Effects Of Conditioning Regimen Research Articles

Effect of Conditioning Regimens and Graft-versus-Host Disease Prophylaxis on the Outcomes of Umbilical Cord Blood Transplantation Performed with Cyclophosphamide/Total Body Irradiation-Based Regimens

Umbilical cord blood (UCB) is a valuable alternative donor source for allogeneic hematopoietic stem cell transplantation. Various conditioning regimens and graft-versus-host disease (GVHD) prophylaxis regimens aimed at improving the outcomes of umbilical cord blood transplantation (UCBT) have been explored; however, the differences in their effects remain unclear. This study was conducted to elucidate the differences in the effects of conditioning and GVHD prophylaxis regimens on UCBT outcomes by disease type in a nationwide, retrospective study. We retrospectively analyzed the effects of conditioning and GVHD prophylaxis regimens on the outcomes of UCBT performed with cyclophosphamide (Cy)/total body irradiation (TBI)-based regimens in patients with acute myeloid leukemia (AML; n=1126), acute lymphoblastic leukemia (ALL; n=620), myelodysplastic syndrome (MDS; n=170), and lymphoma (n=128). Multivariate analysis for overall survival (OS) demonstrated the benefit of adding high-dose cytarabine to the Cy/TBI regimen for the AML group (relative risk [RR], .76; P=.003) and lymphoma group (RR, .54; P=.02), but not for the ALL and MDS groups. In the ALL group, adding etoposide to the Cy/TBI regimen was associated with a lower OS (RR, 1.45; P=.03). For GVHD prophylaxis, a tacrolimus/methotrexate regimen was associated with a lower OS compared with a cyclosporine/methotrexate regimen in the AML group (RR, 1.26; P=.01); this difference was not observed in the other groups. These differences in OS according to the conditioning and GVHD prophylaxis regimen were attributable mainly to differences in relapse risk. Our data show that the effects of conditioning regimens and GVHD prophylaxis on UCBT outcomes differed according to disease type. UCBT outcomes could be improved by selecting optimal conditioning regimens and GVHD prophylaxis for each disease type.

The effect of conditioning regimen and prescribed medications on hyposalivation in haematopoietic cell transplantation (HCT) patients: an 18-month prospective longitudinal study

ObjectivesHaematopoietic cell transplantation (HCT) preceded by a conditioning regimen is an established treatment option for (non)malignant haematologic disorders. We aim to describe the development of hyposalivation over time in HCT recipients, and determine risk indicators.Materials and methodsA multi-centre prospective longitudinal observational study was conducted. Unstimulated (UWS) and stimulated (SWS) whole saliva was collected before HCT, early post-HCT, and after 3, 6, 12, and 18 months. The effect of type of transplantation (allogeneic vs autologous) and intensity (full vs reduced) of the conditioning regimen on hyposalivation (UWS < 0.2 mL/min; SWS < 0.7 mL/min) was explored.ResultsA total of 125 HCT recipients were included. More than half of the patients had hyposalivation early post-HCT; a quarter still had hyposalivation after 12 months. The conditioning intensity was a risk indicator in the development of hyposalivation of both UWS (OR: 3.9, 95% CI: 1.6–10.6) and SWS (OR: 8.2, 95% CI: 2.9–24.6). After 3 and 12 months, this effect was not statistically significant anymore.ConclusionsHyposalivation affects the majority of patients early post-HCT. The conditioning intensity and the type of transplantation were significant risk indicators in the development of hyposalivation. The number of prescribed medications, total body irradiation as part of the conditioning regimen and oral mucosal graft-versus-host disease did not influence hyposalivation significantly.Clinical relevanceBecause of the high prevalence of hyposalivation, HCT recipients will have an increased risk of oral complications. It might be reasonable to plan additional check-ups in the dental practice and consider additional preventive strategies.

Improved Outcome Following Busulfan-Based Conditioning in Children with Functional Neutrophil Disorders Undergoing Hematopoietic Stem Cell Transplant from HLA-Matched Donors.

Hematopoietic stem-cell transplantation (HSCT) is the only curative treatment for chronic granulomatous disease (CGD) and leukocyte-adhesion deficiency (LAD), but both diseases have high rates of graft failure in transplant and patients with these diseases are often referred to HSCT with significant comorbidity. The intensity of the conditioning regimen should be balanced between the need to ensure durable engraftment and to minimize toxicity when transplanting young children with infections and organ damage. We report on 26 children transplanted at our institution with CGD and LAD over 24years. We found a higher incidence of graft failure in patients receiving treosulfan based conditioning for their first transplant. There was no effect of conditioning regimen on overall survival, as all 8 patients that proceeded to a second busulfan-based HSCT were salvaged. We recommend giving patients with CGD and LAD fully myeloablative conditioning with either a busulfan-based regimen or the combination of treosulfan, fludarabine, and thiotepa.

