Stem cell transplantation for primary immune deficiency. Curr Opin Hematol. 2013;20:501-508. [PMID: 24104410 DOI: 10.1097/MOH.0b013e328365a13b]

Assessment of non-myelotoxic agents as a preparatory regimen for hematopoietic stem cell gene therapy

RAG2 deficiency is characterized by a lack of B and T lymphocytes, causing severe lethal infections. Currently, RAG2 deficiency is treated with a Hematopoietic Stem Cell transplantation (HSCT). Most conditioning regimens used before HSCT consist of alkylating myelotoxic agents with or without irradiation and affect growth and development of pediatric patients. Here, we developed a non-myelotoxic regimen using G-CSF, VLA-4I or AMD3100. These agents are known HSC mobilizers or affect bone marrow (BM) permeability and may support the homing of HSCs to the BM, without inducing major side effects. Female Rag2-/- mice were pre-treated with Busulfan (BU), G-CSF, VLA-4I or AMD3100 and transplanted with male BM cells transduced with a lentiviral vector carrying codon optimized human RAG2 (RAG2co). Peripheral blood cell counts increased significantly after G-CSF, VLA-4I and AMD3100 treatment, but not after BU. Reconstitution of PB lymphocytes was comparable for all groups with full immune reconstitution at 6 months post transplantation, despite different methods of conditioning. Survival of mice pre-treated with non-myelotoxic agents was significantly higher than after BU treatment. Here, we show that the non-myelotoxic agents G-CSF, VLA-4I, and AMD3100 are highly effective as conditioning regimen before HSC gene therapy and can be used as an alternative to BU.

Successful Allogeneic Peripheral Blood Stem Cell Transplantation in 4 Wiskott-Aldrich Syndrome Patients

BACKGROUND

Allogeneic hematopoietic stem cell transplantation is a potential curative treatment in Wiskott-Aldrich syndrome (WAS). Here, we analyzed the outcomes in 4 WAS patients who underwent this procedure with peripheral blood stem cell (PBSC) in our center.

PATIENTS AND METHODS

Four patients with severe WAS phenotype have received allogeneic hematopoietic stem cell transplantation between January 2014 and December 2019 from matched sibling donors with PBSC. Two different preparative conditioning regimens were provided: the first associated busulfan-cyclophosphamide (2 patients) and the second with busulfan-fludarabine administered to the others. Cyclosporine gave as preferred graft-versus-host disease prophylaxis with a short course of methotrexate.

RESULTS

All patients achieved engraftment after PBSC with a median CD34+ cell count: 13.6×106/kg (8 to 24.9×106/kg). Chronic graft-versus-host disease developed in 2 patients treated by cyclosporine-steroids with complete resolution. Chimerism for all the patients was fully donor (>95% donor). After a median follow-up of 41 months (8 to 74 mo), all patients (100%) are alive, healthy, with complete clinical, immunologic, and hematologic recovery, without signs of WAS.

CONCLUSION

This limited study with high-dose PBSC transplantation approach for WAS, demonstrated a safe and effective treatment option, with rapid engraftment, without complications, excellent long-term outcomes, independent of conditioning regimen.

Haematopoietic stem cell transplantation for inborn errors of immunity: 25-year experience from University of Malaya Medical Centre, Malaysia

AIM

Inborn errors of immunity (IEI) comprise a heterogeneous group of disorders of the immune system, most of which are curable by haematopoietic stem cell transplantation (HSCT). We present a 25-year audit of HSCT for IEI at a tertiary-level academic hospital in Malaysia.

METHODS

Review of medical records of all cases of IEI who underwent HSCT between January 1993 and December 2018 at our centre. Diagnoses, complications, HSCT protocols and outcome data were studied.

RESULTS

There were 20 patients (19 boys) with a median age at diagnosis of 11 months (range: 2 months to 12 years). Eleven of 19 (58%) had malnutrition at presentation. Donor sources were variable: 13 (65%) matched sibling donor (MSD), 4 (20%) human leukocyte antigen-haploidentical donor (HD) and 3 (15%) matched unrelated donor (MUD). Conditioning regimens were physician-dependent and adapted to each patient's clinical status. Grades III-IV acute graft-versus-host disease occurred in two of three cases who received MUD grafts, 50% in those who received HD, and 8% in the MSD group. Transplant-related mortality at day +100 was 5%. With a median follow-up of 7.5 years, 18 (90%) patients are alive and free of infections.

CONCLUSION

Outcome of HSCT for IEI in our centre is comparable with international reports. HSCT results using HD and MUD grafts are also good despite challenges from acute graft-versus-host disease, providing a feasible alternative for patients without matched donors.

