Matched Family Donor Research Articles

HHV-6 Infection/Reactivation after Allogeneic Stem Cell Transplantation in Pediatric Patients: Epidemiology, Risk Factors and Outcome

Introduction. Hematopoietic stem cell transplantation (HSCT) exposes the recipient to a high risk of developing viral reactivations especially during the first weeks after HSCT. Neutropenia and lymphopenia, together with the breakdown of physical barriers expose patients not only to bacterial and fungal infections but also to viral infection/reactivations. HHV-6 is usually acquired during infancy, and seroprevalence in the adult population may reach 90%. Like other herpesviruses, HHV-6 persists latently within permissive cells and it can reactivate during immunosuppression. A high incidence of HHV-6 reactivation is frequently detected after HSCT, but its clinical relevance is still debated. The objectives of this retrospective study were to estimate the incidence of HHV6 reactivation after pediatric HSCT, analyze the possible risk factors and evaluate the impact on outcome.Patients and methods. We analyzed 234 pediatric subjects given HSCT from a matched family donor (MFD, 17.5%), a matched unrelated donor (MUD, 43.6%) or a partially matched family donor (PMFD, 38.9%) for malignant (55.2%) or non-malignant hematologic diseases (25.6%) between 2010 and 2017. Data have been analyzed according to patient, donor and transplant characteristics. Risk factors analysis was computed throughout the comparison of the cumulative incidence (CI) of HHV-6 reactivation according to descriptive variables. Kaplan Mayer curves were used to illustrate survival results (OS and EFS), and Log-rank test was used to compare groups. The analysis of outcome was completed by analyzing the CI of neutrophils and platelets engraftment, rejection, acute and chronic GvHD, NRM according to presence or absence of HHV-6 reactivation. Gray-test was used to compare different CI curves. The quantification of HHV-6 exposure was calculated using the area under the curve (AUC) of viremia level over time. AUC expresses the kinetics of the DNA viral load in a time-concentration chart. The stratification of patients according to HHV-6 AUC quartiles (AUCq = each of 4 equal groups into which the HHV6 positive population was divided according to distribution of the value of AUC) allowed to describe the viral burden and the intensity of viral exposure. Risk factors analysis and survival analysis were then performed using the parameter AUC and AUC quartiles.Results. The cumulative incidence of HHV-6 reactivation was 58%, with onset usually within the first month after transplantation (median 19 days). The peak viral load was detected at an average time of 55 days after onset (median 25 days) with a median of 5850 cp/mL (range 50 - 219^106 cp/mL). In univariate analysis, a diagnosis of malignant disease (p=0.021), transplant from PMFD (p=0.010), the use of a busulfan/TBI-based vs Treo-based conditioning regimen (p=0.020), the use of ex vivo T cell-depletion (p<0.001) and the use of ATG (p<0.001) were risk factors for HHV6 reactivation. In multivariate analysis, only the use of ATG remained statistically significant (p=0.025). The occurrence of HHV-6 infection, considered as a categorical variable, did not affect transplant outcome, in particular neutrophils and platelets engraftment, acute and chronic GvHD, rejection, OS, EFS and NRM. All analysis for risk factors and outcomes were then repeated using the AUC and AUCq parameters. HHV-6 exposure measured as AUC or AUCq again failed to demonstrate any impact on outcome. However, in the PMFD group, OS and EFS were worse, although not statistically significant, for the 3rd-4th AUCq compared to negative or 1st-2nd AUCq.Conclusions. Based on the results obtained, HHV-6 infection/reactivation, measured as categorical variable or as viral exposure, does not seem to have an impact on HSCT outcomes. Therefore, routine viral monitoring may not give added benefit in the pediatric HSCT setting. However, in selected populations, early restricted monitoring may identify HSCT recipients at risk of HHV6-related disease. DisclosuresZecca:Chimerix: Honoraria.

Stem Cell Transplantation in Advanced Stage Sickle Cell Disease with Haploidentical T-Cell Depleted PBSC Yields Comparable Outcomes to Matched Sibling Donor Bone Marrow: Results of a Pilot Study