Abstract PO-57: Association between cytokine levels and prolonged cytopenia after axicabtagene ciloleucel in patients with refractory large B-cell lymphoma

Abstract Introduction: Prolonged grade 3-4 (G3-4) cytopenias lasting beyond day 30 have been observed with various chimeric antigen receptor (CAR) T-cell products. Their biologic mechanism remains largely unknown, since it is unclear whether it is related to the effects of the conditioning regimen or due to CAR T-cell activity. Methods: We measured 29 analytes associated with CAR-T cell activity by multiplex assays (V-Plex, Meso Scale Diagnostics) and CAR T-cell amplification by RT-PCR in serial plasma samples at baseline and days 7, 14, and 30 (D30) after standard-of-care axicabtagene ciloleucel (axi-cel) in patients with refractory large B-cell lymphoma (LBCL) treated at MD Anderson Cancer Center between March and August 2018. Patients with G3-4 cytopenia before conditioning, defined according to CTCAE v5, and those who progressed and/or died before D30 were excluded from the analysis. Unpaired t-test was used for area under the curve (AUC) and mean peak comparison, and the Benjamini-Hochberg method for adjustment of false discovery rate (FDR). Results: Of 19 patients included in the analysis, 9 (47%) had ongoing G3-4 cytopenia at D30. Baseline clinical characteristics were not significantly different between the 2 groups. Patients with D30 G3-4 cytopenia had a significantly higher AUC for the following cytokine levels: IFN-ɣ, FLT3-L, G-CSF, GM-CSF, CXCL1, IL-1Rα, IL-3, IL-8, IL-10, M-CSF, CCL2 (p&amp;lt;0.05); IL-1β, IL-2Rα, IL-6, IL-15, TNF-α (p&amp;lt;0.01); and VWF (p&amp;lt;0.001). In contrast, a significantly lower AUC was observed for Ang-1 (p=0.0002) and EGF (p=0.05). After adjusting for FDR, the association was maintained only for the following cytokines: Ang-1, IL-10, IL-15, IL-1β, IL-2Rα, IL-6, IL-8, TNF-α, and VWF. As the majority of cytokines outlined above showed a peak at day 7, the association between day 7 peak and D30 G3-4 cytopenia was evaluated. Patients with D30 G3-4 cytopenia showed a significantly higher peak at day 7 for the following cytokines: IFN-ɣ, G-CSF, GM-CSF, CXCL1, IL-1β, IL-2Rα, IL-3, IL-6, IL-8, IL-10, M-CSF, CCL2 (p&amp;lt;0.05), and FLT3-L (p&amp;lt;0.001), and a significantly lower peak for EGF (p=0.005). After adjusting for FDR, the only cytokine maintaining its association was FLT3-L. Patients with D30 G3-4 cytopenia had a significantly higher AUC for CAR T-cell amplification (123794 vs. 71548 DNA copies/µg), though not statistically significant because of small sample size (p=0.57). Conclusions: Development of prolonged cytopenia after axi-cel in patients with LBCL is associated with significant increase in the levels of multiple inflammatory cytokines and with CAR T-cell amplification early after infusion, suggesting this is due to CAR T-cell activity rather than to the myelosuppressive effect of conditioning regimen. The majority of these cytokines appear to be derived from myeloid cells and peak at day 7, providing potential targets for prophylactic intervention in these patients. Citation Format: Paolo Strati, Nahum Puebla-Osorio, Guangchun Han, Jason R. Westin, Loretta J. Nastoupil, Sairah Ahmed, Felipe Samaniego, Nathan H. Fowler, Luis E. Fayad, Hun J. Lee, Christopher R. Flowers, Samer A. Srour, Grace Watson, Linghua Wang, Michael R. Green, Sattva S. Neelapu. Association between cytokine levels and prolonged cytopenia after axicabtagene ciloleucel in patients with refractory large B-cell lymphoma [abstract]. In: Proceedings of the AACR Virtual Meeting: Advances in Malignant Lymphoma; 2020 Aug 17-19. Philadelphia (PA): AACR; Blood Cancer Discov 2020;1(3_Suppl):Abstract nr PO-57.

Abstract 2049: Cytokines associated with prolonged Cytopenia after axicabtagene ciloleucel in patients with refractory large B-cell lymphoma

