International Journal of Cell Cloning, Vol 10, 292-298, Copyright © 1992 by AlphaMed Press
Clonogenic assay is not predictive but reflects therapeutic efficacy of interferons in the treatment of chronic myelogenous leukemia
UB Wandl, N Niederle, M Kranzhoff and S Seeber
Department of Internal Medicine (Cancer Research), West German Cancer Center Essen, University of Essen Medical School.
Patients with chronic myelogenous leukemia (CML) have been treated with
interferon (IFN) alpha-2b alone or in combination with IFN gamma. In order
to predict clinical response to IFN, bone marrow samples from 15 CML
patients were incubated with serial dilutions of IFN alpha-2b to obtain the
IC50 values for erythroid burst forming units (BFU-E) and
granulocyte-macrophage colony forming units (CFU-GM). A dose-dependent
inhibition of at least one lineage was observed in all but one sample. An
inhibitory effect of greater than 50% was reached for BFU-E in 8/14
patients and for CFU-GM in 10/14 patients. All three patients with no
response (NR) to IFN treatment had IFN-sensitive BFU-E and CFU-GM. In four
patients with hematologic remission (HR) or partial hematologic remission
(PHR), BFU-E or CFU-GM were affected very little by the inhibitory effect
of IFN. These observations suggest no predictive value for pretesting IFN
sensitivity in vitro. The in vivo effect of IFN on the hemopoietic
progenitor cells BFU-E and CFU-GM was evaluated in patients treated with
either IFN alpha-2b alone (n = 11), or in combination with low dose IFN
gamma (n = 10). All patients were newly diagnosed and not pretreated. After
a median treatment duration of 11 months (range 3-25) a significant
decrease in BFU-E and CFU-GM was observed in both groups of patients. We
conclude that in vitro colony growth reflects the therapeutic efficacy of
IFN.
