Search

Posttransplant cyclophosphamide (PTCy) effectively prevents graft-versus-host disease (GVHD) after HLA-haploidentical hematopoietic stem cell transplantation (HSCT). The use of PTCy in HLA-identical HSCT is less explored. We conducted a retrospective study of 107 consecutive patients undergoing an HLA-identical sibling (10/10) HSCT in 2 centers in Spain, 50 with GVHD prophylaxis with methotrexate–cyclosporin A (MTX-CsA) and 57 using a PTCy-based regimen with additional immunosuppression. Graft source was unmanipulated mobilized peripheral blood stem cells (PBSC) in most patients (97 patients, 91%). Cumulative incidences of grade II to IV and III to IV acute GVHD at 100 days were lower in the PTCy group (22.6% vs 52.2%, P = .0015; 8.8% vs 24.4%, P = .016), without statistically significant differences in the 2-year cumulative incidence of chronic moderate to severe GVHD (16.7% vs 26%, P = .306). At 2 years, no statistically significant differences were observed in OS (78% vs 56%, P = .088), EFS (62.5% vs 48%, P = .054), relapse (28% vs 27%, P = .47), and NRM (8.8% vs 24%, P = .054). The composite endpoint of GVHD and relapse-free survival (GRFS) was favorable for the PTCy group (24% vs 48%, P = .011), PTCy being the sole independent factor identified in the multivariate analysis for this endpoint. In this study, PTCy combination with additional immunosuppression using mostly PBSCs grafts showed a reduction of acute GVHD rate and an impact on GRFS, with safety results comparable with those obtained with MTX-CsA. Further prospective studies are needed to confirm these observations..

Invasive fungal infections are one of the main infectious complications in allogeneic stem cell transplantation (SCT). Triazoles (voriconazole, posaconazole) are the main prophylactic and therapeutic options for the treatment of invasive aspergillosis. However, pharmacological interactions and hepatotoxicity limit its use. Isavuconazole (ISV) is a recently approved azole with a promising interaction and safety profile. We present a case with invasive aspergillosis in the post-allogeneic SCT setting in a critically ill patient with severe multiorgan failure due to veno-occlusive disease. The patient was treated with ISV and B amphotericin during severe kidney and liver failure and multiple immunosuppressants, without significant drug-related toxicity and with favorable outcome. The interaction and safety profile of ISV is discussed along the reported experience. ISV can be an effective salvage therapy even in complex clinical situations with multiple potential interactions.

Background Drug–drug interactions (DDIs) that involve antiretrovirals (ARVs) tend to cause harm if unrecognized, especially in the context of comorbidity and polypharmacy. Methods A linkage was established between the drug dispensing registry of Madrid and the Liverpool human immunodeficiency virus (HIV) DDI database (January 2017–June 2017). Polypharmacy was defined as the use of ≥5 non-HIV medications, and DDIs were classified by a traffic-light ranking for severity. Results A total of 22 945 people living with HIV (PLWH) and 6 613 506 individuals without HIV had received medications. ARV regimens were predominantly based on integrase inhibitors (51.96%). Polypharmacy was higher in PLWH (32.94%) than individuals without HIV (22.16%; P < .001); this difference was consistently observed across all age strata except for individuals ≥75 years. Polypharmacy was more common in women than men in both PLWH and individuals without HIV. The prevalence of contraindicated combinations involving ARVs was 3.18%. Comedications containing corticosteroids, quetiapine, or antithrombotic agents were associated with the highest risk for red-flag DDI, and the use of raltegravir- or dolutegravir-based antiretroviral therapy was associated with an adjusted odds ratio of 0.72 (95% confidence interval, .60–.88; P = .001) for red-flag DDI. Conclusions Polypharmacy was more frequent among PLWH across all age groups except those aged ≥75 years and was more common in women. The detection of contraindicated medications in PLWH suggests a likely disconnect between hospital and community prescriptions. Switching to alternative unboosted integrase regimens should be considered for patients with risk of harm from DDIs.

Development of de novo hematologic malignancies in donor cells after allogeneic stem cell transplantation (allo-SCT) provides a useful in vivo model to study the process of leukemogenesis. A systematic analysis of the cases reported in the literature was performed to identify risk factors and mechanisms involved in the pathogenesis of donor cell–derived hematologic neoplasms (DCHN) and leukemogenic transformation. Relevant data were extracted from 137 cases. Cases of DCHN show a wide heterogeneity with regard to recipient/donor age, sex mismatch, and conditioning regimen. Some characteristics, such as the type of primary disease, the type of hematologic malignancy of the DCHN, and the stem cell source used in the transplant procedure, differ from those expected. Mechanisms involved in the pathogenesis of DCHN are complex, and several hypotheses have been proposed, such as pre-existing hematologic neoplasms or premalignant clones in the donor, decreased immune surveillance, and damage to bone marrow microenvironment in the recipient. Most likely several if not all these mechanisms play a role in DCHN development. Novel approaches, such as next-generation sequencing to study consecutive samples after allo-SCT in these patients, appear to be promising to decipher the mechanisms of leukemogenesis.

BACKGROUND Development of de novo alloantibodies against recipient's red blood cell (RBC) antigens by engrafted donor's lymphocytes is a known phenomenon in the setting of allogeneic hematopoietic stem cell transplantation (HSCT). This situation is usually clinically insignificant. We report a case of early clinically relevant hemolytic anemia in a blood group A1 D+ patient, due to a limited production of anti-D and anti-A1 produced by nonpreviously sensitized newly engrafted donor's immune system. CASE REPORT A 31-year-old Caucasian woman, blood group A1, D+, with Hodgkin's lymphoma, received an unmanipulated haploidentical allogeneic peripheral blood HSCT after a nonmyeloablative conditioning regimen. Donor blood group was A2B, D–. The patient had an uneventful course until Day +34, when she developed clinically significant hemolytic anemia with a positive direct antiglobulin test. Anti-D and anti-A1 produced by the donor-engrafted lymphocytes were detected both in serum and in eluate. The hemolysis produced an accelerated group change, turning the patient's ABO group into A2B 2 weeks after the detection of the alloantibodies. As the residual patient's RBCs progressively disappeared, anti-D and anti-A1 production decreased and were not detected in serum by Day +41. CONCLUSION This case illustrates that de novo alloantibody production against ABO and D antigens by the newly engrafted donor's lymphocytes can occasionally cause clinically significant anemia. To our knowledge, this is the first case reported of clinically significant hemolytic anemia due to a transient anti-D anti-A1 alloimmunization after T-cell-repleted haploidentical HSCT.

