Inflammatory cytokines and the development of pulmonary complications after allogeneic hematopoietic cell transplantation in patients with inherited metabolic storage disorders

Diffuse Alveolar Hemorrhage in Hematopoietic Cell Transplantation

Diffuse alveolar hemorrhage (DAH) is a morbid syndrome that occurs after autologous and allogeneic hematopoietic cell transplantation in children and adults. DAH manifests most often in the first few weeks following transplantation. It presents with pneumonia-like symptoms and acute respiratory failure, often requiring high levels of oxygen supplementation or mechanical ventilatory support. Hemoptysis is variably present. Chest radiographs typically feature widespread alveolar filling, sometimes with peripheral sparing and pleural effusions. The diagnosis is suspected when serial bronchoalveolar lavages return increasingly bloody fluid. DAH is differentiated from infectious causes of alveolar hemorrhage when extensive microbiological testing reveals no pulmonary pathogens. The cause is poorly understood, though preclinical and clinical studies implicate pretransplant conditioning regimens, particularly those using high doses of total-body-irradiation, acute graft-versus-host disease (GVHD), medications used to prevent GVHD, and other factors. Treatment consists of supportive care, systemic corticosteroids, platelet transfusions, and sometimes includes antifibrinolytic drugs and topical procoagulant factors. Therapeutic blockade of tumor necrosis factor-α showed promise in observational studies, but its benefit for DAH remains uncertain after small clinical trials. Even with these treatments, mortality from progression and relapse is high. Future investigational therapies could target the vascular endothelial cell biology theorized to contribute to alveolar bleeding and pathways that contribute to susceptibility, inflammation, cellular resilience, and tissue repair. This review will help clinicians navigate through the limited evidence to diagnose and treat DAH, counsel patients and families, and plan for future research.

Biomarkers to predict and diagnose pulmonary complications in children post haematopoietic stem cell transplant

OBJECTIVES

Haematopoietic cell transplant (HCT) is a cellular therapy for a group of high-risk children with cancer, immunodeficiency and metabolic disorders. Whilst curative for a child's underlying condition, HCT has significant risks associated, including lung injury. These complications are associated with increased post HCT mortality and require improved methods of risk stratification, diagnosis and treatment.

METHODS

Biomarkers measured in bronchoalveolar fluid and peripheral blood have been identified for both acute and chronic lung injury post HCT.This review evaluates the current research available investigating the use of these biomarkers to improve clinical care, with a focus on the paediatric cohort.

RESULTS

Elevated levels of cytokines such as IL-6, IL-8, G-CSF and TNF were identified as potential predictive biomarkers for the development of post HCT lung disease. The pulmonary microbiome was found to have strong potential as a biomarker pre and post HCT for the development of pulmonary complications. General limitations of the studies identified were study design, retrospective or single centre and not exclusively performed in the paediatric population.

CONCLUSION

To translate biomarker discovery into clinical implementation further research is required, utilising larger cohorts of children in prospective trials to validate these biomarkers and determine how they can be translated into better outcomes for children post HCT.

Risk factors predicting need for the pediatric intensive care unit (PICU) post-hematopoietic cell transplant, PICU utilization, and outcomes following HCT: a single center retrospective analysis

Hematopoietic cell transplant (HCT) is a curative treatment for multiple malignant and non-malignant disorders. While morbidity and mortality have decreased significantly over the years, some patients still require management in the pediatric intensive care unit (PICU) during their HCT course for additional respiratory, cardiovascular, and/or renal support. We retrospectively reviewed pediatric patients (0-18 years) who underwent HCT from January 2015-December 2020 at our institution to determine risk factors for PICU care and evaluate PICU utilization and outcomes. We also assessed pulmonary function testing (PFT) data to determine if differences were noted between PICU and non-PICU patients as well as potential evolution of pulmonary dysfunction over time. Risk factors of needing PICU care were lower age, lower weight, having an underlying inborn error of metabolism, and receiving busulfan-based conditioning. Nearly half of PICU encounters involved use of each of respiratory support types including high-flow nasal cannula, non-invasive positive pressure ventilation, and mechanical ventilation. Approximately one-fifth of PICU encounters involved renal replacement therapy. Pulmonary function test results largely did not differ between PICU and non-PICU patients at any timepoint aside from individuals who required PICU care having lower DLCO scores at one-year post-HCT. Future directions include consideration of combining our data with other centers for a multi-center retrospective analysis with the goal of gathering and reporting additional multi-center data to work toward continuing to decrease morbidity and mortality for patients undergoing HCT.

