HLA-DR- (30% of patients), or have a mixture of phenotypes (14% of
patients). Pre-B cells of the PNA- phenotype are almost always HLA-DR+, and
PNA+ pre-B cells are HLA-DR-. Within the same patient, the pre-B cell
population varies by both quantitative and qualitative definitions. The
number of pre-B cells may increase 460-fold and temporal shifts of surface
phenotype from BA-1+ PNA- to BA-1+ PNA+ or vice versa have been detected.
These observations indicate an abnormality in the B lymphocyte
differentiation pathway leading to pre-B cells in the periphery that vary
in number and cell surface phenotype, and that are unable to express sIg.
Volume 66,
Issue 2,
pp. 416-422,
08/01/1985
Copyright © 1985 by The American Society of Hematology