Background: Sickle cell disease (SCD) is an inherited disorder with an estimate of 300,000 affected newborns per year worldwide. Despite improvements in preventive measures and conventional therapy, substantial morbidity and mortality, resulting in a reduced life expectancy persist. Allogeneic hematopoietic stem cell transplantation (HSCT) with a matched sibling donor (MSD) is currently the curative standard of care. However, matched donor availability is <20% and unrelated donor (MUD) HSCT is associated with unacceptably high rates of severe graft-versus-host disease (GvHD). A T-cell depleted HSCT from a haploidentical relative (T-haplo-HSCT) expands donor availability while exhibiting low GvHD rates and thus could offer cure to the remaining 80% of SCD patients (pts).Methods: We report the results of 29 pts with advanced stage SCD transplanted with either a T-cell depleted haploidentical regimen (20 pts, median age 13 years, range 3-31 years) or with bone marrow from a matched family donor (MSD, 9 pts, median age 14, range 9-25 years). Indication for HSCT was advanced stage SCD related complications. Pts with a MSD received a bone marrow (BM) graft. Pts requiring an alternative donor were transplanted with an αß/CD19 (n=5) or CD3/CD19 (n=15) depleted graft from a haploidentical family donor. The conditioning regimen for both groups was identical except that antithymoglobulin (ATG-Neovii®) was given upfront on day -10 to -8 in T-haplo-HSCT and on day -3 to -1 in MSD. Chemotherapy consisted of thiotepa 2 x 5 mg/kg, fludarabine 4 x 40 mg/m2 and treosulfan 3 x 14 g/m2, given between days -10 and -2. Post-HSCT immunosuppression consisted of mofetil mycophenolate and tacrolimus or cyclosporine A for a duration >6 months in T-haplo-HSCT and <6 months in MSD, depending on chimerism. The MSD group received a graft containing a median of 2.4 x 108 cells/kg body weight (BW). The T-haplo-SCT group received a peripheral stem cell allograft with a median of 13.1 x 106 CD34+ cells/kg BW.Results: The conditioning regimen was well tolerated in all pts with no high-grade transplant related toxicity. The overall (OS) and disease-free survival (DFS) with a median follow-up of 17 months in 20 advanced stage mostly adolescent and adult T-haplo-HSCT pts and 22 months in 9 MSD HSCT pts was 90% vs. 100%, respectively. Engraftment was achieved in most pts with stable chimerism over 90%, except for 4 pts with a stable MC in the T-haplo SCT group and 1 patient in the MSD group off immunosuppression. All pts presented a complete BM engraftment of red cell precursors. Only one patient in the T-haplo-HSCT group with a mixed chimerism is still under immunosuppression.The post-HSCT bacterial infectious complications were comparable in both groups and the most common observed viral infections were systemic cytomegaly virus (CMV), adenovirus (ADV), polyomavirus (BKV) and Epstein Barr virus (EBV) reactivations which were successfully treated with intravenous antiviral drugs or virus specific T-cells.Two patients in the T-haplo-HSCT group achieved a DFS off immunosuppression but succumbed to post-HSCT complications. One developed a rotavirus gastroenteritis and an uncontrolled CMV pneumonitis. The other a late graft failure and succumbed to a macrophage activation syndrome.None of our pts developed a Glucksberg Grade III-IV acute GvHD and in the T-haplo SCT group 4 pts (20%) and in the MSD group 2 pts (22%) developed a steroid sensitive mild to moderate cGvHD (fasciitis/oral as well as mild cutaneous GvHD). No extensive cGvHD was observed.To our knowledge this is the largest group of advanced stage SCD pts transplanted with either a T-haplo-HSCT or a MSD approach, according to donor availability, with an almost identical regimen in a direct comparative design. These preliminary results demonstrate increasing evidence for the feasibility, safety and efficacy of a T-haplo-HSCT using CD3/CD19 or αβ/CD19 depleted grafts, in order to offer a curative option to the majority of pts with SCD. A prospective, stratified non-inferiority trial is in preparation (EudraCT number 2018-002652-33) in order to confirm these preliminary results in a large prospective cohort. DisclosuresCorbacioglu:Gentium: Consultancy, Honoraria; Jazz Pharmaceuticals: Consultancy, Honoraria.

Analysis of Risk Factors Determining Incidence and Outcome of Infections in Children and Adults after Hematopoietic Cell Transplantation

BACKGROUNDRecent EBMT analysis showed that infections are responsible for 21% of deaths after allo-HCT and 11% after auto-HCT. However, the risk, types and outcome of infections vary between age groups. The aim of the study is the direct comparison of risk factors of incidence and outcome of infections in children and adults. PATIENTS AND METHODSWe analyzed risk factors for the incidence and outcome of bacterial, fungal, and viral infections in 650 children and 3200 adults who received HCT between 2012-2015. The risk factors were determined by multivariable logistic regression analysis. RESULTSA total number of 395/650 (60.8%) children and 1122/3200 (35.0%) adults were diagnosed for microbiologically confirmed infection, including 345/499 (69.1%) and 679/1070 (63.5%), respectively after allo-HCT, and 50/151 (33.1%) and 443/2130 (20.8%) respectively, after auto-HCT. At 2 years after HCT, the incidences of microbiologically documented bacterial infection were 36.0% and 27.6%, (p<0.001) for children and adults, respectively. Incidences of proven/probable invasive fungal disease (IFD) were 8.4% and 3.7% (p<0.001), respectively; and incidences of viral infection were 38.3%, and 13.5% (p<0.001), respectively. Overall, 31/650 (4.8%) children and 206/3200 adults (6.4%) have died after these infections. The distribution of deaths was different in children (35.5% bacterial, 48.4% fungal, 16.1% viral) and adults (61.7% bacterial, 24.7% fungal, 13.6% viral). BACTERIAL INFECTIONS: In multivariable analysis, the risk of infections was higher after allo-HCT (HR=1.8; p<0.001). In allo-HCT patients, the risk was higher in children (HR=2.1; p<0.001), in patients with acute leukemia (HR=1.6; p<0.001), matched unrelated (MUD) vs matched family-donor (MFD) HCT (HR=1.6; p<0.001), mismatched unrelated (MMUD) vs MFD HCT (HR=2.0; p<0.001), myeloablative vs reduced-intensity conditioning (RIC) (HR=1.3; p<0.001), delayed (>21d) hematological recovery (HR=3.3; p<0.001), acute GVHD before infection (HR=1.7; p<0.001), and chronic GVHD before infection (HR=1.4; p=0.014). In auto-HCT patients, the risk was higher in children (HR=1.7; p<0.001), and in patients with delayed hematological recovery (HR=2.8; p<0.001). In patients with multiple myeloma (MM) the risk was decreased (HR=0.7; p=0.005). FUNGAL INFECTIONS: The risk of proven/probable IFD was higher after allo-HCT (HR=5.4; p<0.001). In allo-HCT patients, the risk was higher in children (HR=3.9; p<0.001), in patients with acute leukemia (HR=3.8; p<0.001), MUD vs MFD HCT (HR=1.5; p=0.013), MMUD vs MFD HCT (HR=2.5; p<0.001), delayed hematological recovery (HR=3.3; p<0.001), acute GVHD before infection (HR=1.5; p=0.021), and chronic GVHD before infection (HR=2.2; p<0.001). In auto-HCT patients, the risk was higher in children (HR=1.8; p=0.025). Patients with MM were at decreased risk of IFD (HR=0.6; p=0.005). VIRAL INFECTIONS: In multivariable analysis, the risk of infections was higher after allo-HCT (HR=6.1; p<0.001). In allo-HCT patients, the risk was higher in children (HR=1.3; p=0.010), in patients with acute leukemia (HR=1.7; p<0.001), MUD vs MFD HCT (HR=2.0; p<0.001), MMUD vs MFD HCT (HR=3.3; p<0.001), myeloablative vs RIC (HR=1.8; p=0.050), acute GVHD before infection (HR=1.5; p<0.001) and chronic GVHD before infection (HR=2.7; p=0.014). Among auto-HCT patients, diagnosis of MM brought decreased risk of viral infections (HR=0.5; p<0.001). DEATH FROM INFECTION: In allo-HCT patients, adults (HR=3.3; p<0.001), recipients of MMUD-HCT (HR=3.8; p<0.001), patients with acute leukemia (HR=1.5; p=0.023), chronic GVHD before infection (HR=3.6; p=0.014), CMV reactivation (HR=1.4; p=0.038) and with duration of infection treatment >21 days (HR=1.4; p=0.038) were associated with increased risk of death from infection. Among patients with bacterial infections, the risk was higher in G- infections (HR=1.6; p=0.031). Among auto-HCT patients, no child died of infection. In adults, the risk of death was higher if duration of treatment of infection was >21 days (HR=1.7; p<0.001). In patients with MM the risk was decreased (HR=0.4; p<0.001). CONCLUSIONSThe profile of infections and related deaths varies between children and adults. MMUD transplants, diagnosis of acute leukemia, chronic GVHD, CMV reactivation and prolonged infection are relative risk factors for death from infection after HCT. DisclosuresKalwak:Sanofi: Other: travel grants; medac: Other: travel grants.