Prenatal Diagnosis of c.437-1G>A Mutation in the MAN2B1 Gene in a Family With Alpha-Mannosidosis: Unraveling Clinical Presentation and Treatment Outcomes in a Novel Prenatal Case

Alpha-mannosidosis is a rare lysosomal storage disorder with progressive impairments in motor functions, skeletal deformities, and immunodeficiency. Enzyme replacement therapy (ERT) should be initiated early to achieve optimal outcomes. This report describes how alpha-mannosidosis diagnosis in a seven-year-old girl led to a successful prenatal diagnosis in the subsequent pregnancy and pre-symptomatic treatment at the early disease stage. The index patient was a seven-year-old girl who was referred with a confirmed diagnosis of alpha-mannosidosis based on the presence of homozygous c.437-1G>A mutation in the MAN2B1 gene. A prenatal diagnosis was made in the subsequent pregnancy through molecular analysis, which revealed the same homozygous variant. The patient was treated at the fifth week of age and showed mild skeletal involvement and normal development at ERT initiation. At 11 months of age, the ERT level increased to 15.8 µmol/l/h. The motor assessment showed that the patient was developmentally normal and was able to maintain her sitting and walking for a few steps only. Prenatal molecular screening in affected families can allow for the early identification and implementation of appropriate management strategies for alpha-mannosidosis.

Pulmonary microbiome and gene expression signatures differentiate lung function in pediatric hematopoietic cell transplant candidates

Impaired baseline lung function is associated with mortality after pediatric allogeneic hematopoietic cell transplantation (HCT), yet limited knowledge of the molecular pathways that characterize pretransplant lung function has hindered the development of lung-targeted interventions. In this study, we quantified the association between bronchoalveolar lavage (BAL) metatranscriptomes and paired pulmonary function tests performed a median of 1 to 2 weeks before allogeneic HCT in 104 children in The Netherlands. Abnormal pulmonary function was recorded in more than half the cohort, consisted most commonly of restriction and impaired diffusion, and was associated with both all-cause and lung injury-related mortality after HCT. Depletion of commensal supraglottic taxa, such as Haemophilus, and enrichment of nasal and skin taxa, such as Staphylococcus, in the BAL microbiome were associated with worse measures of lung capacity and gas diffusion. In addition, BAL gene expression signatures of alveolar epithelial activation, epithelial-mesenchymal transition, and down-regulated immunity were associated with impaired lung capacity and diffusion, suggesting a postinjury profibrotic response. Detection of microbial depletion and abnormal epithelial gene expression in BAL enhanced the prognostic utility of pre-HCT pulmonary function tests for the outcome of post-HCT mortality. These findings suggest a potentially actionable connection between microbiome depletion, alveolar injury, and pulmonary fibrosis in the pathogenesis of pre-HCT lung dysfunction.

Pulmonary Complications of Pediatric Hematopoietic Cell Transplantation. A National Institutes of Health Workshop Summary

Approximately 2,500 pediatric hematopoietic cell transplants (HCTs), most of which are allogeneic, are performed annually in the United States for life-threatening malignant and nonmalignant conditions. Although HCT is undertaken with curative intent, post-HCT complications limit successful outcomes, with pulmonary dysfunction representing the leading cause of nonrelapse mortality. To better understand, predict, prevent, and/or treat pulmonary complications after HCT, a multidisciplinary group of 33 experts met in a 2-day National Institutes of Health Workshop to identify knowledge gaps and research strategies most likely to improve outcomes. This summary of Workshop deliberations outlines the consensus focus areas for future research.

