Search

IntroductionHematopoietic stem cell transplantation (HCT) can cure chronic granulomatous disease (CGD). However, transplant-associated morbidity or mortality may occur, and it is still controversial which patients benefit from this procedure. The aim of this retrospective study was to evaluate the outcome of pediatric patients who received HCT in one of the Spanish pediatric transplant units. ResultsThirty children with a median age of 6.9 years (range 0.6–12.7) were evaluated: 8 patients received a transplant from a sibling donor (MSD), 21 received a transplant from an unrelated donor (UD), and 1 received a haploidentical transplant. The majority of the patients received reduced-intensity conditioning regimens based on either busulfan plus fludarabine or treosulfan. Relevant post-HCT complications were as follows: i) graft failure (GF), with a global incidence of 28.26% (CI: 15.15–48.88), 11.1% in patients with MSD (1.64–56.70) and 37.08% in unrelated donors (19.33–63.17); and ii) chronic graft-versus-host disease (GVHD), with an incidence of 20.5% (8.9–43.2), 11.1% in patients with MSD (1.64–56.70) and 26.7% in unrelated donors (10.42–58.44). Post-HCT infections were usually manageable, but two episodes of pulmonary aspergillosis were diagnosed in the context of graft rejection. The 2-year OS was 77.3% (55.92–89.23). There were no statistically significant differences among donor types.DiscussionHCT in patients with CGD is a complex procedure with significant morbidity and mortality, especially in patients who receive grafts from unrelated donors. These factors need to be considered in the decision-making process and when discussing conditioning and GVHD prophylaxis.

Background: Transplant-associated thrombotic microangiopathy (TA-TMA) is a serious complication of hematopoietic stem cell transplantation (HSCT) associated with high morbidity and mortality. High-risk TA-TMA (hrTA-TMA) is characterized by multifactorial endothelial damage caused by environmental stressors, dysregulation of the complement system, and genetic predisposition. Complement inhibitors have significantly decreased mortality and are the current treatment of choice. In this article, we describe our experience with the use of eculizumab in pediatric patients diagnosed with hrT-TMA after HSCT.Method: Retrospective study of pediatric patients with hrTA-TMA treated with eculizumab between January 2016 and December 2020.Results: Four pediatric patients aged 1, 12, 14, and 17 years at the time of HSCT were diagnosed with hrTA-TMA and treated with eculizumab during the study. At diagnosis, they all had renal impairment with proteinuria, and hypertension under treatment with at least two antihypertensive drugs. The patient who presented multisystemic involvement died instead of treatment. The three patients with exclusive renal involvement achieved TA-TMA resolution after treatment with eculizumab for 65, 52, and 40.6 weeks and were able to stop treatment. The two patients with follow-up data one year after eculizumab withdrawal sustained a favorable response. Eculizumab was well tolerated, and with adequate vaccination and antibiotic prophylaxis, did not increase the risk of infection.Conclusions: Eculizumab appears to be both safe and effective for the treatment of hrTA-TMA in patients with renal impairment. Early diagnosis and initiation of treatment may improve response. Eculizumab withdrawal can be contemplated in patients who achieve laboratory and clinical resolution of TA-TMA.

Abstract Gene targeting constitutes a new step in the development of gene therapy for inherited diseases. Although previous studies have shown the feasibility of editing fibroblasts from Fanconi anemia (FA) patients, here we aimed at conducting therapeutic gene editing in clinically relevant cells, such as hematopoietic stem cells (HSCs). In our first experiments, we showed that zinc finger nuclease (ZFN)‐mediated insertion of a non‐therapeutic EGFP‐reporter donor in the AAVS1 “safe harbor” locus of FA‐A lymphoblastic cell lines (LCLs), indicating that FANCA is not essential for the editing of human cells. When the same approach was conducted with therapeutic FANCA donors, an efficient phenotypic correction of FA‐A LCLs was obtained. Using primary cord blood CD34+ cells from healthy donors, gene targeting was confirmed not only in in vitro cultured cells, but also in hematopoietic precursors responsible for the repopulation of primary and secondary immunodeficient mice. Moreover, when similar experiments were conducted with mobilized peripheral blood CD34+ cells from FA‐A patients, we could demonstrate for the first time that gene targeting in primary hematopoietic precursors from FA patients is feasible and compatible with the phenotypic correction of these clinically relevant cells.