From Bone Marrow to Mobilized Peripheral Blood Stem Cells: The Circuitous Path to Clinical Gene Therapy for Fanconi Anemia

▪For decades, it has remained challenging to achieve long-term engraftment and correction of blood counts using gene-modified hematopoietic stem cells for Fanconi anemia. Toward this goal, our group conducted preclinical studies using a safety modified lentiviral vector encoding full-length cDNA for FANCA in normal and affected patient hematopoietic progenitor cells, and in a mutant mouse model that supported the IND for a gene therapy clinical trial for Fanconi anemia, complementation group A (NCT01331018). These studies led us to incorporate methods such as addition of N-acetylcysteine and hypoxic incubation during transduction.Because of the low stem cell numbers of Fanconi patients and initial difficulty with using plerixafor off-label for mobilization, we began our study with bone marrow as the source of stem cells. Due to concerns regarding secondary cancers, no conditioning was administered prior to infusion of gene-modified cells. The US Food and Drug Administration approved adult patients initially, but later permitted pediatric patient enrollment with a minimum age of 4 years. The primary objective of our phase I trial was safety. Secondary objectives included in vitro correction of mitomycin C (MMC) sensitivity, procurement of sufficient cell numbers, and ultimately, long-term correction of blood counts in recipients. Eligibility included absolute neutrophil count ≥0.5, hemoglobin ≥8, platelet count ≥20,000, lack of matched family donor, adequate organ function, and not meeting criteria for diagnosis of MDS.Our three enrolled patients were ages 22, 10, and 5 years. All demonstrated defects in the FANCA gene, with two patients sequenced and one patient diagnosed by complementation. Due to in-process learning and the later addition of plerixafor mobilization to the protocol, three different laboratory procedures were used to prepare the gene-modified product for each patient. Cell products were CD34+ selected bone marrow, bone marrow mononuclear cells depleted of red cells by hetastarch, and G-CSF and plerixafor mobilized cells depleted of red blood cells and cells bearing lineage markers, respectively. Transduction efficiencies were 17.7, 42.7 and 26.3% of colony forming cells (CFC) in 0 nM MMC, and 80, 100, and 100% of CFC in 10 nM MMC. Growth of hematopoietic colonies in MMC indicated functional correction of the FANCA defect. The 1st patient received 6.1×10e4, the 2nd 2.9×10e5, and the 3rd 4.3×10e6 CD34+ cells/kg. Serious adverse events included cytopenias in all patients, and hospital admission for fever due to viral upper respiratory infection in one patient. The patients remain alive at 46, 38, and 12 months after receipt of gene-modified cells. Due to worsening cytopenias, the third patient underwent hematopoietic cell transplant from an unrelated donor 10 months after infusion of gene-modified cells. To date, he has done well with transplant, and no indication that prior gene therapy impacted the outcome. The blood counts for the first 2 patients who have not undergone allogeneic transplant remain stable at 1,111 and 1,077 days post infusion compared to the first blood counts when they arrived at our center. For the 1st patient, vector was detectable in white blood cells (WBC) up to 21 days, in the 2nd up to 582 days, and the 3rd up to 81 days post infusion. Thus, in these patients, despite dramatic improvement in cell dose during the study, there was lack of persistence in detection of gene-modified WBCs beyond 1.5 years. A number of factors may have contributed, including lack of conditioning, in vitro cell manipulation including cytokine exposure, inability to transduce primitive hematopoietic stem cells, and paucity of long-term repopulating cells at the ages of the patients, suggesting earlier collection may be beneficial.This study is now closed to enrollment. Valuable information gained as a result of this study will contribute to future clinical gene therapy trials. Current work focuses on how to evaluate stem cell fitness prior to attempting gene therapy, minimizing manipulation required for gene correction and/or in vivo genetic correction and non-chemotherapy-based conditioning to facilitate engraftment.We would like to personally thank each patient and their families for participating in this study, as we could not have learned these lessons without their support. DisclosuresBecker:GlycoMimetics: Research Funding; Abbvie: Research Funding; Amgen: Research Funding; BMS: Research Funding; CVS Caremark: Consultancy; Trovagene: Research Funding; Rocket Pharmaceuticals: Research Funding; Novartis: Research Funding; Pfizer: Consultancy; JW Pharmaceuticals: Research Funding. Adair:Miltenyi Biotec: Honoraria; RX Partners: Honoraria; Rocket Pharmaceuticals: Patents & Royalties: PCT/US2017/037967 and PCT/US2018/029983. Kiem:Rocket Pharmaceuticals: Consultancy; Homology Medicine: Consultancy; Magenta: Consultancy.