Considerations for hematopoietic stem cell transplantation in primary immunodeficiency disorders

Primary immunodeficiency disorders (PIDs) result from inborn errors in immunity. Susceptibility to infections and oftentimes severe autoimmunity pose life-threatening risks to patients with these disorders. Hematopoietic cell transplant (HCT) remains the only curative option for many. Severe combined immunodeficiency disorders (SCID) most commonly present at the time of birth and typically require emergent HCT in the first few weeks of life. HCT poses an unusual challenge for PIDs. Donor source and conditioning regimen often impact the outcome of immune reconstitution after HCT in PIDs. The use of matched or unmatched, as well as related versus unrelated donor has resulted in variable outcomes for different subsets of PIDs. Additionally, there is significant variability in the success of engraftment even for a single patient’s lymphocyte subpopulations. While certain cell lines do well without a conditioning regimen, others will not reconstitute unless conditioning is used. The decision to proceed with a conditioning regimen in an already immunocompromised host is further complicated by the fact that alkylating agents should be avoided in radiosensitive PIDs. This manuscript reviews some of the unique elements of HCT in PIDs and evidence-based approaches to transplant in patients with these rare and challenging disorders.

Hematopoietic Stem Cell Transplantation for Combined Immunodeficiencies, on Behalf of IEWP-EBMT

Combined immunodeficiencies (CIDs) are a clinically and genetically heterogeneous group of primary immunodeficiencies (PIDs) that affect T-lymphocyte immunity with abnormal development or function. As compared to severe combined immune deficiencies (SCID), these patients are usually diagnosed later. They display a broad infectious susceptibility; immune dysregulation manifestations and chronic lymphoproliferation are also frequent. These complications and their specific treatments can lead to persistent damage to several organs. Prognosis of CIDs is worse as compared to other PIDs. The curative treatment is usually hematopoietic stem cell transplantation (HSCT), but difficult questions remain regarding the definitive indication of HSCT and its timing; the final decision depends on a conjunction of factors such as immunological parameters, severity of clinical manifestations, and natural history of the disease, when molecular diagnosis is known. CD40L deficiency, a CID caused by mutations in CD40LG gene, well illustrates the dilemma between HSCT vs. long-term supportive treatment. This disease leads to higher risk of developing infections from bacterial and intracellular pathogens, especially Pneumocystis and Cryptosporidium spp. While supportive care allows improved survival during childhood, organ damages may develop with increasing age, mainly chronic lung disease and biliary tract disease (secondary to Cryptosporidium spp. infection) that may evolve later to sclerosing cholangitis, a severe complication associated with increased mortality. Early HSCT before organ damage development is associated with best survival and cure rate, while HSCT remains a risky therapeutic option for older patients, for those with organ damage, especially severe liver disease, and/or for those with limited or no donor availability. Prospective studies are needed to analyze risks of HSCT compared to those of life-long supportive therapy, including quality of life measures.

Successful hematopoietic stem cell transplantation for osteopetrosis using reduced intensity conditioning

BACKGROUND

Infantile malignant osteopetrosis (IMO) is an autosomal recessive condition characterized by defective osteoclast activity, with hematopoietic bone marrow transplant being the only available cure. Over the past several years, new conditioning regimes and donor options have emerged, thus extending the possibility of cure to a greater number of patients and improving the outcomes of bone marrow transplant. Here we detail the outcomes of bone marrow transplant in a cohort of 31 patients treated with a combination of fludarabine, treosulphan, thiotepa, and antithymocyte globulin.

PROCEDURES

Thirty-one patients with IMO who underwent hematopoietic stem cell transplantation with fludarabine, treosulphan, thiotepa, and antithymocyte globulin at our center from 2012 to 2017 are retrospectively reviewed in this study. Twenty-six patients were transplanted from 10/10 matched donors (13 from siblings, 11 from unrelated, and two from extended family donors), four from 9/10 matched unrelated donors, and one from a 9/10 matched family donor.

RESULTS

Overall survival was 100% with a median follow-up of 363 days (range 74-1891). There were 12 cases of acute graft versus host disease (GvHD) (38.7%), no cases of veno-occlusive disease, and eight cases of hypercalcemia (25.8%). Almost 80% of patients suffered viral reactivations with two cases of Epstein-Barr-virus-driven post-transplant lymphoproliferative disease. All cases of GvHD and viral reactivation were successfully treated.

