Allogeneic hematopoietic stem cell transplantation from sibling and unrelated donors in pediatric patients with sickle cell disease-A single center experience.

HSCT is curative in SCD. Patients with HLA-identical sibling donor have an excellent outcome ranging from 90%-100% overall and event-free survival. However, due to the lack of matched sibling donors this option is out of reach for 70% of patients with SCD. The pool of potential donors needs to be extended. Transplantations from HLA-matched unrelated donors were reported to be less successful with shorter event-free survival and higher incidences of complications including graft-vs-host disease, especially in patients with advanced stage SCD. Here we report transplantation outcomes for 25 children with SCD transplanted using HLA-matched grafts from related or unrelated donors. Overall survival was 100% with no severe (grade III-IV) graft-vs-host disease and a 12% rejection rate. Mixed donor chimerisms only occurred in transplantations from siblings, while transplantations from unrelated donors resulted in either complete donor chimerism or rejection. Despite the small patient number, overall and disease-free survival for unrelated donor transplantations is excellent in this cohort. The advanced disease state, higher alloreactive effect and stronger immunosuppression in unrelated donor transplantations raises patient risk, for which possible solutions could be found in optimization of transplant preparation, graft manipulation or haploidentical transplantation using T cell receptor α/ß-depleted grafts.

Successful recovery from COVID-19 pneumonia after receiving baricitinib, tocilizumab, and remdesivir. A case report: Review of treatments and clinical role of computed tomography analysis.

The novel coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a pandemic, threatening global public health. In the current paper, we describe our successful treatment of one COVID-19 pneumonia patient case with high mortality risk factors. Our experience underlines the importance of the use of a multidisciplinary therapeutic approach in order to achieve a favorable clinical outcome. Further, enhancing the capability of the COVID-19 diagnosis with the use of the chest imaging modalities is discussed.

Status quo of allogeneic stem cell transplantation for patients with sickle cell disease using matched unrelated donors.

This mini review is based on an oral presentation reflecting the current status quo of allogeneic hematopoietic stem cell transplantation (HSCT) for patients with sickle cell disease (SCD) using matched unrelated donors (MUDs) presented at the EBMT Sickle Disease Meeting held in Regensburg, Germany, in May 2019. Although the clinical trial landscape for MUD HSCT in patients with SCD is limited to date, some attempts to improve patient outcome in terms of overall survival and event-free survival have been made recently, including optimization of conditioning regimens and prevention of engraftment failure as well as graft-versus-host disease. The results achieved by these approaches are summarized in this review and are still unsatisfactory. Whether new haploidentical transplantation protocols will achieve superior results and are able to replace MUD HSCT for patients with SCD remains to be elucidated.

HLA-haploidentical hematopoietic stem cell transplantation in pediatric patients with hemoglobinopathies: current practice and new approaches.

We review current approaches in HLA-haploidentical hematopoietic stem cell transplantation (haplo-HSCT) for pediatric patients with hemoglobinopathies with a focus on recent developments using TCRα/ß+/CD19+ depleted grafts in patients with ß-thalassemia major (TM) or sickle cell disease (SCD) in two European transplant units. Eleven TM and three SCD patients (Roma cohort) received a preparative regimen consisting of busulfan/thiotepa/cyclophosphamide/ATG preceded by fludarabine/hydroxyurea/azathioprine. The preparative regimen for 5 SCD patients included treosulfan/thiotepa/fludarabine/ATG (Berlin pilot cohort). All grafts were PBSC engineered by TCR-α/ß+/CD19+ depletion. In both cohorts, rates for graft failure, treatment related mortality (TRM) and GvHD were encouraging. Overall survival (OS) and disease-free survival (DFS) in the Roma cohort were 84 and 69%, respectively, while OS and DFS are 100% in the Berlin cohort. Immune reconstitution was satisfactory. Although asymptomatic viral reactivation was common, no severe viral infection occured. These data confirm that TCR-α/ß+/CD19+ depletion is a well-suited haplo-HSCT strategy for children with hemoglobinopathies. We discuss the results in the context of additional optimization strategies and introduce our concepts for multicenter trial protocols in Germany.