Umbilical cord blood transplant recipients are exposed to an increased risk of graft failure, a complication leading to a higher rate of transplant-related mortality. The decision and timing to offer a second transplant after graft failure is challenging. With the aim of addressing this issue, we analyzed engraftment kinetics and outcomes of 1268 patients (73% children) with acute leukemia (64% acute lymphoblastic leukemia, 36% acute myeloid leukemia) in remission who underwent single-unit umbilical cord blood transplantation after a myeloablative conditioning regimen. The median follow-up was 31 months. The overall survival rate at 3 years was 47%; the 100-day cumulative incidence of transplant-related mortality was 16%. Longer time to engraftment was associated with increased transplant-related mortality and shorter overall survival. The cumulative incidence of neutrophil engraftment at day 60 was 86%, while the median time to achieve engraftment was 24 days. Probability density analysis showed that the likelihood of engraftment after umbilical cord blood transplantation increased after day 10, peaked on day 21 and slowly decreased to 21% by day 31. Beyond day 31, the probability of engraftment dropped rapidly, and the residual probability of engrafting after day 42 was 5%. Graft failure was reported in 166 patients, and 66 of them received a second graft (allogeneic, n=45). Rescue actions, such as the search for another graft, should be considered starting after day 21. A diagnosis of graft failure can be established in patients who have not achieved neutrophil recovery by day 42. Moreover, subsequent transplants should not be postponed after day 42.

There are very few disease-specific studies focusing on outcomes of umbilical cord blood transplantation for Philadelphia chromosome-positive acute lymphoblastic leukemia. We report the outcome of 45 patients with Philadelphia chromosome-positive acute lymphoblastic leukemia who underwent myeloablative single unit cord blood transplantation from unrelated donors within the GETH/GITMO cooperative group. Conditioning regimens were based on combinations of thiotepa, busulfan, cyclophospamide or fludarabine, and antithymocyte globulin. At the time of transplantation, 35 patients (78%) were in first complete remission, four (8%) in second complete remission and six (14%) in third or subsequent response. The cumulative incidence of myeloid engraftment was 96% at a median time of 20 days and significantly better for patients receiving higher doses of CD34+ cells. The incidence of acute grade II–IV graft-versus-host disease was 31%, while that of overall chronic graft-versus-host disease was 53%. Treatment-related mortality was 17% at day +100 and 31% at 5 years. The 5-year relapse, event-free survival and overall survival rates were 31%, 36% and 44%, respectively. Although the event-free and overall survival rates in patients without BCR/ABL transcripts detectable at time of transplant were better than those in whom BCR/ABL transcripts were detected (46% versus 24% and 60% versus 30%, respectively) these differences were not statistically significant in the univariate analysis (P=0.07). These results demonstrate that umbilical cord blood transplantation from unrelated donors can be a curative treatment for a substantial number of patients with Philadelphia chromosome-positive acute lymphoblastic leukemia.

Background: Food protein‐induced enterocolitis syndrome (FPIES) is a non–IgE‐mediated food allergy. In the last few years, after the publication of the consensus guidelines, with refined diagnostic criteria and improved awareness, FPIES is diagnosed with increased frequency. However, despite having a background of immune dysregulation, this complication has just been described once in the posttransplant setting, in an adult patient. To the best of our knowledge, there are no reports of pediatric patients developing FPIES after a hematopoietic stem cell transplant (HCT). Methods: Retrospective review of a pediatric patient who developed severe FPIEs after a HCT. Results: In this case report, the clinical presentation and diagnosis challenges of a pediatric patient who developed severe FPIES after HCT are described. The patient developed severe vomiting, diarrhea, lethargy, and shock and required admission to the pediatric intensive care unit in three occasions before the diagnosis was made. Conclusions: To the best of our knowledge, this is the first report of severe FPIES post‐HCT in a pediatric patient. Physicians who are looking after pediatric patients in the post‐HCT setting need to be aware of this possibility and include this entity in the differential diagnosis in order to reduce its associated morbidity. [ABSTRACT FROM AUTHOR]

