Autologous Bone Marrow Transplantation - Blog Science Connections

CALLA-Negatiœ Clonogenic BCell ALL Blasts 159
Table 1. Differences in Expression of B-lineage Surface Determinants on
Fresh Marrow Blasts and Colony Blasts From Patients With B-cell
Precursor Acute Lymphoblastic Leukemia
Fresh Marrow Samples Pooled Blast Colonies on Day 7
Positive Mean of Positive Mean of
Surface Determinant Cases(%) Positive Blasts (%)" Cases(%) Positive Blasts (%) a
CALLA/CD 10, BA-3 100 83 67 40
B43 100 86 94 69
CD 24, BA-1 100 84 94 66
a
All 33 cases were included in calculating the mean percentage of positive blasts.
Table 2. Immunophenotypic Comparison of Cultured B-cell Precursors From
Primary and Secondary Blast Colonies
Surface Fresh Marrow Primary Colony Secondary Colony
Determinant Blasts Blasts Blasts
Patient 2
CD 10/CALLA +++ +++ +++
B43 +++ ++ +++
CD 24/BA-1 + ++ +++
Patient 4
CD 10/CALLA +++ +++ +++
B43 +++ +++ +++
CD 24/BA-1 +++ +++ +++
Patient 6
CD 10/CALLA ++
- -
B43 +++ +++ +++
CD 24/BA-1 +++ + +
Patient 7
CD 10/CALLA +++
- -
B43 ND ++ ++
CD 24/BA-1 +++ + +
Nofe: -, 0-24% of cells positive; +, 25-49% of cells positive; ++, 50-74% of cells positive;
+++, 75-100% of cells positive; ND, not determined.
In the second group (11 patients, 33%), colony blasts did not express CALLA. In
both groups, cultures of colony blasts were always positive for at least two
distinct B-lineage markers but did not react with a T-lineage MAb. In replating
experiments, we found that the immunophenotype of secondary colony blasts
was identical to that of primary colony blasts.
We compare in Table 2 B-lineage surface marker expression of blasts from
primary and secondary colonies with expression of fresh marrow blasts in four
representative cases (nine were analyzed). Most important, colony blasts
positive for CALLA yielded only secondary leukemic B-cell precursor colonies