Abstract Introduction. Prolonged grade 3-4 (G3-4) cytopenias lasting beyond day 30 have been observed with various chimeric antigen receptor (CAR) T-cell products, suggesting a class effect. However, the mechanism(s) of prolonged cytopenias remains largely unknown, being unclear whether it is related to the effects of the conditioning regimen or due to CAR T-cell activity. Methods. To investigate whether CAR T-cell activity is associated with prolonged cytopenia, we measured 29 analytes associated with CAR-T cell activity by multiplex assays (V-Plex, Meso Scale Diagnostics) in serial plasma samples at baseline and days 7, 14 and 30 (D30) after standard of care axicabtagene ciloleucel (axi-cel) therapy in patients with refractory large B-cell lymphoma treated at MD Anderson Cancer Center between March and August 2018. Patients with G3-4 cytopenia before conditioning, defined according to CTCAE v5, and those who progressed and/or died before D30 were excluded from the analysis. Unpaired t-test was used for area under the curve (AUC) comparison, independent sample t-test for mean peak comparison, and the Benjamini-Hochberg method for adjustment of false discovery rate (FDR). Results. Of 19 patients included in the analysis, 9 (47%) had ongoing G3-4 cytopenia at D30. Baseline clinical characteristics were not significantly different between the 2 groups. Patients with D30 G3-4 cytopenia had a significantly higher AUC for the following cytokine levels: IFN-γ, FLT3-L, G-CSF, GM-CSF, CXCL1, IL-1Rα, IL-3, IL-8, IL-10, M-CSF, CCL2 (p≤0.05); IL-1β, IL-2Rα, IL-6, IL-15, TNF-α (p&amp;lt;0.01); and VWF (p&amp;lt;0.001). In contrast, a significantly lower AUC was observed for Ang-1 (p=0.0002) and EGF (p=0.05). After adjusting for FDR, the association was maintained only for the following cytokines: Ang-1, IL-10, IL-15, IL-1β, IL-2Rα, IL-6, IL-8, TNF-α and VWF. As the majority of cytokines outlined above showed a peak at day 7, the association between day 7 peak and D30 G3-4 cytopenia was evaluated. Patients with D30 G3-4 cytopenia showed a significantly higher peak at day 7 for the following cytokines: IFN-γ, G-CSF, GM-CSF, CXCL1, IL-1β, IL-2Rα, IL-3, IL-6, IL-8, IL-10, M-CSF, CCL2 (p≤0.05); and FLT3-L (p&amp;lt;0.001); and a significantly lower peak for EGF (p=0.005). After adjusting for FDR, the only cytokine maintaining its association was FLT3-L. Conclusions. Development of prolonged cytopenia after axi-cel in patients with large B-cell lymphoma is associated with significant increase in the levels of multiple inflammatory cytokines early after CAR T infusion, suggesting this may be due to CAR T-cell activity rather than to the myelosuppressive effect of conditioning regimen. The majority of these cytokines appear to be derived from myeloid cells and peak at day 7, providing potential targets for prophylactic intervention in these patients. Analysis of CAR-T expansion is ongoing and will be presented at the meeting. Citation Format: Paolo Strati, Nahum Puebla-Osorio, Guangchun Han, Jason Westin, Loretta Nastoupil, Felipe Samaniego, Nathan Fowler, Luis Fayad, Hun Ju Lee, Christopher Flowers, Samer Srour, Grace Watson, Linghua Wang, Michael Green, Sattva Neelapu. Cytokines associated with prolonged Cytopenia after axicabtagene ciloleucel in patients with refractory large B-cell lymphoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2049.

Five year follow-up after autologous peripheral blood hematopoietic stem cell transplantation for refractory, chronic, corticosteroid-dependent systemic lupus erythematosus: effect of conditioning regimen on outcome.

Some patients with systemic lupus erythematosus (SLE) are refractory to traditional therapies, dependent on chronic corticosteroids, have organ damage, and are at high risk of mortality. In this group of patients, we report outcome at a median of five years after autologous hematopoietic stem cell transplant (HSCT) using two different non-myeloablative regimens. Four patients received a conditioning regimen of cyclophosphamide (200 mg/kg) and alemtuzumab (60 mg), while 26 patients underwent conditioning with cyclophosphamide (200 mg/kg), rATG (Thymoglobulin) (5.5 mg/kg), and rituximab 1000 mg. Unselected peripheral blood stem cells were infused on day 0. There were no treatment related deaths. Of the four patients treated with cyclophosphamide and alemtuzumab, none entered remission. For the 26 patients treated with cyclophosphamide, rATG, and rituximab, disease remission defined as no immune suppressive drugs except hydroxychloroquine and/or 10 mg or less of prednisone a day was 92% at 6 months, 92% at one year, 81% at 2 years, 71% at 3 years, and 62% at 4 and 5 years post-HSCT. Autologous HSCT outcome is dependent on the conditioning regimen but prior organ damage may cause lingering symptoms.

Comparison of myeloablative vs reduced intensity conditioning regimens in stem cell transplantations for acute myeloid leukemia.

e18518 Background: The development of reduced intensity conditioning (RIC) regimens enabled allogeneic hematopoietic stem cell transplantations (allo-HSCT) also for patients who had contraindications and comorbidities for myeloablative conditioning (MAC) regimens. The aim of this study is to evaluate the effects of conditioning regimens on outcomes of alllo-HSCT for patients with acute myeloid leukemia. Methods: We retrospectively analysed 362 acute myeloid leukemia patients who underwent allo-HSCT between November 1989 to November 2016. We compared the outcomes of MAC vs RIC by Fisher’s test and chi-square test. Results: Engraftment was achieved in 87% of RIC and 95% of MAC recipients (p = 0.03).Incidences of acute and chronic graft vs host disease were not statistically different in groups (41% vs 47%, p = 0.7; 32% vs 43%, p = 0.2).Relapse rate was higher in RIC group (45% vs 25%, p = 0.02).Both 1-year overall survival (OS) and 1-year relapse free survival (RFS) rate were lower in the patients treated with RIC (71% vs 35%; 55% vs 16%).The higher OS was related with patients who were transplanted in remission, received grafts from related donors as well as having acute and chronic graft vs host disease. Conclusions: In the treatment of young patients who do not have comorbidities for intense conditioning regimens, show good performance status and are high risk; the initial use of standard myeloablative conditioning regimens is feasible. However, the lower number of RIC transplants and the variations between groups in terms of patient and donor characteristics might effect the results of this study. [Table: see text]

Impact of Hyperbaric Oxygen Treatment on Time to Transfusion Independency Post-UCB Transplant

