Folinic Acid Supplementation in Higher Doses is Associated with Graft Rejection in Pediatric Hematopoietic Stem Cell Transplantation

AbstractFolinic acid is widely used in hematopoietic stem cell transplantation (SCT), mainly to reverse antifolate effects of such drugs as methotrexate and cotrimoxazole but also empirically to reduce toxicity and support hematopoietic recovery. However, concerns have been raised in oncohematology about reduced curative rates associated with folinic acid administration. The clinical impact of folinic acid with regard to graft-versus-host disease (GVHD), relapse, and rejection in pediatric SCT is largely undetermined. In this single-center retrospective study we investigated folinic acid administration in 87 children undergoing SCT between 2007 and 2010. Data on folinic acid dosage and duration were analyzed along with SCT parameters using univariate and multivariate statistics. Folinic acid treatment was not correlated with relapse or GVHD grades ≥ II. However, significantly higher folinic acid doses until day +21 post-SCT had been administered to patients rejecting their grafts (P < .005). In a subanalysis of nonmalignant disease and reduced-intensity conditioning (RIC) SCTs, higher total folinic acid doses were found to be associated with rejection (P = .015 and P = .026). Multivariate analysis identified RIC (odds ratio, 19.9; P < .01) and an early total folinic acid dose of >185 mg/m2 (odds ratio, 11.4; P = .03) as risk factors for graft rejection. Late folinic acid treatment had no impact on relapse, GVHD, and rejection. To conclude, administration of folinic acid in pediatric SCT seems safe in terms of relapse and GVHD. However, it should be carried out with caution, especially in patients with nonmalignant conditions and those receiving RIC to avoid graft rejection

Individualization of Hematopoietic Stem Cell Transplantation Using Alpha/Beta T-Cell Depletion

Allogeneic hematopoietic stem cell transplantation (HSCT) is associated with several potentially lethal complications. Higher levels of CD3+ T-cells in the graft have been associated with increased risk of graft-versus-host disease (GVHD), but also beneficial graft-versus-leukemia effect and reduced infections. To tackle post-transplant complications, donor lymphocyte infusions have been used but with an increased risk of GVHD. To reduce this risk, we performed depletion of αβ T-cells and treated 12 patients post-HSCT suffering from infections and/or poor immune reconstitution. The αβ T-cell depleted cell products were characterized by flow cytometry. The median log depletion of αβ T-cells was −4.3 and the median yield of γδ T-cells was 73.5%. The median CD34+ cell dose was 4.4 × 106/kg. All 12 patients were alive 3 months after infusion and after 1 year, two patients had died. No infusion-related side effects were reported and no severe acute GVHD (grade III-IV) developed in any patient post-infusion. Overall, 3 months after infusion 11 out of 12 patients had increased levels of platelets and/or granulocytes. In conclusion, we describe the use of αβ T-cell depleted products as stem cell boosters with encouraging results

Combining Flow and Mass Cytometry in the Search for Biomarkers in Chronic Graft-versus-Host Disease

Chronic graft-versus-host disease (cGVHD) is a debilitating complication arising in around half of all patients treated with an allogeneic hematopoietic stem cell transplantation. Even though treatment of severe cGVHD has improved during recent years, it remains one of the main causes of morbidity and mortality in affected patients. Biomarkers in blood that could aid in the diagnosis and classification of cGVHD severity are needed for the development of novel treatment strategies that can alleviate symptoms and reduce the need for painful and sometimes complicated tissue biopsies. Methods that comprehensively profile complex biological systems such as the immune system can reveal unanticipated markers when used with the appropriate methods of data analysis. Here, we used mass cytometry, flow cytometry, enzyme-linked immunosorbent assay, and multiplex assays to systematically profile immune cell populations in 68 patients with varying grades of cGVHD. We identified multiple subpopulations across T, B, and NK-cell lineages that distinguished patients with cGVHD from those without cGVHD and which were associated in varying ways with severity of cGVHD. Specifically, initial flow cytometry demonstrated that patients with more severe cGVHD had lower mucosal-associated T cell frequencies, with a concomitant higher level of CD38 expression on T cells. Mass cytometry could identify unique subpopulations specific for cGVHD severity albeit with some seemingly conflicting results. For instance, patients with severe cGVHD had an increased frequency of activated B cells compared to patients with moderate cGVHD while activated B cells were found at a reduced frequency in patients with mild cGVHD compared to patients without cGVHD. Moreover, results indicate it may be possible to validate mass cytometry results with clinically viable, smaller flow cytometry panels. Finally, no differences in levels of blood soluble markers could be identified, with the exception for the semi-soluble combined marker B-cell activating factor/B cell ratio, which was increased in patients with mild cGVHD compared to patients without cGVHD. These findings suggest that interdependencies between such perturbed subpopulations of cells play a role in cGVHD pathogenesis and can serve as future diagnostic and therapeutic targets