Resumen: Introducción: Los resultados de los pacientes con diagnóstico de leucemia linfoblástica aguda con cromosoma de Philadelphia (LLA-Ph) continúan siendo desfavorables comparados con los otros tipos de leucemias linfoblásticas agudas, pese a las mejoras en los tratamientos farmacológicos y los avances del trasplante de progenitores hematopoyéticos (TPH). Pacientes y métodos: Se ha analizado el papel del TPH alogénico en pacientes diagnosticados de LLA-Ph mediante un estudio multicéntrico donde se recogen datos pertenecientes a 70 pacientes reportados por el Grupo Español de Trasplante Hematopoyético (GETH), diagnosticados de esta enfermedad trasplantados en distintos hospitales españoles entre los años 1998 y 2014. Resultados: La realización del TPH a partir del año 2004, en primera remisión completa (RC) y con el empleo de timoglobulina (ATG) como parte del acondicionamiento, impactó favorablemente en la supervivencia global (SG). El TPH a partir del año 2004 en primera RC, así como el tratamiento con ATG y el desarrollo de enfermedad de injerto contra receptor aguda (EICRa), aumentaron la supervivencia libre de eventos (SLE). La administración de imatinib, así como la ausencia de enfermedad mínima residual previas al TPH, junto con la EICRa redujeron la probabilidad de recaída. La edad del paciente inferior a 10 años, el estado de primera RC y el empleo de ATG en el acondicionamiento disminuyeron la mortalidad relacionada con el TPH. Conclusiones: Los pacientes en primera RC que han recibido ATG durante el acondicionamiento presentan mayores SG y SLE. La indicación de TPH debería considerarse en estas situaciones. Abstract: Introduction: Outcomes in patients diagnosed of acute lymphoblastic leukemia with Philadelphia chromosome (Ph-ALL) remains unfavourable compared to other subtypes of acute lymphoblastic leukemia despite improvements in drug treatments as well as advances in hematopoietic stem cell transplantation (HSCT). Patients and methods: The role of allogeneic HSCT in Ph-ALL patients has been analysed through a multicentric study where data belonging to 70 patients diagnosed of this entity in different center that received HSCT between years 1998 and 2014, were reported by the Grupo Español de Trasplante Hematopoyético (GETH). Results: The performance of HSCT from year 2004, in first complete remission (CR) status with thymoglobulin (ATG) based conditioning had a favorable impact on overall survival (OS). HSTC performance from year 2004, in first CR with ATG-based conditioning in addition to acute graft versus host disease (aGvHD) development, increased event free survival (EFS). Treatment with imatinib as well as undetectable minimal residual disease (MRD) prior to HSCT, combined with aGvHD, reduced risk of relapse (RR). Patient age less than 10 years when HSCT, first CR and ATG-based conditioning were associated to a lower transplant related mortality (TRM). Conclusions: Patients that could achieve first CR that also received ATG-based conditioning had a better OS and EFS, so HSCT should be considered for this group of patients.

