Shifts in blast cell phenotype and karyotype at relapse of childhood
lymphoblastic leukemia [published erratum appears in Blood 1987
Mar;69(3):996]
CH Pui, SC Raimondi, FG Behm, J Ochs, WL Furman, NJ Bunin, RC Ribeiro, PA Tinsley and J Mirro
Analyses of bone marrow blast cells collected at diagnosis and relapse from
68 children with acute lymphoblastic leukemia (ALL) demonstrated changes in
the expression of cell markers in one-fourth of the patients. Loss of the
common ALL antigen (CALLA) was a frequent change, occurring in 8 of the 51
cases initially classified as common or pre-B ALL. The HLA-DR antigen was
either acquired or lost in 5 of the 68 cases, terminal deoxynucleotidyl
transferase was lost in 6 of 25 cases, and reactivity of the T10 antigen
with monoclonal antibodies was increased in 6 of 17 cases of non-T cell
ALL. Conversion to acute nonlymphoblastic leukemia, so-called lineage
switch, was noted in two cases of common ALL and one of pre-B ALL,
coinciding with the loss of CALLA. Results of chromosomal analyses in cases
with a loss of CALLA implicated several mechanisms in the observed
phenotypic changes. In six cases, including each instance of lineage
switch, the original karyotype had been replaced by an entirely different
abnormal karyotype, suggesting clonal selection or induction of a second
malignancy. In another case, the evidence suggested clonal evolution. Our
findings demonstrate that sequential phenotypic and cytogenetic studies may
yield valuable insights into the mechanisms of leukemic recurrence and may
have implications for treatment selection.
Volume 68,
Issue 6,
pp. 1306-1310,
12/01/1986
Copyright © 1986 by The American Society of Hematology