International audience; Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the only medical intervention that has led to an HIV cure. Whereas the HIV reservoir sharply decreases after allo-HSCT, the dynamics of the T cell reconstitution has not been comprehensively described. We analyzed the activation and differentiation of CD4+ and CD8+ T cells, and the breadth and quality of HIV- and CMV-specific CD8+ T cell responses in 16 patients with HIV who underwent allo-HSCT (including five individuals who received cells from CCR5Δ32/Δ32 donors) to treat their underlying hematological malignancy and who remained on antiretroviral therapy (ART). We found that reconstitution of the T cell compartment after allo-HSCT was slow and heterogeneous with an initial expansion of activated CD4+ T cells that preceded the expansion of CD8+ T cells. Although HIV-specific CD8+ T cells disappeared immediately after allo-HSCT, weak HIV-specific CD8+ T cell responses were detectable several weeks after transplant and could still be detected at the time of full T cell chimerism, indicating that de novo priming, and hence antigen exposure, occurred during the time of T cell expansion. These HIV-specific T cells had limited functionality compared with CMV-specific CD8+ T cells and persisted years after allo-HSCT. In conclusion, immune reconstitution was slow, heterogeneous, and incomplete and coincided with de novo detection of weak HIV-specific T cell responses. The initial short phase of high T cell activation, in which HIV antigens were present, may constitute a window of vulnerability for the reseeding of viral reservoirs, emphasizing the importance of maintaining ART directly after allo-HSCT.

Molecular diagnosis of myeloid neoplasms (MN) is based on the detection of multiple genetic alterations using various techniques. Next-generation sequencing (NGS) has been proved as a useful method for analyzing many genes simultaneously. In this context, we analyzed diagnostic samples from 121 patients affected by MN and ten relapse samples from a subset of acute myeloid leukemia patients using two enrichment-capture NGS gene panels. Pathogenicity classification of variants was enhanced by the development and application of a custom onco-hematology score. A total of 278 pathogenic variants were detected in 84% of patients. For structural alterations, 82% of those identified by cytogenetics were detected by NGS, 25 of 31 copy number variants and three out of three translocations. The detection of variants using NGS changed the diagnosis of seven patients and the prognosis of 15 patients and enabled us to identify 44 suitable candidates for clinical trials. Regarding AML, six of the ten relapsed patients lost or gained variants, comparing with diagnostic samples. In conclusion, the use of NGS panels in MN improves genetic characterization of the disease compared with conventional methods, thus demonstrating its potential clinical utility in routine clinical testing. This approach leads to better-adjusted treatments for each patient.

Autologous hematopoietic stem cell transplantation (ASCT) is a well-established treatment strategy in HIV-related lymphoma patients (HIV+ Ly). Nevertheless, current evidence is mainly based on reports from specialized centers, multicentre heterogeneous studies, noncomparative analyses, or registry data-based comparisons. Likewise, the risk of infections reported so far for this population, seems to be similar to that of HIV- patients, and it does not seem to impact on mortality. We report a single-center retrospective comparative analysis of AHCT procedural results, infectious complications and survival in HIV+ Ly matched with a non-HIV comparative cohort. Thirty-three HIV+ patients and 45 matched controls, who underwent ASCT between 2000 and 2016, were included. Transplant-related toxicity, event-free survival, relapse rate, and overall survival were similar in both groups. Engraftment was delayed in HIV+ Ly (neutrophils: 15 vs 12 days (p = 0.0001), and platelets 39 vs 16 days (p = 0.00001)). Bacterial infections during the pre-engraftment period were more frequent in HIV+ Ly (RR 2.24, p = 0.017), as well as viral infections in the postengraftment period (RR 3.22, p = 0.004). CMV reactivation was more frequent in HIV+ Ly (39% vs 15% p = 0.007). In conclusion, ASCT is viable and effective in HIV+ Ly, but it is associated with a higher risk of infection.

The present study aimed at describing the outcome of patients with HIV-associated lymphomas following autologous hematopoietic stem cell transplantation (autoHCT) in the rituximab and combined antiretroviral therapy (cART) era. Eligible for this retrospective study were HIV-positive patients with lymphoma who received autoHCT between 2007 and 2013. A total of 118 patients were included with a median age of 45 years (range 24-66). Underlying diagnoses were diffuse large B cell lymphoma in 47%, Hodgkin lymphoma in 24%, Burkitt lymphoma in 18%, and plasmablastic lymphoma in 7% of patients. Disease status at autoHCT was complete remission in 44%, partial remission (PR) in 38%, and less than PR in 18% of the patients. With a median follow-up of 4 years, 3-year non-relapse mortality, incidence of relapse, progression-free survival (PFS) and overall survival (OS) were 10%, 27%, 63% and 66%, respectively. By multivariate analysis, disease status less than PR but not CD4+ cell count at the time of autoHCT was a significant predictor of unfavorable PFS and OS. In conclusion, in the era of cART and chemoimmunotherapy, the outcome of autoHCT for HIV-related lymphoma is driven by lymphoma-dependent risk factors rather than by characteristics of the HIV infection.

BackgroundHigh-risk acute leukemia (AL) and myelodysplastic syndrome (MDS) remain a therapeutic challenge. Unmanipulated haploidentical-related donor transplantation based on a myeloablative conditioning regimen (HAPLO-MAC) and post-transplant cyclophosphamide (PT-Cy) as prophylaxis against graft vs host disease (GvHD) is now a promising rescue strategy that could become universally available. ObjectiveTo evaluate the results of HAPLO-MAC with PT-Cy in patients with AL and MDS reported to the Haploidentical Transplantation Subcommittee of the Spanish Group for Hematopoietic Transplantation (GETH). Patients and methodsWe report our multicenter experience using an IV busulfan-based HAPLO-MAC regimen and PT-Cy for treatment of 65 adults with high-risk AL and MDS. ResultsEngraftment was recorded in 64 patients (98.5%), with a median time to neutrophil and platelet recovery of 16 and 27days, respectively. The cumulative incidence of grade II-IV acute GvHD and chronic GvHD was 28.6% and 27.5%, respectively. After a median follow-up of 31months for survivors, the cumulative incidence of non-relapse mortality and relapse at 2years was 18.8% and 25%, respectively. Estimated 30-month event-free survival and overall survival were 56% and 54.5%, respectively. ConclusionHAPLO-MAC comprising an IV busulfan-based conditioning regimen enabled long-term disease control with acceptable toxicity in high-risk AL and MDS.

Among the strategies to optimize engraftment of cord blood (CB) stem cell transplantation (SCT), single CB with the coinfusion of CD34+ stem cells from an HLA-mismatched auxiliary donor (haplo-cord) provides a valid alternative for adult patients without a suitable donor. A total of 132 high-risk adult patients with hematological malignancies from 3 Spanish institutions underwent myeloablative haplo-cord SCT. The median age was 37 years and median weight was 70 kg; 37% had active disease. The median number of postprocessing CB total nucleated and CD34+ cells was 2.4 × 107/kg (interquartile range [IQR], 1.8 to 2.9) and 1.4 × 105/kg (IQR, .9 to 2), respectively. Neutrophil engraftment occurred in a median of 11.5 days (IQR, 10.5 to 16.5) and platelet engraftment at 36 days (IQR, 25.5 to 77). Graft failure was 2% overall and only 9% for CB. Cumulative incidence of acute graft-versus-host disease (GHVD) grades II to IV was 21% and cumulative incidence of chronic GVHD was 21%. Median follow-up was 60 months (range, 3.5 to 163). Overall survival was 43.5%, event-free survival was 38.3%, nonrelapse mortality was 35%, and relapse was 20% at 5 years. Myeloablative haplo-cord SCT results in fast engraftment of neutrophils and platelets, low incidences of acute and chronic GVHD, and favorable long-term outcomes using single CB units with relatively low cell content. Moreover, CB cell dose had no impact on CB engraftment and survival in this study. Therefore, haplo-cord SCT expands donor availability while reducing CB cell dose requirements.