BackgroundLimitations in umbilical cord blood (UCB) transplantations result from decreased cell numbers available for infusion at time of transplant. Delayed engraftment and higher rates of engraftment failure subsequently increase the need for post-transplant growth factor use and transfusion support. Hyperbaric oxygen (HBO) has been shown to improve engraftment in an animal model of UCB transplantation. These experiments proved sufficient to initiate a first-in-human trial of HBO for UCB transplantation.ObjectivesThis study compared growth factor use and time to packed red blood cell (PRBC) and platelet transfusion independence between the HBO study population and historical UCB cases from the same institution. The effects of conditioning regimen and the number of cord units infused at time of transplant were analyzed.Study DesignSubjects underwent HBO therapy at the University of Kansas Medical Center after reduced intensity conditioning (RIC) (n=9) or myeloablative conditioning (MAC) (n=6) regimens. Six hours following HBO therapy, they received single (n=8) or double (n=7) UCB units. Charts of HBO-treated patients and historical controls (n=44) were reviewed for post-transplant growth factor use and transfusion requirements. These were further stratified by preparative regimen and number of UCB units infused. Kaplan-Meier curves were compared between HBO and control subjects using log-rank tests as some observations were right-censored if the patient experienced relapse or expired within the first 100 days post-transplant. A small quantity was imputed to values of 0 to facilitate including these subjects in the analyses.ResultsBy days +66 and +74 post-transplant, 100% of HBO-patients were PRBC and platelet independent, respectively. This compares to incomplete platelet (88.63%) and PRBC (86.36%) independence in the control cohort at day 100. Though time to transfusion independence (TTI) for PRBCs was consistently shorter in the HBO cohort, it was only statistically significant in the RIC setting and approached significance in the single cord setting (Table-1). TTI for platelets was shorter for the HBO cohort and approached statistical significance in the single cord setting. Similarly, the consecutive days of filgrastim support post-transplant were consistently fewer for HBO patients, with values approaching statistical significance in the MAC and single cord settings.ConclusionsIn vitro data with HBO and UCB showed improved rates of engraftment in animal models. Similarly, data in this small pilot study suggests that HBO facilitates less growth factor use and shorter TTI. However, these effects did not reach statistical significance in all settings, most likely due to small sample size of the HBO cohort. Further studies are needed to examine the effect of HBO on growth factor use, PRBC and platelet independence post-UCB transplantation.Table 1A comparison of supportive transfusion means, between standard and HBO-UCB transplant recipients. These data are segregated for conditioning regimens and units of UCB infused for transplant.GroupPRBC UnitsPlatelet UnitsDays G-CSF SupportTTI - PRBCTTI - PlateletsHBO-total (n=15)9 (p=0.30)16.35 (p=0.31)29.4 (p=0.08)32.87 (p=0.07)33.53 (p=0.11)Standard-Total (n=44)9.2917.1435.0256.0954.8HBO-Ablative (n=6)5.43(p=0.23)7.86 (p=0.16)26.63 (p=0.07)24 (p=0.53)25.5 (p=0.45)Standard-Ablative (n=23)11.9322.2935.6566.1367.78HBO-RIC (n=9)6.13 (p=0.66)11.89 (p=0.78)31.67 (p=0.44)22.56 (p=0.02)25.56 (p=0.11)Standard-RIC (n=21)7.5213.7134.3345.0940.57HBO-Single UCB (n=8)5.43 (p=0.19)7.87 (p=0.26)26.63 (p=0.06)24 (p=0.06)25.5 (p=0.06)Standard-Single UCB (n=4)10.252436.274.470.2HBO-Double UCB (n=7)12.57 (p=0.87)24.86 (p=0.95)33.57 (p=0.70)43 (p=0.74)42.71 (p=0.95)Standard-Double UCB (n=40)9.1916.1934.8753.7452.82 DisclosuresNo relevant conflicts of interest to declare.

Positive Impact of Chronic Graft-Versus Host Disease on Survival in 928 Allogeneic Hematopoietic Stem Cell Transplant Recipients

Introduction:Allogeneic hematopoietic stem cell transplantation (Allo-HSCT) is a standard curative treatment option in hematological diseases. The anti-leukemic activity relies not only the effects of conditioning regimen but also the immune mediated graft-versus leukemia (GVL) effect. Donor T cells are responsible for the GVL and causes complications namely acute and chronic graft versus host disease (GVHD). Herein, we aim to present the relation of graft versus host disease with survival and relapse.Patients and Methods:We retrospectively evaluated 928 Allo-HSCT between 1989 and 2015 followed in our institution. Chi-square test and student's t test were used in comparison. P <0.05 was considered statistically significant.Results:551 patients were male (59%) and 377 patients (41%) were female. The median age of the group was 34 (range 15 -71). Patients received stem cell from related donors more frequently (85%) with HLA full match (66%). Peripheral blood was the source of stem cells in 645 recipient (70%) followed by bone marrow (28%). 75 patients were diagnosed as benign hematological disorders. The most common malign hematological diagnosis was acute myeloid leukemia in 366 patients (39%). Patients received 80% of myeloablative conditioning regimen prior to transplantation. 43% of the patients diagnosed as acute GVHD and 45% had chronic GVHD. 798 achieved engraftment (86%) neutrophil engraftment median of 16 days, platelet engraftment median of 14 days. Relapse was detected in 6% of patients. The overall survival (OS) was 59 months and progression free survival (PFS) was 33 months. Acute GVHD had no impact on OS, PFS, relapse rate. The OS in patients with chronic GVHD was significantly higher than in GVHD negative patients (68.8 vs 56.9, P=0.009). Although chronic GVHD patients had lower risk of relapse and higher PFS, the results were not statistically significant.Conclusion:GVHD is a serious complication and important cause of post transplant morbidity. Chronic GVHD is associated with lower risk of relapse in previous studies. In this study, we have concluded the improved OS in patients with chronic GVHD. The immune mediated GVL effect may be the reason for anti-leukemia effect and improved survival. DisclosuresNo relevant conflicts of interest to declare.

