flow-cytometry-to-estimate-leukemia-stem-cells-primary-acute-myeloid

Flow Cytometry to Estimate Leukemia Stem Cells in Primary Acute Myeloid Leukemia and in Patient-derived-xenografts, at Diagnosis and Follow Up

Acute myeloid leukemia (AML) is a heterogeneous, and if not treated, fatal disease. It is the most common cause of leukemia-associated mortality in ...

Univ. Lille, Inserm, CHU Lille, UMR-S 1172 - JPArc - Centre de Recherche Jean-Pierre AUBERT Neurosciences et Cancer

CHU Lille

Antifungal prophylaxis (AP) has dramatically changed the epidemiology of invasive aspergillosis (IA). To better understand the differences in terms of clinical significance of IA between allogeneic stem cell transplantation (allo-SCT) recipients and patients treated for leukemia, we report a single-center study of 735 unselected consecutive patients treated between 2000 and 2004, before the era of systematic AP. Probable or confirmed IA were observed in 29 patients (2008 EORTC/MSG criteria), including 7/235 undergoing allo-SCT (5.2%), 19/380 treated for acute leukemia (5.0%), 1/116 for chronic lymphocytic leukemia (0.9%) and 2/104 for myelodysplastic syndrome (1.9%). In allo-SCT recipients, IA occurred later than in leukemia patients, after the neutropenic period. The median time between the last treatment and the diagnosis of IA was 231 days (range, 68-341) in allo-SCT recipients and 17 days (6-57) in leukemia patients (P<0.001). Importantly, the 7 cases of IA after allo- SCT occurred only in patients treated with corticosteroids for graft-versus-host disease (GVHD). Mortality directly related to IA was 24%. The 100-day, 2-year and 10-year overall survival were 42.9%, 0%, 0% in allo-SCT recipients compared to 68.1%, 18.2%, 13.6% in leukemia patients, respectively (P≥0.05). These poor outcomes were mainly attributable to non-relapse mortality (NRM). In conclusion, our data allows distinguishing 2 types of IA occurring at different time in the treatment course. In both cases, the NRM is very high and treatment remains challenging. Thus, systematic broad-spectrum AP against Aspergillus should be considered in acute leukemia patients during the neutropenic phase and in all patients undergoing allo-SCT who develop GVHD.

Long-term follow up of invasive aspergillosis in allogeneic stem cell transplantation recipients and leukemia patients: Differences in risk factors and outcomes.

The characterization of protein interactions has become essential in many fields of life science, especially drug discovery. Microscale thermophoresis (MST) is a powerful new method for the quantitative analysis of protein-protein interactions (PPIs) with low sample consumption. In addition, one of the major advantages of this technique is that no tedious purification step is necessary to access the protein of interest. Here, we describe a protocol using MST to determine the binding affinity of the PD-1/PD-L1 couple, which is involved in tumour escape processes, without purification of the target protein from cell lysates. The method requires the overexpression of fluorescent proteins in CHO-K1 cells and describes the optimal conditions for determining the dissociation constant. The protocol has a variety of potential applications in studying the interactions of these proteins with small molecules and demonstrates that MST is a valuable method for studying the PD-1/PD-L1 pathway.

Bruno Quesnel

Univ. Lille, Inserm, CHU Lille, UMR-S 1172 - JPArc - Centre de Recherche Jean-Pierre AUBERT Neurosciences et Cancer

Flow Cytometry to Estimate Leukemia Stem Cells in Primary Acute Myeloid Leukemia and in Patient-derived-xenografts, at Diagnosis and Follow Up