One single bone marrow harvesting from donors under 3 years of age: assessing safety and efficacy of the procedure.

To candidate children as bone marrow donors raises two main concerns: donor safety and adequate marrow cell dose. Data in the field are limited and guidelines for child donor care management are lacking. In this context, we herein report the experience collected in our center by comparing very-young donors (defined as age ≤ 3 years) with young donors (defined as age > 3 years) who donated bone marrow (BM) for patients affected by beta-globin disorders.

Haploidentical HSCT for hemoglobinopathies: improved outcomes with TCRαß+/CD19+-depleted grafts.

We examined outcomes of haploidentical hematopoietic cell transplantation (haplo-HCT) using T-cell receptor αß+ (TCRαß+)/CD19+-depleted grafts (TCR group, 14 patients) in children with hemoglobinopathies. Patients received a preparative regimen consisting of busulfan, thiotepa, cyclophosphamide, and antithymocyte globulin preceded by fludarabine, hydroxyurea, and azathioprine. The median follow-up among surviving patients was 3.9 years. The 5-year probabilities of overall survival (OS) and disease-free survival (DFS) were 84% and 69%, respectively. The incidence of graft failure was 14%. We compared outcomes to a historical group of 40 patients with hemoglobinopathies who received CD34+-selected grafts (CD34 group). The median follow-up of surviving patients for the CD34 group was 7.5 years. The 5-year probabilities of OS and DFS were 78% and 39%, respectively. The CD34 group had a significantly higher incidence of graft failure (45%) than the TCR group (14%) (P = .048). The incidences of grades 2 to 4 acute graft-versus-host disease (GVHD) in the TCR and CD34 groups were 28% and 29%, respectively, and 21% and 10% (P = .1), respectively, for extensive chronic GVHD. Viral reactivation was common in both groups. The overall incidence of posttransplant lymphoproliferative disorders for the entire group was 16%. Among all patients, 5 developed autoimmune hemolytic anemia or thrombocytopenia, with the overall cumulative incidence of 11%. The 2 groups showed suboptimal CD4+ recovery within the first 6 months of transplantation with no significant difference between groups. These data demonstrate that TCRαß+/CD19+-depleted grafts are associated with a reduced incidence of graft failure, but delayed immune reconstitution and associated morbidity and mortality remain a significant challenge.

Structural and Functional Insights on an Uncharacterized Aγ-Globin-Gene Polymorphism Present in Four ß0-Thalassemia Families with High Fetal Hemoglobin Levels.

INTRODUCTION: Several DNA polymorphisms have been associated with high production of fetal hemoglobin (HbF), although the molecular basis is not completely understood. In order to identify and characterize novel HbF-associated elements, we focused on five probands and their four families (from Egypt, Iraq and Iran) with thalassemia major (either ß(0)-IVSII-1 or ß(0)-IVSI-1) and unusual HbF elevation (>98 %), congenital or acquired after rejection of bone marrow transplantation, suggesting an anticipated favorable genetic background to high HbF expression. METHODS: Patient recruitment, genomic DNA sequencing, western blotting, electrophoretic mobility shift assays, surface plasmon resonance (SPR) biospecific interaction analysis, bioinformatics analyses based on docking experiments. RESULTS: A polymorphism of the Aγ-globin gene is here studied in four families with ß(0)-thalassemia (ß(0)-IVSII-1 and ß(0)-IVSI-1) and expressing unusual high HbF levels, congenital or acquired after rejection of bone marrow transplantation. This (G→A) polymorphism is present at position +25 of the Aγ-globin genes, corresponding to a 5'-UTR region of the Aγ-globin mRNA and, when present, is physically linked in chromosomes 11 of all the familiar members studied to the XmnI polymorphism and to the ß(0)-thalassemia mutations. The region corresponding to the +25(G→A) polymorphism of the Aγ-globin gene belongs to a sequence recognized by DNA-binding protein complexes, including LYAR (Ly-1 antibody reactive clone), a zinc-finger transcription factor previously proposed to be involved in down-regulation of the expression of γ-globin genes in erythroid cells. CONCLUSION: We found a novel polymorphism of the Aγ-globin gene in four families with ß(0)-thalassemia and high levels of HbF expression. Additionally, we report evidence suggesting that the Aγ-globin gene +25(G→A) polymorphism decreases the efficiency of the interaction between this sequence and specific DNA binding protein complexes.