Early left ventricular dysfunction in children after hematopoietic stem cell transplantation for acute leukemia: a case control study using speckle tracking echocardiography.

Background and ObjectivesCardiovascular complications are the leading cause of morbidity and mortality in childhood cancer survivors. Hematopoietic stem cell transplantation (HSCT) is a curable therapy for pediatric cancer. However, changes in cardiac function in children after HSCT are not well known. We assessed left ventricular (LV) function in children after HSCT using speckle tracking echocardiography (STE).Subjects and MethodsForty consecutive patients with median age of 11.9 years (range, 1.5-16 years) who received HSCT for acute leukemia and had comprehensive echocardiography before and after (median 9.2 month) HSCT were included in this study. The LV function parameters including conventional tissue Doppler imaging (TDI) and STE data were collected from pre- and post-HSCT echocardiography. These data were compared to those of 39 age-matched normal controls.ResultsCompared to normal controls, post HSCT patients had similar (p=0.06) LV ejection fraction. However, the following three LV function parameters were significantly decreased in post HSCT patients: rate-corrected velocity of circumferential fiber shortening (p=0.04), mitral inflow E velocity (p<0.001), and mitral septal annular E' velocity (p=0.03). The following four STE parameters were also significantly decreased in post HSCT patients: LV global circumferential systolic strain (p<0.01), strain rate (SR, p=0.01), circumferential diastolic SR (p<0.01), and longitudinal diastolic SR (p<0.001). There was no significant change in TDI or STE parameters after HSCT compared to pre-HSCT. Patients with anthracycline cumulative dose >400 mg/m2 showed significantly (p<0.05) lower circumferential systolic strain and circumferential diastolic SR.ConclusionSubclinical cardiac dysfunction is evident in children after HSCT. It might be associated with pre-HSCT anthracycline exposure with little effect of conditioning regimens. Serial monitoring of cardiac function is mandatory for all children following HSCT.

Unmanipulated Peripheral Blood Stem Cells Can be Safely Used to Allograft Patients with Severe Aplastic Anemia; The Impact of ATG in Latin American Experience

Severe aplastic anemia (SAA) is characterized by the absence of progenitor hematopoietic cells in bone marrow caused mainly by autoimmunity. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the treatment of choice for young newly diagnosed patients with SAA. The preferred source of stem cells is bone marrow (BM) due to improved overall survival (OS) and lower incidence of graft versus host disease (GVHD).In Latin American countries, many patients have received peripheral blood stem cell transplantation (PBSCT) for several reasons: lower cost, apheresis without anesthesia, no bone punctures and faster hematological recovery. Moreover, due to patient family or donors idiosyncratic factors, there is a lack of acceptance to surgical harvesting of bone marrow. Therefore we describe the Latin American experience with allo-HSCT using PBSC in SAA patients.One hundred and ninety patients with acquired SAA that received allo-HSCT using PBSC between 1997- 2014 were included. The allo-HSCT was performed at 4 centers of Perú, Colombia and México. All donors were HLA-identical siblings mobilized with G-CSF. The choice of the conditioning regimens was made on each institution. Primary outcome was OS; incidence of GVHD, outcome of patients > 40 years old and effect of conditioning regimens on survival were studied.The median of CD 34+ cells administered was 4.22 X 10⁶/kg (range 0.70-22.28). Median of neutrophil and platelet recovery was 11 days (range 7-35) and 12 days (range 8-25) respectively. Neutrophil recovery for anti-thymocyte globulin (ATG)-based regimens presented at a median of 11 days (range 7-28) and for non-ATG based regimens 14 days (range 9-35) (P<0.001). Median platelet recovery for ATG based regimens was 10 days (range 8-17) and 14 days (range 8-25) for non ATG based regimens. (P=0.02) Engraftment did not occur in 5% of recipients (n=10).The incidence of acute graft versus host disease (aGVHD) was 19.5% (8.4% was grade III-IV). Chronic GVHD (cGVHD) was 24.7% and extensive manifestations presented in 5.9% of patients. No relation between the conditioning regimen used (ATG vs non-ATG based regimens) and the incidence of aGVHD (P=0.066) or cGVHD (p=0.613) was found. The administration of ≥3.0X10⁶ CD 34/Kg related to higher incidence of aGVHD grade III and IV (P=0.05), but not cGVHD (P=0.709) or extensive cGVHD (P=0.428). The presence of aGVDH and cGVHD was associated with higher mortality (P<0.0001 and P=0.0001 respectively). OS was 71% at 10-years follow-up. OS for patients ≥40 years was 75%; similar than those younger (P=0.661).Comparing ATG based regimens (n=127) vs non-ATG based regimens (n= 63) OS was 82% vs 59% respectively (P=.001). Mortality within the first 100 days post-transplant was 7%.Time from diagnosis to transplant ≥ 100 days was not a predictor of death (P=0.458). A total of 63% of patients were considered heavily transfunded and this factor was not related to relapse (P=0.96), aGVHD (P=0.75) or cGVHD (P=0.39). Nineteen patients (10%) lost their grafts; most of them had received non-ATG conditioning regimens (P=.016). Four patients (2%) developed secondary malignancies after transplant: acute myeloid leukemia (2), myelodisplastic syndrome (1) and hairy cell leukemia (1).In multivariate analysis, the use of non-ATG based regimens (P<0.0001), presence of grade III-IV aGVHD (P<0.0001), extensive cGVHD (P=0.009) and >3 X10⁶/kg CD34(P=0.04) were independent negative predictors of survival.Infections were the leading cause of death. The second cause was GVDH and related complications. The transplant was successful in 95% of patients. The OS achieved in this study at 10 years with ATG-based regimens and PBSC (82%) is comparable to that (84%) reported from the WPSAA-EBMT (Haematologica 2009) using BM. In the study reported by EBMT-CIBMTR (Blood 2007) the 5 years OS was 85% using BM in patients ≤20 years and 64% in patients > 20 years. In our study the incidence of aGVHD and cGVHD was similar the aforementioned study of WPSAA-EBMT using PBSC (19.5% vs 17%) and (24.5 vs 22%) respectively.In conclusion allo-HSCT in SAA patients using PBSC is an effective treatment resulting in cure in the majority of cases. Patients conditioned with ATG had a 10-year OS similar to that reported with BM as the source of stem cells, a prospective and comparative study is needed to definitively establish if it is safe to perform a HSCT using peripheral blood as a source of stem cells. DisclosuresNo relevant conflicts of interest to declare.

