Mn. Dworzak et al., MULTIPARAMETER PHENOTYPE MAPPING OF NORMAL AND POSTCHEMOTHERAPY B-LYMPHOPOIESIS IN PEDIATRIC BONE-MARROW, Leukemia, 11(8), 1997, pp. 1266-1273
We studied the differentiation profiles of B cell precursors (BCP) in
normal and post-chemotherapy pediatric bone marrow (BM) using multipar
ameter flow cytometry. The goal of our study was to draw a comprehensi
ve phenotypic map of the three major maturational BCP stages in BM. By
correlating lineage-associated markers, CD45RA, and several adhesion
molecules, the stage-specific patterns were found to differ in certain
details from previously published concepts. Among the earliest BCP, a
subset of CD34(+)CD10(lo) precursors was repeatedly observed in addit
ion to the well characterized CD34(+)CD10(hl)CD19(+) majority of cells
. Only two-thirds of these CD34(+)CD10(lo) cells expressed CD19. Howev
er, uniformity of phenotypic features, absence of T lineage markers, a
nd the regeneration kinetics after chemotherapy suggest the B lineage
affiliation of the CD34(+)CD10(lo) precursors in general. In the more
mature BCP, expression of CD10, CD20, cytoplasmic and surface mu chain
s (c mu and s mu) was observed to overlap more than previously recogni
zed. We found that CD20 and c mu appear early during B cell ontogeny (
already on CD34(+) BCP), and that CD10 is lost late, following the ons
et of s mu expression. Differences between normal and post-chemotherap
y BM specimens regarding the phenotypic appearance of BCP were exclusi
vely due to differences in the subset composition, as post-chemotherap
y samples showed a preponderance of immature stages. Our observations
may build a framework for comparing leukemic cells with their normal c
ounterparts to define possible leukemia-associated aberrations useful
for residual disease studies.