Optimal Outcomes in Young Class 3 Patients With Thalassemia Undergoing HLA-Identical Sibling Bone Marrow Transplantation.

BACKGROUND: Bone marrow transplantation (BMT) for class 3 patients with thalassemia is challenging due to high rates of graft rejection and transplant-related mortality. Since the first studies of BMT in the late 1980s, a number of conditioning regimens have been designed to improve outcomes, but with suboptimal results. Here we report the outcome of transplantation in class 3 patients using a modified protocol. METHODS: Sixty-three patients between 5 and 16.7 years of age with class 3 thalassemia received HLA-matched sibling BMT following either the original protocol (26 patients) or the modified protocol (37 patients). Both regimens comprised preconditioning cytoreduction with hydroxyurea and azathioprine starting at -45 days pretransplant, and fludarabine from days -16 to -12. Conditioning was performed with busulfan and cyclophosphamide (original protocol) or with busulfan, thiotepa, and cyclophosphamide (modified protocol). RESULTS: The 2 groups showed similar patient demographics. At day 0, the degree of cytoreduction (lymphopenia, neuthropenia, and thrombocytopenia) achieved by the modified protocol was greater than the original protocol. The incidence of graft failure/rejection was significantly higher in the original group (15%; 95% confidence interval [95% CI], 5-32%) compared with the modified group (0%) (P = 0.014). The respective 5-year thalassemia-free survival rates were 73% (95% CI, 51-86%) and 92% (95% CI, 77-97%) (P = 0.047). Both groups showed similar incidences of grades II to IV acute graft-versus host disease. Modified protocol did not increase nonhematological toxicity or infectious complications. CONCLUSIONS: The modified treatment protocol effectively and safely prevented graft failure/rejection and significantly increased thalassemia-free survival of class 3 patients with thalassemia.

Haematopoietic stem cell transplantation in Nigerian sickle cell anaemia children patients.

BACKGROUND: Sickle cell anaemia (SCA) remains associated with high risks of morbidity and early death. Children with SCA are at high risk for ischaemic stroke and transient ischaemic attacks, secondary to intracranial arteriopathy involving carotid and cerebral arteries. Allogeneic haematopoietic stem cell transplantation (HSCT) is the only curative treatment for SCA. We report our experience with transplantation in a group of patients with the Black African variant of SCA. PATIENTS AND METHODS: This study included 31 consecutive SCA patients who underwent bone marrow transplantation from human leukocyte antigen (HLA)-identical sibling donors between 2010 and 2014 following a myeloablative-conditioning regimen. RESULTS: The median patient age was 10 years (range 2-17 years). Before transplantation, 14 patients had recurrent, painful, vaso-occlusive crisis; ten patients had recurrent painful crisis in association with acute chest syndrome; three patients experienced ischaemic stroke and recurrent vaso-occlusive crisis; two patients experienced ischaemic stroke; one patient exhibited leukocytosis; and one patient exhibited priapism. Of the 31 patients, 28 survived without sickle cell disease, with Lansky/Karnofsky scores of 100. All surviving patients remained free of any SCA-related events after transplantation. CONCLUSION: The protocols used for the preparation to the transplant in thalassaemia are very effective also in the other severe haemoglobinopathy as in the sickle cell anaemia with 90% disease free survival. Today, if a SCA patient has a HLA identical family member, the cellular gene therapy through the transplantation of the allogeneic haemopoietic cell should be performed. Tomorrow, hopefully, the autologous genetically corrected stem cell will break down the wall of the immunological incompatibility.

