Abstract 4966

Background

Recent studies have shown that interleukin-3 receptor α(CD123) is highly expressed on leukemia stem cells of patients with acute myeloid leukemia, and is correlated with tumor load and poor prognosis. The expression of CD123 may also be high in patients with myelodysplastic syndromes (MDS). In this study, the expression of CD123 as well as granulocyte colony stimulating factor (G-CSF) receptor (CD114) on the bone marrow cells of patients with MDS was investigated in order to explore the molecular marker of the malignant clone of MDS.

Methods

Forty-two patients with MDS, who were diagnosed in the hematological department of General Hospital of Tianjin Medical University from 2008 to 2009, and twelve normal controls were enrolled in this study. FACS was used to measure the expression of CD123 on CD34+CD38- cells and CD114 on CD34+ cells of the bone marrow of these patients and controls and the clinical significance was analyzed. The expression of CD114 on CD123+CD34+CD38- cells was further measured to explore the molecular marker of the malignant clone in MDS.

Results

The ratio of CD34+CD38-/CD34+ in the bone marrow cells of MDS patients was [(14.03±5.27)%], significantly higher than that of normal controls [(7.70±4.36)%] (P<0.01); The ratio of CD123+CD34+CD38-/CD34+CD38- in the bone marrow cells of MDS patients[(48.39±28.15)%]was significantly higher than that of normal controls [(8.75±11.71)%] (P<0.01), and was significantly positively correlated with the proportion of bone marrow blasts(r=0.457, P<0.05). The ratio of CD114+CD34+/CD34+ in the bone marrow cells of MDS patients [(33.05±21.71)%] was lower than that of normal controls [(38.99±19.07)%], but with no significance(P>0.05). The expression of CD114 on CD123+CD34+CD38-cells [(34.82±29.58)%] was significantly lower than that on CD123-CD34+CD38-cells [(53.48±27.41)%] of MDS patients (P<0.05).

Conclusions

MDS patients displayed higher proportion of CD34+CD38-/CD34+ than normal controls. CD123 was highly expressed in the bone marrow of patients with MDS, significantly correlated with the proportion of bone marrow blasts, thus might be the marker of MDS malignant clone. CD123+CD34+CD38-cells exhibited lower expression of G-CSF receptors, which might partly explain why MDS clone responsed worse to G-CSF in vitro and in vivo.

Disclosures:

No relevant conflicts of interest to declare.

Author notes

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Asterisk with author names denotes non-ASH members.

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