Improved collection of hematopoietic stem cells and progenitors from Fanconi anemia patients for gene therapy purposes

Anèmia de Fanconi; Mozobil; Teràpia gènicaAnemia de Fanconi; Mozobil; Terapia génicaFanconi anemia; Mozobil; Gene therapyDifficulties in the collection of hematopoietic stem and progenitor cells (HSPCs) from Fanconi anemia (FA) patients have limited the gene therapy in this disease. We have investigated (ClinicalTrials.gov, NCT02931071) the safety and efficacy of filgrastim and plerixafor for mobilization of HSPCs and collection by leukapheresis in FA patients. Nine of eleven enrolled patients mobilized beyond the threshold level of 5 CD34+ cells/μL required to initiate apheresis. A median of 21.8 CD34+ cells/μL was reached at the peak of mobilization. Significantly, the oldest patients (15 and 16 years old) were the only ones who did not reach that threshold. A median of 4.27 million CD34+ cells/kg was collected in 2 or 3 aphereses. These numbers were markedly decreased to 1.1 million CD34+ cells/kg after immunoselection, probably because of weak expression of the CD34 antigen. However, these numbers were sufficient to facilitate the engraftment of corrected HSPCs in non-conditioned patients. No procedure-associated serious adverse events were observed. Mobilization of CD34+ cells correlated with younger age, higher leukocyte counts and hemoglobin values, lower mean corpuscular volume, and higher proportion of CD34+ cells in bone marrow (BM). All these values offer crucial information for the enrollment of FA patients for gene therapy protocols.This work was supported by grants from the European Commission’s Seventh Framework Program (HEALTH-F5-2012-305421 to the EUROFANCOLEN Consortium, J.A.B., J. Sevilla, C.D.-d.-H., J. Soulier, and J. Surralles), Ministerio de Sanidad, Servicios Sociales e Igualdad (EC11/060 and EC11/550 to C.D.-d.-H., J. Sevilla, J.A.B., and J. Surralles), Ministerio de Economía, Comercio y Competitividad and Fondo Europeo de Desarrollo Regional (SAF2015-68073-R, RTI2018-097125-B-I00 to P.R. and RTI2018-098419-B-I00 to J. Surralles), Fondo de Investigaciones Sanitarias at the Instituto de Salud Carlos III (RD12/0019/0023 to J.C.S.), and Consejería de Educación, Juventud y Deporte de la Comunidad de Madrid (AvanCell Project; B2017/BMD3692). CIBERER is an initiative of the Instituto de Salud Carlos III and Fondo Europeo de Desarrollo Regional. J. Surralles is supported by ICREA Academia and FARF

Adverse events related to central venous catheters (CVC) and the influence of CVC characteristics on peripheral blood hematopoietic progenitor cell collection in children

Introduction: The use of peripheral blood progenitor cells (PBPCs) as a source for hematopoietic stem cell transplantation (HSCT) in pediatric healthy donors is still under debate. The risk of a central venous catheter (CVC) placement and catheter-related complications continue to be the main arguments to discourage its use. Methods: we present a retrospective analysis of 140 PBPC collections in pediatric patients and donors, describing adverse events (AE) related to CVCs as well as the influence of catheterrelated variables on the efficiency of the leukapheresis. Results: 14 CVC-related AEs were recorded (10%). The most common was fever in 5 patients, 4 of which had a catheter-related bacteriemia. Thrombotic events were only observed in 3 patients with active malignancy. A healthy donor presented a moderate bleeding after catheter withdrawal that resolved with local measures, and none of the rest presented any AE. Regarding variables related to the development of AEs, the subject group (patient or donor) was the only one significantly associated (p < 0.0001). Of interest, efficiency was also related to catheter location, being worse in those located in the femoral vein than in into the jugular or the subclavian veins (p < 0.05). In a multivariate analysis, the only variable significantly associated was catheter size (beta 0.238, p < 0.01). Discussion: Placing a CVC for PBPC collection in pediatric subjects is overall safe; CVC-related complications in pediatric healthy donors are very rare. Furthermore, we should try to place catheters of the largest caliber possible, since the efficiency of the collection is related to this variabl

Next-generation sequencing in bone marrow failure syndromes and isolated cytopenias: experience of the spanish network on bone marrow failure sundromes