Introduction: Outcomes in patients diagnosed of acute lymphoblastic leukemia with Philadelphia chromosome (Ph-ALL) remains unfavourable compared to other subtypes of acute lymphoblastic leukemia despite improvements in drug treatments as well as advances in hematopoietic stem cell transplantation (HSCT). Patients and methods: The role of allogeneic HSCT in Ph-ALL patients has been analysed through a multicentric study where data belonging to 70 patients diagnosed of this entity in different centers that received HSCT between years 1998 and 2014, were reported by the Grupo Español de Trasplante Hematopoyético (GETH). Results: The performance of HSCT from year 2004, in first complete remission (CR) status with thymoglobulin (ATG) based conditioning had a favorable impact on overall survival (OS). HSTC performance from year 2004, in first CR with ATG-based conditioning in addition to acute graft versus host disease (aGvHD) development, increased event free survival (EFS). Treatment with imatinib as well as undetectable minimal residual disease (MRD) prior to HSCT, combined with aGvHD, reduced risk of relapse (RR). Patient age less than 10 years when HSCT, first CR and ATG-based conditioning were associated to a lower transplant related mortality (TRM). Conclusions: Patients that could achieve first CR that also received ATG-based conditioning had a better OS and EFS, so HSCT should be considered for this group of patients. Resumen: Introducción: Los resultados de los pacientes con diagnóstico de leukemia linfoblástica aguda con cromosoma de Philadelphia (LLA-Ph) continúan siendo desfavorables comparados con los otros tipos de leucemias linfoblásticas agudas, pese a las mejoras en los tratamientos farmacológicos y los avances del trasplante de progenitores hematopoyéticos (TPH). Pacientes y Métodos: Se ha analizado el papel del TPH alogénico en pacientes diagnosticados de LLA-Ph mediante un estudio multicéntrico donde se recogen datos pertenecientes a 70 pacientes reportados por el Grupo Español de Trasplante Hematopoyético (GETH ), diagnosticados de esta enfermedad trasplantados en distintos hospitales españoles entre los años 1998 y 2014. Resultados: La realización del TPH a partir del año 2004, en primera remisión completa (RC) y con el empleo de timoglobulina (ATG) como parte del acondicionamiento, impactó favorablemente en la supervivencia global (SG). El TPH a partir del año 2004 en primera RC, así como el tratamiento con ATG y el desarrollo de enfermedad de injerto contra receptor aguda (EICRa), aumentaron la supervivencia libre de eventos (SLE). La administración de imatinib así como la ausencia de enfermedad mínima residual (EMR) previas al TPH, junto con la EICRa redujeron la probabilidad de recaída (PR). La edad del paciente inferior a 10 años, el estado de primera RC y el empleo de ATG en el acondicionamiento, disminuyeron la mortalidad relacionada con el TPH (MRT). Conclusiones: Los pacientes en primera RC que han recibido ATG durante el acondicionamiento presentan mayores SG y SLE. La indicación de TPH debería considerarse en estas situaciones.

IntroductionStudies addressing the role of haploidentical as alternative to HLA-matched donors for stem cell transplantation (SCT) often include patients with diverse hematological malignancies in different remission statuses.MethodsWe compared outcomes of children with acute lymphoblastic leukemia (ALL) undergoing SCT in second complete remission (CR2) from haploidentical (n = 25) versus HLA-matched donor (n = 51).ResultsPatients were equally distributed across both groups according to age, immunophenotype, time to and site of relapse, relapse risk-group allocation, and minimal residual disease (MRD) before SCT. Incidence of graft failure, acute graft versus host disease (GVHD), and other early complications did not differ between both groups. We found no differences in overall survival (58.7% versus 59.5%; p = .8), leukemia free survival (LFS) (48% versus 36.4%; p = .5), event free survival (40% versus 34.4%; p = .69), cumulative incidence (CI) of subsequent relapse (28% versus 40.9%; p = .69), treatment related mortality (24% versus 23.6%; p = .83), CI of cGVHD (4.5% versus 18.7%; p = .2), and chronic GVHD-free and leukemia-free survival (44% versus 26.3%; p = .3) after haploidentical donor SCT. Chronic GVHD (HR = 0.09; p=.02) had protective impact, and MRD ≥ 0.01% before SCT (HR = 2.59; p=.01) had unfavorable impact on LFS.DiscussionThese results support the role of haploidentical donor SCT in children with ALL in CR2.