O-092a Left Ventricular Function In Children With Acute Leukaemia Receiving Hematopoietic Stem Cell Transplantation

Hematopoietic stem cell transplantation (HSCT) is a curable therapy for paediatric cancer. Cardiovascular complications are the leading cause of late morbidity and mortality in long-term childhood cancer survivors. However, cardiac function in children after HSCT is not well known. We assessed left-ventricular (LV) function in children after HSCT for acute leukaemia by using tissue Doppler imaging (TDI) and speckle tracking echocardiography (STE). Forty consecutive patients (median 11.9 years) who had HSCT for acute leukaemia between 2011 and 2014 had undergone an echocardiographic assessment before and after (median 9.2 month) HSCT. LV function parameters, including conventional, TDI, and STE data, were collected from patients’ echocardiographic data, and were compared with those of controls (n = 39, median age 9 years). All patients had anthracycline as a pre-HSCT chemotherapy. At post-HSCT, patients had decreased LV ejection fraction (p = 0.06), rate-corrected velocity of fibre shortening (p = 0.04), and mitral septal annular E’ velocity (p = 0.03) compared with controls. STE parameters also decreased in patients; mid LV global circumferential strain (p 400 mg/m2 showed significantly lower mid LV global circumferential strain (p < 0.05) and mid LV global circumferential diastolic SR (p < 0.05). Patients who received HSCT for acute leukaemia had subclinical cardiac dysfunction, which may be associated with pre-HSCT anthracycline exposure with little effect of conditioning regimens. Serial monitoring of cardiac function is mandatory in all children following HSCT.

Targeting the minimal residual disease in acute myeloid leukemia: the role of alloreactive natural killer cells

SUMMARY The clinical results of AML patients, especially if elderly, are particularly dismal, although the achievement of CR with MRD after combined chemotherapy appears as possible in a good fraction of patients. Indeed, the persistence of MRD leads to progression and patients ultimately die. For these reasons, alternative approaches for the prevention of relapse in CR patients are necessary and are currently under active investigation. Allogeneic stem cell transplantation (SCT), which combines the cytotoxic effect of conditioning regimen with adoptive immunotherapy, has been shown to offer a clear advantage in terms of relapse prevention, thus providing the proof-of-principle of the capacity of immune cells of eradicating MRD. However, such approach has several and important limitations and is not applicable to all the patients, especially if elderly. In this scenario, the role of immunological therapies in the post-remission management of adult AML patients, such as NK therapy, beside the SCT setting, have been recently exploited with promising results in terms of immunological and clinical responses.

Unresolved issues in hematopoietic stem cell transplantation for severe combined immunodeficiency: Need for safer conditioning and reduced late effects

In this review we discuss recent outcomes of hematopoietic cell transplantation (HCT) for patients with severe combined immunodeficiency (SCID), including survival, T- and B-cell reconstitution, and late effects, particularly those related to genotype, use of conditioning regimen, and use of alternative donors. We identify the following issues that require additional data, which can be obtained through cooperative studies: outcomes of patients with SCID who did not receive conditioning before alternative donor HCT; outcomes of patients with SCID who did not receive graft-versus-host disease prophylaxis after T cell-replete HCT; late effects of HCT for patients with SCID, including neurocognitive outcomes, growth, and development; and their relationship to genotype and use of alkylating agents for conditioning. Careful follow-up of outcomes of all newborns receiving diagnoses based on newborn screening programs for SCID is essential because data are scarce on the effects of conditioning regimens in very young patients. A consensus on the definition of T- and B-cell recovery, criteria for additional "boosts," pharmacokinetic data of chemotherapy agents used in young children, and uniformity of the use of various chemotherapy agents are needed to compare results among institutions. Finally, development of new nontoxic conditioning regimens for HCT that can be safely used in very young children is required.

