Immunophenotypic heterogeneity of bone marrow-derived mesenchymal stromal cells from patients with hematologic disorders: correlation with bone marrow microenvironment.

The immunophenotypic analysis of ex vivo-expanded mesenchymal stromal cells (MSC) has so far been confined to single or dual staining analysis in normal subjects. In this study, using a four-color cytofluorimetric protocol, we demonstrated that cultured MSC derived from the bone marrow of patients with hematologic malignancies showed alterations in the expression of CD105, CD90, CD184, and HLA-DR molecules. The decrease in the percentage of CD105+ and CD90+ MSC correlated with an increased bone marrow angiogenesis.

"In vitro" evaluation of bone marrow angiogenesis in myelodysplastic syndromes: a morphological and functional approach.

In myelodysplastic syndromes (MDS), ineffective hematopoiesis and cytopenia may arise either from increased susceptibility to apoptosis of hematopoietic cells, or possibly from alterations of bone marrow stroma that contributes to defective development of marrow lineages. In order to test the significance of the endothelial growth in MDS patients, two in vitro assays are presented in this study: a long-term culture method for the detection of human bone marrow endothelial colonies (CFU-En) (77 patients) and a human primary model for the evaluation of the influence of a "bone marrow conditioned medium" on the formation of new vessels in a culture matrix ("angio-kit assay") (in 24 out 77 patients). The in vitro growth pattern of bone marrow CFU-En as well as the generation of microvessels in the angio-kit system was increased in RA, RARS and RAEB in comparison with controls.

CXCR-4 expression on bone marrow CD34+ cells prior to mobilization can predict mobilization adequacy in patients with hematologic malignancies.

To investigate the mechanisms of mobilization and of the factors implicated in the homing of progenitors and possibly understand the reasons for unpredicted mobilization failure, we analyzed CXCR-4 (CD184) expression on bone marrow (BM) CD34+ cells prior to peripheral blood stem cell (PBSC) mobilization in 24 patients affected by hematologic malignancies (non-Hodgkin lymphoma, multiple myeloma, and acute myeloid leukemia). We wanted to determine whether the level of CXCR-4 expressed by hematopoietic stem cells could influence mobilization process and therefore could be considered a predictive factor for mobilization adequacy. These data were also compared with stromal cell function as assessed by colony forming unit-fibroblast (CFU-F) and CFU endothelial cells (CFU-En) assays and stromal layer confluence capacity exhibited by patients' BM cells.