Restoration of impaired cytokine secretion from monocytes of patients with myelodysplastic syndromes after in vivo treatment with GM-CSF or IL-3.

Cytokine treatment in patients with myelodysplastic syndrome (MDS) aims to overcome the maturation defects of myeloid lineage cells associated with cytopenia and cellular dysfunction of mature cells. Since phagocytes play a major role in host defense against microbial infection, we investigated cytokine secretion and oxygen radical release (ORR) from peripheral blood monocytes (PBMC) in a total of 16 MDS patients, 12 patients with refractory anemia (RA) and four patients with RA and excess of blasts (RAEB). Interleukin (IL-6), tumour necrosis factor alpha (TNF alpha), IL-1 beta, and IL-8 secretion from monocytes in response to lipopolysaccharide (LPS) was significantly reduced in the 12 patients with RA compared to 12 healthy controls, whereas no difference was seen in ORR. We further assessed cytokine secretion from monocytes of 10 MDS patients before and after therapy with granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-3, or a combination therapy with GM-CSF and cytosine arabinoside (AraC). In all 10 patients, secretion of IL-1 beta, IL-6, and TNF alpha from PBMC increased after cytokine therapy, whereas IL-8 secretion increased only in five patients with GM-CSF or IL-3 therapy receiving a dosage > or = 250 micrograms/m2 per day but decreased in all other patients. ORR increased in all patients on either GM-CSF or IL-3 therapy. These data indicate that the ability of monocytes to secrete secondary cytokines is impaired in MDS patients but can be restored by in vivo administration of GM-CSF and IL-3.