We retrospectively compared the clinical outcomes of adults with acute leukemia who received single-unit umbilical cord blood (UCB) transplantation (sUCBT) (n = 135) or stem cell transplant using coinfusion of a UCB graft with CD34+ cells from a third-party donor (Haplo-Cord) (n = 72) at different institutions within the Grupo Espanol de Trasplante Hematopoyetico. In multivariable analysis, patients in the Haplo-Cord group showed more rapid neutrophil (hazard ratio [HR], 2.3; 95% confidence interval [CI], 1.5-3.3; P < .001) and platelet recovery (HR, 1.6; 95% CI, 1.2-2.3; P = .015) and lower incidence of chronic graft-versus-host disease (GVHD) (relative risk, 0.5; 95% CI, 0.3-0.8; P = .01). Nonrelapse mortality, relapse, disease-free survival (DFS), and GVHD/relapse-free survival were similar in the 2 groups. Regarding disease-specific outcomes, DFS in both acute myeloid leukemia (AML) and acute lymphoblastic leukemia patients was not significantly different; however, a significantly higher relapse rate was found in patients with AML treated with Haplo-Cord (HR, 2.3; 95% CI, 1-5.4; P = .04). Our study confirms that Haplo-Cord was an effective strategy to accelerate neutrophil and platelet recovery and shows that, in the context of specific treatment platforms, sUCBT and Haplo-Cord offer similar long-term outcomes.

Development of de novo alloantibodies against recipient's red blood cell (RBC) antigens by engrafted donor's lymphocytes is a known phenomenon in the setting of allogeneic hematopoietic stem cell transplantation (HSCT). This situation is usually clinically insignificant. We report a case of early clinically relevant hemolytic anemia in a blood group AA 31-year-old Caucasian woman, blood group AThis case illustrates that de novo alloantibody production against ABO and D antigens by the newly engrafted donor's lymphocytes can occasionally cause clinically significant anemia. To our knowledge, this is the first case reported of clinically significant hemolytic anemia due to a transient anti-D anti-A

For patients with AML, the best alternative donor remains to be defined. We analyze outcomes of patients who underwent myeloablative umbilical cord blood or haploidentical hemopoietic stem cell transplantation (HSCT) in Spain. Fifty-one patients underwent single umbilical cord blood transplantation supported by a third party donor (Haplo-Cord) between 1999 and 2012, and 36 patients received an haploidentical HSCT with post-transplant cyclophosphamide (PTCY-haplo) between 2012 and 2014 in GETH centers. The Haplo-Cord cohort included a higher proportion of patients with high disease risk index and use of TBI in the conditioning regimen, and hematopoietic cell transplantation-age Comorbidity Age Index was higher in PTCY-haplo patients. Cumulative incidence of neutrophil engraftment was 97% in the Haplo-Cord and 100% in the PTCY-haplo group, achieved in a median of 12 and 17 days, respectively (P = 0.01). Grade II-IV acute GvHD rate was significantly higher in the PTCY-haplo group (9.8% vs 29%, P = 0.02) as well as chronic GvHD rates (20% vs 38%, P = 0.03). With a median follow-up of 61 months for the Haplo-Cord group and 26 months for the PTCY-haplo cohort, overall survival at 2 years was 55% and 59% (P = 0.66), event-free survival was 45% vs 56% (P = 0.46), relapse rate was 27% vs 21% (P = 0.79), and non-relapse mortality was 17% vs 23% (P = 0.54), respectively. In this multicenter experience, Haplo-Cord and PTCY-haplo HSCT offer valid alternatives for patients with AML. Neutrophil engraftment was faster in the Haplo-Cord cohort, with similar survival rates, with higher GvHD rates after haploidentical HSCT.

Single-unit umbilical cord blood (CB) SCT is limited by low total nucleated cell (TNC) dose. Co-infusion of CD34+ cells from a third party HLA-mismatched donor, known as dual or haplo-cord transplant, reduces the period of post-transplant neutropenia and related complications. The aim of this study was to analyze the value of early post-transplant peripheral blood (PB) and T cell chimerism after 28 dual transplants regarding CB engraftment. Cumulative incidence of myeloid engraftment at 30 days was 93% with a median time to engraftment of 14 days (10-29). Patients who developed CB graft failure (n=5) showed very low percentages of CB cells on days +14, +21 and +28 with decreasing dynamics. On the other hand, percentages of CB cells in patients who achieved CB engraftment increased over time. Interestingly, such patients showed two distinct chimerism dynamics in PB, but all of them showed a predominance of CB T cells early after SCT with increasing dynamics over time. Early post-transplant chimerism dynamics in PB and T cells predicts CB graft failure enabling rapid therapeutic measures to be applied. On the other hand, early increasing percentages of CB T cells correlates with ultimate CB engraftment.

Relapse remains the main cause of treatment failure in patients with acute myelogeous leukemia (AML) after allogeneic hemopoietic stem cell transplantation (SCT). The Wilms’ tumor 1 gene (WT1) is reportedly overexpressed in >90% of patients with AML and thus can be useful for minimal residual disease (MRD) monitoring. The aim of this study was to evaluate the usefulness of WT1 expression as a relapse predictor marker in patients with AML after SCT and compare it with flow cytometry (FC) and chimerism studies. WT1 expression was assessed retrospectively using quantitative RT-PCR in bone marrow and peripheral blood from 21 patients. Patients were classified according to WT1 dynamics posttransplantation. Eleven of the 21 patients had low and stable WT1 levels. All of these 11 patients showed complete chimerism and negative MRD by FC and remained in complete remission with a median follow-up of 27 months (range, 18-98 months). In contrast, 10 of 21 patients showed WT1 overexpression after SCT, and 9 of these 10 patients relapsed. The incidence of relapse differed significantly between the 2 groups of patients according to WT1 expression post-SCT (P = .00003). Relapse in the 9 patients occurred at a median of 314 days (range, 50-560 days). Interestingly, in these patients, relapse was first predicted by WT1 (with negative FC and complete chimerism) in 7 patients. WT1 overexpression was correlated with disease burden in patients with AML before and after allogeneic SCT. In patients who relapsed, both medullary and extramedullary relapse were better anticipated by WT1 overexpression compared with FC and chimerism.