Invasive pulmonary aspergillosis in a haematopoietic stem cell transplant recipient with sickle cell disease: a successful treatment.

Sickle Cell Anaemia (SCA) is the most common inherited blood disorder and is associated with severe morbidity and decreased survival. Allogeneic Haematopoietic Stem Cell Transplantation (HSCT) is the only curative approach. Nevertheless the decision to perform a bone marrow transplant includes the risk of major complications and transplant-related mortality. Infections represent the leading cause of death in SCA patients undergoing HSCT. Invasive Pulmonary Aspergillosis (IPA) is a devastating opportunistic infection and remains a significant cause of morbidity and mortality in HSCT recipients. Data regarding IPA in the setting of SCA are lacking. In the present report, we describe a patient with SCA, who developed IPA after allogeneic bone marrow transplant. The fungal infection was treated by systemic antifungal therapy in addition to surgery, despite mild chronic graft versus host disease (GVHD) and continuing immunosuppressive therapy. This case shows that IPA occurring in bone marrow recipients with SCA can be successfully treated.

New insights into the pharmacokinetics of intravenous busulfan in children with sickle cell anemia undergoing bone marrow transplantation.

BACKGROUND: Busulfan (Bu) is an integral part of conditioning regimens for patients with sickle cell anemia (SCA) undergoing transplantation. Patients with SCA might predispose to transplant-related neurological and pulmonary toxicities due to pre-existing disease-related cerebrovascular and lung injury. Bu therapy appears to be an important contributing factor in this context. PROCEDURE: We studied the pharmacokinetics of intravenous Bu and clinical outcomes of 36 children with SCA undergoing bone marrow transplantation. Most patients had pre-existing organ system damage. Busulfan was administered every 6 hr for 4 days with pharmacokinetic-guided dose adjustment to target a conservative area under the concentration versus time curve (AUC) range of 900-1,350 µMol*min. RESULTS: We found that the first-dose Bu clearance was significantly higher (P < 0.0005) than the subsequent daily clearance, which remained unchanged during the following days. After the first-dose, 69% of patients achieved the target range. We adapted a new dose-adjustment strategy targeting exposures to the lower end (900 µMol*min) of the AUC range after the first dose of Bu to avoid unnecessary dose increases on subsequent days due to differences in clearance. This strategy enabled most patients to maintain the AUC within therapeutic range following dose adjustments. CONCLUSIONS: Differences in Bu clearance after the first-dose and subsequent daily doses in patients with SCA should be considered for pharmacokinetic-guided dose adjustment. Conservative AUC range and targeting exposures to the lower end of the range after the first dose was associated with negligible toxicity, and high engraftment and sickle cell-free survival rates.

Peripheral red blood cell split chimerism as a consequence of intramedullary selective apoptosis of recipient red blood cells in a case of sickle cell disease.

Allogeneic cellular gene therapy through hematopoietic stem cell transplantation is the only radical cure for congenital hemoglobinopathies like thalassemia and sickle cell anemia. Persistent mixed hematopoietic chimerism (PMC) has been described in thalassemia and sickle cell anemia. Here, we describe the clinical course of a 6-year-old girl who had received bone marrow transplant for sickle cell anemia. After the transplant, the patient showed 36% donor hematopoietic stem cells in the bone marrow, whereas in the peripheral blood there was evidence of 80% circulating donor red blood cells (RBC). The analysis of apoptosis at the Bone Marrow level suggests that Fas might contribute to the cell death of host erythroid precursors. The increase in NK cells and the regulatory T cell population observed in this patient suggests that these cells might contribute to the condition of mixed chimerism.

Reduction of intramedullary apoptosis after stem cell transplantation in black african variant of pediatric sickle cell anemia.