Fanconi anemia (FA) is the most prevalent inherited bone marrow failure (BMF) syndrome. Nevertheless, the pathophysiological mechanisms of BMF in FA have not been fully elucidated. Since FA cells are defective in DNA repair, we hypothesized that FA hematopoietic stem and progenitor cells (HSPCs) might express DNA damage–associated stress molecules such as natural killer group 2 member D ligands (NKG2D-Ls). These ligands could then interact with the activating NKG2D receptor expressed in cytotoxic NK or CD8+ T cells, which may result in progressive HSPC depletion. Our results indeed demonstrated upregulated levels of NKG2D-Ls in cultured FA fibroblasts and T cells, and these levels were further exacerbated by mitomycin C or formaldehyde. Notably, a high proportion of BM CD34+ HSPCs from patients with FA also expressed increased levels of NKG2D-Ls, which correlated inversely with the percentage of CD34+ cells in BM. Remarkably, the reduced clonogenic potential characteristic of FA HSPCs was improved by blocking NKG2D–NKG2D-L interactions. Moreover, the in vivo blockage of these interactions in a BMF FA mouse model ameliorated the anemia in these animals. Our study demonstrates the involvement of NKG2D–NKG2D-L interactions in FA HSPC functionality, suggesting an unexpected role of the immune system in the progressive BMF that is characteristic of FA.

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.

Robust and applicable risk-stratifying genetic factors at diagnosis in pediatric T-cell acute lymphoblastic leukemia (T-ALL) are still lacking, and most protocols rely on measurable residual disease (MRD) assessment. In our study, we aimed to analyze the impact of NOTCH1, FBXW7, PTEN, and RAS mutations, the measurable residual disease (MRD) levels assessed by flow cytometry (FCM-MRD) and other reported risk factors in a Spanish cohort of pediatric T-ALL patients. We included 199 patients treated with SEHOP and PETHEMA consecutive protocols from 1998 to 2019. We observed a better outcome of patients included in the newest SEHOP-PETHEMA-2013 protocol compared to the previous SHOP-2005 cohort. FCM-MRD significantly predicted outcome in both protocols, but the impact at early and late time points differed between protocols. The impact of FCM-MRD at late time points was more evident in SEHOP-PETHEMA 2013, whereas in SHOP-2005 FCM-MRD was predictive of outcome at early time points. Genetics impact was different in SHOP-2005 and SEHOP-PETHEMA-2013 cohorts: NOTCH1 mutations impacted on overall survival only in the SEHOP-PETHEMA-2013 cohort, whereas homozygous deletions of CDKN2A/B had a significantly higher CIR in SHOP-2005 patients. We applied the clinical classification combining oncogenetics, WBC count and MRD levels at the end of induction as previously reported by the FRALLE group. Using this score, we identified different subgroups of patients with statistically different outcome in both Spanish cohorts. In SHOP-2005, the FRALLE classifier identified a subgroup of high-risk patients with poorer survival. In the newest protocol SEHOP-PETHEMA-2013, a very low-risk group of patients with excellent outcome and no relapses was detected, with borderline significance. Overall, FCM-MRD, WBC count and oncogenetics may refine the risk-stratification, helping to design tailored approaches for pediatric T-ALL patients.

Unstable hemoglobinopathies (UHs) are rare anemia disorders (RADs) characterized by abnormal hemoglobin (Hb) variants with decreased stability. UHs are therefore easily precipitating, causing hemolysis and, in some cases, leading to dominant beta-thalassemia (dBTHAL). The clinical picture of UHs is highly heterogeneous, inheritance pattern is dominant, instead of recessive as in more prevalent major Hb syndromes, and may occur de novo. Most cases of UHs are not detected by conventional testing, therefore diagnosis requires a high index of suspicion of the treating physician. Here, we highlight the importance of next generation sequencing (NGS) methodologies for the diagnosis of patients with dBTHAL and other less severe UH variants. We present five unrelated clinical cases referred with chronic hemolytic anemia, three of them with severe blood transfusion dependent anemia. Targeted NGS analysis was performed in three cases while whole exome sequencing (WES) analysis was performed in two cases. Five different UH variants were identified correlating with patients’ clinical manifestations. Four variants were related to the beta-globin gene (Hb Bristol—Alesha, Hb Debrousse, Hb Zunyi, and the novel Hb Mokum) meanwhile one case was caused by a mutation in the alpha-globin gene leading to Hb Evans. Inclusion of alpha and beta-globin genes in routine NGS approaches for RADs has to be considered to improve diagnosis’ efficiency of RAD due to UHs. Reducing misdiagnoses and underdiagnoses of UH variants, especially of the severe forms leading to dBTHAL would also facilitate the early start of intensive or curative treatments for these patients.