Background and objective Several studies have demonstrated the feasibility of autologous stem cell transplantation (ASCT) in patients with lymphoma and human immunodeficiency virus (HIV) infection. HIV infection has been described as a risk factor for poor mobilization. The aim of this study was to compare the results of two mobilization strategies of peripheral blood stem cells (PBSC) in patients with lymphoma and HIV infection in seven Spanish hospitals.

The commitment and evaluation of the quality management plan by professionals from accredited stem cell transplant centers in Spain

Introduction: Invasive Fungal Infection (IFI) is a serious complication after allogeneic stem cell transplantation (alloSCT). Its incidence and outcome are not well characterized in the setting of peripheral blood, non-manipulated haploidentical stem cell transplantation with postransplant cyclophosphamide (HaploSCT). The aim of the study is to analyze our experience among patients who underwent HaploSCT at our institution and developed an IFI, in order to identify the incidence, risk factors and its impact in survival. Materials and methods: One hundred and thirty-three patients underwent peripheral blood HaploSCT with postransplant cyclophosphamide at our institution between 2011 and 2017. IFI was classified according to the EORTC definitions. Proven and probable IFI were included. Results: Patients´ characteristics are shown in Table 1. Patients received primary antifungal prophylaxis with micafungin from the day before stem cell infusion, during admission and until neutrophil engraftment was stablished. Patients on steroid treatment due to GVHD received prophylaxis with micafungin or posaconazole. Twenty-three episodes of IFI were observed in 20 patients, 10 proven and 13 probable, with a cumulative incidence of IFI of 15% at 500 days. Most commonly isolated organism was Aspergillus spp (5 cases), followed by Candida spp (4 cases: 1 C. kruseii and 3 C. parapsilosis) and Fusarium spp (2 cases). Additionally we observed some isolated cases of Inonotus spp,Mucor spp and Trichosporon Ashii. Pulmonary involvement was the most frequent presentation (11 cases), followed by fungemia (5 cases, 4 Candida and 1 Trichosporon Ashii) and skin-pulmonary involvement (2 cases). Thirteen cases were diagnosed early, in the pre-engraftment period, 5 just after the engraftment and 5 cases developed later. Among patients with late occurrence of IFI, median time of IFI was 220 days, and all of them were associated with GVHD (3 grade III-IV acute GVHD and 2 moderate/severe chronic GVHD). IFI outcome was favorable in 14 out of the 23 documented IFI, with antifungal therapy. Treatment chosen was liposomal amphotericin B in 7 cases, voriconazole in 5 and combined treatment (with amphotericin B and azole) in 6. Death related to IFI was documented in 7 out of the 20 patients, with an IFI mortality cumulative incidence of 6.4%. Prior transplant (OR 4.5, p Conclusions: In our experience, cumulative incidence of IFI in the setting of HaploSCT was similar than the one observed in other studies with alloSCT. Mortality associated to IFI in the whole cohort was low (6.4 %). The most significant factor related to IFI development was having received a previous transplant, especially alloSCT. Therefore, this high risk population should be closely monitored and could benefit from prophylaxis with azoles. Disclosures No relevant conflicts of interest to declare.

Background: Post-transplant high dose cyclophosphamide (PT-CY) effectively prevents graft-versus-host disease (GVHD) after HLA-haploidentical hematopoietic stem cell transplantation (HSCT). However, the use of PT-CY in HLA-identical HSCT is less explored. In this study, we analyzed the results of PT-CY as GVHD prophylaxis in HLA-identical sibling HSCT and compared them with those obtained after prophylaxis with methotrexate (MTX) plus cyclosporine (CsA). Methods: 107 HLA-identical sibling (10/10) HSCT from 2 Spanish centers have been analyzed: 50 performed consecutively between 2010 and 2015 using MTX-CsA as GVHD prophylaxis, and 57 performed consecutively between 2014 and 2018 using PT-CY. Results: Baseline characteristics and post-transplant complications are shown in Table 1. GVHD prophylaxis consisted in MTX days +1, +3, +6 and +11, and CsA from day -1 in the MTX-CsA group. The PT-CY group received cyclophosphamide 50 mg/kg/d on days +3 and +5 in 38 patients (65%), combined with CsA from day +5, and cyclophosphamide on days +3 and +4 in 19 patients (35%), followed by CsA and mycophenolate mofetil from day +5. Graft source was PBSC in 96% in the MTX-CsA group and 86% in the PT-CY group. Conditioning regimen was myeloablative in 64% and 40%, respectively. Neutrophil and platelet engraftment was significantly delayed in the PT-CY group (14.5 (11-27) vs 15.5 (13-37), p=0.02; 11.5 (8-180) vs 20.5 (10-43), p=0.02). After a median follow-up of 60 months for the MTX-CsA group and 15 months for the PT-CY group, 2-year overall survival (OS) was 56% (42-70) and 78% (67-90) (p=0.088), and event-free survival (EFS) was 48% (34-62) and 62.5% (42.5-82.5) (p=0.054), respectively. Cumulative incidence at 100 days of grade II-IV (52.2% vs. 22.6%, p=0.0015), and III-IV (24.4% vs. 8.8%, p=0.016) acute GVHD were significantly higher in the MTX-CsA group (Figure 1A). No differences were observed in the 2-year cumulative incidence of chronic moderate to severe GVHD (26% vs. 16.7% (p=0.306)). No differences were observed in the 2-years cumulative incidence of relapse (27% vs. 28% (p=0.47)). Non-relapse mortality (NRM) at 2-years showed a higher trend in the MTX-CsA cohort (24% vs. 8.8%, p=0.054). Finally, the composite endpoint of GVHD and relapse-free survival (GRFS) at 2-years was significantly better in the PT-CY group (48% vs. 24%, p=0.011) (Figure 1B). Conclusions: In our experience, GVHD prophylaxis using PT-CY combined with additional immunosuppression after HLA-identical sibling HSCT, using mostly peripheral blood as graft source, reduced the cumulative incidence of acute GVHD compared to standard prophylaxis with MTX-CsA, leading to an impact on GRFS. To our knowledge, this is the largest comparative retrospective cohort reported. Further prospective studies with longer follow-up are needed to confirm these observations. Disclosures No relevant conflicts of interest to declare.

