Key Points• T SCM are abundant early after allogeneic hematopoietic stem cell transplantation and derive from naive T cells that survived pt-Cy.• Pt-Cy allows the generation of donor primary and recall responses in transplanted patients, even in the presence of persistent antigen.Early T-cell reconstitution following allogeneic transplantation depends on the persistence and function of T cells that are adoptively transferred with the graft. Posttransplant cyclophosphamide (pt-Cy) effectively prevents alloreactive responses from unmanipulated grafts, but its effect on subsequent immune reconstitution remains undetermined.Here, we show that T memory stem cells (T SCM ), which demonstrated superior reconstitution capacity in preclinical models, are the most abundant circulating T-cell population in the early days following haploidentical transplantation combined with pt-Cy and precede the expansion of effector cells. Transferred naive, but not T SCM or conventional memory cells preferentially survive cyclophosphamide, thus suggesting that posttransplant T SCM originate from naive precursors. Moreover, donor naive T cells specific for exogenous and self/tumor antigens persist in the host and contribute to peripheral reconstitution by differentiating into effectors. Similarly, pathogen-specific memory T cells generate detectable recall responses, but only in the presence of the cognate antigen. We thus define the cellular basis of T-cell reconstitution following pt-Cy at the antigen-specific level and propose to explore naive-derived T SCM in the clinical setting to overcome immunodeficiency. These trials were registered at www.clinicaltrials.gov as #NCT02049424 and #NCT02049580. (Blood. 2015;125(18):2855-2864
Twenty-six patients with advanced Hodgkin's disease received a related HLA haploidentical unmanipulated BMT, following a nonmyeloablative conditioning with low-dose TBI, proposed by the Baltimore group; GvHD prophylaxis consisted of high-dose posttransplantation CY (PT-CY), mycophenolate and a calcineurin inhibitor. All patients had received a previous autograft, and 65% had active disease at the time of BMT. Sustained engraftment of donor cells occurred in 25 patients (96%), with a median time to neutrophil recovery (40.5 Â 10 9 /L) and platelet recovery (420 Â 10 9 /L) of þ 18 and þ 23 days from BMT. The incidence of grade II-IV acute GVHD and of chronic GVHD was 24% and 8%, respectively. With a median follow-up of 24 months (range 18-44) 21 patients are alive, 20 disease free. The cumulative incidence of TRM and relapse was 4% and 31%, respectively. The actuarial 3-year survival is 77%, the actuarial 3-year PFS is 63%. In conclusion, we confirm that high-dose PT-CY is effective as prophylaxis of GVHD after HLA haploidentical BMT, can prevent rejection and does not appear to eliminate the allogeneic graft versus lymphoma effect.
Natural killer cells are the first lymphocyte population to reconstitute early after non-myeloablative and T cell-replete haploidentical hematopoietic stem cell transplantation with post-transplant infusion of cyclophosphamide. The study herein characterizes the transient and predominant expansion starting from the second week following haploidentical hematopoietic stem cell transplantation of a donor-derived unconventional subset of NKp46neg-low/CD56dim/CD16neg natural killer cells expressing remarkably high levels of CD94/NKG2A. Both transcription and phenotypic profiles indicated that unconventional NKp46neg-low/CD56dim/CD16neg cells are a distinct natural killer cell subpopulation with features of late stage differentiation, yet retaining proliferative capability and functional plasticity to generate conventional NKp46pos/CD56bright/CD16neg-low cells in response to interleukin-15 plus interleukin-18. While present at low frequency in healthy donors, unconventional NKp46neg-low/CD56dim/CD16neg cells are greatly expanded in the seven weeks following haploidentical hematopoietic stem cell transplantation, and express high levels of the activating receptors NKG2D and NKp30 as well as of the lytic granules Granzyme-B and Perforin. Nonetheless, NKp46neg-low/CD56dim/CD16neg cells displayed a markedly defective cytotoxicity that could be reversed by blocking the inhibitory receptor CD94/NKG2A. These data open new and important perspectives to better understand the ontogenesis/homeostasis of human natural killer cells and to develop a novel immune-therapeutic approach that targets the inhibitory NKG2A check-point, thus unleashing natural killer cell alloreactivity early after haploidentical hematopoietic stem cell transplantation.