The pulmonary metatranscriptome prior to pediatric HCT identifies post-HCT lung injury

Lung injury after pediatric allogeneic hematopoietic cell transplantation (HCT) is a common and disastrous complication that threatens long-term survival. To develop strategies to prevent lung injury, novel tools are needed to comprehensively assess lung health in HCT candidates. Therefore, this study analyzed biospecimens from 181 pediatric HCT candidates who underwent routine pre-HCT bronchoalveolar lavage (BAL) at the University Medical Center Utrecht between 2005 and 2016. BAL fluid underwent metatranscriptomic sequencing of microbial and human RNA, and unsupervised clustering and generalized linear models were used to associate microbiome gene expression data with the development of post-HCT lung injury. Microbe-gene correlations were validated using a geographically distinct cohort of 18 pediatric HCT candidates. The cumulative incidence of post-HCT lung injury varied significantly according to 4 pre-HCT pulmonary metatranscriptome clusters, with the highest incidence observed in children with pre-HCT viral enrichment and innate immune activation, as well as in children with profound microbial depletion and concomitant natural killer/T-cell activation (P < .001). In contrast, children with pre-HCT pulmonary metatranscriptomes containing diverse oropharyngeal taxa and lacking inflammation rarely developed post-HCT lung injury. In addition, activation of epithelial-epidermal differentiation, mucus production, and cellular adhesion were associated with fatal post-HCT lung injury. In a separate validation cohort, associations among pulmonary respiratory viral load, oropharyngeal taxa, and pulmonary gene expression were recapitulated; the association with post-HCT lung injury needs to be validated in an independent cohort. This analysis suggests that assessment of the pre-HCT BAL fluid may identify high-risk pediatric HCT candidates who may benefit from pathobiology-targeted interventions.

Enzyme replacement combinational therapy: effective treatments for mucopolysaccharidoses

INTRODUCTION

Mucopolysaccharidoses (MPS), as a group of inherited lysosomal storage disorders (LSDs), are clinically heterogeneous and characterized by multi-systemic manifestations, such as skeletal abnormalities and neurological dysfunctions. The currently used enzyme replacement therapy (ERT) might be associated with several limitations including the low biodistribution of the enzymes into the main targets, immunological responses against foreign enzymes, and the high cost of the treatment procedure. Therefore, a suitable combination approach can be considered for the successful treatment of each type of MPS.

AREAS COVERED

In this review, we provide comprehensive insights into the ERT-based combination therapies of MPS by reviewing the published literature on PubMed and Scopus. We also discuss the recent advancements in the treatment of MPS and bring up the hopes and hurdles in the futuristic treatment strategies.

EXPERT OPINION

Given the complex pathophysiology of MPS and its involvement in different tissues, the ERT of MPS in combination with stem cell therapy or gene therapy is deemed to provide a personalized precision treatment modality with the highest therapeutic responses and minimal side effects. By the same token, new combinational approaches need to be evaluated by using drugs that target alternative and secondary pathological pathways.

Brain Pathology in Mucopolysaccharidoses (MPS) Patients with Neurological Forms

Mucopolysaccharidoses (MPS) are the group of lysosomal storage disorders caused by deficiencies of enzymes involved in the stepwise degradation of glycosaminoglycans. To identify brain pathology common for neurological MPS, we conducted a comprehensive analysis of brain cortex tissues from post-mortem autopsy materials of eight patients affected with MPS I, II, IIIA, IIIC, and IIID, and age-matched controls. Frozen brain tissues were analyzed for the abundance of glycosaminoglycans (heparan, dermatan, and keratan sulfates) by LC-MS/MS, glycosphingolipids by normal phase HPLC, and presence of inflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor superfamily member 10 (TNFSF10) by Western blotting. Fixed tissues were stained for the markers for microgliosis, astrogliosis, misfolded proteins, impaired autophagy, and GM2ganglioside. Our results demonstrate that increase of heparan sulfate, decrease of keratan sulfate, and storage of simple&nbsp; monosialogangliosides 2 and 3 (GM2 and GM3) as well as the neutralglycosphingolipid, LacCer, together with neuroinflammation and neuronal accumulation of misfolded proteins are the hallmarks of brain pathology in MPS patients. These biomarkers aresimilar to those reported in the corresponding mouse models, suggesting that the pathological mechanism is common for all neurological MPS in humans and mice.

