Serum Stem Cell Factor (SCF) Levels and In Vitro Response of Hematopoietic Progenitors to Recombinant Human SCF (rhSCF) in Patients with Aplastic Anemia

Jo, Deog Yeon; Kim, Chul Hee; Bae, Kwang Bong; Kim, Hyun Soo; Park, Sang Jun; Kim, Jong Suk; Choi, Jee Young; Yun, Hwan Jung; Kim, Samyong

Abstract

BACKGROUND: Stem cell factor (SCF), which is produced from stromal cells of bone marrow, is a growth factor acting in early stages of hematopoiesis. Bone marrow failure in aplastic anemia seems to be mainly due to hematopoietic stem cell defect. However, there has been some evidence that microenvironmental defects contribute to the pathophysiology of this disorder.
METHODS
We measured serum SCF levels in 29 patients with aplastic anemia at diagnosis using ELISA to define the status of soluble SCF in this disorder. We also examined the effect of serum from 15 patients with aplastic anemia on the colony growth (CFU-GM and BFU-E) of normal bone marrow cells and the ability of recombinant human SCF to stimulate in vitro colony growth of bone marrow cells from 10 patients with aplastic anemia.
RESULTS
Levels of serum SCF in patients with aplastic anemia were not different from those in 25 healthy controls (1,493+/-392pg/mL vs. 1,563+/-322pg/mL) or those in patients with idiopathic thrombocytopenic purpura, acute myeloid leukemia, and myelodysplastic syndrome. No correlation was found between serum SCF levels and hematologic parameters at diagnosis such as neutrophil count, hemoglobin, and platelet count. No difference was noted in the serum SCF levels according to severity of the disease. The effect of serum from patients with aplastic anemia on the colony growth of normal bone marrow cells were variable and were not correlated with serum SCF levels. rhSCF increased the colony numbers of bone marrow cells from patients with aplastic anemia.
CONCLUSION
These results indicate that soluble SCF is not deficient in aplastic anemia, but SCF can stimulate the proliferation of bone marrow cells from aplastic anemia.