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Simple Summary: Relapse following allogeneic hematopoietic stem cell transplantation (alloHSCT) for acute myeloid leukemia (AML) is the main reason for treatment failure. Most relapses occur during the first six months. We have observed in recent years that some patients relapse late, beyond 2 years after allograft. We sought to evaluate the frequency and the risk factors associated with these late relapses. We observed that these late relapses affect a significant number of patients, that the absence of chronic GvHD is more often associated. In addition, the intensity of the conditioning regimen does not seem to play a role and it is possible to re-treat successfully these patients. We conclude that prolonged monitoring after alloHSCT for AML is recommended. Late relapse, beyond 2 years following alloHSCT for AML, is rare. Among the 376 patients allografted for AML in our center between 1990 and 2016, 142 (38%) relapsed. The majority (68%) of relapses occurred during the first year following transplantation. Beyond 2 years after alloHSCT, relapse was observed in 26 patients, representing 6.9% of the whole transplanted cohort and 18.3% of the relapsing patients. Cytogenetics at relapse was available in 21 patients and remained for 15 of them concordant to that at diagnosis. The majority (85.7%) of the patients were in CR prior to transplant. Thirteen patients had grade 1–2 acute GvHD, while 13 other patients had grade 3–4 acute GvHD. None of these patients subsequently developed chronic GvHD. In multivariate analyses, a predictive factor of the absence of relapse 2 years after transplantation was the development of extensive chronic GVHD. Salvage therapy achieved new CR in 77% of these patients. We conclude that late relapse can affect a significant minority of patients allografted for AML, and the intensity of the conditioning regimen does not seem to have an impact on these relapses. Moreover, we were able to show that those patients can receive effective salvage therapy. [ABSTRACT FROM AUTHOR]

Our main objective was to determine new factors associated with engraftment and single-unit predominance after double umbilical cord blood (UCB) allogeneic stem-cell transplantation. Engraftment occurred in 78% of cases in this retrospective study including 77 adult patients. Three-year overall survival, disease-free survival, relapse incidence, and nonrelapse mortality were 55 ± 6%, 44 ± 6%, 33 ± 5%, and 23 ± 4%, respectively. In multivariate analysis, Human herpesvirus 6 reactivation during aplasia (hazard ratio [HR] = 2.63; 95% confidence interval [CI]: 1.64–4.17; p < 0.001), younger recipient age (<53 years) (HR = 1.97; 95% CI: 1.16–3.35; p = 0.012), and lower human leukocyte antigen matching between the two units (3 of 6 or 4 of 6) (HR = 2.09; 95% confidence interval: 1.22–3.59; p = 0.013) were the three factors independently associated with graft failure. Also, factors independently predicting the losing UCB unit were younger age of the UCB unit (odds ratio [OR] = 1.01; 95% CI: 1–1.02; p = 0.035), lower CD34 + cell dose contained in the UCB unit (≤0.8 × 10 5 /kg) (OR = 2.55; 95% CI: 1.05–6.16; p = 0.04), and presence of an ABO incompatibility between the UCB unit and the recipient (OR = 2.53; 95% CI: 1.15–5.53; p = 0.02). Thus, Human herpesvirus 6 reactivation during aplasia, lower unit-unit human leukocyte antigen matching, and younger UCB unit age, as new unfavorable predictive factors, may represent new parameters to take into account after double UCB allogeneic stem-cell transplantation in adults. These results need to be confirmed prospectively, as they may influence unit selections and patient outcomes. [ABSTRACT FROM AUTHOR]

Higher incidence of human herpesvirus 6 (HHV-6) infection has been documented after umbilical cord blood allo-transplant in adults. Here we demonstrate that HHV-6 reactivation persists for a very long time in half of the patients after this type of graft. Long-term immune reconstitution does not explain this event, which remains to be explained. [ABSTRACT FROM PUBLISHER]

