Lung function and late pulmonary complications among survivors of hematopoietic stem cell transplantation during childhood

Detection of Bronchiolitis Obliterans Syndrome Using Nitrogen Multiple Breath Washout in Children Posthemopoietic Stem Cell Transplant

Bronchiolitis obliterans syndrome (BOS) is a severe complication following hemopoietic stem cell transplantation (HSCT) and is often undetected until there is significant deterioration in pulmonary function. Lung clearance index (LCI2.5) derived from the nitrogen multiple breath washout (N2MBW) test may be more feasible and sensitive than spirometry, which is currently used for surveillance and detection of BOS. We aimed to examine the feasibility of performing surveillance N2MBW in children post-HSCT, and in an exploratory analysis, determine if LCI2.5 led to earlier detection of BOS when compared to spirometric indices. Participants aged 5 to 17 years were recruited prior to receiving HSCT into a prospective, single-center, feasibility study at the Royal Children's Hospital, Melbourne. N2MBW and spirometry were performed within the month prior to transplant and repeated at 3, 6, 9, and 12 months post-transplant. Data were also collected on the presence of graft-versus-host (GVHD) disease in any organ, including the lungs. Twenty-one (12 male) children with a mean age of 13.4 (range 9.2 to 17.1) years at recruitment participated in this study. Prior to HSCT, all participants had normal LCI2.5, while 16 (76%) demonstrated normal forced expiratory volume in 1 second (FEV1). Ninety-nine percent of N2MBW tests were technically acceptable, compared with 66% of spirometry tests. Three participants developed BOS, while 2 participants died of other respiratory complications. At 6 and 12 months post-transplant, the BOS group had increases in LCI2.5 ranging from 3 to 5 units and mean reductions in FEV1 % predicted of 40% to 53% relative to pre HSCT values, respectively. In those who developed BOS, post-HSCT LCI2.5 values were significantly worse when compared with the no BOS group (P < .001). Relative changes in LCI2.5 and FEV1 were both predictive of BOS at 6 months post HSCT. This study demonstrates that N2MBW is a more feasible test compared with spirometry in children post HSCT. However, in an exploratory analysis, LCI2.5 did not lead to earlier detection of BOS, when compared to spirometry.

Multiple breath washout and oscillometry after allogenic HSCT: a scoping review

Pulmonary chronic graft-versus-host disease (cGVHD) is a substantial cause of pulmonary morbidity and mortality post-haematopoietic stem cell transplantation (HSCT). Current spirometry-based monitoring strategies have significant limitations. Understanding the utility of novel peripheral airway function tests - multiple breath washout (MBW) and oscillometry - is critical in efforts to improve detection, facilitate earlier intervention and improve outcomes. In this scoping review, we identified 17 studies investigating MBW or oscillometry, or both, after allogenic HSCT. Despite small study numbers limiting the ability to draw firm conclusions, several themes were evident. Detectable peripheral airway abnormality in MBW occurred in a substantial proportion prior to HSCT. MBW indices post-HSCT were more frequently abnormal than spirometry when reporting group data and among those with extrapulmonary cGVHD and pulmonary cGVHD. Changes in MBW indices over time may be more indicative of pulmonary complications than absolute values at any given time point. Oscillometry indices were often normal at baseline, but more frequently abnormal in those who developed pulmonary cGVHD. Pooling currently available individual participant data across these studies may improve our ability to formally compare their respective sensitivity and specificity at specific time points and assess the trajectory of MBW and oscillometry indices over time.

A longitudinal analysis of early lung function trajectory in survivors of childhood Hodgkin lymphoma

BACKGROUND

Childhood Hodgkin lymphoma survivors suffer from long-term effects decades after treatment completion with a prevalence of pulmonary dysfunction of up to 65.2%.

AIMS

This study explored the early trajectory of pulmonary function in pediatric cancer patients with Hodgkin lymphoma who received pulmonary toxic therapy.

METHODS AND RESULTS

In this single-center, 20-year retrospective cohort study, we included patients who were <18 years old at diagnosis of Hodgkin lymphoma between January 1994 and December 2014, and received bleomycin or thoracic radiation. We measured pulmonary function and reported on percent predicted values for forced expiratory volume in 1 s, total lung capacity, and diffusing capacity of the lungs. We used linear mixed models to identify the association of clinical factors with longitudinal changes in lung function at time points before and after treatment completion. Of 80 children who met inclusion criteria, all were treated with bleomycin, and 83.8% received thoracic radiation. More than half (51.2%) of patients had any abnormalities in lung function measures during the study observation period which averaged 24.2 months (±31.1SD). Females, younger age at diagnosis and treatment with radiation were associated with lower lung function measurements at various time points. While the majority of children experienced a recovery of their lung function within 1-2 years after treatment completion, some children with these risk factors did not.

CONCLUSION

Pulmonary function abnormalities begin early in children treated for Hodgkin lymphoma. While the majority of children demonstrate a slow and continuous improvement in lung function back to baseline over time, we recommend routine asymptomatic screening of pulmonary function in certain childhood cancer survivors, particularly females, those diagnosed young and patients who received radiation therapy.