Current Approach to Non-Infectious Pulmonary Complications of Hematopoietic Stem Cell Transplantation

Hematopoietic stem cell transplantation is an established treatment for patients with a wide range of malignant and nonmalignant conditions. Noninfectious pulmonary complications still remain a leading cause of morbidity and mortality in these patients. Treating hematopoietic stem cell transplantation recipients with noninfectious pulmonary complications is still challenging, and the current treatment armamentarium and strategies are not adequate for patients receiving hematopoietic stem cell transplantation. Further trials are needed for a better description of the pathogenesis and the complete diagnostic criteria as well as for the development of effective therapeutic approaches for the management of noninfectious pulmonary complications of the hematopoietic stem cell transplantation. This review outlines the incidence, risk factors, pathogenesis, and clinical spectrum and discusses the current approaches to the management of noninfectious pulmonary complications of Hematopoietic stem cell transplantation.

Transplantation as disease modifying therapy in adults with inherited metabolic disorders

Transplantation is an established disease modifying therapy in selected children with certain inherited metabolic diseases (IMDs). Transplantation of hematopoietic stem cells or solid organs can be used to partially correct the underlying metabolic defect, address life threatening disease manifestations (such as neutropenia) or correct organ failure caused by the disease process. Much less information is available on the use of transplantation in adults with IMDs. Transplantation is indicated for the same IMDs in adults as in children. Despite similar disease specific indications, the actual spectrum of diseases for which transplantation is used differs between these age groups and this is partly related to the natural history of disease. There are diseases (such as urea cycle defects and X-linked adrenoleukodystrophy) for which transplantation is recommended for selected symptomatic patients as a treatment strategy in both adults and children. In those diseases, the frequency with which transplantation is used in adults is lower than in children and this may be related in part to a reduced awareness of transplantation as a treatment strategy amongst adult clinicians as well as limited donor availability and allocation policies which may disadvantage adult patients with IMDs. Risks of transplantation and disease-specific prognostic factors influencing outcomes also differ with age. We review the use of transplantation as a disease modifying strategy in adults focusing on how this differs from use in children to highlight areas for future research.

Alpha-Mannosidosis: Therapeutic Strategies

Alpha-mannosidosis (α-mannosidosis) is a rare lysosomal storage disorder with an autosomal recessive inheritance caused by mutations in the gene encoding for the lysosomal α-d-mannosidase. So far, 155 variants from 191 patients have been identified and in part characterized at the biochemical level. Similarly to other lysosomal storage diseases, there is no relationship between genotype and phenotype in alpha-mannosidosis. Enzyme replacement therapy is at the moment the most effective therapy for lysosomal storage disease, including alpha-mannosidosis. In this review, the genetic of alpha-mannosidosis has been described together with the results so far obtained by two different therapeutic strategies: bone marrow transplantation and enzyme replacement therapy. The primary indication to offer hematopoietic stem cell transplantation in patients affected by alpha-mannosidosis is preservation of neurocognitive function and prevention of early death. The results obtained from a Phase I⁻II study and a Phase III study provide evidence of the positive clinical effect of the recombinant enzyme on patients with alpha-mannosidosis.

Interstitial Lung Disease in Childhood: Clinical and Genetic Aspects

Interstitial lung disease (ILD) in childhood is a heterogeneous group of rare pulmonary conditions presenting chronic respiratory disorders. Many clinical features of ILD still remain unclear, making the treatment strategies mainly investigative. Guidelines may provide physicians with an overview on the diagnosis and therapeutic directions. However, the criteria used in different clinical studies for the classification and diagnosis of ILDs are not always the same, making the development of guidelines difficult. Advances in genetic testing have thrown light on some etiologies of ILD, which were formerly classified as ILDs of unknown origins. The need of genetic testing for unexplained ILD is growing, and new classification criteria based on the etiology should be adopted to better understand the disease. The purpose of this review is to give an overview of the clinical and genetic aspects of ILD in children.