© 2021 the Author(s).Inherited bone marrow failure syndromes (IBMFSs) are a group of congenital rare diseases characterized by bone marrow failure, congenital anomalies, high genetic heterogeneity, and predisposition to cancer. Appropriate treatment and cancer surveillance ideally depend on the identification of the mutated gene. A next-generation sequencing (NGS) panel of genes could be 1 initial genetic screening test to be carried out in a comprehensive study of IBMFSs, allowing molecular detection in affected patients. We designed 2 NGS panels of IBMFS genes: version 1 included 129 genes and version 2 involved 145 genes. The cohort included a total of 204 patients with suspected IBMFSs without molecular diagnosis. Capture-based targeted sequencing covered > 99% of the target regions of 145 genes, with more than 20 independent reads. No differences were seen between the 2 versions of the panel. The NGS tool allowed a total of 91 patients to be diagnosed, with an overall molecular diagnostic rate of 44%. Among the 167 patients with classified IBMFSs, 81 patients (48%) were diagnosed. Unclassified IBMFSs involved a total of 37 patients, of whom 9 patients (24%) were diagnosed. The preexisting diagnosis of 6 clinically classified patients (6%) was amended, implying a change of therapy for some of them. Our NGS IBMFS gene panel assay is a useful tool in the molecular diagnosis of IBMFSs and a reasonable option as the first tier genetic test in these disorders

Next-generation Sequencing in Bone Marrow Failure Syndromes and Isolated Cytopenias : Experience of the Spanish Network on Bone Marrow Failure Syndromes

Inherited bone marrow failure syndromes (IBMFSs) are a group of congenital rare diseases characterized by bone marrow failure, congenital anomalies, high genetic heterogeneity, and predisposition to cancer. Appropriate treatment and cancer surveillance ideally depend on the identification of the mutated gene. A next-generation sequencing (NGS) panel of genes could be 1 initial genetic screening test to be carried out in a comprehensive study of IBMFSs, allowing molecular detection in affected patients. We designed 2 NGS panels of IBMFS genes: version 1 included 129 genes and version 2 involved 145 genes. The cohort included a total of 204 patients with suspected IBMFSs without molecular diagnosis. Capture-based targeted sequencing covered > 99% of the target regions of 145 genes, with more than 20 independent reads. No differences were seen between the 2 versions of the panel. The NGS tool allowed a total of 91 patients to be diagnosed, with an overall molecular diagnostic rate of 44%. Among the 167 patients with classified IBMFSs, 81 patients (48%) were diagnosed. Unclassified IBMFSs involved a total of 37 patients, of whom 9 patients (24%) were diagnosed. The preexisting diagnosis of 6 clinically classified patients (6%) was amended, implying a change of therapy for some of them. Our NGS IBMFS gene panel assay is a useful tool in the molecular diagnosis of IBMFSs and a reasonable option as the first tier genetic test in these disorders

Papel del estroma medular en el fallo medular de los pacientes diagnosticados de Anemia de Fanconi

Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Medicina, Departamento de Pediatría. Fecha de Lectura: 31-03-2022Esta Tesis tiene embargado el acceso al texto completo hasta el 01-10-2023En los últimos años son varios los trabajos que han demostrado la importancia de la célula mesenquimal (MSC, del inglés mesenchymal stem cells) en el desarrollo de fallo medular y mielodisplasia de algunos pacientes no Fanconi. Este mismo hecho podría reproducirse en el caso del fallo medular de los pacientes diagnosticados de Anemia de Fanconi (AF). De este modo, la caracterización de este grupo celular y los cambios inducidos por los diferentes tratamientos sobre estas células podría ayudar a dilucidar su implicación en la evolución del cuadro clínico. Por otro lado, la identificación de biomarcadores y los estudios transcriptómicos de las propias MSC en estos pacientes podrían ayudar a encontrar dianas para orientar futuros tratamientos encaminados a modificar la evolución del fallo medular en los pacientes con AF. Para evaluar esa hipótesis, este trabajo realizó en la caracterización fenotípica, funcional y transcriptómica de células mesenquimales de pacientes diagnosticados de AF. Se observó que en su conjunto, las MSC de los pacientes con AF tienen las mismas características fenotípicas y funcionales que las MSC de controles sanos o sujetos sin hemopatía. No obstante, se han encontrado en algunos experimentos algunas alteraciones en subgrupos específicos de pacientes que no se han confirmado en otros, pero que convendrá tener en cuenta en futuros estudios. Entre estas alteraciones podemos describir que las MSC derivadas de pacientes sometidos a terapia génica presentaron menor capacidad clonogénica a la hora de generar unidades formadoras de colonias de fibroblastos (UFC-F) y las MSC derivadas de pacientes sometidos a trasplante de progenitores hematopoyéticos presentaron menor capacidad de inmunomodulación en los cultivos mixtos con linfocitos. Como ya hemos comentado, esos hallazgos no fueron confirmados en otros ensayos fenotípicos o funcionales, ni en la población MSC de pacientes con AF en global o en conjunto. Tampoco se demostraron rutas de señalizaciones sobre-expresadas o reprimidas en las MSC de los nichos medulares de pacientes con diagnóstico de AF en comparación a controles sanos. Por lo tanto, este trabajo no ha demostrado alteraciones de las MSC que justifiquen ningún cambio en los mecanismos regulatorios de las interaciones entre la célula madre hematopoyética (CMH) y el nicho medular que promueva o acelere el fallo medula

