Normal Hematopoietic Progenitor Subsets Have Distinct Reactive Oxygen Species, BCL2 and Cell-Cycle Profiles That Are Decoupled from Maturation in Acute Myeloid Leukemia.

In acute myeloid leukemia (AML) quiescence and low oxidative state, linked to BCL2 mitochondrial regulation, endow leukemic stem cells (LSC) with treatment-resistance. LSC in CD34+ and more mature CD34- AML have heterogeneous immunophenotypes overlapping with normal stem/progenitor cells (SPC) but may be differentiated by functional markers. We therefore investigated the oxidative/reactive oxygen species (ROS) profile, its relationship with cell-cycle/BCL2 for normal SPC, and whether altered in AML and myelodysplasia (MDS). In control BM (n = 24), ROS levels were highest in granulocyte-macrophage progenitors (GMP) and CD34- myeloid precursors but megakaryocyte-erythroid progenitors had equivalent levels to CD34+CD38low immature-SPC although they were ki67high. BCL2 upregulation was specific to GMPs. This profile was also observed for CD34+SPC in MDS-without-excess-blasts (MDS-noEB, n = 12). Erythroid CD34- precursors were, however, abnormally ROS-high in MDS-noEB, potentially linking oxidative stress to cell loss. In pre-treatment AML (n = 93) and MDS-with-excess-blasts (MDS-RAEB) (n = 14), immunophenotypic mature-SPC had similar ROS levels to co-existing immature-SPC. However ROS levels varied between AMLs; Flt3ITD+/NPM1wild-type CD34+SPC had higher ROS than NPM1mutated CD34+ or CD34- SPC. An aberrant ki67lowBCL2high immunophenotype was observed in CD34+AML (most prominent in Flt3ITD AMLs) but also in CD34- AMLs and MDS-RAEB, suggesting a shared redox/pro-survival adaptation. Some patients had BCL2 overexpression in CD34+ ROS-high as well as ROS-low fractions which may be indicative of poor early response to standard chemotherapy. Thus normal SPC subsets have distinct ROS, cell-cycle, BCL2 profiles that in AML /MDS-RAEB are decoupled from maturation. The combined profile of these functional properties in AML subpopulations may be relevant to differential treatment resistance.

Physical activity in adults with cystic fibrosis receiving intravenous antibiotics in hospital and in the community.

INTRODUCTION: Intravenous antibiotic therapy (IVAT) for CF acute pulmonary exacerbations (APE) can be delivered in hospital or in the community. This study aimed to compare physical activity in CF patients receiving hospital and community-delivered IVAT, as well as other health outcomes. MATERIALS AND METHODS: This was a non-randomised parallel group prospective observational study. Hospitalised and community-treated CF adults receiving IVAT for APE were asked to wear ActiGraph® activity monitors, complete the habitual activity estimation scale (HAES), food diary, modified shuttle test (MST) and CFQ-R at the start and end of therapy. Nutritional and clinical outcomes were also compared between the cohorts. The primary outcomes was physical activity measured by the ActiGraph® activity monitors at the beginning and end of treatment in both cohorts. RESULTS: Physical activity (measured and self-reported) was no different between the cohorts, with both hospitalised and community-treated subjects being generally sedentary. Body weight increased significantly in the hospitalised cohort, whereas no difference was seen in the community-treated cohort. FEV1 % predicted and FVC % predicted increased in community-treated subjects, whereas only FVC % predicted increased in hospitalised subjects. CFQ-R respiratory domain increased to a greater extent in community-treated subjects. CONCLUSION: CF adults receiving IVAT for APE, both in hospital and in the community, are generally sedentary and we found no difference in physical activity between the two groups. These findings suggests the need to further promote physical activity in suitable patients during APE where considered appropriate.