Development of a patient education pamphlet: Effects of conditioning regimens in stem cell transplantation on gonadal function

Development of a patient education pamphlet: Effects of conditioning regimens in stem cell transplantation on gonadal function

Results of Haematopoietic Stem Cell Transplantation (HSCT) for Hurler's Syndrome: European Experience 1994–2004.

Worldwide more than 400 patients with Hurler's syndrome (HS), characterized by severe neurodegeneration, cardiac disease, skeletal abnormalities and death in early childhood, have undergone allogeneic-HSCT since 1980. Although, long term follow up of successfully transplanted children is very encouraging, the engraftment and survival results are very variable between the various studies, ranging from less than 25% up to more than 85%. We retrospectively analyzed the results of 146 patients transplanted in Europe from 1994–2004, to assess: 1) the effect of conditioning regimen and grafts (-manipulation) used on the “alive and engrafted” rate and 2) the transplantation-related morbidity/mortality.HSCT with a family donor was performed in 52 patients. An unrelated donor was used in 94 patients. The majority of patients received marrow (n=103). The rest received cordblood (n=23) or peripheral blood (n=20). Twenty-eight patients received a T-cell depleted (TCD) graft. Conditioning regimens used were grouped as follows: busulfan-cyclofosfamide 200mg/kg (n=68), busulfan- with high dose cyclofosfamide (either 240mg/kg or 260mg/kg; n=41), fludarabine-based myelo-ablative (n=19) and reduced intensity conditioning regimens (RIC: n=18). Fourteen patients received dose-adjusted busulfan. Engrafted was defined as a donor chimerism of more than 10%, and an alpha-L-iduronidase level of more than the lower limit of normal for the heterozygote individuals (>4.5 nmol/hr/mg).The “alive and engrafted” rate after first transplantation and overall “alive and engrafted” rate after one to three transplantations was 83/146 (57%) and 111/146 (76%), respectively. The median follow up was 39 mth (5–120mths). Multivariate analysis (confounders: age, sex, heterozygote donor, unrelated donor, stem cell source, HLA-disparity, conditioning regimen, TCD and busulfan targeting) on the primary endpoint “alive and engrafted” showed that RIC (RR 13,4: 2,6–67,1) and TCD (RR 5,7: 1,14–28,4) are individual risk factor for graft failure. Busulfan targeting suggests to be an individual protective factor (RR 0,27; 0,04–1,8); 12/14 (86%) were “alive and engrafted” after 1st HSCT. Thirthy three patients received a 2nd graft, of whom 26/33 (82%) are alive and engrafted: 16/21 using the same, 10/12 using a different donor, and 16/19 after myeloabaltive, 10/14 after RIC. Two of the 3rd HSCTs were successful. After 1st HSCT moderate to severe aGvHD (grade ≥2) occurred in 23/146 (16%) patients. Extensive cGvHD was seen in 2/114 (1.4%) patients, only. IPS/DAH was seen in 4/134 (2.3%) patients and VOD in 12/134 (9%) patients. Main cause of death (n=28) was infectious (n=15: mainly viral). Other causes of death: GvHD (n=3), Cardiac ECI (n=2), VOD (n=2), DAH (n=1), unknown (n=1), Hurler (n=4). The majority of the “alive and engrafted” patients have a donor chimerism of >95% (91/111; 82%), 11/111 (9,9%) between 75–95%, 6/111 (5,4%) between 50–75% and 3/111 (2.7%) between 10–50%.In summary, no stem cell source (BM, cordblood and PBSC) is superior and no conditioning regimen used is superior. RIC and TCD results in inferior engraftment rates. Second HSCTs are successful in more than 80%. Relatively low morbidity rates are seen. The engraftment of HSCT for HS can be optimized by avoiding T-cell depletion, RIC and probably by busulfan-targeting.

Function of the hypothalamic–pituitary–gonadal axis in long-term survivors of hematopoietic stem cell transplantation for hematological diseases

Gonadal dysfunction in adult long-term survivors of hematopoietic stem cell transplantation (HSCT) is an adverse effect of conditioning regimens consisting of chemotherapy and total body irradiation (TBI). The impact of conditioning regimens consisting of chemotherapy alone on the function of the hypothalamic–pituitary–gonadal (HPG) axis was evaluated in a series of 41 female and 31 male patients who had undergone either autologous or allogeneic bone marrow/peripheral blood stem cell transplantation; mean age at transplantation was 32.6 years and mean time interval from transplantation was 1.5 years (range 0.2–9.8 years). Provocative testing of the HPG axis by administration of luteinizing hormone-releasing hormone was included in the first endocrinological evaluation. The follow-up period extended to three consecutive years. Gonadal dysfunction was not reported by any of the patients prior to their underlying illness. Hypergonadotrophic hypogonadism was observed in 97% of female and 19% of male patients. Leydig cell strain (normal testosterone, high luteinizing hormone levels) was evident in 32% and spermatogenesis damage (high follicle-stimulating hormone levels) in 68% of the male population. At the conclusion of the study four women (10%) had regained spontaneous menses and all hypogonadal men had resumed normal testosterone levels. Our results indicate a high incidence of gonadal dysfunction due to target organ failure in HSCT recipients not treated by TBI.

