Granulocyte Colony-Stimulating Factor Receptors on CD34++Cells in Patients with Myelodysplastic Syndrome (MDS) and MDS-Acute Myeloid Leukemia

GCSF-R expression in myelodysplastic and myeloproliferative disorders and blast dysmaturation in CML

OBJECTIVES

To characterize granulocyte colony-stimulating factor receptor (CD114) expression in normal (n = 20), myelodysplastic (n = 34), and chronic myelogenous leukemia (CML; n = 5) bone marrow by flow cytometry.

METHODS

Clinical bone marrow samples were analyzed using CD33/CD114/CD34/CD117/CD45. CD114 density (mean fluorescence intensity) and cellular distribution were evaluated on early blasts (CD33-), late blasts (CD33+), promyelocytes, and granulocytes.

RESULTS

Normal CD114 acquisition occurred on early blasts, peaked on promyelocytes, and decreased on granulocytes. Forty percent of CD34+ blasts expressed CD114 and one-third were early blasts. In myelodysplastic syndromes, altered CD114 distribution was more informative than density changes. In CML, CD114 density was significantly decreased on early blasts and expression was essentially limited to late blasts. We observed a specific blast dysmaturation pattern in CML involving CD33, CD34, and CD114 that was 83% sensitive and 100% specific in initial diagnosis.

CONCLUSIONS

CD114 provides useful additional detail in phenotypic assessment of hematopoietic precursor maturation.

G-CSF Control of Neutrophils Dynamics in the Blood

White blood cell neutrophil is a key component in the fast initial immune response against bacterial and fungal infections. Granulocyte colony stimulating factor (G-CSF) which is naturally produced in the body, is known to control the neutrophils production in the bone marrow and the neutrophils delivery into the blood. In oncological practice, G-CSF injections are widely used to treat neutropenia (dangerously low levels of neutrophils in the blood) and to prevent the infectious complications that often follow chemotherapy. However, the accurate dynamics of G-CSF neutrophil interaction has not been fully determined and no general scheme exists for an optimal G-CSF application in neutropenia. Here we develop a two-dimensional ordinary differential equation model for the G-CSF-neutrophil dynamics in the blood. The model is built axiomatically by first formally defining from the biology the expected properties of the model, and then deducing the dynamic behavior of the resulting system. The resulting model is structurally stable, and its dynamical features are independent of the precise form of the various rate functions. Choosing a specific form for these functions, three complementary parameter estimation procedures for one clinical (training) data set are utilized. The fully parameterized model (6 parameters) provides adequate predictions for several additional clinical data sets on time scales of several days. We briefly discuss the utility of this relatively simple and robust model in several clinical conditions.