Potential Risks to Stable Long-term Outcome of Allogeneic Hematopoietic Stem Cell Transplantation for Children With Cerebral X-linked Adrenoleukodystrophy

Allogeneic hematopoietic stem cell transplantation is the standard intervention for childhood cerebral X-linked adrenoleukodystrophy. However, the pretransplant conditions, demyelination patterns, complications, and neurological outcomes of this therapy are not well characterized. To identify the risks to stable neurocognitive survival after hematopoietic stem cell transplantation and to describe subgroups of patients with distinct clinical long-term outcomes. This case series analyzed the treatment and outcome of a cohort of 36 boys who underwent hematopoietic stem cell transplantation at Charité Universitätsmedizin Berlin, Germany, between January 1, 1997, and October 31, 2014. Case analysis was performed from January 1, 2016, through November 30, 2017. During this retrospective review, the adrenoleukodystrophy-disability rating score and the neurological function score were used. Demyelinating lesions in the brain were quantified by the Loes score. Overall survival, survival without major functional disabilities, and event-free survival were analyzed. Patients' clinical symptoms, demyelination patterns, and stem cell source were stratified. Of the 36 boys who underwent hematopoietic stem cell transplantation, the median (range) age was 7.2 (4.2-15.4) years; 18 were presymptomatic and 18 were symptomatic. Twenty-seven patients (75%) were alive at a median (interquartile range [IQR]) follow-up of 108 (40-157) months. Sixteen of 18 presymptomatic patients (89%) survived, and 13 (72%) had an event-free survival with a median (IQR) survival time of 49 (37-115) months. Among the symptomatic patients, 11 of 18 (61%) survived, but only 1 was an event-free survival (6%) (median [IQR] time, 9 [3-22] months). Of the 9 patients who received a bone marrow transplant from a matched family donor, all survived. Among the 36 patients, 6 disease-related deaths (17%) and 3 transplant-related deaths (8%) occurred. Deaths from disease progression (n = 6) occurred only in patients with demyelination patterns other than parieto-occipital. In total, 18 patients (50%) displayed limited parieto-occipital (Loes score <9) or frontal (Loes score <4) demyelination before transplant (favorable). None of these patients died of progressive disease or developed major functional disabilities, 15 of them were characterized by stable neuroimaging after the transplant, and event-free survival was 77% (95% CI, 60%-100%). In contrast, the other 18 patients with more extended parieto-occipital demyelination (n = 6), frontal involvement (n = 4), or other demyelination patterns (n = 8) progressed (unfavorable): 13 patients developed epilepsy and 10 developed major functional disabilities, and their event-free survival was 0%. This newly defined neuroimaging assessment correlated best with neurocognitive deterioration after transplant (hazard ratio, 16.7; 95% CI, 4.7-59.6). All patients with favorable neuroimaging who received matched bone marrow remained stable after transplant, while some of the other patients developed major functional disabilities. Newborn screening for the disease and regular neuroimaging are recommended, and patients who lack a matched bone marrow donor may need to find new therapeutic options.

Hematopoietic stem cell transplantation for isolated extramedullary relapse of acute lymphoblastic leukemia in children.

Relapse of acute lymphoblastic leukemia (ALL) may occur in extramedullary sites, mainly central nervous system (CNS) and testis. Optimal post-remissional treatment for isolated extramedullary relapse (IEMR) is still controversial. We collected data of children treated with hematopoietic stem cell transplantation (HSCT) for ALL IEMR from 1990 to 2015 in Italy. Among 281 patients, 167 had a relapse confined to CNS, 73 to testis, 14 to mediastinum, and 27 to other organs. Ninety-seven patients underwent autologous HSCT, 79 received allogeneic HSCT from a matched family donor, 75 from a matched unrelated donor, and 30 from an HLA-haploidentical donor. The 10-year overall survival was 56% and was not influenced by gender, ALL blast immune-phenotype, age, site of relapse, duration of first remission, and type of HSCT. In multivariable analysis, the only prognostic factors were disease status at HSCT and year of transplantation. Patients transplanted in third or subsequent complete remission (CR) had a risk of death 2.3 times greater than those in CR2. Children treated after 2000 had half the risk of death than those treated before that year. Our results suggest that both autologous and allogeneic HSCT may be considered for the treatment of pediatric ALL IEMR after the achievement of CR2.

Frequency of Finding Family Donors: A Single Center Experience.

Allogeneic hematopoietic stem cell transplant is a curative treatment option for many hematologic diseases. The existence of a fully compatible donor for recipients is the first condition for minimized transplant-related mortality and morbidity. The best donor for hematopoietic stem cell transplant is an HLA-matched sibling donor. The possibility of finding an HLA-matched sibling is less than 30% worldwide. Hematopoietic stem cell transplant is needed for an increasing number of patients every year, but the ability to find a fully compatible donor has limited its use. From August 2012 to May 2017, we screened 412 adult patients who required AHSCT and their families for HLA tissue groups who were seen at our center (Baskent University Adana Dr. Turgut Noyan Research and Medical Center Hematology Unit). To screen tissue groups at our center, we perform lowresolution typing for HLA-A, -B, -C, -DRB1, and -DQB. If an HLA genotype cannot be identified, verification typing is done using highresolution testing. We found matched family donors in 227 (55%) of 412 patients screened at our center. The ratio of HLAmatched related donors was 83% for 279 patients who received allogeneic stem cell transplant. The likelihood of finding eligible unrelated donors has been gradually increasing, in part due to the development of the National Bone Marrow Bank. However, a careful screening for related donors is still important. Our findings indicate the importance of careful examination of family genealogy and of careful family screening in our region.