A Phase II Trial of a Personalized, Dose-Intense Administration Schedule of (177)Lutetium-DOTATATE in Children With Primary Refractory or Relapsed High-Risk Neuroblastoma-LuDO-N

Background:& nbsp;Half the children with high-risk neuroblastoma die with widespread metastases. Molecular radiotherapy is an attractive systemic treatment for this relatively radiosensitive tumor. I-131-mIBG is the most widely used form in current use, but is not universally effective. Clinical trials of (177)Lutetium DOTATATE have so far had disappointing results, possibly because the administered activity was too low, and the courses were spread over too long a period of time, for a rapidly proliferating tumor. We have devised an alternative administration schedule to overcome these limitations. This involves two high-activity administrations of single agent Lu-177-DOTATATE given 2 weeks apart, prescribed as a personalized whole body radiation absorbed dose, rather than a fixed administered activity. "A phase II trial of (177)Lutetium-DOTATATE in children with primary refractory or relapsed high-risk neuroblastoma - LuDO-N " (EudraCT No: 2020-004445-36, Identifier: NCT04903899) evaluates this new dosing schedule.& nbsp;Methods:& nbsp;The LuDO-N trial is a phase II, open label, multi-center, single arm, two stage design clinical trial. Children aged 18 months to 18 years are eligible. The trial is conducted by the Nordic Society for Pediatric Hematology and Oncology (NOPHO) and it has been endorsed by SIOPEN (). The Karolinska University Hospital, is the sponsor of the LuDO-N trial, which is conducted in collaboration with Advanced Accelerator Applications, a Novartis company. All Scandinavian countries, Lithuania and the Netherlands participate in the trial and the UK has voiced an interest in joining in 2022.& nbsp;Results:& nbsp;The pediatric use of the Investigational Medicinal Product (IMP) Lu-177-DOTATATE, as well as non-IMPs SomaKit TOC (R) (Ga-68-DOTATOC) and LysaKare (R) amino acid solution for renal protection, have been approved for pediatric use, within the LuDO-N Trial by the European Medicines Agency (EMA). The trial is currently recruiting. Recruitment is estimated to be finalized within 3-5 years.& nbsp;Discussion:& nbsp;In this paper we present the protocol of the LuDO-N Trial. The rationale and design of the trial are discussed in relation to other ongoing, or planned trials with similar objectives. Further, we discuss the rapid development of targeted radiopharmaceutical therapy and the future perspectives for developing novel therapies for high-risk neuroblastoma and other pediatric solid tumors.Peer reviewe

Human Bone Marrow Mesenchymal Stromal Cell-Derived CXCL12, IL-6 and GDF-15 and Their Capacity to Support IgG-Secreting Cells in Culture Are Divergently Affected by Doxorubicin

Various subsets of bone marrow mesenchymal stromal cells (BM MSCs), including fibroblasts, endothelial, fat and reticular cells, are implicated in the regulation of the hematopoietic microenvironment and the survival of long-lived antibody-secreting cells (ASCs). Nowadays it is widely acknowledged that vaccine-induced protective antibody levels are diminished in adults and children that are treated for hematological cancers. A reason behind this could be damage to the BM MSC niche leading to a diminished pool of ASCs. To this end, we asked whether cell cytotoxic treatment alters the capacity of human BM MSCs to support the survival of ASCs. To investigate how chemotherapy affects soluble factors related to the ASC niche, we profiled a large number of cytokines and chemokines from in vitro-expanded MSCs from healthy donors or children who were undergoing therapy for acute lymphoblastic leukemia (ALL), following exposure to a widely used anthracycline called doxorubicin (Doxo). In addition, we asked if the observed changes in the measured soluble factors after Doxo exposure impacted the ability of the BM niche to support humoral immunity by co-culturing Doxo-exposed BM MSCs with in vitro-differentiated ASCs from healthy blood donors, and selective neutralization of cytokines. Our in vitro results imply that Doxo-induced alterations in BM MSC-derived interleukin 6 (IL-6), CXCL12 and growth and differentiation factor 15 (GDF-15) are not sufficient to disintegrate the support of IgG-producing ASCs by the BM MSC niche, and that serological memory loss may arise during later stages of ALL therapy.</jats:p

Outcomes of Unmanipulated Haploidentical Transplantation Using Post-Transplant Cyclophosphamide (PT-Cy) in Pediatric Patients With Acute Lymphoblastic Leukemia

