[Application of flow cytometry-fluorescence in situ hybridization in the measurement of relative telomere length of bone marrow CD34(+) cells in patients with myelodysplastic syndrome].

This study was aimed to investigate the feasibility of flow cytometry-fluorescence in situ hybridization (Flow-FISH) in measuring the telomere length of bone marrow cell subgroups in patients with myelodysplastic syndrome (MDS). Seven newly diagnosed patients with low-risk MDS and seven nutritional anemia patients who were matched with age and sex, were enrolled in this study. Heparinized bone marrow were sampled. Taking Molt-4 cell line as internal control cells, leukocytes isolated from whole bone marrow were labeled with CD34-Alexa Fluork ® 647, then denatured by high temperature and hybridized with FITC-conjugated telomere probe. The DNA was counterstained and the relative telomere length (RTL) of nucleated cells and CD34(+) cells in bone marrow were measured by four-color flow cytometry. The results showed that CD34(+) cells could be gated for the measurement of RTL in both groups, undergoing the denaturation and hybridization. Primary analysis indicated that the RTL of bone marrow CD34(+) cells in MDS patients was significantly shorter than that of bone marrow nucleated cells (P = 0.001), and the RTL of both CD34(+) cells and nucleated cells in bone marrow of MDS patients were significantly shorter than that of control group (P = 0.020, 0.002). It is concluded that the application of Flow-FISH in the measurement of RTL of certain cell subgroup is feasible by labeling the cell with thermostable fluorescence-conjugated antibody, and this technique is worthy to be investigated further.