CONCLUSIONS

We conclude that transplantation in children with IMO using fludarabine, treosulphan, thiotepa, and antithymocyte globulin is safe and effective and should be performed as early as possible following diagnosis, prior to the development of severe disease sequelae.

Adoptive T Cell Therapy for Epstein-Barr Virus Complications in Patients With Primary Immunodeficiency Disorders

Patients with primary immunodeficiency disorders (PID) have an increased risk from acute and chronic Epstein–Barr Virus (EBV) viral infections and EBV-associated malignancies. Hematopoietic stem cell transplantation (HSCT) is a curative strategy for many patients with PID, but EBV-related complications are common in the immediate post-transplant period due to delayed reconstitution of T cell immunity. Adoptive T cell therapy with EBV-specific T cells is a promising therapeutic strategy for patients with PID both before and after HSCT. Here we review the methods used to manufacture EBV-specific T cells, the clinical outcomes, and the ongoing challenges for future development of the strategy.

Adoptive T Cell Immunotherapy for Patients with Primary Immunodeficiency Disorders

Primary immunodeficiency disorders (PID) are a group of inborn errors of immunity with a broad range of clinical severity but often associated with recurrent and serious infections. While hematopoietic stem cell transplantation (HSCT) can be curative for some forms of PID, chronic and/or refractory viral infections remain a cause of morbidity and mortality both before and after HSCT. Although antiviral pharmacologic agents exist for many viral pathogens, these are associated with significant costs and toxicities and may not be effective for increasingly drug-resistant pathogens. Thus, the emergence of adoptive immunotherapy with virus-specific T lymphocytes (VSTs) is an attractive option for addressing the underlying impaired T cell immunity in many PID patients. VSTs have been utilized for PID patients following HSCT in many prior phase I trials, and may potentially be beneficial before HSCT in patients with chronic viral infections. We review the various methods of generating VSTs, clinical experience using VSTs for PID patients, and current limitations as well as potential ways to broaden the clinical applicability of adoptive immunotherapy for PID patients.

[Reduced-intensity conditioning haematopoietic stem cell transplantation in genetic diseases: Experience of the Spanish Working Group for Bone Marrow Transplantation in Children]

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.

RNA-based therapies for genodermatoses

Genetic disorders affecting the skin, genodermatoses, constitute a large and heterogeneous group of diseases, for which treatment is generally limited to management of symptoms. RNA-based therapies are emerging as a powerful tool to treat genodermatoses. In this review, we discuss in detail RNA splicing modulation by antisense oligonucleotides and RNA trans-splicing, transcript replacement and genome editing by in vitro-transcribed mRNAs, and gene knockdown by small interfering RNA and antisense oligonucleotides. We present the current state of these therapeutic approaches and critically discuss their opportunities, limitations and the challenges that remain to be solved. The aim of this review was to set the stage for the development of new and better therapies to improve the lives of patients and families affected by a genodermatosis.

Non-genotoxic conditioning for hematopoietic stem cell transplantation using a hematopoietic-cell-specific internalizing immunotoxin

Hematopoietic stem cell transplantation (HSCT) offers curative therapy for patients with hemoglobinopathies, congenital immunodeficiencies, and other conditions, possibly including AIDS. Autologous HSCT using genetically corrected cells would avoid the risk of graft-versus-host disease (GVHD), but the genotoxicity of conditioning remains a substantial barrier to the development of this approach. Here we report an internalizing immunotoxin targeting the hematopoietic-cell-restricted CD45 receptor that effectively conditions immunocompetent mice. A single dose of the immunotoxin, CD45-saporin (SAP), enabled efficient (>90%) engraftment of donor cells and full correction of a sickle-cell anemia model. In contrast to irradiation, CD45-SAP completely avoided neutropenia and anemia, spared bone marrow and thymic niches, enabling rapid recovery of T and B cells, preserved anti-fungal immunity, and had minimal overall toxicity. This non-genotoxic conditioning method may provide an attractive alternative to current conditioning regimens for HSCT in the treatment of non-malignant blood diseases.

Adoptive immunotherapy for primary immunodeficiency disorders with virus-specific T lymphocytes

BACKGROUND

Viral infections are a leading fatal complication for patients with primary immunodeficiencies (PIDs) who require hematopoietic stem cell transplantation (HSCT). Use of virus-specific T lymphocytes (VSTs) has been successful for the treatment and prevention of viral infections after HSCT for malignant and nonmalignant conditions. Here we describe the clinical use of VSTs in patients with PIDs at 4 centers.

OBJECTIVE

We sought to evaluate the safety and efficacy of VSTs for treatment of viral infections in patients with PIDs.