Introduction Donor cell derived myeloid neoplasm (DCMN), defined as the development of de novohematological malignancies from cells of donor origin,is a late complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT). We report on seven cases of DCMN in which whole-exome sequencing (WES) at different time-points after allo-HSCT, as well as in a sample from each donor, was performed. The ultimate objective was to accurately described the clonal architecture, spatial heterogeneity and identify somatic mutations that are induced in the process of leukemogenesis and clonal evolution of myeloid neoplasm. Donors were also analyzed to detect underlying condition predisposing to the development of DCMN. Patient and Methods Seven patients with a confirmed diagnosis of DCMN and their donors were recruited from different Spanish institutions. This cohort included a total of 32 BM samples at different time points after allo-HSCTand one PB sample from each donor (one case received dual allo-HSCT, CB and PB from both donors were obtained), which provided a total of 40 samples. Genomic DNA samples were prepared according to Agilent SureSelect-XT Human exon 50Mb enrichment kit (Agilent Technlogies, Santa Clara, CA) preparation guide and libraries were sequenced on Illumina HiSeq platform (Illumina, San Diego, CA). DNA sequencing data from recipient post-transplant BM samples, were matched against their donor PB sample and previous post-transplant BM samples to identify the acquisition of mutations along the post allo-HSCT period.Germline variants in donors were studied in order to detect mutations that predisposed to the development of a myeloid neoplasm.The research protocol was approved by the Ethic Committee of Gregorio Marañón General University Hospital. Patients´ and donors´ information was collected from their medical records. Results Clinical and biological characteristics of the 7 patients with DCMN and their donors are shown in Table 1. Mutational profiles obtained from the follow-up samples at different time-points post-HSCT demonstrated high intra-tumor genetic heterogeneity and clonal dynamic for all cases. The number of variants are increased over time and at the moment of DCMN diagnosis, the median number of variants was 28, ranging from 18 to 92 variants (Figure 1). WES identified in DCMN patients gene mutations commonly seen in adult AML or MDS, such as in SETBP1, DNMT3A, TET2, RUNX1, CSF3R, EP300and IDH2.In addition, others non-silent variants were acquired in all cases. Among the additional novel alterated genes, we found 23 strong candidateswith oncogenic potential. LUC7L2, NOP14, LAMA5, SKOR2, EML1, SNX13, RHPN2, IRS1, MTG2, TENM2, MEFV, GSE1, NOTCH4, DTX1, CNOT4, PNKP, GRB7,SENP7,TAF1L, ZKSCAN2, ZBTB20, ZNF461 and MEGF10. Analysis of CNVs revealed numerical alterations across the post allo-HSCT samples in patients 1, 2, 3, 4, 5 and 7. The most common chromosomal alterations in DCMN were monosomy 7 and other chromosome 7 abnormalities, which detected in the 86% (6/7) of the patients. Although none of the donors developed a myeloid neoplasm at the moment of diagnosis of DCMN in recipient, donor 1 revealed an abnormal karyotype (45,XY,-7) at the moment of the allo-HSCT. All other donors harbored at least one pathogenic or probably-pathogenic variants, most probably of germline origin, in genes involved in hematological or solid tumor predisposition. Conclusions The development of DCMN involves dynamic genomic processes that begin months before the clinical onset. In this study, our integrated multi-step analysis revealed the intra-tumor heterogeneity and evolutionary history of seven DCMN. The present study reveals a process of sequential clonal expansions promoted by the acquisition of somatic mutations in donor hematopoietic cells. Detection of heritable or acquired gene mutations in donors associated with predisposition to haematological malignancies could have clinical implications for the patients undergoing to allo-HSCT. Leukemic transformation ofdonor hematopoietic stem cells provides a useful in vivomodel to study the mechanisms involved in leukemogenesis. Novel approaches based on high-depth next generation sequencing to study consecutive samples from post-transplant period in these patients, appear promising to discover new genes involved in myeloid neoplasm and to decipher the mechanisms of leukemogenesis. Disclosures No relevant conflicts of interest to declare.

Introduction: Multidrug-resistant organisms (MDRO) are a challenge in patients undergoing stem cell transplant (SCT) which often result in an increase in mortality. To our knowledge, current literature defines only screening at the time of work-up for SCT-patients. The aims of the study were to assess the rate of MDRO colonization with weekly screening, rate of infection and the associated mortality in patients undergoing SCT. Patients and methods: Consecutive patients admitted at the SCT unit between January-18 to July-18 were reviewed in our institution. Screening consisted of rectal and perineal swab on admission and weekly until the date of discharge. In case of detection of MDRO , patients were isolated and infection control strategies were applied. Results: 41 patients were analysed, with 47 admissions, 6 patients had 2 admissions. The median duration of hospitalization was 27 days/patient (range 8-100). 168 rectal-and perineal swab were performed with a median of 3 swabs/patient (range 1-7). Patient characteristics are shown in Table 1. 36 patients (87%) spiked fever in a median of 8,5 days after admission (1-38days). 24,4% (n=10) had a positive screening: 2/10 patients at baseline and 8/10 patients (80%) were detected for the first time beyond baseline screen. Rate of MDRO colonization was 3% per week (95%CI 1.4-5.4). MDRO identified were : 4 patients with Extended-spectrum beta-lactamases producing E. Coli (ESBL-EC), Multidrug-resistant (MR) Pseudomonas aeruginosa (n=3), Vancomycin-resistant Enterococci (n=2) and 1 patient with carbapenem-resistant Citrobacter freundii. 6/10 patients developed MDRO infection (60%), all with previous MDRO positive detection: MR-Pseudomonas aeruginosa in urine culture (n=3) 2 treated with ceftolozane/tazobactam, 1 with meropenem+amikacin; ESBL-EC in urine culture (n=2) both treated with meropenem and 1 with Klebsiella pneumoniae carbapenemase in urine culture treated with ceftazidime/avibactam. The infection rate was 4,6% (95% CI 3.9-5.2). In 80% patients (n=8) antibiotic treatment was guided by positive screening, 3 patients were admitted to intensive care unit for sepsis. No mortality was associated to MDRO. In 76%of patients (n=28) screening was negative for MDRO. 24/28 (85%) spiked fever with a median of 10 days after admission (1-38days). None MDRO-infections in negative-screened patients were detected. Conclusions : Weekly screening for MDRO identified a high number of MDRO colonizations allowing to apply early strategies of infection control in high risk patients . Besides, MDRO infection occurred only in patients previously colonized, therefore, 80% of our cohort could benefit from guided treatment by the time of the febrile episode. Early identification of MDRO colonization might have helped to reduce MDRO related mortality. However, these findings should be confirmed with further studies, comparing baseline with weekly MDRO screening strategies. Disclosures No relevant conflicts of interest to declare.

