Comparative analysis of the in vitro proliferation and expansion of hematopoietic progenitors from patients with aplastic anemia and myelodysplasia

Low IPSS score and bone marrow hypocellularity in MDS patients predict hematological responses to antithymocyte globulin

“…There is skewing of CD4:CD8 ratios, restricted T-cell receptor Vb usage together with high plasma levels of tumor necrosis factor-a and interferon-g indicating a T-cell-mediated myelosuppression. 10,12,24,25 ATG has been used successfully in the alleviation of cytopenias in severe aplastic anemia, 25 and while earlier reports from Molldrem et al and Killick et al had identified BM hypocellularity as an important factor predicting with ATG response, several recent reports have failed to confirm this association. [14][15][16]22 Our study indicates that patients with hypocellular MDS have the highest response to ATG, although responses are observed in some patients with normo/hypercellular BMs.…”

Distinctive gene expression profiles of CD34 cells from patients with myelodysplastic syndrome characterized by specific chromosomal abnormalities

“…31 The close correlation of cytogenetic abnormalities with patterns of dysplastic marrow morphology, ineffective hematopoiesis, and leukemic transformation strongly suggests their pathophysiologic roles in marrow failure and leukemogenesis. 11,32,33 As early hematopoietic cells are readily identified and isolated based on the presence of the CD34 antigen, we examined purified populations of hematopoietic stem and progenitor cells using DNA microarrays, which allow assessment in minimally manipulated cells of the expression levels of thousands of genes simultaneously.…”

Quantitative analysis of bone marrow CD34 cells in aplastic anemia and hypoplastic myelodysplastic syndromes

“…5,30,31 As some cases of moderate AA 5,30,31 and lowgrade MDS (e.g., the 5qÀ syndrome 32,33 ) never progress to 34,35 whereas hypoplastic MDS patients generally have higher bone marrow CD34 þ cell counts. 9,10,36,37 However, significant overlap in the CD34 percentages between these two disorders has precluded using this assay diagnostically. 9,10,36,37 Technical issues and difficulty precisely diagnosing AA and hMDS may account for the differences between previous reports and our findings.…”

“…9,10,36,37 However, significant overlap in the CD34 percentages between these two disorders has precluded using this assay diagnostically. 9,10,36,37 Technical issues and difficulty precisely diagnosing AA and hMDS may account for the differences between previous reports and our findings. Low CD34 þ cell percentages seen in some hMDS patients in other studies may have been the result of contamination of bone marrow aspirates with peripheral blood, as there was no description of criteria for validating the quality of their marrow samples.…”

“…Low CD34 þ cell percentages seen in some hMDS patients in other studies may have been the result of contamination of bone marrow aspirates with peripheral blood, as there was no description of criteria for validating the quality of their marrow samples. 9,36,37 We only considered marrow aspirate samples adequate if normal B cell and nucleated red cell precursors could be identified. Although Orazi et al 10 found that bone marrow biopsies from some hMDS patients also displayed low percentages of CD34 þ cells by immunohistochemistry, many of their patients had normal cytogenetics and no clinical outcome was provided; thus, these patients may have been misclassified.…”