BACKGROUND AND PURPOSE: Allogeneic hematopoietic stem cell transplantation (HSCT) is the only curative treatment for sickle cell anemia (SCA). We report our experience with transplantation in children with the Black African variant of SCA and the effects of transplant on erythroid compartment in bone marrow (BM). PATIENTS AND METHODS: Twenty-seven consecutive patients who underwent BM transplantation from HLA-identical donors following a myeloablative conditioning regimen were included. Using both CD71 and FSC parameters, we obtained three erythroid populations: EryA-C. Ery A (CD71(high) FSC(high)) are basophilic; Ery B (CD71(high) FSC(low)) are late basophilic and polychromatic; and Ery C (CD71(low) FSC(low)) are orthochromatic erythroblasts and reticulocytes. To analyze the effect of transplantation on intramedullary apoptosis, we studied Fas (CD95+) and caspase-3 expression in erythroblast subpopulations. RESULTS: All patients experienced sustained engraftment, and all surviving patients remained free of SCA-related events after transplantation. The erythroid population showed expansion in the BM at baseline. After transplant, levels decreased, especially of Ery C, in parallel to reduced Fas expression and an initial caspase 3 increase in erythroid population, similar to reported later steps of "normal" erythroid maturation. CONCLUSIONS: The results suggest a good chance of cure for children with SCA, with an excellent survival rate. We also observed "normalization" of erythroid populations in parallel with a decreased intramedullary apoptosis rate, suggesting normal erythroid maturation in ex-SCA patients after HSCT.

Mixed chimerism evolution is associated with T regulatory type 1 (Tr1) cells in a ß-thalassemic patient after haploidentical haematopoietic stem cell transplantation.

In a cohort of ß-Thalassemia (ß-Thal) transplanted with haploidentical-HSCT we identified one transplanted patient characterized by persistent mixed chimerism (PMC) for several months after HSCT. In this unique ß-Thal patient we assessed the donor engraftment overtime after transplantation, the potential loss of the non-shared HLA haplotype, and the presence of CD49b(+)LAG-3(+) T regulatory type 1 (Tr1) cells, previously demonstrated to be associated with PMC after HLA-related HSCT for ß-Thal. The majority of the patient's erythrocytes were of donor origin, whereas T cells were initially mostly derived from the recipient, no HLA loss, but an increased frequency of circulating Tr1 cells were observed. For the first time, we showed that when the proportion of residual donor cells decreases, the frequency of CD49b(+)LAG-3(+) Tr1 cells declines, reaching the levels present in healthy subjects. These findings confirm previous results obtained in transplant related settings for ß-Thal, and supported the central role of Tr1 cells in promoting and maintaining PMC after allo-HSCT.

Bone marrow transplantation for thalassemia from alternative related donors: improved outcomes with a new approach.

Bone marrow transplantation (BMT) performance can be limited by a lack of ideal donors, and the role of alternative donor hematopoietic cell transplantation in thalassemia is not well established. Here we used a new treatment protocol (Pc 26.1) in 16 thalassemia patients to perform BMT using phenotypically HLA-identical or 1-antigen-mismatched relatives (related donors [RDs]). We compared these results with HLA-matched sibling (matched sibling donors [MSDs]) BMT in 66 patients. The entire RD group and 88% of MSD group had sustained engraftment. Rejection incidence was 0% in the RD and 12% (95% confidence interval [95% CI], 6%-21%) in MSD groups (P = .15), with respective thalassemia-free survival probabilities of 94% (95% CI, 63%-99%) and 82% (95% CI, 70%-89%) (P = .24). Transplant-related mortality was 6% (95% CI, 1%-26%) in the RD group and 8% (95% CI, 3%-16%) in the MSD group (P = .83). The intensified new protocol was not associated with increased nonhematologic toxicity. The present data show that the Pc 26.1 preparative regimen allows thalassemia patients to safely undergo BMT from RDs who are not HLA-matched siblings, with transplant outcomes similar to patients with MSD grafts.

Optimization of the immunomagnetic selection in microcythemic donors enrolled for haploidentical transplantation.