HLA-haploidentical transplantation (haplo-HCT) using post-transplantation-cyclophosphamide (PT-Cy) is a feasible procedure in children with malignancies. However, large studies on Haplo-HCT with PT-Cy for childhood acute lymphoblastic leukemia (ALL) are lacking. We analyzed haplo-HCT outcomes in 180 children with ALL. Median age was 9 years, and median follow-up was 2.7 years. Disease status was CR1 for 24%, CR2 for 45%, CR+3 for 12%, and active disease for 19%. All patients received PT-Cy day +3 and +4. Bone marrow (BM) was the stem cell source in 115 patients (64%). Cumulative incidence of 42-day engraftment was 88.9%. Cumulative incidence of day-100 acute graft-versus-host disease (GVHD) grade II-IV was 28%, and 2-year chronic GVHD was 21.9%. At 2 years, cumulative incidence of nonrelapse mortality (NRM) was 19.6%. Cumulative incidence was 41.9% for relapse and 25% for patients in CR1. Estimated 2-year leukemia free survival was 65%, 44%, and 18.8% for patients transplanted in CR1, CR2, CR3+ and 3% at 1 year for active disease. In multivariable analysis for patients in CR1 and CR2, disease status (CR2 [hazard ratio {HR} = 2.19; P = .04]), age at HCT older than 13 (HR = 2.07; P = .03) and use of peripheral blood stem cell (PBSC) (HR = 1.98; P = .04) were independent factors associated with decreased overall survival. Use of PBSC was also associated with higher NRM (HR = 3.13; P = .04). Haplo-HCT with PT-Cy is an option for children with ALL, namely those transplanted in CR1 and CR2. Age and disease status remain the most important factors for outcomes. BM cells as a graft source is associated with improved survival

Hematopoietic cell transplantation in severe combined immunodeficiency : The SCETIDE 2006-2014 European cohort

Publisher Copyright: © 2021 The AuthorsBackground: Hematopoietic stem cell transplantation (HSCT) represents a curative treatment for patients with severe combined immunodeficiency (SCID), a group of monogenic immune disorders with an otherwise fatal outcome. Objective: We performed a comprehensive multicenter analysis of genotype-specific HSCT outcome, including detailed analysis of immune reconstitution (IR) and the predictive value for clinical outcome. Methods: HSCT outcome was studied in 338 patients with genetically confirmed SCID who underwent transplantation in 2006-2014 and who were registered in the SCETIDE registry. In a representative subgroup of 152 patients, data on IR and long-term clinical outcome were analyzed. Results: Two-year OS was similar with matched family and unrelated donors and better than mismatched donor HSCT (P 0.5 × 10e3/μL at +1 year were identified as independent predictors of favorable clinical and immunologic outcome. Conclusion: Recent advances in HSCT in SCID patients have resulted in improved OS and EFS in all genotypes and donor types. To achieve a favorable long-term outcome, treatment strategies should aim for optimal naive CD4 T lymphocyte regeneration.Peer reviewe

Multipotent mesenchymal stromal cell transplantation : Possible viral complications and alloimmunity

In the last few years, human multipotent mesenchymal stromal cells (MSC) have been increasingly used in novel therapeutic strategies due to their intrinsic immunosuppressive, anti-inflammatory and regenerative properties. In hematopoietic stem cell transplantation (HSCT), a curable treatment of hematological malignancies and several non-malignant conditions, MSC have been used as a therapy for graft-versus host-disease (GvHD) and other complications. The aim of MSC infusions in HSCT is to use the cells immunomodulatory effects to reduce the immunological reactions giving rise to GvHD and to achieve tissue regeneration. This thesis evaluates the clinical safety from a virological point of view and the immunogenicity of MSC in HSCT recipients. MSC were PCR screened for human herpesviruses and parvovirus B19 (B19), pathogens associated with severe infections in HSCT. The cells did not harbor herpesviruses, but presence of B19 DNA was detected in one MSC out of 20 screened. The presence of B19 is surprising since B19 is known for its extreme tropism for erythroid bone marrow cells. Upon exposure to the viruses, MSC supported infection of cytomegalovirus, herpes simplex virus and B19, but not Epstein-Barr virus as visualized by immunofluorescence. These infections could be passed to other uninfected cells implying that the infections of MSC were productive. Even though MSC are typically regarded as lowly immunogenic, data on rejection exist. MSC immunogenicity was evaluated at both the humoral and cellular levels. No alloantibodies could be detected by flow cytometric cross matches. However, MSC bound antibodies directed to FCS a component of the MSC culture medium. These antibodies are of uncertain clinical significance as they are constitutively expressed in humans. When evaluating MSC recipient lymphocytes in lymphocyte proliferation assays, there was no sign of allosensitization against the MSC donor, i.e. no immunological memory, 1 week to 6 months post-MSC infusion. In all instances, donor and third-party MSC failed to mount proliferative responses. In vitro studies revealed that MSC failed to prime responder cells to rechallenge with lymphocytes from the MSC donor and MSC rechallenge after PBL priming only gave weak responses. MSC failed to induce activated and effector CD4+ and CD8+ T lymphocyte subsets regardless of priming. To conclude, MSC occasionally carry viruses and may constitute a viral reservoir of persistent viruses associated with considerably disease in HSCT recipients. The MSC do not seem to induce humoral or cellular immune responses after infusions of HLA disparate MSC as therapy of complications to HSCT