In contrast, marrow fibroblasts from a Diamond-Blackfan anemia patient in untreated hematologic remission constitutively expressed high levels of SCF mRNA (21 +/- 4 copies/cell) and soluble protein (0.40 ng/mL per 10(6) cells at 24 hours).
M-07e cells detected active soluble kit-ligand from normal bone marrow fibroblasts as well as from DBA BMEF which produce constitutively significant amounts of SCF.
These results demonstrate that this group of DBA patients responds to SF and produces SF mRNA normally, indicating that SF itself is not involved in DBA pathophysiology.