Successful hematopoietic stem cell transplantation for osteopetrosis using reduced intensity conditioning.

Infantile malignant osteopetrosis (IMO) is an autosomal recessive condition characterized by defective osteoclast activity, with hematopoietic bone marrow transplant being the only available cure. Over the past several years, new conditioning regimes and donor options have emerged, thus extending the possibility of cure to a greater number of patients and improving the outcomes of bone marrow transplant. Here we detail the outcomes of bone marrow transplant in a cohort of 31 patients treated with a combination of fludarabine, treosulphan, thiotepa, and antithymocyte globulin. Thirty-one patients with IMO who underwent hematopoietic stem cell transplantation with fludarabine, treosulphan, thiotepa, and antithymocyte globulin at our center from 2012 to 2017 are retrospectively reviewed in this study. Twenty-six patients were transplanted from 10/10 matched donors (13 from siblings, 11 from unrelated, and two from extended family donors), four from 9/10 matched unrelated donors, and one from a 9/10 matched family donor. Overall survival was 100% with a median follow-up of 363 days (range 74-1891). There were 12 cases of acute graft versus host disease (GvHD) (38.7%), no cases of veno-occlusive disease, and eight cases of hypercalcemia (25.8%). Almost 80% of patients suffered viral reactivations with two cases of Epstein-Barr-virus-driven post-transplant lymphoproliferative disease. All cases of GvHD and viral reactivation were successfully treated. We conclude that transplantation in children with IMO using fludarabine, treosulphan, thiotepa, and antithymocyte globulin is safe and effective and should be performed as early as possible following diagnosis, prior to the development of severe disease sequelae.

457 - Challenges of Haematopoietic Stem Cell Transplantation in Primary Immunodeficiency Disorders in a Developing Country

Hematopoietic stem cell transplant (HSCT) is required in a subset of patients with primary immunodeficiency disorders (PID). The diagnosis of PID is often delayed in a developing country, and active infections and delay in transplantation may lead to poorer outcomes in this setting. This is a retrospective analysis of allogeneic HSCTs carried out from January 1998 to August 2017 in patients with PID in a tertiary care centre in India. Thirty-two patients with a median age 36 months (Range 6 months to 18 years) underwent allogeneic HSCT. The two most common disorders were Wiskott Aldrich syndrome (n = 8) and severe combined immunodeficiency (n = 7). Six patients had active infection at the time of transplant (1 patient with tuberculosis, 2 with nocardiosis and tuberculosis, 1 patient with fungal pneumonia and 2 with skin/soft tissue infection). Haploidentical transplants were carried out in 12 (37.5%) patients, matched sibling donor (MSD) in 10 (31.2%), matched family donor (MFD) and matched unrelated donor (MUD) in 5 (15.6%) each. Stem cells were derived from peripheral blood in 19 (59.3%) patients, bone marrow in 12 (37.5%) and cord blood in one (3.1%). Median CD34+ cell dose infused was 10.4 × 106/kg. Conditioning regimes used were busulfan based in 9 (28.1%) patients and treosulfan based in 22 (68.8%). One patient did not receive conditioning. Six patients expired prior to engraftment due to infectious complications. Of the remaining patients, all except one engrafted. Grade 3-4 acute GVHD occurred in 8 (25%) patients. Bacterial, viral and fungal infections were noted in 22 (68.8%), 19 (59.3%) and 11 (34.3%) patients respectively in peri-transplant period. Seven (21.8%) patients had chronic GVHD. The 2 year OS and EFS in MSD was 88.9 ± 10.5%, with a significantly lower OS in MUD/MFD and Haplo-identical transplants, 33.3 ± 17.2% and 40.0 ± 14.6% respectively (P = .033), and EFS 33.3 ± 17.2% and 33.3 ± 13.6% respectively (P = .022) (Figure 1). Outcomes in matched sibling donor HSCT is comparable to data in the West, however there are significant challenges associated with haplo-identical transplants in the Indian setting, with a significant mortality secondary to infections.

Outcomes of Children with Hemophagocytic Lymphohistiocytosis Given Allogeneic Hematopoietic Stem Cell Transplantation in Italy

We report on 109 patients with hemophagocytic lymphohistiocytosis (HLH) undergoing 126 procedures of allogeneic hematopoietic stem cell transplantation (HSCT) between 2000 and 2014 in centers associated with the Italian Pediatric Hematology Oncology Association. Genetic diagnosis was FHL2 (32%), FHL3 (33%), or other defined disorders known to cause HLH (15%); in the remaining patients no genetic abnormality was found. Donor for first transplant was an HLA-matched sibling for 25 patients (23%), an unrelated donor for 73 (67%), and an HLA-partially matched family donor for 11 children (10%). Conditioning regimen was busulfan-based for 61 patients (56%), treosulfan-based for 21 (20%), and fludarabine-based for 26 children (24%). The 5-year probabilities of overall survival (OS) and event-free survival (EFS) were 71% and 60%, respectively. Twenty-six patients (24%) died due to transplant-related causes, whereas 14 (13%) and 10 (9%) patients experienced graft rejection and/or relapse, respectively. Twelve of 14 children given a second HSCT after graft failure/relapse are alive and disease-free. Use of HLA-partially matched family donors was associated with higher risk of graft failure and thus with lower EFS (but not with lower OS) in multivariable analysis. Active disease at transplantation did not significantly affect prognosis. These data confirm that HSCT can cure most HLH patients, active disease not precluding successful transplantation. Because in HLH patients HLA-haploidentical HSCT performed through CD34+ cell positive selection was found to be associated with poor sustained engraftment of donor cells, innovative approaches able to guarantee a more robust engraftment are warranted in patients given this type of allograft.