Resumen: Introducción: El trasplante de progenitores hematopoyéticos (TPH) consiste en implantar elementos celulares capaces de generar un sistema hematopoyético nuevo y sano. El régimen de intensidad reducida (RIR) consiste en un tratamiento predominantemente inmunosupresor, para facilitar un implante progresivo con menor morbilidad. Este tipo de acondicionamiento puede también provocar mielosupresión, aunque potencialmente reversible en el tiempo.El acondicionamiento RIR permite aplicar TPH a pacientes con enfermedad genética en los que no es deseable añadir comorbilidad por las altas dosis de quimioterapia que conlleva el régimen mieloablativo convencional. Pacientes y métodos: Se analiza la evolución de 68 pacientes pediátricos con enfermedades genéticas que entre los años 2005-2013 se han sometido a un TPH con RIR en las Unidades pediátricas de Trasplante Hematopoyético de los hospitales españoles integrantes del Grupo Español para Trasplante de Médula Ósea en niños.Se trata de un estudio multicéntrico que incluye a 68 pacientes, de los cuales 43 presentan inmunodeficiencia primaria, 21 presentan hemopatía congénita y 4 están afectados de metabolopatía. Resultados: Cincuenta de los 68 pacientes se encuentran vivos (73,5%). La supervivencia global (SG) a 9 años es de 0,74. Veintitrés (33,8%) han presentado en el transcurso del TPH algún evento. Supervivencia libre de evento de 0,66. La SG en los pacientes con hemopatía es de 0,81; en las inmunodeficiencias primarias es de 0,70 y en las metabolopatías es de 0,4. No se observa diferencia significativa entre los 3 grupos de enfermedades. Respecto a la fuente de progenitores hematopoyéticos, la SG en los pacientes trasplantados con sangre periférica es de 0,74; con médula ósea es de 0,70 y con la sangre de cordón umbilical es de 0,70. No se observa tampoco diferencia estadística significativa. Conclusiones: En nuestro trabajo, de ámbito nacional, hemos evidenciado unos resultados favorables en TPH con régimen de intensidad reducida en las enfermedades genéticas. Cabe destacar que las metabolopatías requieren una consideración individualizada para sopesar en cada paciente los riesgos y beneficios que comporta el RIR. Abstract: Introduction: Haematopoietic stem cell transplantation (HSCT) involves implanting cellular elements capable of generating a new and healthy haematopoietic system. Reduced intensity conditioning (RIC) consists of an immunosuppressive treatment to facilitate a progressive implant with lower morbidity. This type of conditioning can also lead to myelosuppression, which is potentially reversible over time.Reduced intensity conditioning enables HSCT to be performed on patients with genetic diseases for whom added comorbidity is undesirable due to the high doses of chemotherapy that accompanies conventional myeloablative regimens. Patients and methods: An analysis was performed on the outcomes of 68 paediatric patients with genetic diseases who underwent HSCT with RIC between 2005 and 2013 in the of Paediatric Haematopoietic Stem Cell Transplantation Units that are part of the Spanish Working Group for Bone Marrow Transplantation in Children.A multicentre study was conducted including 68 patients, of whom 43 had Primary Immunodeficiency, 21 with congenital haematological diseases, and 4 with metabolic diseases. Results: Fifty (73.5%) of the 68 patients were still alive. The Overall Survival (OS) at nine years was 0.74. Twenty-three (33.8%) had some event during the course of the HSCT, with an event-free survival rate of 0.66. The OS in patients with haematological diseases was 0.81, being 0.7 in primary immunodeficiencies, and 0.4 in metabolic diseases. No significant difference was observed between the 3 groups of diseases. As regards the source of haematopoietic progenitors, there was an OS rate of 0.74 in patients transplanted with peripheral blood, 0.70 with bone marrow, and 0.70 and with cord blood, with no statistically significant differences. Conclusions: Favourable results have been obtained in HSCT with reduced intensity conditioning in genetic diseases. It should be noted that the risks and benefits of the RIC in patients with metabolic diseases need to be assessed on an individual basis.

