Stem Cells, Vol 11, 562-567, Copyright © 1993 by AlphaMed Press
c-kit ligand augments granulocyte-macrophage colony growth from patients with 5q- syndrome
CS Rosenfeld, J Nemunaitis, CR Sherer, ZR Zeigler and RK Shadduck
West Penn Hospital, Western Pennsylvania Cancer Institute, Pittsburgh 15224.
In vitro studies may serve as a guide to clinical strategies with
cytokines. In this study, marrows from 26 patients with myelodysplastic
syndrome (MDS) were assayed for myeloid progenitor cells in agar gel.
Colony stimulating activity was provided by the recombinant human colony
stimulating factors granulocyte-macrophage colony stimulating factor
(GM-CSF), granulocyte colony stimulating factor (G-CSF), interleukin 3
(IL-3), fusion protein (FP), c-kit ligand (KL) or GM-CSF combined with
other cytokines (KL, IL-3). Decreased colony forming units
granulocyte-macrophage (CFU-GM) were detected in most cases (69%) compared
with normal controls. Neither FP nor the combination of GM-CSF + IL-3
produced more colonies than GM-CSF alone. The number of CFU-GM did not
correlate with French American British (FAB) class. All marrows (7) from
patients with 5q- showed augmentation of GM-CSF induced colonies with the
addition of KL. In contrast, KL augmentation was noted in only 42% of other
MDS marrows (p = 0.01). This in vitro result suggests that 5q- may predict
a group of MDS patients with a likelihood to respond to the combination of
GM-CSF + KL.
