Peripheral FLT-3 ligand levels as a pathobiological parameter duringthe clinical course of acute myeloid leukemia.

BACKGROUND/AIM: FLT-3 ligand is a growth factor affecting the hematopoietic lineage. The aim of this study was to evaluate the variability of peripheral FLT-3 ligand during the clinical course of acute myeloid leukemia (AML) patients.

MATERIALS AND METHODS: Twenty-four patients were enrolled in this study in order to assess alterations in the circulating levels of FLT-3 ligand during the clinical course of AML.

RESULTS: We studied the association in the diagnostic period between the FLT-3 ligand and peripheral blood cells together with serum electrolytes. FLT-3 ligand levels (pg/mL) during the aplastic period due to remission induction and consolidation were higher than the levels at initial diagnosis. On the other hand, the diagnostic and remission induction values of leukocytes and FLT-3 ligand showed an inverse association. These results indicate to us that higher white cell counts are associated with lower FLT-3 ligand levels. We also found a reversed association between FLT-3 ligand and serum lactate dehydrogenase level. However, there was no association between FLT-3 ligand and other serum electrolyte levels. We also found higher FLT-3 ligand levels in male patients.

CONCLUSION: Our study demonstrates the inverse proliferative action of FLT-3 ligand on the early myeloid lineage. In addition, this study showed us that FLT-3 receptor inhibition during chemotherapy-induced aplasia causes a compensative ligand overexpression.