Introduction: Cytokine Release Syndrome (CRS) is a systemic inflammatory response síndrome related to aberrant immune activation or immune hyperstimulation, leading to elevated cytokine levels (including IL-6, interferon-γ, IL-2) and inflammation. CRS has been described after infusion of T-repleted haploidentical progenitors in post-transplant cyclophosphamide (PTCy) based conditioning regimens. We analyzed the outcomes of 144 T cell-repleted transplants with PTCy (days +3, +4), MMF and CsA as GVHD prophylaxis in our institution. Patients and methods: A total of 105 haplo-HSCT and 39 HLA-identical HSCT (19 and 20 from sibling and unrelated donor, respectively) with PTCy were analyzed retrospectively in 141 consecutive patients from 2010 to 2017. Two patients with haplo-HSCT were excluded, one due to early death on day +1 and other for lack of information. CRS was defined and graduated according to Lee et al. criteria published in 2014.1 Chi-squared test was used to study the association of different qualitative clinical variables and CRS and Mann-Whitney U test for the association between CRS and total nucleated cells (TNC) infused. The determination of the best cut-off of TNC to stratify patients with CRS was performed with ROC curves. The stadistical program used was R v2.15.0. Results: The characteristics of the 142 transplants analyzed are shown in Table 1. CRS occurred in 77% of haplo-HSCT (79/103) and in 18% of identical HSCT (7/39). Most patients with CRS presented sings and symptoms in the first 24 hours after the infusión.The majority was grade 1. Only 5 patients who underwent haplo-HCT showed grade 2 CRS. They needed vasoactive drug, oxygen therapy (without mechanical ventilation) and low doses of corticosteroids. Of those 5 patients, 4 were lymphomas with a previous autologous transplant. The stem cell source of the 5 patients was peripheral blood (PB). We did not have cases of grades 3-4 CRS. No patient required Tocilizumab. The clinical and analytical characteristics of CRS are shown in Table 2. In the univariate analysis, the use of PB was significantly associated with the development of CRS (p = 0.001). No statistical association was found with other variables (underlying disease, disease status, cryopreserved product, previous autologous or allogeneic transplant, conditioning, age, sex, CD34 infused, etc.). In the haplo-HSCT cohort, patients who presented CRS showed higher content of TNC infused (median (range): 9.1 (1.17-18.77) vs. 6.9 (0.63-26) x108 / kg, p = 0.023). The best cut-off of TNC calculated was 6.02 x108 / kg (S 82%, E 47%, p = 0.02).CI of CRS in patients with TNC greater than 6.02x108 / kg was 84% compared to 53% in lower (HR 6.6, p = 0.0099, Figure1). Patients with CRS developed grade II-IV acute GVHD more frequently than those who did not present CRS (60% vs. 28.6%, p = 0.012). No association was observed between CRS and chronic GVHD, relapse, non relapse mortality, overal survival or event free survival. Conclusion: CRS appears more frequently in patients with haplo-HSCT compared to HLA-identical donors using PTCy and PB as stem cell source. In our experience, cases with grades 3-4 CRS are infrequent. The majority of CRS cases remit after PTCy and progress well with symptomatic treatment. In the haplo-HSCT cohort, the number of cells infused is associated with higher incidence of CRS and with the presentation of EICRa grade II-IV.Lee DW, Gardner R, Porter DL, et al. Current concepts in the diagnosis and management of cytokine release syndrome How I Treat Current concepts in the diagnosis and management of cytokine release syndrome. Blood. 2014; 124(2):188-195. DOI: 10.1182/blood-2014-05-552729 Disclosures No relevant conflicts of interest to declare.

Background: Graft failure (GF) is an unusual but threatening complication after allogeneic HSCT (allo-HSCT). Early diagnosis is crucial for therapeutic interventions to be effective. The monitoring of chimerism in peripheral blood (PB) and T lymphocytes (TL) has shown to contribute in the early detection of this complication. The objective of this study was to describe chimerism dynamics in patients who developed GF after allo-HSCT. Methods: Nineteen patients out of 416 procedures were diagnosed with GF after allo-HSCT since 2003 in our center. Chimerism studies were performed by STR-PCR (AmpFLSTR™ SGM Plus™, Thermo Fisher) in PB and TL weekly since day +14. Patients were classified into three groups: primary GF (absence of neutrophil engraftment by day +28), secondary GF (development of severe cytopenias and progressive mixed chimerism (MC) after initial achievement of neutrophil engraftment), and incipient GF (development of increasing MC with non severe cytopenias) [1]. Relapse/progression was ruled out in all cases. [1] Díez-Martín et al. Bone Marrow Transplant. (2004) 33, 1037-1041. Results: Seven patients were diagnosed with primary GF, 7 with secondary GF and 5 with incipient GF (Table 1). No evident causes of GF were detected in all primary GF cases. Chimerism analysis on day +14, +21 y +28 revealed persistent high percentages of recipient cells before GF were diagnosed, in PB and mainly and earlier in TL (Fig. 1A). Median time to salvage allo-HSCT was 45 days (range 35-77). Two patients were treated with donor lymphocytes infusion (DLI) and five with second allo-HSCT. Five patients achieved engraftment, and six achieved complete chimerism (CC). Six-months OS after salvage was 43%. The 7 patients diagnosed with secondary GF had achieved initial neutrophil engraftment in a median of 17 days (range 13-28). Median time to GF after allo-HSCT was 75 days (range 39-108). Six of them developed CMV reactivation before GF. Chimerism analysis before and at diagnosis of secondary GF, showed persistent high percentages of recipient cells, with a trend towards increasing dynamics in PB and mainly in TL (Fig. 1B). Median time to salvage therapy was 35 days (range 8-817) after GF confirmation. One patient was treated with DLI and six with second allo-HSCT. Five patients achieved engraftment and CC. Six-months OS was 57%. The 5 patients diagnosed with incipient GF showed persistent high percentages of recipient cells, with a trend towards increasing dynamics particularly in TL before and at diagnosis of GF (Fig. 1C). As salvage treatment, patients were treated with immunosuppression withdrawal followed by at least one DLI as salvage theraphy, in a median of 83 days (range 61-126) after allo-HSCT. All patients achieved CC in both PB and TL. Four patients developed grade II-IV GVHD. Six-months OS was 57%. Conclusions: Patients with primary GF presented MC in serial chimerism analysis after allo-HSCT, with persistent high percentages of recipient cells particularly in TC. Patients with secondary and incipient GF showed increasing MC mainly in TC, before GF was established. Early T-cell chimerism dynamics may be the best predictor of GF, allowing early therapeutic interventions. In our experience, timely and individualized second allo-HSCT after GF may improve outcome after primary or secondary GF. On the other hand, early DLI could benefit patients with incipient GF. Disclosures No relevant conflicts of interest to declare.