Introduction: Haematopoietic stem cell transplantation (HSCT) involves implanting cellular elements capable of generating a new and healthy haematopoietic system. Reduced intensity conditioning (RIC) consists of an immunosuppressive treatment to facilitate a progressive implant with lower morbidity. This type of conditioning can also lead to myelosuppression, which is potentially reversible over time.Reduced intensity conditioning enables HSCT to be performed on patients with genetic diseases for whom added comorbidity is undesirable due to the high doses of chemotherapy that accompanies conventional myeloablative regimens. Patients and methods: An analysis was performed on the outcomes of 68 paediatric patients with genetic diseases who underwent HSCT with RIC between 2005 and 2013 in the of Paediatric Haematopoietic Stem Cell Transplantation Units that are part of the Spanish Working Group for Bone Marrow Transplantation in Children.A multicentre study was conducted including 68 patients, of whom 43 had Primary Immunodeficiency, 21 with congenital haematological diseases, and 4 with metabolic diseases. Results: Fifty (73.5%) of the 68 patients were still alive. The overall survival (OS) at nine years was 0.74. Twenty-three (33.8%) had some event during the course of the HSCT, with an event-free survival rate of 0.66. The OS in patients with haematological diseases was 0.81, being 0.7 in primary immunodeficiencies, and 0.4 in metabolic diseases. No significant difference was observed between the 3 groups of diseases. As regards the source of haematopoietic progenitors, there was an OS rate of 0.74 in patients transplanted with peripheral blood, 0.70 with bone marrow, and 0.70 and with cord blood, with no statistically significant differences. Conclusions: Favourable results have been obtained in HSCT with reduced intensity conditioning in genetic diseases. It should be noted that the risks and benefits of the RIC in patients with metabolic diseases need to be assessed on an individual basis. Resumen: Introducción: El trasplante de progenitores hematopoyéticos (TPH) consiste en implantar elementos celulares capaces de generar un sistema hematopoyético nuevo y sano. El régimen de intensidad reducida (RIR) consiste en un tratamiento predominantemente inmunosupresor, para facilitar un implante progresivo con menor morbilidad. Este tipo de acondicionamiento puede también provocar mielosupresión, aunque potencialmente reversible en el tiempo.El acondicionamiento RIR permite aplicar TPH a pacientes con enfermedad genética en los que no es deseable añadir comorbilidad por las altas dosis de quimioterapia que conlleva el régimen mieloablativo convencional. Pacientes y métodos: Se analiza la evolución de 68 pacientes pediátricos con enfermedades genéticas que entre los años 2005-2013 se han sometido a un TPH con RIR en las Unidades pediátricas de Trasplante Hematopoyético de los hospitales españoles integrantes del Grupo Español para Trasplante de Médula Ósea en niños.Se trata de un estudio multicéntrico que incluye a 68 pacientes, de los cuales 43 presentan inmunodeficiencia primaria, 21 presentan hemopatía congénita y 4 están afectados de metabolopatía. Resultados: Cincuenta de los 68 pacientes se encuentran vivos (73,5%). La supervivencia global (SG) a 9 años es de 0,74. Veintitrés (33,8%) han presentado en el transcurso del TPH algún evento. Supervivencia libre de evento de 0,66. La SG en los pacientes con hemopatía es de 0,81; en las inmunodeficiencias primarias es de 0,70 y en las metabolopatías es de 0,4. No se observa diferencia significativa entre los 3 grupos de enfermedades. Respecto a la fuente de progenitores hematopoyéticos, la SG en los pacientes trasplantados con sangre periférica es de 0,74; con médula ósea es de 0,70 y con la sangre de cordón umbilical es de 0,70. No se observa tampoco diferencia estadística significativa. Conclusiones: En nuestro trabajo, de ámbito nacional, hemos evidenciado unos resultados favorables en TPH con régimen de intensidad reducida en las enfermedades genéticas. Cabe destacar que las metabolopatías requieren una consideración individualizada para sopesar en cada paciente los riesgos y beneficios que comporta el RIR.

