Absence of terminal transferase may predict failure of remission induction
in childhood ALL
SB Shurin and JJ Scillian
Two children with acute lymphoblastic leukemia (ALL), whose lymphoblasts
lacked terminal deoxynucleotidyl transferase (TdT) by both enzyme and
fluorescent antibody assay, responded poorly or not at all to vincristine
and prednisone. Both patients had high presenting white counts and mixed
L1-L2 morphology. Lymphoblasts from one patient, an adolescent boy with a
mediastinal mass, possessed surface membrane receptors for sheep red cells
(E) and for complement (EAC) and had elevated adenosine deaminase activity
(ADA). Lymphoblasts from a 2.5-yr- old boy without a mediastinal mass did
not form E or EAC rosettes and did not express the la-like antigen or carry
surface immunoglobulin. The poor response to therapy and absence of TdT
were associated with a lymphoblast phenotype suggestive of a highly
differentiated T-cell- derived line in one instance and an undifferentiated
cell in the other instance. It is postulated that absence of TdT may
predict poor therapeutic efficacy of vincristine and prednisone in acute
lymphoblastic leukemia in childhood. The absence of TdT may correlate with
other developmental characteristics of lymphoblasts, such as altered
function or low numbers of glucocorticoid receptors or resistance to lysis
by steroid drugs. Determination of many parameters of lymphoblast phenotype
at diagnosis to characterize the nature of the malignant cells more
precisely may ultimately enhance our understanding of, and improve therapy
for, the group of leukemic children who fail to respond to standard
regimens.
Volume 62,
Issue 1,
pp. 81-84,
07/01/1983
Copyright © 1983 by The American Society of Hematology