Reticular dysgenesis: international survey on clinical presentation, transplantation, and outcome

AbstractReticular dysgenesis (RD) is a rare congenital disorder defined clinically by the combination of severe combined immunodeficiency (SCID), agranulocytosis, and sensorineural deafness. Mutations in the gene encoding adenylate kinase 2 were identified to cause the disorder. Hematopoietic stem cell transplantation (HSCT) is the only option to cure this otherwise fatal disease. Retrospective data on clinical presentation, genetics, and outcome of HSCT were collected from centers in Europe, Asia, and North America for a total of 32 patients born between 1982 and 2011. Age at presentation was <4 weeks in 30 of 32 patients (94%). Grafts originated from mismatched family donors in 17 patients (55%), from matched family donors in 6 patients (19%), and from unrelated marrow or umbilical cord blood donors in 8 patients (26%). Thirteen patients received secondary or tertiary transplants. After transplantation, 21 of 31 patients were reported alive at a mean follow-up of 7.9 years (range: 0.6-23.6 years). All patients who died beyond 6 months after HSCT had persistent or recurrent agranulocytosis due to failure of donor myeloid engraftment. In the absence of conditioning, HSCT was ineffective to overcome agranulocytosis, and inclusion of myeloablative components in the conditioning regimens was required to achieve stable lymphomyeloid engraftment. In comparison with other SCID entities, considerable differences were noted regarding age at presentation, onset, and type of infectious complications, as well as the requirement of conditioning prior to HSCT. Although long-term survival is possible in the presence of mixed chimerism, high-level donor myeloid engraftment should be targeted to avoid posttransplant neutropenia.

332 - Familial Haploidentical (FHI) T-Cell Depleted (TCD) with T-Cell Addback Stem Cell Transplantation for Patients with High-Risk Sickle Cell Disease (SCD) (IND 14359)

Allogeneic stem cell transplantation (AlloSCT) from HLA-matched unaffected sibling donors (MSD) has been successful for high-risk SCD, and is the only known curative therapy (Freed/Cairo et al, BMT, 2012). We have recently demonstrated 100% event free survival and absence of sickle cell symptoms following reduced toxicity conditioning and HLA matched sibling bone marrow or cord blood AlloSCT (Bhatia/Cairo et al, BMT, 2014). However, 5 out of 6 children who might benefit from this therapy lack an HLA matched family donor. Identifiable matched unrelated adult donors (URD) in this ethnic group are extremely limited and results from unrelated cord blood transplants are poor (Radhakrishnan K/Cairo et al., BBMT 2013, Kamani et al., BBMT, 2012). We previously demonstrated the use of positive CD34 selection followed by T cell add back (2 x 105 CD3/kg) from unrelated donors in pediatric recipients with both malignant and nonmalignant disease lead to 100% engraftment with minimal acute GVHD (aGVHD). In a high-risk FHI TCD thalassemia study, 16/22 cases engrafted without aGVHD and with 90% overall survival (Sodani et al., Blood, 2010). FHI TCD AlloSCT could expand the donor pool and improve outcomes for patients with high risk SCD. This SCD consortium trial is investigating the safety, feasibility, EFS, donor chimerism, graft failure, aGVHD and chronic GVHD (cGVHD), and infectious mortality after FHI TCD AlloSCT in high-risk SCD patients ([Figure 1][1]). High risk features included one or more of the following: ≥1 CVA, ≥2 ACS, ≥3 VOC in past 2 years, or 2 abnormal TCDs. Patients (2-20.99 yrs) without an 8/8 HLA MSD or URD and who have ≥1 high-risk SCD features were eligible. Patients received hydroxyurea 60 mg/kg/d and azathioprine 3mg/kg/d, day -59 – day -11, fludarabine (30mg/m2/d x5d), busulfan (3.2 mg/kg/d x4d [<4yrs of age: 4 mg/kg/d x4d]), thiotepa (10 mg/kg/d x1d), cyclophosphamide (50mg/kg/d x4d), R-ATG (2mg/kg/d x4d), and TLI (500cGy) followed by FHI T-cell depleted AlloSCT. AGVHD prophylaxis included tacrolimus single agent. We utilized the CliniMACS (IND 14359) to enrich for peripheral blood hematopoietic progenitor cells (HPC's); target dose of 10 x 106 CD34+ cells/kg with 2 x 105 CD3+ T cells/kg added back as a final CD3/kg concentration. Six patients have received AlloSCT to date ([Figure 2][2]). All patients utilized maternal donors who encountered no complications during collection. All had early neutrophil engraftment (median day +9), ≥98% whole blood chimerism and ≥85% RBC donor chimerism, no aGVHD or cGVHD ([Figure 2][2]). One patient developed late hepatic SOS and died at day +59; the remainder are alive and free of disease (day +12 to +642). One more patient has been enrolled and has begun conditioning and others are in the early part of their transplant process. Early results indicate FHI TCD AlloSCT is feasible in high-risk SCD patients who lack a MSD or URD. A larger cohort with longer term follow-up is needed to assess long-term safety and outcomes (Supported by FDA 5R01FD004090 and a grant from Otsuka) (IND #14359 and NCT 01461837). http://www.sicklecelltransplantconsortium.org ![Figure 1][3] Figure 1 ![Figure 2][3] Figure 2 Disclosures No relevant conflicts of interest to declare. [1]: #F1 [2]: #F2 [3]: pending:yes

How We Manage Adenosine Deaminase-Deficient Severe Combined Immune Deficiency (ADA SCID).

Adenosine deaminase-deficient severe combined immune deficiency (ADA SCID) accounts for 10-15% of cases of human SCID. From what was once a uniformly fatal disease, the prognosis for infants with ADA SCID has improved greatly based on the development of multiple therapeutic options, coupled with more frequent early diagnosis due to implementation of newborn screening for SCID. We review the various treatment approaches for ADA SCID including allogeneic hematopoietic stem cell transplantation (HSCT) from a human leukocyte antigen-matched sibling or family member or from a matched unrelated donor or a haplo-identical donor, autologous HSCT with gene correction of the hematopoietic stem cells (gene therapy-GT), and enzyme replacement therapy (ERT) with polyethylene glycol-conjugated adenosine deaminase. Based on growing evidence of safety and efficacy from GT, we propose a treatment algorithm for patients with ADA SCID that recommends HSCT from a matched family donor, when available, as a first choice, followed by GT as the next option, with allogeneic HSCT from an unrelated or haplo-identical donor or long-term ERT as other options.