Haplo-identical or mismatched unrelated donor hematopoietic cell transplantation for Fanconi anemia: Results from the Severe Aplastic Anemia Working Party of the EBMT

Allogeneic hematopoietic cell transplantation (HCT) is the only curative option for bone marrow failure or hematopoietic malignant diseases for Fanconi anemia (FA) patients. Although results have improved over the last decades, reaching more than 90% survival when a human leukocyte antigen (HLA)-identical donor is available, alternative HCT donors are still less reported. We compared HCT outcomes using HLA-mismatched unrelated donors (MMUD; n = 123) or haplo-identical donors (HDs), either using only in vivo T cell depletion (n = 33) or T cells depleted in vivo with some type of graft manipulation ex vivo (n = 59) performed for FA between 2000 and 2018. Overall survival (OS) by 24 months was 62% (53-71%) for MMUD, versus 80% (66-95%) for HDs with only in vivo T cell depletion and 60% (47-73%) for HDs with in vivo and ex vivo T cell depletion (p = .22). Event-free survival (EFS) was better for HD-transplanted FA patients with only in vivo T cell depletion 86% (73-99%) than for those transplanted from a MMUD 58% (48-68%) or those with graft manipulation 56% (42-69%) (p = .046). Grade II-IV acute graft-versus-host disease (GVHD) was 41% (MMUD) versus 40% (HDs with no graft manipulation) versus 17% (HDs with T cell depleted graft), (p = .005). No differences were found for the other transplant related outcomes. These data suggest that HDs might be considered as an alternative option for FA patients with better EFS using unmanipulated grafts

Gene therapy restores the transcriptional program of hematopoietic stem cells in Fanconi anemia

Clinical trials have shown that lentiviral-mediated gene therapy can ameliorate bone marrow failure (BMF) in non-conditioned Fanconi anemia (FA) patients resulting from the proliferative advantage of corrected FA hematopoietic stem and progenitor cells (HSPC). However, it is not yet known if gene therapy can revert affected molecular pathways in diseased HSPC. Single-cell RNA sequencing was performed in chimeric populations of corrected and uncorrected HSPC co-existing in the BM of gene therapy-treated FA patients. Our study demonstrates that gene therapy reverts the transcriptional signature of FA HSPC, which then resemble the transcriptional program of healthy donor HSPC. This includes a down-regulated expression of TGF-β and p21, typically up-regulated in FA HSPC, and upregulation of DNA damage response and telomere maintenance pathways. Our results show for the first time the potential of gene therapy to rescue defects in the HSPC transcriptional program from patients with inherited diseases; in this case, in FA characterized by BMF and cancer predisposition

Venous thromboembolism in pediatric patients with acute lymphoblastic leukemia under chemotherapy treatment. Risk factors and usefulness of thromboprophylaxis. Results of LAL-SEHOP-PETHEMA-2013.

Symptomatic venous thromboembolism (VTE) is diagnosed in 3%-14% of patients during pediatric acute lymphoblastic leukemia (ALL) therapy. There are well-known risk factors, but the role of others as inherited thrombophilia is still controversial. Prophylaxis with low molecular weight heparin (LMWH) has been described, but its use is not globally accepted. A retrospective multicentric study in ALL patients 1-18 years old following SEHOP-PETHEMA-2013 treatment guideline was performed to evaluate VTE rate, anticoagulant treatment, outcome, risk factors, and safety and usefulness of LMWH administration as primary thromboprophylaxis in children with inherited thrombophilia. A total of 652 patients were included in the study. VTE incidence was 8.7%. Most of the cases occurred during induction therapy associated with central venous catheter. Univariant analysis showed that family history of thrombosis, presence of mediastinal mass, high-risk treatment group, and inherited thrombophilia were statistically significant risk factors. LMWH administration seemed to decrease VTE rate in patients with inherited thrombophilia and those with T-cell ALL phenotype. Most of the VTE cases occurred in patients without inherited thrombophilia, but when it is present, the VTE risk is higher. LMWH administration was useful to decrease VTE in these patients