Long-term functional outcomes of children with hurler syndrome treated with unrelated umbilical cord blood transplantation

OBJECTIVES

Hurler syndrome is characterized by progressive multisystem deterioration leading to early death in childhood. This prospective study evaluated the long-term outcomes of patients with Hurler syndrome who underwent umbilical cord blood transplantation from unrelated donors.

STUDY DESIGN

Only patients with Hurler syndrome who underwent umbilical cord blood transplantation between December 1995 and March 2006 (n = 25) and who were followed for at least 5 years (n = 19) were included in the analysis. The patients were longitudinally evaluated by a multidisciplinary team of specialists following a standardized protocol.

RESULTS

Median age at transplantation was 15.9 months (range 2.1-35), and patients were followed up until a median age of 10.1 years (range 7.2-14.9). Overall survival was 80%. All successfully transplanted patients achieved full donor chimerism and normal enzyme levels, and all children continue to make gains in development. Gross motor function was the most affected area. Vision and hearing were compromised in a minority of the patients, with some requiring corneal transplant or hearing aids. Cardiopulmonary function improved. Some children required orthopedic surgery, but severe complications were prevented in most patients. Although longitudinal growth was lower than that of unaffected children, it was considerably higher than expected from the natural course of the disease. Head circumference normalized. Hydrocephalus was not observed at longer follow-up, and cerebral atrophy decreased over time.

CONCLUSIONS

In this descriptive study of children with Hurler syndrome, unrelated umbilical cord blood transplantation was associated with improved somatic disease and neurodevelopment.

Stem cell transplantation and lung dysfunction

PURPOSE OF REVIEW

To identify factors that impact the incidence and severity of lung dysfunction after haematopoietic stem cell transplantation (HSCT) for preventive and therapeutic purposes.

RECENT FINDINGS

Respiratory failure from lung dysfunction after HSCT is a serious and often fatal transplant-related complication, but recent data reveal decreasing incidence and improving outcome over time. Idiopathic pneumonia syndrome (IPS) and bronchiolitis obliterans are now recognized as part of a spectrum of post-HSCT lung diseases involving both aspects of innate and adaptive immune responses, but may differ in the main lung structure affected: alveolar versus airway epithelium. There exists a strong association between acute graft-versus-host disease (GVHD) and IPS, and bronchiolitis obliterans is pathognomonic of chronic GVHD. Experimental models of IPS and bronchiolitis obliterans have proven useful to test strategies designed to limit lung injury including the effects of allogeneity, chemoradiotherapy and stem cell therapy. Recent advances in critical care practices, early diagnosis and utilizing ARDS Network ventilatory and conservative fluid management recommendations have also contributed to better outcome from lung dysfunction after HSCT.

SUMMARY

Understanding the factors that contribute to post-HSCT lung injury should lead to safer transplant practices that will allow the broader use of HSCT for sicker children with comorbidities.

Unusual pulmonary findings in mucolipidosis II

We report undescribed pulmonary findings in a child with mucolipidosis II (ML-II). Children with ML-II bear significant pulmonary morbidity that may include extensive pulmonary fibrosis, persistent hemosiderosis as well as pulmonary airway excrescences as they reach preschool age.

High rate of postoperative mortality in patients with mucopolysaccharidosis I: findings from the MPS I Registry

BACKGROUND/PURPOSE

Mucopolysaccharidosis I (MPS I) is a rare lysosomal storage disorder caused by deficiency of α-L-iduronidase, which results in progressive multisystemic disease. Patients with MPS I often require multiple common and uncommon surgeries and are at risk for surgical and anesthetic complications because of respiratory and cardiac disease. Surgery often precedes diagnosis; thus, surgeons and anesthesiologists may be unaware of potential risks.