Introduction: Immune reconstitution (IR) has a significant impact in HSCT outcome with a role against opportunistic infections and in disease control. In the setting of unmanipulated haploidentical transplantation (Haplo-HSCT), some groups have identified the absolute leukocyte count on day +30 (ALC30) as an independent prognostic factor in terms of overall survival (OS), disease free survival (DFS) and infection related mortality (IM). The aim of this study was to evaluate the impact of early IR on different HSCT outcomes in patients who underwent Haplo-HSCT with postransplant cyclophosphamide (PTCy) at our institution. Patients and methods: Eighty-eight patients received a Haplo-HSCT from 2011 to 2016. Thirty-six percent of the patients received myeloablative conditioning regimen and 64% received reduced intensity regimen. Graft-versus-host disease (GVHD) prophylaxis was based on PTCy, cyclosporine and mycophenolate mofetil. Early IR was assessed through the analysis of different lymphocyte subpopulations at days +30 and +90 after transplantation, including ALC30 (cellular analyzer DXH, Beckman Coulter®); CD3+ lymphocyte count and their different subpopulations (CD4+ and CD8+ lymphocytes, naive and memory T cells) and NK cells count. Lymphocytes subpopulations were determined by multiparametric flow cytometry (FC500 and Navios, Beckman Coulter®). ROC curves were used to determine the optimal cut-off values for each of the studied variables. Results: Eighty-one patients were studied, excluding 7 who died before day +30. Median follow-up was 26 months (10-43). Patient´s characteristics are shown in Table 1. CMV reactivation was documented in 76% (62) of the patients, 4% (3) developed a proven invasive fungal infection, and 31% (25) presented hemorrhagic cystitis. Median OS and DFS were 26 months (10-43) and 24 months (9-39), respectively. IM rate and NRM rate were 10% and 24%, respectively, at the end of follow up. Median lymphocyte populations counts at day +30 are shown in Table2. ALC30 below 100 cells/uL (p= 0.027) and CD4+ naïve lymphocytes below 12 cells/uL (p=0.033) (both corresponding to the 25 percentile) were associated with lower OS compared to patients with higher counts at day +30 (Figure 1). Patients with ALC30 lower than 300 cells/uL (p=0.026) showed significantly higher NRM; CD8+ count lower than 20 cells/uL (p=0.022) also showed higher NRM. NK cells counts at day +30 lower than 14 cells/uL (p=0.014), near to percentile 25, predicted higher IM (62.5% vs 37.5%). We did not identify any lymphocyte subpopulation that could predict DFS. Patients with acute GVHD grades II-IV showed values of ALC30 lower than 200 cells/uL (p=0.051), although non-statistically significant. No relationship was found between lymphocytes subpopulations at day +90 and HaploSCT outcomes. Conclusions: Our study supports the prognostic significance of early IR after unmanipulated haploidentical transplantation with PTCy, as previously described by other groups. ALC30, CD4+ naïve lymphocytes, and CD8+ lymphocyte count at day +30 may be good early predictors for OS and NRM in this setting. On the other hand, low NK cells counts (lower than percentile 25) predicted higher IM. Patients with very low lymphocyte counts should be monitored closely as they are at high risk for infectious complications, NRM and OS. Disclosures No relevant conflicts of interest to declare.

Background: The multifactorial mechanisms associated with radical reductions in HIV-1 reservoirs after allogeneic hematopoietic stem cell transplant (allo-HSCT), including a case of HIV cure, are not fully understood. Objective: To investigate the mechanism of HIV-1 eradication associated with allo-HSCT. Design: Nested case series within the IciStem observational cohort. Setting: Multicenter European study. Participants: 6 HIV-infected, antiretroviral-treated participants who survived more than 2 years after allo-HSCT with CCR5 wildtype donor cells. Measurements: HIV DNA analysis, HIV RNA analysis, and quantitative viral outgrowth assay were performed in blood, and HIV DNA was also measured in lymph nodes, ilea, bone marrow, and cerebrospinal fluid. A humanized mouse model was used for in vivo detection of the replication-competent blood cell reservoir. HIV-specific antibodies were measured in plasma. Results: Analysis of the viral reservoir showed that 5 of 6 participants had full donor chimera in T cells within the first year after transplant, undetectable proviral HIV DNA in blood and tissue, and undetectable replication-competent virus (

Many patients receiving allogeneic stem cells develop chronic graft-versus-host disease (cGVHD), which remains as the main cause of morbidity and mortality. Although the first line of therapy is generally with steroids, it is not well known how to manage refractory cases. Those patients are usually treated with alternative experimental agents. Sirolimus (Rapamycin), a new immunosuppressive agent, inhibits signal transduction and cell cycle progression after binding to FKBP12. We report a retrospective analysis with sirolimus in transplant recipients with cGVHD refractory to previous immunosuppressive therapy. Forty-seven patients with refractory or relapsed cGVHD were treated with the combination of sirolimus and calcineurin inhibitors (n = 33), mycophenolate (n = 9), or prednisone (n = 5). Thirty-eight of 47 (81%) patients had clinical responses (complete = 18, partial = 20). The main toxicity was mild renal failure, particularly at the start of therapy. Four patients who presented thrombotic microangiopathy were managed with plasmapheresis and the discontinuation of sirolimus and calcineurin inhibitors. Statistical analysis showed the type of cGVHD onset and presirolimus clinical status as the main variables influencing the response to treatment. The Kaplan-Meier estimate of survival was 57.4% at 3 years. The current study shows the efficacy and safety of sirolimus in refractory cGVHD patients. Further investigation is warranted to elucidate the role of sirolimus in cGVHD, and find the best combination (sirolimus + calcineurin inhibitors versus others) for therapeutic use.

We carried out a longitudinal study to analyze the immune recovery of four patients with aggressive HIV-associated lymphoma (HIV+ Ly+) treated with highly active antiretroviral therapy (HAART) and high-dose chemotherapy followed by autologous peripheral blood stem cell transplantation (ASCT). We also studied three control non-HIV-infected patients with lymphoma (HIV-Ly+) and six HIV patients on HAART without lymphoma (HIV+ Ly-). After 12 months of follow-up, the HIV HIV+Ly+ patients reached the pre-ASCT CD4+ levels, despite a transient decrease after the ASCT. All ASCT patients (HIV+Ly+ and HIV-Ly+) showed an increase in CD4+, CD4+ CD45RO+, and CD4+CD28+ T cells/microl. Although HIV+Ly+ patients had values of CD4+, CD4+CD45RO+, and CD4+CD28+ T cells/microl lower than the HIV-Ly+ patients, their recovery rate over the 12 months after ASCT appeared to be better. HIV+Ly+ patients had higher pre-ASCT plasma IL-7 levels than HIV-Ly+, however, these values decreased after ASCT. All ASCT patients showed a slight increase of TCR rearrangement excision circles (TRECs) and they did not have a different pattern of TREC evolution. We could not find differences between HIV+Ly+ patients 12 months after ASCT and HIV+Ly- in DNA-HIV (copies/10(6) cell). Overall, HIV+Ly+ patients showed an appropriate immune reconstitution 12 months after ASCT, and, interestingly, they had an amount of DNA-HIV copies similar to HIV+Ly- control patients in their CD4+ cells.

s / Biol Blood Marrow Transplant 21 (2015) S266eS321 S284 percentage of hCD68+ cells (linear regression; r21⁄40.70, p

Objective To evaluate feasibility, safety, and efficacy of peripheral blood stem cell collection (PBSCC) and autologous stem cell transplantation (ASCT), to treat patients diagnosed of high-risk or relapsed HIV-associated lymphoma (HIV + Ly), responding to highly active antiretroviral therapy (HAART). Methods Prospective and multicentric study in patients with high-risk or relapsed chemosensitive HIV + Ly, candidate for consolidation with ASCT. Eligibility criteria were similar to those of HIV − lymphoma. HAART was aimed to be maintained during the procedure. Results Fourteen patients were admitted. Adequate PBSCC was obtained from all patients (median CD34 + cells was 4.7 × 10 6 /kg). Three patients died before ASCT; two had disease progression and one died from VHC-liver failure. Eleven transplanted patients showed neutrophil engraftment after a median time of 16 days (range, 9–33 days), and nine patients showed platelet engraftment after a median time of 20 days (range, 11–36 days). CD4 + cell counts and HIV viral load (VL) were appropriately preserved along the procedure. No patients died from treatment-related complications. One patient died from lymphoma progression (day +19), and another died in complete remission (CR) with undetectable VL, 15 months after transplant, due to infection. One patient relapsed at 32 months after ASCT. The remaining eight patients are alive in CR with an event-free survival of 65% and a median follow-up of 30 months after ASCT (range, 7–36 months). Conclusions These results show that feasibility, safety, and efficacy of PBSCC and ASCT in HIV + Ly patients responding to HAART are similar to those observed in the HIV − lymphoma setting.

