Identification of the human eosinophil lineage-committed progenitor: revision of phenotypic definition of the human common myeloid progenitor

To establish effective therapeutic strategies for eosinophil-related disorders, it is critical to understand the developmental pathway of human eosinophils. In mouse hematopoiesis, eosinophils originate from the eosinophil lineage-committed progenitor (EoP) that has been purified downstream of the granulocyte/macrophage progenitor (GMP). We show that the EoP is also isolatable in human adult bone marrow. The previously defined human common myeloid progenitor (hCMP) population (Manz, M.G., T. Miyamoto, K. Akashi, and I.L. Weissman. 2002. Proc. Natl. Acad. Sci. USA. 99:11872–11877) was composed of the interleukin 5 receptor α chain+ (IL-5Rα+) and IL-5Rα− fractions, and the former was the hEoP. The IL-5Rα+CD34+CD38+IL-3Rα+CD45RA− hEoPs gave rise exclusively to pure eosinophil colonies but never differentiated into basophils or neutrophils. The IL-5Rα− hCMP generated the hEoP together with the hGMP or the human megakaryocyte/erythrocyte progenitor (hMEP), whereas hGMPs or hMEPs never differentiated into eosinophils. Importantly, the number of hEoPs increased up to 20% of the conventional hCMP population in the bone marrow of patients with eosinophilia, suggesting that the hEoP stage is involved in eosinophil differentiation and expansion in vivo. Accordingly, the phenotypic definition of hCMP should be revised to exclude the hEoP; an “IL-5Rα–negative” criterion should be added to define more homogenous hCMP. The newly identified hEoP is a powerful tool in studying pathogenesis of eosinophilia and could be a therapeutic target for a variety of eosinophil-related disorders

Graft-versus-Host Disease after HLA-Matched Sibling Bone Marrow or Peripheral Blood Stem Cell Transplantation: Comparison of North American Caucasian and Japanese Populations

The risk of acute graft-versus-host disease (GVHD) after HLA-matched sibling bone marrow (BM) transplantation is lower in Japanese than in Caucasian patients. However, race may have differential effect on GVHD dependent on the graft source. North American Caucasian and Japanese patients receiving their first allogeneic BM or peripheral blood stem cell (PBSC) transplantations from an HLA-matched sibling for leukemia were eligible. BM was used in 13% and 53% of Caucasian and Japanese patients, respectively. In multivariate analysis, the interaction term between race and graft source was not significant in any of the models, indicating that graft source does not affect the impact of race on outcomes. The risk of grades III–IV acute GVHD was significantly lower in Japanese than in Caucasian patients (hazard ratio (HR) 0.74, 95% confidence interval (CI) 0.57–0.96), which resulted in lower risk of non-relapse mortality in Japanese patients (HR 0.69, 95% CI 0.54–0.89). The risk of relapse was also lower in this group. Lower risk of non-relapse mortality and relapse resulted in lower overall mortality rates among Japanese patients. In conclusion, irrespective of graft source, the risk of severe acute GVHD is lower in Japanese patients, which results in lower risk of non-relapse mortality

Clinicopathological analysis of polyploid diffuse large B-cell lymphoma.

Polyploid chromosomes are those with more than two sets of homologous chromosomes. Polyploid chromosomal abnormalities are observed in various malignant tumors. The prognosis in such cases is generally poor. However, there are no studies examining the prognosis of diffuse large B-cell lymphoma (DLBCL) with polyploid chromosomal abnormalities. Therefore, we statistically compared the clinicopathological features between polyploid DLBCL and DLBCL without polyploid abnormalities. Herein, 51 polyploid DLBCL and 53 control (without polyploid chromosomal abnormalities) cases were examined. G-banding method was employed to define polyploidy by cytogenetic analysis. Subsequently, flow cytometric immunophenotyping and immunohistochemical staining were performed. Polyploid DLBCL was defined as DLBCL with either near-tetraploid or greater number of chromosomes, as detected by the G-band. In a survival analysis, a significantly worse overall survival (OS) was observed for polyploid DLBCL (p = 0.04; p = 0.02 in cases who received R-CHOP regimens). In a multivariate analysis of OS, polyploid chromosomal abnormalities were an independent prognostic factor. Our results suggest that polyploid chromosomal abnormalities detected through G-band may represent a new poor prognostic factor for DLBCL

CD34-selected versus unmanipulated autologous haematopoietic stem cell transplantation in the treatment of severe systemic sclerosis: a post hoc analysis of a phase I/II clinical trial conducted in Japan

Abstract Background The effectiveness of autologous haematopoietic stem cell transplantation (auto-HSCT) in treating severe systemic sclerosis (SSc) is established; however, the necessity of purified CD34+ cell grafts and the appropriate conditioning regimen remain unclear. This study aimed to compare the efficacy and safety of CD34-selected auto-HSCT with unmanipulated auto-HSCT to treat severe SSc. Methods This study was a post hoc analysis of a phase I/II clinical trial conducted in Japan. Nineteen patients with severe SSc were enrolled. Peripheral blood stem cells (PBSCs) were mobilised with cyclophosphamide (4 g/m2) and filgrastim (10 μg/kg/day). Following PBSC collection by apheresis, CD34+ cells were immunologically selected in 11 patients. All patients were treated with high-dose cyclophosphamide (200 mg/kg) monotherapy as a conditioning regimen and received CD34-selected (n = 11) or unmanipulated auto-HSCT (n = 8). Changes in skin sclerosis and pulmonary function were assessed over an 8-year follow-up period. Differences in the changes, toxicity, progression-free survival (PFS) and overall survival were compared between patients who had received CD34-selected auto-HSCT and those who had received unmanipulated auto-HSCT. Results Skin sclerosis progressively improved after transplantation over an 8-year follow-up period in both groups, and the improvement was significantly greater in the CD34-selected group than in the unmanipulated group. Forced vital capacity in the CD34-selected group continuously increased over 8 years, whereas in the unmanipulated group it returned to baseline 3 years after transplantation. Toxicity and viral infections, such as cytomegalovirus infection and herpes zoster, were more frequently found in the CD34-selected group than in the unmanipulated group. The frequency of severe adverse events, such as bacterial infections or organ toxicity, was similar between the two groups. No treatment-related deaths occurred in either treatment group. PFS of the CD34-selected group was greater than that of the unmanipulated group, and the 5-year PFS rates of the CD34-selected and unmanipulated group were 81.8% and 50% respectively. Conclusions CD34-selected auto-HSCT may produce favourable effects on improvement of skin sclerosis and pulmonary function compared with unmanipulated auto-HSCT. Use of CD34-selected auto-HSCT with high-dose cyclophosphamide monotherapy as a conditioning regimen may offer an excellent benefit-to-risk balance