METHODS

We analyzed data from the MPS I Registry, a voluntary observational database, for deaths occurring within 1 month of a surgical procedure among the 932 patients enrolled as of July 2010.

RESULTS

Among the 196 deceased patients, 186 reported 1 surgery or more, and 32 had 1 surgery or more within 1 month of death, including 20 who had 1 surgery or more within 10 days of death. Surgeries before death included hernia repair, central line placement, spinal surgery, tracheostomy, and ventriculo-peritoneal shunt. Most patients (28/32) had severe MPS I (Hurler), and 20 of 32 patients (all Hurler) died at 3 years or younger. In 6 of 32 patients, surgery was directly noted in the cause of death, including 4 patients with an attenuated form of MPS I.

CONCLUSIONS

Patients with mucopolysaccharidosis have a high postoperative mortality because of underlying respiratory and cardiac diseases.

An official American Thoracic Society research statement: noninfectious lung injury after hematopoietic stem cell transplantation: idiopathic pneumonia syndrome

RATIONALE

Acute lung dysfunction of noninfectious etiology, known as idiopathic pneumonia syndrome (IPS), is a severe complication following hematopoietic stem cell transplantation (HSCT). Several mouse models have been recently developed to determine the underlying causes of IPS. A cohesive interpretation of experimental data and their relationship to the findings of clinical research studies in humans is needed to better understand the basis for current and future clinical trials for the prevention/treatment of IPS.

OBJECTIVES

Our goal was to perform a comprehensive review of the preclinical (i.e., murine models) and clinical research on IPS.

METHODS

An ATS committee performed PubMed and OVID searches for published, peer-reviewed articles using the keywords "idiopathic pneumonia syndrome" or "lung injury" or "pulmonary complications" AND "bone marrow transplant" or "hematopoietic stem cell transplant." No specific inclusion or exclusion criteria were determined a priori for this review.

MEASUREMENTS AND MAIN RESULTS

Experimental models that reproduce the various patterns of lung injury observed after HSCT have identified that both soluble and cellular inflammatory mediators contribute to the inflammation engendered during the development of IPS. To date, 10 preclinical murine models of the IPS spectrum have been established using various donor and host strain combinations used to study graft-versus-host disease (GVHD). This, as well as the demonstrated T cell dependency of IPS development in these models, supports the concept that the lung is a target of immune-mediated attack after HSCT. The most developed therapeutic strategy for IPS involves blocking TNF signaling with etanercept, which is currently being evaluated in clinical trials.

CONCLUSIONS

IPS remains a frequently fatal complication that limits the broader use of allogeneic HSCT as a successful treatment modality. Faced with the clinical syndrome of IPS, one can categorize the disease entity with the appropriate tools, although cases of unclassifiable IPS will remain. Significant research efforts have resulted in a paradigm shift away from identifying noninfectious lung injury after HSCT solely as an idiopathic clinical syndrome and toward understanding IPS as a process involving aspects of both the adaptive and the innate immune response. Importantly, new laboratory insights are currently being translated to the clinic and will likely prove important to the development of future strategies to prevent or treat this serious disorder.

The effects of early and late bone marrow transplantation in siblings with alpha-mannosidosis. Is early haematopoietic cell transplantation the preferred treatment option?

This article documents both the neurological and physical outcomes of the first published set of siblings undergoing transplantation at differing ages for α-mannosidosis. The older brother, the index case, was diagnosed at the age of 3 years and underwent transplantation at 13 years for the treatment of increasing somatic problems and recurrent infections. The younger brother had undergone transplantation pre-symptomatically at 6 months of age. Their clinical, radiological and developmental outcomes are documented and compared with the previous published cases, with the case for early transplantation being weighted against other potential therapies.

Successful use of extracorporeal life support in a hematopoietic stem cell transplant patient with diffuse alveolar hemorrhage

OBJECTIVE

To describe the successful use of extracorporeal life support in a hematopoietic stem cell transplant patient with diffuse alveolar hemorrhage.