Graft rejection is a major cause of treatment failure after T-cell-depleted stem cell transplantation (TCD-SCT) and remains a therapeutic challenge. Donor leukocyte infusions (DLIs) have an efficient graft versus host effect, which has been successfully used to treat recipient relapses. We hypothesized that this effect could be exploited to counteract the host versus graft reactions responsible for graft rejection. We report two adult patients with haematological malignancies who underwent sex-mismatched TCD-SCT from HLA-identical sibling donors. Peripheral blood (PB) counts and bone marrow (BM) cellularity were studied on a serial basis. Sequential chimaerism and minimal residual disease analysis were performed by FISH on PB and BM samples as well as on leukocyte lineages (T and B lymphocytes and myeloid cells) purified from PB using immunomagnetic technology. Both patients were diagnosed with incipient graft rejection 2-3 months after engraftment, based on persistently decreasing PB counts and BM cellularity together with the observation of decreasing mixed chimaerism (increasing percentage of recipient cells), mostly in whole PB and T lymphocytes. Both patients were successfully treated with a single DLI (1 x 10(7) CD3+ cells/kg), thereafter achieving normal PB counts and BM cellularity as well as complete chimaerism. Interestingly, the only side effect observed was mild graft versus host disease that did not require treatment. In conclusion, provided that an early diagnosis is made, the graft versus host lymphohaemopoietic effect harboured by immunocompetent donor cells can be successfully used for the treatment of incipient graft rejection.

121 Background: The advent of highly active antiretroviral therapy (HAART) allowed to extend autologous stem cell transplantation (ASCT) to HIV-positive patients affected by lymphoma. In the literature, data are lacking on long-term events developed by this population. Methods: Herein we are reporting the preliminary analysis of long-term data of 43 pts out of 61 pts, affected by high-risk or relapsed lymphoma and treated by ASCT in different European countries. These 61 pts reached a complete response after ASCT and received HAART concomitantly to chemotherapy. We considered the following events after ASCT: lymphoma relapses, second cancers, opportunistic infections (OIs) and cardiovascular events. Results: Thirteen pts experienced OIs, after 0.36 years from ASCT (IQR: 0.12 -2.91). Twelve pts had a secondary malignancy and 6 pts had a lymphoma relapse, at a median time of 4.90 years (IQR: 2.56 – 9.90) and 2.88 years (IQR: 0.57 – 4.27) from ASCT, respectively. Six pts developed a cardiovascular event at 6.29 years (IQR: 4.84 – 9.32) from ASCT. Eight pts died: 3 of lymphoma relapse, 3 of second malignancy, 1 of acute myocardial infarction and 1 of car accident. With a median of 9.18 years of follow-up, (IQR: 5.99-12.43) the OS, PFS and EFS of the entire sample of pts were 82%, 75% and 35% at 10 years, respectively. Conclusions: Thirty-five out of 43 pts are still alive and in long-term complete remission after ASCT. These data confirm the long-term dramatic efficacy of ASCT. We support surveillance of OIs early after ASCT and of second cancers, lymphoma relapses and cardiovascular events from ASCT. Secondary malignancies developed by our pts are non-AIDS-defining cancers and a majority are linked to a viral pathogenesis or lifestyle behaviours (i.e. smoking). Secondary cancers and lymphoma relapses are the main causes of death in this population. Cardiovascular events may represent a cause of death but also a major reason of disability.

Chimerism dynamics in bone marrow, peripheral blood (PB), and T lymphocytes (TL) has been associated with the development of various complications after allogeneic stem-cell transplantation (allo-SCT). In the present study, the usefulness of chimerism monitoring in CD25 + -activated leukocytes (AL), together with that in bone marrow, PB, and TL, for the anticipation of complications after allo-SCT, has been analyzed in 68 patients. In AL, we observed a slower dynamics toward complete chimerism (CC) than in PB ( p = 0.042), while no significant differences were found between TL and PB ( p = 0.12). Complete chimerism achievement in AL at day +30 has shown to be an independent risk factor for the development of grade II–IV acute graft-versus-host disease (aGvHD; hazard ratio [95% confidence interval]: 11.9 [1.5–91.7]; p = 0.017). Moreover, among patients achieving CC in TL and AL at different time-points after SCT ( n = 17/68), the incidence of grade II–IV aGvHD was significantly higher in patients who achieved CC earlier in AL (5/5) than in those who achieved CC earlier in TL (1/11; p = 0.001). Therefore, achievement of early complete donor chimerism in CD25 + AL is a strong predictor for the development of aGvHD. Prospective analysis of chimerism in AL could improve the post-SCT management of immunosuppressive therapy in transplanted patients.

Allogeneic stem cell transplantation (allo-SCT) has become the treatment of choice in patients with intermediate-risk and high-risk acute myeloid leukemia (AML). The quality of response to treatment, assessed in terms of detection of minimal residual disease (MRD), has been consistently associated with prognosis and clinical outcome in patients with AML. The aim of the present study was to evaluate the prognostic impact of analyzing MRD in bone marrow using 4-color multiparametric flow cytometry (MFC) in 29 patients with AML before and after allo-SCT. Eighteen patients who were shown to be MRD-negative [≤0.1% leukemia-associated immunophenotypes (LAIPs)] by MFC at transplantation and underwent allo-SCT had lower rates of relapse (15% vs. 66%, P = 0.045), better overall 1-yr survival (83% vs. 52%, P = 0.021) and a lower cumulative incidence of relapse (P = 0.032) than patients who were MRD-positive (>0.1%). All post-transplant MRD-positive patients underwent a therapeutic intervention after transplant (tapering of immunosuppression, donor lymphocyte infusion, or re-transplant) with the intention of preventing relapse. Disease was controlled and MRD disappeared in five of these patients. Disease recurred in the other seven patients. We can conclude that follow-up with MFC for the detection of MRD in AML before and after SCT is useful for predicting relapse. In the post-transplant setting, monitoring of MRD by MFC could be a key preemptive intervention.