Background: Immunodeficiencies (ID), in particular primary immunodeficiencies (PID), are often associated with haematological manifestations, such as peripheral cytopenias or lymphoproliferative syndromes. Early diagnosis and management have significant prognostic implications. Secondary immunodeficiencies (SID) may also be induced by oncohaematological diseases and their treatments. Haematologists and oncologists must therefore be aware of the association between blood disorders and cancer and ID, and be prepared to offer their patients appropriate treatment without delay. Our aim was to define the warning signs of primary and secondary IDs in paediatric and adult patients with oncohaematological manifestations.Methods: A multidisciplinary group of six experts (2 haematologists, 2 immunologists, and 2 paediatricians specializing in ID) conducted a literature review and prepared a document based on agreements reached an in-person meeting. An external group of 44 IDs specialists from all over Spain assessed the document and were consulted regarding their level of agreement.Results: This document identifies the haematological and extra-haematological diseases that should prompt a suspicion of PIDs in adults and children, in both primary care and haematology and oncology departments. Cytopenia and certain lymphoproliferative disorders are key diagnostic pointers. The diagnosis must be based on a detailed clinical history, physical exploration, complete blood count and standard laboratory tests. The immunological and haematological tests included in the diagnostic process will depend on the care level. Patients who are candidates for immunoglobulin replacement therapy must be carefully selected, and treatment should be offered as soon as possible to avoid the development of complications. Finally, this document recommends procedures for monitoring these patients.Conclusions: This document combines scientific evidence with the opinion of a broad panel of experts, and emphasizes the importance of an early diagnosis and treatment to avoid complications. The resulting document is a useful tool for primary care physicians and specialists who see both adult and paediatric patients with oncohaematological diseases.

Abstract: Detectable clonal mosaicism for large chromosomal events has been associated with aging and an increased risk of hematological and some solid cancers. We hypothesized that genetic cancer predisposition disorders, such as Fanconi anemia (FA), could manifest a high rate of chromosomal mosaic events (CMEs) in peripheral blood, which could be used as early biomarkers of cancer risk. We studied the prevalence of CMEs by single-nucleotide polymorphism (SNP) array in 130 FA patients' blood DNA and their impact on cancer risk. We detected 51 CMEs (4.4-159 Mb in size) in 16 out of 130 patients (12.3%), of which 9 had multiple CMEs. The most frequent events were gains at 3q (n = 6) and 1q (n = 5), both previously associated with leukemia, as well as rearrangements with breakpoint clustering within the major histocompatibility complex locus (P = 7.3 × 10−9). Compared with 15 743 age-matched population controls, FA patients had a 126 to 140 times higher risk of detectable CMEs in blood (P < 2.2 × 10−16). Prevalent and incident hematologic and solid cancers were more common in CME carriers (odds ratio [OR] = 11.6, 95% confidence interval [CI] = 3.4-39.3, P = 2.8 × 10−5), leading to poorer prognosis. The age-adjusted hazard risk (HR) of having cancer was almost 5 times higher in FA individuals with CMEs than in those without CMEs. Regarding survival, the HR of dying was 4 times higher in FA individuals having CMEs (HR = 4.0, 95% CI = 2.0-7.9, P = 5.7 × 10−5). Therefore, our data suggest that molecular karyotyping with SNP arrays in easy-to-obtain blood samples could be used for better monitoring of bone marrow clonal events, cancer risk, and overall survival of FA patients.