Role of HLA match on results of hematopoietic stem cell transplantations from unrelated donors in children with acute leukemia and bone marrow failure syndromes

BackgroundIn case of the lack of matched family donors (MFD), hematopoietic stem cell transplantation (HSCT) from unrelated donor (UD) is an established procedure for many acquired and congenital disorders of the hematopoietic system, including malignancies and bone marrow failure (BMF) syndromes. ObjectiveThe analysis of the results of HSCT in patients with acute leukemia or BMF syndromes from UDs with respect to human leukocyte antigen (HLA) match. Patients and methodsA total number of 97 of HSCT from UDs performed in single center between 2007 and 2015 in children and adolescents with acute lymphoblastic (ALL) or myeloblastic leukemia (AML) and BMF syndromes were included into this analysis. HLA match between donor and recipient was analyzed at the allele level and classified as 10/10, 9/10 or 8/10. Data were compared to results of 56 MFD-HSCTs. Probability of overall survival (pOS) was given for 3-year and 1-year (as required by JACIE standards) time periods. ResultsThe mean survival for all patients estimated by Kaplan–Meier method was 4.8 years (95%CI=4.1–5.5 years). The 3-year pOS after all UD-HSCT was 0,60±0,05, and with respect to 10/10, 9/10 and 8/10 HLA match: 0,61±0,06; 0,59±0,09 and 0,60±0,22, respectively (ns). In patients with AML, 3-year pOS reached 52%, 60% and 60%, respectively. In patients with ALL, 3-year pOS was 73% and 62% (ns) for 10/10 and 9/10 HLA match, respectively, while for BMF syndromes 86% and 57% (ns), respectively. ConclusionCurrent data suggest that results of mismatched and matched UD-HSCT in children with acute leukemia might be comparable.

Excess Treatment-Related Mortality in Obese Children and Adolescents with Acute Myeloid Leukemia on AAML0531: A Report from the Children's Oncology Group

Background: Therapy for children with acute myeloid leukemia (AML) is intensive and treatment-related mortality (TRM) occurs in about 5 to 10% of patients. Previous data illustrated that obese children and adolescents with AML treated according to CCG 2961 were more likely to experience TRM, with HR 2.66 (95% CI 1.38-5.11; P = 0.003), when compared to middleweight patients. Since this trial, the backbone of AML chemotherapy and supportive care have changed and thus, it is unknown whether the impact of obesity persists in contemporary trials. The objective was to determine whether obesity was associated with increased TRM, reduced survival and prolonged compared to middleweight patients with AML.Methods: AAML0531 enrolled patients between August 14, 2006 and June 15, 2010. For this analysis, we included patients 0 to 18 years of age with de novo AML. Chemotherapy consisted of 5 cycles of chemotherapy and patients were randomized to receive or not receive gemtuzumab once during Induction I and Intensification II. Best allogeneic donor hematopoietic stem cell transplantation (HSCT) was recommended for those with > 15% bone marrow blasts after Induction I in those without favorable risk cytogenetics and poor risk cytogenetics irrespective of response following Induction I. Matched family donor HSCT was recommended for those with good response after Induction I with standard risk cytogenetics and an available donor.Obesity was defined using definitions from the Centers for Disease Control and Prevention (CDC). Underweight was defined as a body mass index percentile less than 5th percentile, and obese 95th percentile and greater. Categories were determined using z-scores for the weight-for-height data for those 0 to 2 years of age.All outcomes were censored at the time of HSCT. The primary outcome was TRM, defined as death as first event occurring on therapy or within 30 days of going off therapy. Cumulative incidence of TRM was estimated treating relapse and failure as competing events. Kaplan Meier analysis was conducted for overall survival (OS), event free survival (EFS), and disease free survival (DFS). Cumulative incidence of relapse rate (RR) was estimating treating deaths as competing events.Results: There were 1004 patients included. When comparing middleweight and obese patients, there was no significant difference in gender (P=0.814), white vs non-white race (P=0.116), cytogenetic risk group (all P>0.05) or MRD positivity after Induction 1 (P=0.750). The median age was higher for obese patients (12.0 vs 9.4 years; P=0.007 years) compared with middle weight patients. The proportion of patients who were Hispanic or Latino patients was higher among obese compared with middle weight patients (28% vs 17%; P=.001). Survival outcomes are shown in Table 1.When evaluating median time to neutrophil recovery, obese patients, when compared to middleweight patients, had shorter duration of neutropenia for cycles 1-3 (P<0.05).Conclusions: TRM rates continue to be higher for obese patients treated with contemporary AML protocols. Toxicity is not mediated through prolonged neutropenia. Future work should compare the rate of toxicity among obese versus non-obese patients and evaluate the impact of underweight status. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Transplantation for thalassemia major: alternative donors.

Lack of a human leukocyte antigen (HLA)-matched family donor is a major obstacle limiting the use of allogeneic hematopoietic stem cell transplantation (HSCT) to cure thalassemia major. Use of alternative donors, if found well tolerated enough, may be a viable option for transplantation in this setting, allowing to expand the number of patients treatable by HSCT. This review will provide an overview of alternative HSCT approaches in thalassemia major. With the introduction of high-resolution molecular HLA-typing techniques, the outcome of matched unrelated donor HSCT recipients has become comparable with that of patients given matched family donor HSCT. On the contrary, the use of unrelated cord blood transplantation has been limited by the risk of graft failure and slow hematopoietic recovery, although novel techniques of ex vivo graft manipulation are emerging as promising strategies for overcoming these obstacles. Although experience with haploidentical HSCT in thalassemia major is still limited, currently explored platforms hold the potential to extend the access to HSCT to thalassemia major patients lacking an HLA-matched either related or unrelated donor. The significant advances achieved in transplantation techniques, both in the matched unrelated and in the haploidentical setting, are expected to significantly broaden the applicability of HSCT to patients with thalassemia major.

