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Neoplasms involving plasmacytoid dendritic cells (pDC) include blastic pDC neoplasms (BPDCN) and other pDC proliferations, where pDC are associated with myeloid malignancies: most frequently chronic myelomonocytic leukemia (CMML) but also acute myeloid leukemia (AML), hereafter named pDC-AML. We aimed to determine the reactive or neoplastic origin of pDC in pDC-AML, and their link with the CD34+ blasts, monocytes or conventional DC (cDC) associated in the same sample, by phenotypic and molecular analyses (targeted next-generation sequencing, 70 genes). We compared 15 pDCAML at diagnosis with 21 BPDCN and 11 normal pDC from healthy donors. CD45low CD34+ blasts were found in all cases (10-80% of medullar cells), associated with pDC (4-36%), monocytes in 14 cases (1-10%) and cDC (two cases, 4.8-19%). pDC in pDC-AML harbor a clearly different phenotype from BPDCN: CD4+ CD56– in 100% of cases, most frequently CD303+, CD304+ and CD34+; lower expression of cTCL1 and CD123 with isolated lymphoid markers (CD22/CD7/CD5) in some cases, suggesting a prepDC stage. In all cases, pDC, monocytes and cDC are neoplastic since they harbor the same mutations as CD34+ blasts. RUNX1 is the most commonly mutated gene: detected in all AML with minimal differentiation (M0-AML) but not in the other cases. Despite the low number of cases, the systematic association between M0-AML, RUNX1 mutations and an excess of pDC is puzzling. Further evaluation in a larger cohort is required to confirm RUNX1 mutations in pDC-AML with minimal differentiation and to investigate whether it represents a proliferation of blasts with macrophage and DC progenitor potential.

Acute graft-versus-host disease (aGvHD) is an unpredictable immunological complication that affects the skin, gut, or liver following allogeneic hematopoietic cell transplantation (HCT). Donor Th1 cells can initiate aGvHD after recognition of recipient alloantigens and migration to target tissues via homing receptors.1 Paradoxically, experiments in animal models of transplantation suggest that deficiency of the inflammatory Th1 cytokine IFN-γ can exacerbate aGvHD severity and mortality.2,3 Investigators have interpreted these results to mean that other cell types are capable of generating aGvHD or that loss of a protective function related to IFN-γ was responsible for the intensified alloreactivity observed in these animal models.

Treatment of acute myeloid leukemia (AML) is generally dictated by the patient’s age and performance status and the biological, genetic, and molecular characteristics of the disease.[1][1] Specific cytogenetic alterations divide AML classification into three risk-based categories: favorable

The role of reduced intensity allogeneic stem cell transplantation for the treatment of relapsed/refractory Hodgkin’s lymphoma remains controversial. We retrospectively analyzed 191 patients who underwent reduced intensity allogeneic stem cell transplantation between 1998 and 2008 for relapsed or refractory Hodgkin’s lymphoma and whose data were reported to the French registry. The median follow-up was 36 months. The estimated 3-year overall survival rate, progression-free survival rate, cumulative incidence of relapse and cumulative incidence of non-relapse mortality were 63%, 39%, 46%, and 16%, respectively. There was no difference in outcome between patients in complete response and in partial response at the time of transplantation with regards to overall survival (70% versus 74%, no significant difference) and progression-free survival (51% versus 42%, no significant difference). Patients with chemoresistant disease had a shorter overall survival (39% at 3 years; P=0.0003) and progression-free survival (18% at 3 years; P=0.001) than patients in complete remission. The use of umbilical cord blood as the source of stem cells was associated with a poor outcome with an increased risk of death with a hazard ratio of 3.49 (95% confidence interval: 1.26 to 9.63; P=0.016). The use of peripheral blood was associated with a better outcome for patients who where alive 1 year after transplantation with a hazard ratio of 0.38 (95% confidence interval: 0.17 to 0.83; P=0.016). Disease status at transplantation remains the most important risk factor for outcome. Our data suggest that the use of peripheral blood should be preferred whereas umbilical cord blood should be used with caution.

Recent studies have suggested that plasma-derived proteins may be potential biomarkers relevant for graft-versus-host disease and/or non-relapse mortality occurring after allogeneic blood or marrow transplantation. However, none of these putative biomarkers have been assessed in patients treated either with human leukocyte antigen-haploidentical blood or marrow transplantation or with post-transplantation cyclophosphamide, which has been repeatedly associated with low rates of severe acute graft-versus-host disease, chronic graft-versus-host disease, and non-relapse mortality. We explored whether seven of these plasma-derived proteins, as measured by enzyme-linked immunosorbent assays, were predictive of clinical outcomes in post-transplantation cyclophosphamide-treated patients using plasma samples collected at serial predetermined timepoints from patients treated on prospective clinical studies of human leukocyte antigen-haploidentical (n=58; clinicaltrials.gov Identifier: 00796562) or human leukocyte antigen-matched-related or -unrelated (n=100; clinicaltrials.gov Identifiers: 00134017 and 00809276) T-cell-replete bone marrow transplantation. Day 30 levels of interleukin-2 receptor α, tumor necrosis factor receptor 1, serum STimulation-2 (IL1RL1 gene product), and regenerating islet-derived 3-α all had high areas under the curve of 0.74-0.97 for predicting non-relapse mortality occurrence by 3 months post-transplant in both the human leukocyte antigen-matched and human leukocyte antigen-haploidentical cohorts. In both cohorts, all four of these proteins were also predictive of subsequent non-relapse mortality occurring by 6, 9, or 12 months post-transplant and were significantly associated with non-relapse mortality in univariable analyses. Furthermore, day 30 elevations of interleukin-2 receptor α were associated with grade II-IV and III-IV acute graft-versus-host disease occurring after day 30 in both cohorts. These data confirm that plasma-derived proteins previously assessed in other transplantation platforms appear to retain prognostic and predictive utility in patients treated with post-transplantation cyclophosphamide.