Allogeneic stem cell transplantation (allo-SCT) represents the most beneficial treatment for patients with active relapsed/refractory (R/R) hematologic malignancies. Recently, sequential regimens combining debulking chemotherapy followed by reduced-intensity conditioning (RIC) have shown encouraging results for these patients. In this retrospective study, we report the extended results of a sequential regimen of clofarabine, cytosine arabinoside, and RIC in 131 adults with active R/R myeloid disease at transplant. Conditioning consisted of clofarabine (30 mg/m2/day) and cytosine arabinoside (1 g/m2/day) for 5 days, followed, after a rest of 3 days, by an RIC combining cyclophosphamide (60 mg/kg) for 1 day, iv busulfan (3.2 mg/kg/day) for 2 days, and anti-thymocyte globulin (2.5 mg/kg/day) for 2 days. Between 2007 and 2016, 131 patients (males n = 75, median age: 52.6 years) were identified from the SFGM-TC registry. There were 111 acute myeloid leukemia (AML) patients and 20 cases with myelodysplastic or myeloproliferative syndrome. Status at transplant was known for all but 4 patients and was primary refractory (n = 81) and 1st or 2nd relapse (n = 46). All patients received allo-SCT from a matched donor (sibling n = 64, unrelated n = 67). Engraftment was observed in 105/122 (86%) evaluable cases and 63% of the patients achieved complete remission (CR) after transplant. The 1-year overall survival, disease-free survival, relapse incidence, non-relapse mortality, and graft-versus-host disease-free/relapse-free survival were 39.2%, 28.1%, 41.0%, 30.8%, and 22.2%, respectively. This study confirms that this sequential clofarabine-based regimen provides a high CR rate in this critical population, although relapse remains a matter of concern. [ABSTRACT FROM AUTHOR]

We studied the impact of a set of immune cells contained within granulocyte colonystimulating factor-mobilized peripheral blood stem cell grafts (naïve and memory T-cell subsets, B cells, regulatory T cells, invariant natural killer T cells [iNKTs], NK cells, and dendritic cell subsets) in patients (n = 80) undergoing allogeneic stem cell transplantation (SCT), using the composite end point of graft-versus-host disease (GVHD)-free and progression-free survival (GPFS) as the primary end point. We observed that GPFS incidences in patients receiving iNKT doses above and below the median were 49% vs 22%, respectively (P=.007). In multivariate analysis, the iNKT dose was the only parameter with a significant impact on GPFS (hazard ratio50.48; 95% confidence interval, 0.27-0.85; P=.01). The incidences of severe grade III to IV acuteGVHD and National Institutes of Health grade 2 to 3 chronic GVHD (12% and 16%, respectively) were low and associated with the use of antithymocyte globulin in 91% of patients. No difference in GVHD incidence was reported according to the iNKT dose. In conclusion, a higher dose of iNKTs within the graft is associated with an improved GPFS. These data may pave the way for prospective and active interventions aiming to manipulate the graft content to improve allo-SCT outcome. (Blood. 2016;127(14):1828-1835) [ABSTRACT FROM AUTHOR]

Unrelated umbilical cord blood (UCB) is being increasingly used as an alternative stem cell source for allogeneic stem cell transplantation (allo-SCT). This retrospective study assessed infectious complications occurring in adult patients after UCB transplantation (UCBT). 31 patients received a single (n=4) or double UCBT (n=27) with a median dose of 4.7×107 nucleated cells/kg (range: 2.4-7.7). Patients received either a reduced-intensity conditioning (RIC; n=23) or a standard myeloablative (MA) regimen (n=8). The cumulative incidence of neutrophil recovery was 90%. Neutrophil recovery was achieved at a median time of 24 (range: 8-60) days after UCBT. The cumulative incidences of bacterial, fungal, and parasitic infections were, respectively, 16%, 10%, and 6%. Bloodstream infections were neither lethal nor required any intensive care therapy. Similarly, invasive fungal infections and parasitic infections did not cause any death in those patients with sustained engraftment. Although the cumulative incidence of cytomegalovirus (CMV) recurrence was 21%, no CMV disease was observed. With a median follow-up of 10 (range: 3-30) months, 10 patients have died (relapse, n=5; nonrelapse mortality, [NRM] n=5). Overall, the cumulative incidence of infectious-related mortality (IRM) was 8%. In conclusion, this data suggests that UCBT can be performed in adult patients with hematologic malignancies with an acceptable incidence of IRM provided a sufficient dose of nucleated cells is infused to the patient. [Copyright &y& Elsevier]