METHODS

Patients with PIDs who have received VST therapy on previous or current protocols were reviewed in aggregate. Clinical information, including transplantation details, viral infections, and use of antiviral and immunosuppressive pharmacotherapy, were evaluated. Data regarding VST production, infusions, and adverse reactions were compared.

RESULTS

Thirty-six patients with 12 classes of PID diagnoses received 37 VST products before or after HSCT. Twenty-six (72%) patients had received a diagnosis of infection with cytomegalovirus, EBV, adenovirus, BK virus, and/or human herpesvirus 6. Two patients were treated before HSCT because of EBV-associated lymphoproliferative disease. Partial or complete responses against targeted viruses occurred in 81% of patients overall. Time to response varied from 2 weeks to 3 months (median, 28 days). Overall survival at 6 months after therapy was 80%. Four patients had graft-versus-host disease in the 45 days after VST infusion, which in most cases was therapy responsive.

CONCLUSION

VSTs derived from either stem cell donors or third-party donors are likely safe and effective for the treatment of viral infections in patients with PIDs.

Hematopoietic Stem Cell Transplantation for Primary Immune Deficiency Disorders

Hematopoietic stem cell transplantation provides a curative option for children with primary immune deficiency disorders. Increased awareness and rapid diagnosis of these conditions has resulted in early referral and the chance to offer a curative option for affected children. Management of these children involves a multidisciplinary team including infectious disease specialists and intensivists. The use of reduced intensity conditioning chemotherapy, advances in detection and therapy of viral and fungal infections, optimal supportive care and techniques in stem cell processing, including T cell depletion has enabled doctors to transplant children with co-morbid conditions and no matched donors. Transplantation for these children has also brought in deep insights into the world of immunology and infectious diseases.

Eosinophilia Associated with Disorders of Immune Deficiency or Immune Dysregulation

Increased serum eosinophil levels have been associated with multiple disorders of immune deficiency or immune dysregulation. Although primary immunodeficiency diseases are rare, it is important to consider these in the differential diagnosis of patients with eosinophilia. In this review, the clinical features, laboratory findings, diagnosis, and genetic basis of disease of several disorders of immune deficiency or dysregulation are discussed. The article includes autosomal dominant hyper IgE syndrome, DOCK8 deficiency, phosphoglucomutase 3 deficiency, ADA-SCID, Omenn syndrome, Wiskott-Aldrich syndrome, Loeys-Dietz syndrome, autoimmune lymphoproliferative syndrome, immunodysregulation, polyendocrinopathy, enteropathy, X-linked syndrome, Comel-Netherton syndrome, and severe dermatitis, multiple allergies, and metabolic wasting syndrome.

Hospital Use in the Last Year of Life for Children With Life-Threatening Complex Chronic Conditions

BACKGROUND AND OBJECTIVES

Although many adults experience resource-intensive and costly health care in the last year of life, less is known about these health care experiences in children with life-threatening complex chronic conditions (LT-CCCs). We assessed hospital resource use in children by type and number of LT-CCCs.

METHODS

A retrospective analysis of 1252 children with LT-CCCs, ages 1 to 18 years, who died in 2012 within 40 US children's hospitals of the Pediatric Health Information System database. LT-CCCs were identified with International Classification of Diseases, 9th Revision, Clinical Modification codes. Using generalized linear models, we assessed hospital admissions, days, costs, and interventions (mechanical ventilation and surgeries) in the last year of life by type and number of LT-CCCs.

RESULTS

In the last year of life, children with LT-CCCs experienced a median of 2 admissions (interquartile range [IQR] 1-5), 27 hospital days (IQR 7-84), and $142 562 (IQR $45 270-$410 087) in hospital costs. During the terminal admission, 76% (n = 946) were mechanically ventilated; 36% (n = 453) underwent surgery. Hospital use was greatest (P < .001) among children with hematologic/immunologic conditions (99 hospital days [IQR 51-146]; cost = $504 145 [IQR $250 147-$879 331]) and children with ≥3 LT-CCCs (75 hospital days [IQR 28-132]; cost = $341 222 [IQR $146 698-$686 585]).

CONCLUSIONS

Hospital use for children with LT-CCCs in the last year of life varies significantly across the type and number of conditions. Children with hematologic/immunologic or multiple conditions have the greatest hospital use. This information may be useful for clinicians striving to improve care for children with LT-CCCs nearing the end of life.