When citing, please refer to the published version.Link to this full text: http://hdl.handle.net/ Allogeneic hematopoietic stem cell transplantation in patients with diffuse large B cell lymphoma relapsed after autologous stem cell transplantation: A GITMO study
AbstractPatients who relapse after an autologous hematopoietic stem cell transplantation (SCT) have a very poor prognosis. We have retrospectively analyzed diffuse large B cell lymphoma patients who underwent an allo-SCT after an auto-SCT relapse reported in the Gruppo Italiano Trapianto di Midollo Osseo (GITMO) database. From 1995 to 2008, 3449 autologous transplants were reported in the GITMO database. Eight hundred eighty-four patients relapsed or progressed after transplant; 165 patients, 19% of the relapsed patients, were treated with allo-transplant. The stem cell donor was related to the patient in 108 cases. A reduced intensity conditioning regimen was used in 116. After allo-SCT, 72 patients (43%) obtained a complete response and 9 obtained a partial response with an overall response rate of 49%; 84 patients (51%) experienced rapid progression of disease. Ninety-one patients died, 45 due to disease and 46 due to treatment-related mortality. Acute graftversus-host disease was recorded in 57 patients and a chronic GvHD in 38 patients. With a median follow-up of 24 months (2-144) after allo, overall survival (OS) was 39%, and after a median of 21 months (2-138) after allo, progression-free survival (PFS) was 32%. Multivariate analysis indicated that the only factors affecting OS were status at allo-SCT, and those affecting PFS were status at allo-SCT and stem cell donor. This retrospective analysis shows that about one-fifth of patients with diffuse large B cell lymphoma who experience relapse after autologous transplantation may be treated with allogeneic transplantation. Moreover, the only parameter affecting either OS or PFS was the response status at the time of allo-SCT.
KeywordsDiffuse large B cell lymphomaSalvage therapyAutologous stem cell transplantationAllogeneic stem cell transplantationReduced intensity conditioning regimenGraft versus lymphoma
Summary
This retrospective study evaluated whether early 2‐[fluorine‐18]fluoro‐2‐deoxy‐D‐glucose positron emission tomography (FDG‐PET) after two cycles of salvage chemotherapy (PET2) could predict survival after high‐dose chemotherapy (HDC). Twenty‐four Hodgkin lymphoma (HL) patients were included. PET2 was negative in 58% and positive in 42% of patients. Ninety per cent of patients (9/10) with positive PET2 relapsed after HDC while all but one patient with negative PET2 maintained a complete remission. The 2‐year progression‐free survival was 93% vs. 10% for patients with negative and positive PET2, respectively (P < 0.001). This study shows that interim PET can predict the outcome after high‐dose chemotherapy in HL patients.
Thrombotic and haemorrhagic complications are the main causes of morbidity in Essential Thrombocythemia (ET). We investigated the clinical and laboratory characteristics associated with the occurrence of these events with the aim of identifying subgroups of patients who might benefit from anti-aggregant and/or cytoreductive therapy. The study involved 306 consecutive ET patients (median age 58 years and median follow-up 96 months); the investigated variables were age, gender, platelet count, previous history of thrombotic or haemorrhagic events, disease duration and cardiovascular risk factors. Forty-six patients (15%) experienced thrombotic complications during the follow-up: 26/64 patients with a previous history of thrombosis (40.6%) and 20/242 patients without (8.3%; p < 0.0001). Thirty-one patients (10%) experienced major haemorrhagic complications, mainly gastrointestinal tract bleeding: 3 with and 28 without a history of haemorrhagic events (p = 0.052). When the patients with a negative history of thrombosis were stratified on the basis of the number of cardiovascular risk factors (none vs. one vs. more than one), there was a significant correlation with the occurrence of thrombotic events (p < 0.05). ET patients with a positive history of thrombosis are at high risk of thrombotic complications, and should receive cytoreductive and anti-aggregant treatment. Asymptomatic patients with a negative thrombotic history and no cardiovascular risk factors are at low risk, and should not be treated. Patients with a negative thrombotic history and one or more cardiovascular risk factors are at intermediate risk, and should be treated with anti-aggregant and/or cytoreductive therapy. The need for treatment should be periodically re-evaluated. Age and platelet count, generally accepted as very important risk factors for thrombosis, did not seem in our series associated with an increased risk for thrombosis.
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