Blood concentration of cyclosporine during early post-transplant period may have influence on the occurrence of chronic graft versus host disease in patients who received allogeneic hematopoietic stem cell transplantation.

IntroductionIt has rarely been studied that how the blood level of CsA affect the incidence of chronic GVHD after allogeneic hematopoietic stem cell transplantation (allo-HSCT).MethodsA total of 183 patients who underwent allo-HSCT from an HLA-matched or haplo matched family donors between 2006 and 2014 were reviewed.ResultsThe average monthly CsA blood concentration (CsAavr, ng/ml) was calculated in each patient: 0-1, 1-2, and 2-3 months after allo-HSCT. CsAavr at the first month showed significant association with the occurrence of moderate to severe cGVHD in multivariate analysis adjusted for gender, age, total body irradiation, anti-thymocyte globulin, acute GVHD ≥ grade 2 and CsAavr levels of other periods. The risk of cGVHD development was lowest in patients with CsAavr of 200-250 ng/ml when compared to those with CsAavr of ≥ 250 or < 200 ng/ml (p=0.003).ConclusionsCsA level between 200 and 250 mg/ml during the first month after transplantation was significantly associated with the decreased risk of moderate to severe cGVHD.

T-cell depleted haploidentical hematopoietic stem cell transplantation is the optimal graft source for patients with familial hemophagocytic lymphohistiocytosis who do not have matched family donors.

Abstract Familial hemophagocytic lymphohistiocytosis (HLH) is a fatal disorder of immune regulation. When managed appropriately with systemic chemotherapy, cure can be achieved by subsequent allogeneic hematopoietic stem cell transplantation (HSCT). Although the best results are obtained with matched-family donors (MFD), alternative donor transplants may be necessary when such donors are not available. As there is urgency to proceed with curative therapy, T-cell depleted haploidentical HSCT could be a viable option as a parent or other haploidentical family member would be available instantly. Between August 2010 and September 2015 we performed haploidentical HSCT for six patients with HLH in this institution. These patients did not have MFDs, and in our center it was logistically easier to perform an haploidentical HSCT rather than to pursue with an unrelated donor or cord blood search from the international registries. The median age at transplant was 6 months (5–31 months) and all had perforin gene mutations. The first two patients had CD3/CD19 depleted procedures while the rest underwent TCR alpha/beta and CD19 depletion for faster immune reconstitution. All six patients engrafted following the transplant with minimal graft versus hot disease. Four patients are cured from the disease with a median follow-up of 3 years (7mths to 5 years). Two patients (siblings) who were transplanted in partial remission expired 2 months following transplant from multi-organ failure after successful engraftment. In the presence of an appropriate transplant laboratory facility, T-cell depleted haploidentical HSCT should be considered as the graft of choice for patients with HLH who do not have HLA-matched family donors.

Effect of stem cell source on long-term chimerism and event-free survival in children with primary immunodeficiency disorders after fludarabine and melphalan conditioning regimen

Reduced-intensity conditioning (RIC) regimens are increasingly being used in the transplantation of patients with primary immunodeficiency disorders (PIDs), but there are no large studies looking at long-term lineage-specific chimerism. We sought to analyze long-term chimerism and event-free survival in children undergoing transplantation for PIDs using RIC with fludarabine and melphalan (Flu/Melph) and to study the effect of donor type and stem cell source. One hundred forty-two children underwent transplantation with RIC by using Flu/Melph and for PIDs by using bone marrow (n=93) or peripheral blood stem cells (PBSCs; n=49). Donors were matched unrelated donors (n=72), mismatched unrelated donors (n=37), matched sibling donors (n=14), matched family donors (n=12), and mismatched family donors (n=7). Overall survival at a median follow-up of 7.5years was 78%, irrespective of stem cell source or donor type. When bone marrow was used as the stem cell source, 26% of patients ended up with very low levels of donor chimerism (<10% donor), especially in the myeloid lineage. Event-free survival in this group was significantly lower compared with that in the rest of the group (25% vs 70%, P<.001). With the use of PBSCs, more than 90% of patients achieved complete donor chimerism or high-level mixed chimerism (>50% donor chimerism) in all lineages. On the basis of our experience, we would suggest that PBSCs should be the stem cell source of choice in children with PIDs undergoing transplantation with Flu/Melph RIC from a matched donor source. This is most likely to ensure sustained high-level donor chimerism.

Haploidentical Transplantation in Children with Acute Leukemia: The Unresolved Issues.

Allogeneic hematopoietic stem cell transplantation (HSCT) remains a curative option for children with high risk and advanced acute leukemia. Yet availability of matched family donor limits its use and although matched unrelated donor or mismatched umbilical cord blood (UCB) are viable options, they fail to meet the global need. Haploidentical family donor is almost universally available and is emerging as the alternate donor of choice in adult patients. However, the same is not true in the case of children. The studies of haploidentical HSCT in children are largely limited to T cell depleted grafts with not so encouraging results in advanced leukemia. At the same time, emerging data from UCBT are challenging the existing paradigm of less stringent HLA match requirements as perceived in the past. The use of posttransplantation cyclophosphamide (PTCY) has yielded encouraging results in adults, but data in children is sorely lacking. Our experience of using PTCY based haploidentical HSCT in children shows inadequacy of this approach in younger children compared to excellent outcome in older children. In this context, we discuss the current status of haploidentical HSCT in children with acute leukemia in a global perspective and dwell on its future prospects.