DESIGN

Case report.

SETTING

Pediatric intensive care unit in a freestanding quaternary children's hospital.

PATIENT

A 20-mo-old male with Hurler syndrome who developed respiratory failure from diffuse alveolar hemorrhage after hematopoietic stem cell transplant and was managed successfully with extracorporeal life support.

INTERVENTION

Placement on extracorporeal membrane oxygenation.

MEASUREMENTS AND MAIN RESULTS

Diffuse alveolar hemorrhage is a well-known complication in hematopoietic stem cell transplant patients, with an even higher occurrence in those with Hurler syndrome. Extracorporeal membrane oxygenation has been contraindicated traditionally in both pulmonary hemorrhage and hematopoietic stem cell transplant patients. We report the successful use of extracorporeal membrane oxygenation and survival to hospital discharge in a hematopoietic stem cell transplant patient with diffuse alveolar hemorrhage.

CONCLUSION

Although the reported survival of hematopoietic stem cell transplant patients on extracorporeal membrane oxygenation remains low, each patient must be evaluated for potential benefit of extracorporeal life support.

Pre-transplant risk factors affecting outcome in Hurler syndrome

Allogeneic transplantation remains the standard of care for patients with Hurler syndrome. As enzyme replacement therapy (ERT) has become available, controversy has emerged in regards to whether the use of enzyme in the peri-transplant period is appropriate. An analysis was performed on 74 patients with Hurler syndrome transplanted at the University of Minnesota between 1990 and 2003, before our use of ERT associated with transplant, with the intention of determining if patients at higher risk during the transplant can be identified based on evaluations and events before transplantation. Age, the presence of hydrocephalus, a history of cardiovascular issues or upper airway obstruction before transplant was not associated with significant differences in survival. In contrast, patients who had a history of lower airway disease, including reactive airway disease or bronchiolitis, or a history of pneumonia, had a significantly inferior outcome based on OS. The risk for serious respiratory complications was also assessed by evaluating the incidence of intubation. Overall, 31% of these patients were intubated. The risk of intubation was higher in older patients and in those with a history of lower airway disease. These findings have implications for the care of patients with high-risk features.

Respiratory complications after haematopoietic stem cell transplantation in a patient with chronic granulomatous disease

Chronic granulomatous disease (CGD) is an inherited immunodeficiency disorder caused by defects in NADPH oxidase and characterized by recurrent life-threatening bacterial and fungal infections. Although CGD has been considered to be a target for gene therapy, bone marrow transplantation (BMT) is now selected as the radical treatment in most cases. We performed BMT in a patient with CGD with severe infections and experienced respiratory complications of diffuse alveolar haemorrhage and/or infection-associated alveolar haemorrhage. We suggest that attention be paid to signs of onset of alveolar haemorrhage during BMT in CGD patients.

Allogeneic hematopoietic cell transplantation (HCT) in Hurler's syndrome using a reduced intensity preparative regimen

Allogeneic hematopoietic cell transplantation (HCT) in patients with Hurler's syndrome can improve survival and ameliorate many aspects of Hurler's syndrome including neurologic decline and cardiac compromise. Unfortunately, the toxicity of traditional preparative regimens to organs affected by the syndrome may have deleterious effects. Additionally, despite the intensity of these regimens, achieving stable donor chimerism can be difficult. We report transplant outcomes following a reduced intensity, highly immunosuppressive preparative regimen consisting of alemtuzumab, fludarabine and melphalan prior to HCT in seven patients with Hurler's syndrome treated at two centers. Six patients received grafts from unrelated donors and one received a sibling donor graft. The preparative regimen was well tolerated. All patients had initial donor engraftment at 100 days; one patient had delayed loss of donor chimerism. There was no severe acute GVHD (no GI GVHD of grade II or more, no grade IV skin GVHD). Six of the seven children are surviving at a median of 1014 (726-2222) days post transplant. This reduced intensity preparative regimen has the potential to support engraftment and improve survival and outcome in patients with Hurler's syndrome undergoing HCT.