Keratinocyte apoptosis following bone marrow transplantation: evidence for CTL-dependent and -independent pathways.

Acute graft-versus-host disease (GVHD) is a complication of bone marrow transplantation (BMT). The histopathologic features used to diagnose GVHD are nonspecific, and may be secondary to chemotherapy or irradiation given before BMT. The presence of apoptotic keratinocytes or activated CTL may distinguish GVHD from conditioning effects. This study investigated the relationship in BMT recipients between keratinocyte apoptosis and the effects of conditioning regimens or immune-mediated GVHD. Inflammatory cells, apoptotic keratinocytes, and CTL expressing TIA-1 (a molecule associated with the lytic granules of CTL) were quantitated in allogeneic and autologous recipients. Allogeneic recipients could exhibit keratinocyte apoptosis secondary to a combination of conditioning effects and immune-mediated GVHD. In contrast, autologous recipients should show conditioning effects only. 'Capped' TIA-1-positive lymphocytes and apoptotic keratinocytes were much more frequent in the allogeneic group than the autologous group (16.1% of total TIA-1 positive lymphocytes vs 4.5%, P=0.02; and 37.6/mm2 vs 3.9/mm2, P = 0.005, respectively), although there was some overlap in their frequency. Among individual recipients of allogeneic BMT, the number of epidermal lymphocytes or macrophages correlated with the number of apoptotic keratinocytes. A similar, but weaker, correlation was seen between the number of 'capped' TIA-1-positive lymphocytes and apoptotic keratinocytes. No such relationship was seen in autologous recipients. In allogeneic recipients, TIA-1 expressing CTL were seen in intimate contact with apoptotic keratinocytes, some of which also had detectable cytoplasmic TIA-1. No CTL/keratinocyte interactions were identified in autologous recipients. Our results suggest that apoptotic keratinocytes arise in the skin of BMT patients due to both GVHD and conditioning effects, and that the keratinocyte damage in GVHD is mediated by both CTL-dependent and -independent mechanisms. Increased numbers of apoptotic keratinocytes, in the presence of increased epidermal lymphocytes or 'capped' TIA-l-expressing lymphocytes, support a diagnosis of GVHD, but must be interpreted in the context of clinical information and other histopathologic findings.

TBI containing regimens followed by hematopoietic stem cell transplantation in acute lymphoblastic leukemia of childhood

Acute lymphoblastic leukemia in childhood is the domain of chemotherapy giving rates of event free survival of up to 80% for the vast majority of children. Only 6% of well defined high risk patients during frontline treatment but on the other side the majority of children following relapse do not have a satisfying chance of cure by chemotherapy alone. The controversy persists, whether hematopoietic stem cell transplants provide a superior chance of cure. The answer can only be given by c1early defined prospective studies including patients with the intention to transplant but finally events before the transplant can be performed. The BMF group is currentlyconducting such a study during frontline therapy. Out of 3050 children with newly diagnosed ALL 197 patients fulfilled the criteria for a matched related bone marrow transplantation. An acceptable family donor was available in 53 children, which is in the expected range of 27% of HLA-identical siblings or family members in Germany. Only 30 children have been transplanted at the end, using a conditioning regimen of fractionated TBI (6 × 2 Gy) and VP16 (60 mg/kg). Although the transplanted children have an EFS of about 70% and the whole group with a donor and the intention to transplant of about 60% compared to 30% EFS in the complementary group, the transplant group is by far too small lead to furtherincrease of survival in the whole group of children with ALL. Some children received alternative conditioning regimens with obviously less chance of cure. But the major question for the future remains the donor availability for high risk frontline patients but more important for relapse patients in order to prove the transplant approach in general in such patients. Clearly autografts seem not to give any advantage in these type of children, unless any new approach of maintenance/immunotherapy is providing a significant additional effect. Unrelated grafts on the other side might be one option but still require a significant reduction of treatment risks, which are currently still in the range of 30–50% compared to 10% and less in matched related transplants. Cord blood transplants especially – in children may be superior to adult marrow or peripheral blood stem cell transplants. And finally, first steps have been done now to overcome the high rejection rate of mismatched related grafts by increasing for example the stem cell dose and thus offering another source of stem cell grafts also for ALL patients. Unfortunately, also these transplants are still associated with high transplant related risks. Almost all centers employing haploidentical stem cell transplants are using TBI containing regimens even with an increased dose. Our own approach on this fields is to understand the side effects of conditioning regimens containing TBI on the homing process of stem cells in the microenvironment of the marrow, and to overcome ex vivo as well as in vivo such critical dysfunctions with the aim to ensure engraftment and limit transplant risks by accelerating the hematopoietic and lymphopoietic reconstitution. This model will be discussed.