BACKGROUND: Immunomagnetic cell selection (ICS) cells is increasingly used in allogeneic hematopoietic transplantation in order to reduce the T cells quantity. The aim of this study was to evaluate an protocol based on Ficoll method before ICS. STUDY DESIGN AND METHODS: The automated procedure was compared with the standard method. In the group 1 the cell processing involves the extraction of the buffy-coat by Ficoll before incubation with antibodies. This procedure was performed with the Sepax S-100 device. The efficacy of this automated procedure was compared with the group 2. In this group, the cell washing and the incubation were performed through the standard method. The CD34+ cells collected by apheresis (HPC-A) were selected with ICS. RESULTS: The results obtained after Ficoll procedure, showed a total nucleated cells (TNCs) and CD34+ cells recovery of 85.73% (75.90-90.63; SD 4.25) and 79.31% (51.77-112.31; SD 18.40), respectively. The TNC and CD34+ cells recovery after the pre-incubation washing performed through the standard method, was 75.54% (38.36-97.76; SD 22.5) and 61.51% (30.87-81.79; SD 19.3), respectively. The CD34+ cells recovery after ICS was 79% (51.77-100; SD 18.40) and 44% (15.57-88.24; SD 25.91) in the group 1 and the group 2, respectively. This difference was statistically significant (p=0.001). CONCLUSION: The efficacy of the ICS which resulted to be higher in the group 1 compared to the group 2. Overall, our data suggest that the Ficoll procedure before incubation is suitable for the clinical routine in the ICS for haploidentical transplantation in patients affected by thalassemia.

Hematopoietic stem cell transplantation in thalassemia and sickle cell anemia.

The globally widespread single-gene disorders ß-thalassemia and sickle cell anemia (SCA) can only be cured by allogeneic hematopoietic stem cell transplantation (HSCT). HSCT treatment of thalassemia has substantially improved over the last two decades, with advancements in preventive strategies, control of transplant-related complications, and preparative regimens. A risk class-based transplantation approach results in disease-free survival probabilities of 90%, 84%, and 78% for class 1, 2, and 3 thalassemia patients, respectively. Because of disease advancement, adult thalassemia patients have a higher risk for transplant-related toxicity and a 65% cure rate. Patients without matched donors could benefit from haploidentical mother-to-child transplantation. There is a high cure rate for children with SCA who receive HSCT following myeloablative conditioning protocols. Novel non-myeloablative transplantation protocols could make HSCT available to adult SCA patients who were previously excluded from allogeneic stem cell transplantation.

Cell processing for haplo-identical hematopoietic stem cell transplantation: automated washing and immunomagnetic-positive selection.

BACKGROUND AIMS: Immunomagnetic cell selection (ICS) of CD34(+) cells is being used increasingly in allogeneic transplantation in order to reduce T-cell quantity. The aim of this study was to evaluate an automated washing protocol before immunomagnetic selection. METHODS: The automated method was compared with a conventional washing procedure. In the study group the cell processing using the automated procedure, both before and after antibody incubation, was performed with a Sepax S-100 device. The efficacy of the automated procedure was compared with the control group, where washing were performed using a standard method. RESULTS: The results obtained after pre-incubation washing performed using the automated system showed a total nucleated cell (NC) and CD34(+) cell recovery of 84.87% (71.80-105, SD 8.62; range, standard deviation) and 83.45% (47-109, SD 16.12), respectively. The NC and CD34(+) cell recovery after the pre-incubation washing cycle was performed using the standard method was 75.54% (38.36-97.76, SD 22.5) and 61.51% (30.87-81.79, SD 19.3), respectively. The CD34(+) cell recovery after ICS was 51.27% (13.77-98.82, SD 24.97) and 48.89% (15.57-88.24, SD 25.91) for group 1 and group 2, respectively. The average purity in group 1 was 86.46% (67.4-96.10, SD 13.07) and in group 2 84.97% (58.1-97.8, SD 15.58). CONCLUSIONS: The efficacy of the ICS led to an optimal purity without affecting cell recovery, which was higher in group 1. Overall, our data suggest that the automated method is suitable for washing hematopoietic progenitor cell apheresis (HPC-A) concentrates before immunomagnetic cell selection in daily clinical routines.