The clinical features of autoimmunity in 53 patients with Wiskott-Aldrich syndrome in China: a single-center study

Autoimmune disease (AD) is common in patients with Wiskott-Aldrich syndrome (WAS) and patients with WAS who has an AD usually constitute a high-risk group with poor outcome. However, knowledge of AD in WAS is limited in China. In this study, medical records of 53 patients with WAS at Children´s Hospital of Chongqing Medical University from April 2004 to January 2014 were evaluated retrospectively and 14 patients (26%) had at least one AD. Autoimmune hemolytic anemia (AIHA) was the most common and detected in 12 patients (23%), other complications included immune thrombocytopenia (n = 1), immune neutropenia (n = 1), autoimmune arthritis (n = 1), and renal injury (n = 1). No significant differences were found in the level of serum immunoglobulins and lymphocyte subsets between the AD group and non-AD group. Although eight patients with AD received hematopoietic stem cell transplantation (HSCT), three patients died of pulmonary infection after HSCT.

CONCLUSIONS

AD is frequent in Chinese patients with WAS and AIHA was the most common. AD is a poor prognosis factor for WAS and should be treated as early as possible by HSCT.

WHAT IS KNOWN

• Autoimmune disease is common in patients with WAS. • Manifestations, follow-up finding, and treatment approaches of autoimmune disease in Chinese patients with WAS have received less attention in the literature. What is New: • This study is firstly intended for evaluation of the clinical and immune characteristics of autoimmune disease in a large series Chinese patients with WAS. • AD is frequent in Chinese patients with WAS and AIHA is the most common.

History and current status of newborn screening for severe combined immunodeficiency

The development of a T-cell receptor excision circle (TREC) assay utilizing dried blood spots in universal newborn screening has allowed the early detection of T-cell lymphopenia in newborns. Diagnosis of severe combined immunodeficiency (SCID) in affected infants in the neonatal period, while asymptomatic, permits early treatment and restoration of a functional immune system. SCID was the first immunodeficiency disease to be added to the Recommended Uniform Screening Panel of Core Conditions in the United States in 2010, and it is now implemented in 26 states in the U.S. This review covers the development of newborn screening for SCID, the biology of the TREC test, its current implementation in the U.S., new findings for SCID in the newborn screening era, and future directions.

Cord blood clinical processing, cryopreservation, and storage

Allogeneic umbilical cord blood (UCB) hematopoietic stem cell transplantation has become a crucial advancement in the treatment for a variety of diseases including hematopoietic and non-hematopoietic malignancies, BM failure syndromes, hemoglobinopathies, and metabolic and immunodeficiency disorders. It has been well documented that the success of UCB engraftment is tied to UCB banking processes, and now there are established guidelines for standardization of collection, banking, processing, and cryopreservation for unrelated UCB units with purpose of achieving consistent production of high quality placental and UCB units for administration. In 2011, Canada's Ministry of Health has announced Canada's first national, publicly funded umbilical cord blood bank, which aims to provide altruistic donations for unrelated allogeneic hematopoietic stem cell transplant. In this chapter, we describe specific protocols for clinical processing, cryopreservation, and storage of UCB used by the Canadian Blood Services National Public Umbilical Cord Blood Bank.

[Survival analysis of hematopoietic stem cell transplantation in children with primary immunodeficiency in Spain]

INTRODUCTION

Children with primary immunodeficiency have severe life-threatening infections and a higher prevalence of autoimmune problems, allergy and lymphoproliferative disorders. Allogenic hematopoietic stem cell transplantation has been the only potentially curative option.

PATIENTS AND METHODS

Patients with primary immunodeficiency underwent allogenic stem cell transplantation in the period 1985-2011, and registered in the Spanish Working Party for Bone Marrow Transplantation in Children.

RESULTS

One hundred and fifty nine patients underwent 173 allogenic stem cell transplantations, of whom 97 had severe combined immunodeficiency, 30 with immune dysregulation disorders, 25 Wiskott-Aldrich syndrome, and 21 phagocyte disorders. The median patient age at diagnosis was 6 months (range: 17 days - 168 months) and the median patient age at transplant was 12 months (range: 1 month - 189 months). The donors were 30 (19%) identical siblings, 40 (25%) alternative family donors, and 89 (56%) unrelated donors. The source of stem cells was bone marrow in 68 (43%), cord blood in 52 (33%), and peripheral blood in 39 (24%). Ninety eight (61.6%) are alive, 57 (35.9%) died. Event-free survival at 10 years was 63%, with 90% for children transplanted from identical siblings, 36% for those transplanted from alternative family donors, and 66% for those transplanted from unrelated donors.

CONCLUSIONS

The best results have been obtained with identical siblings, but other options may be considered.