Long-Term Health Effects of Curative Therapies on Heart, Lungs, and Kidneys for Individuals with Sickle Cell Disease Compared to Those with Hematologic Malignancies

The goal of curing children and adults with sickle cell disease (SCD) is to maximize benefits and minimize intermediate and long-term adverse outcomes so that individuals can live an average life span with a high quality of life. While greater than 2000 individuals with SCD have been treated with curative therapy, systematic studies have not been performed to evaluate the long-term health effects of hematopoietic stem cell transplant (HSCT) in this population. Individuals with SCD suffer progressive heart, lung, and kidney disease prior to curative therapy. In adults, these sequalae are associated with earlier death. In comparison, individuals who undergo HSCT for cancer are heavily pretreated with chemotherapy, resulting in potential acute and chronic heart, lung, and kidney disease. The long-term health effects on the heart, lung, and kidney for children and adults undergoing HSCT for cancer have been extensively investigated. These studies provide the best available data to extrapolate the possible late health effects after curative therapy for SCD. Future research is needed to evaluate whether HSCT abates, stabilizes, or exacerbates heart, lung, kidney, and other diseases in children and adults with SCD receiving myeloablative and non-myeloablative conditioning regimens for curative therapy.

The impact of changing to the Global Lung Function Initiative reference equations for transfer factor in paediatrics

The Global Lung Function Initiative (GLI) all-age reference equations for carbon monoxide transfer factor were published in 2017 and endorsed by the European Respiratory Society and American Thoracic Society. In order to understand the impact of these new reference equations on the interpretation of results in children referred from haematology and oncology paediatric services, we retrospectively analysed transfer factor results from any paediatric patient referred from haematology/oncology in the period 2010–2018. We examined transfer factor of the lung for carbon monoxide (T_LCO), transfer coefficient of the lung for carbon monoxide (K_CO) and alveolar volume (V_A) from 241 children (age range 7–18 years, 130 male). The predicted values from Rosenthal and GLI were plotted against height. The difference in interpretation of results was analysed by looking at the percentage of patients below the lower limit of normal for each parameter. Overall, the Rosenthal predicted values for T_LCO were higher than those predicted by GLI. Predicted K_CO using Rosenthal was higher in all observations. In contrast, the Rosenthal predicted V_A was generally lower than the GLI value. The GLI predicted values for transfer factor show considerable differences compared with currently used paediatric UK reference values, differences that will have a significant impact on interpretation of results.

There will be significant clinical differences in the results of transfer factor when switching to the GLI-2017 from Rosenthal-1993 reference values, strongly recommending implementing the use of GLI-2017 reference equations for paediatricshttps://bit.ly/3o0zR4f

Late Effects After Haematopoietic Stem Cell Transplantation in ALL, Long-Term Follow-Up and Transition: A Step Into Adult Life

Haematopoietic stem cell transplant (HSCT) can be a curative treatment for children and adolescents with very-high-risk acute lymphoblastic leukaemia (ALL). Improvements in supportive care and transplant techniques have led to increasing numbers of long-term survivors worldwide. However, conditioning regimens as well as transplant-related complications are associated with severe sequelae, impacting patients' quality of life. It is widely recognised that paediatric HSCT survivors must have timely access to life-long care and surveillance in order to prevent, ameliorate and manage all possible adverse late effects of HSCT. This is fundamentally important because it can both prevent ill health and optimise the quality and experience of survival following HSCT. Furthermore, it reduces the impact of preventable chronic illness on already under-resourced health services. In addition to late effects, survivors of paediatric ALL also have to deal with unique challenges associated with transition to adult services. In this review, we: (1) provide an overview of the potential late effects following HSCT for ALL in childhood and adolescence; (2) focus on the unique challenges of transition from paediatric care to adult services; and (3) provide a framework for long-term surveillance and medical care for survivors of paediatric ALL who have undergone HSCT.

Pediatric pulmonology year in review 2019: Physiology

Pulmonary physiologic assessments are critical for the care and study of pediatric respiratory disease. In 2019, there were numerous contributions to this topic in Pediatric Pulmonology.

Lung clearance index for early detection of pulmonary complications after allo-HSCT in children

BACKGROUND

Pulmonary chronic graft-vs-host disease (cGvHD) after hematopoietic stem cell transplantation (HSCT) is characterized by impairment of the small airways. Assessment of lung clearance index (LCI) gained from multiple breath washout (MBW) is more sensitive than spirometry in detection of small airways disease. The aim of this study was to describe the development of LCI during the first year after pediatric HSCT and how LCI relates to other pulmonary function parameters and cGvHD.

METHODS

This prospective, longitudinal study included 28 pediatric HSCT-recipients. Spirometry, Sulfur hexafluoride MBW and diffusion capacity of the lungs were performed before and at 3, 6, 9, and 12 months after HSCT. Respiratory symptoms and signs of cGvHD were recorded at each visit.

