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.