Interphase cytogenetic analysis detects minimal residual disease in a case
of acute lymphoblastic leukemia and resolves the question of origin of
relapse after allogeneic bone marrow transplantation
J Anastasi, M Thangavelu, JW Vardiman, AL Hooberman, ML Bian, RA Larson and MM Le Beau
Department of Pathology, University of Chicago, IL.
We used in situ hybridization with a probe for the X chromosome to study
interphase cells of bone marrow and peripheral blood specimens from a male
patient with acute lymphoblastic leukemia characterized by hyperdiploidy,
including trisomy X. In a posttreatment bone marrow specimen, which was
interpreted as a regenerating bone marrow morphologically and which
demonstrated a normal karyotype cytogenetically, trisomy X was found in 16
of 1,000 interphase cells. This finding indicated the presence of leukemic
cells that were undetected by conventional morphologic and cytogenetic
techniques (ie, minimal residual disease). Cytogenetic studies of a relapse
specimen obtained after a sex-mismatched bone marrow transplant showed only
a normal female karyotype in each of 40 metaphase cells, suggesting that
the relapse occurred in donor cells. However, interphase analysis
demonstrated trisomy X in more than 80% of interphase cells and indicated
that the relapse was of the original clone and was not a transformation of
donor cells. This case illustrates that interphase analysis can be useful
as an adjunct to conventional cytogenetic analysis in the detection of
minimal residual disease and in the analysis of interphase cells that are
not accessible to routine cytogenetic methods. It also illustrates that
previously reported instances of relapse of leukemia in donor cells could
have been incorrect if supported by cytogenetic data alone.
Volume 77,
Issue 5,
pp. 1087-1091,
03/01/1991
Copyright © 1991 by The American Society of Hematology