RESULTS

Before HSCT, 47.8% had abnormal LCI and 12.5% had abnormal forced expiratory volume in 1 second (FEV₁ )_. Patients with persisting respiratory symptoms 12 months post-HSCT had higher median LCI (factor 5.7, P = 0.0018) and lower FEV₁ z-scores (-1.5, P = 0.033) post-HSCT compared to patients free of respiratory symptoms. Overall, post-HSCT LCI values were 3.49 times higher and FEV₁ was 2.31 z-scores lower in eight patients with cGvHD in any organ system compared with patients without cGvHD (P = 0.0089 and P < 0.0001). LCI values during the first 3 months were not predictive of pulmonary cGvHD.

CONCLUSION

LCI is a sensitive marker for cGvHD and high LCI values were associated with persisting respiratory symptoms after 1 year. Further evaluation of MBW in early detection of HSCT-related pulmonary complications require larger patient cohorts and closer follow-up during the first months after HSCT.

Pediatric pulmonology year in review 2017: Part 1

Pediatric Pulmonology publishes original research, case reports and review articles on topics related to a wide range of children's respiratory disorders. In this article (Part 1 of a series), we summarize the past year's publications in our major topic areas, as well as selected literature in these areas from other journals. In Part 1, we review selected articles on diagnostic testing/endoscopy, respiratory complications of neuromuscular disorders, and rare lung diseases.

Exercise capacity in young adults after hematopoietic cell transplantation in childhood

A symptom-limited incremental cycle ergometer test was performed in 17 young adult patients treated with hematopoietic cell transplantation and total body irradiation for hematologic malignancies during childhood. These 17 young adult patients were compared with 17 sex- and age-matched healthy control subjects. Assessments of pulmonary function, cardiac function, body composition, and levels of growth hormone were made. The median follow-up was 17.7 years. Patients achieved 63.2% of the predicted peak workload, whereas controls achieved 96.1% (P < .001). All patients, but only 1 control, failed to achieve a peak workload >80% (P < .001). Fat-free mass was significantly lower (43.5 vs 57.6 kg, P < .001) and fat mass percentage was significantly higher (31.8% vs 24.2%, P = .011) in the patients. The peak workload adjusted for fat-free mass was significantly lower in the patients (3.3 vs 4.3, P < .001). In the patients, peak workload correlated significantly with total lung capacity (r = .54, P = .025). In summary, long-term survivors have significantly decreased exercise capacity compared with healthy individuals. Together with their altered body composition, this may predispose them to cardiovascular disease.

Pulmonary Complications of Childhood Cancer Treatment

Pulmonary complications of childhood cancer treatment are frequently seen. These can lead to adverse sequelae many years after treatment, with important impact on morbidity, quality of life and mortality in childhood cancer survivors. This review addresses the effects of chemotherapy, radiotherapy, surgery and alloimmunity (in haematopoietic cell transplantation) on the lung in children. It highlights the complexity of lung damage and lung disease in relation to growth and development, infections and other external factors. Screening high risk childhood cancer survivors for treatment related late effects, with therapy based screening protocols, using full medical assessment and pulmonary function tests is important. This will lead to recognition of pulmonary sequelae of cancer treatment, early detection of lung damage in survivors and better treatment and prevention.

Small airways dysfunction in long-term survivors of pediatric stem cell transplantation

BACKGROUND

Chronic graft-versus-host disease (cGvHD) in the lungs is a life-threatening complication of allogeneic hematopoietic stem cell transplantation (HSCT). Pulmonary cGvHD is initiated in the peripheral airways, and diagnosis may be delayed by low sensitivity of standard pulmonary function tests. Multiple breath nitrogen washout (MBWN2 ) is a promising, sensitive method to assess small airways function. This is the first report on MBWN2 in survivors of pediatric HSCT.

METHODS

This cross-sectional study undertaken 3-10 years post-HSCT, included 64 patients and 64 matched controls who all performed spirometry, whole-body plethysmography and MBWN2 . From MBWN2 the lung clearance index (LCI) and indices reflecting ventilation inhomogeneity arising close to the acinar lung zone (Sacin ) and in the conductive airway zone (Scond ) were derived. Subjective respiratory morbidity was assessed using the St. George Respiratory Questionnaire.

RESULTS

LCI, Sacin , and Scond were significantly higher in HSCT-patients compared with controls. Despite few reported symptoms and normal forced expiratory volume in 1 sec (FEV1 ) in 91%, LCI, Scond , and Sacin were abnormal in 34%, 52%, and 25% of HSCT-patients, respectively. LCI and Scond correlated weakly with spirometric findings in HSCT-patients, but not in controls. Scond was abnormal in 82% (9/11) of patients with evidence of cGvHD, and was associated with cGvHD in the multivariate analysis (r(2)  = 0.26, P = 0.001).

CONCLUSIONS

Small airways dysfunction as measured by MBWN2 was a common finding at long term follow-up of children after allogeneic HSCT and was associated with cGvHD. The majority of these subjects had normal spirometric values and did not report any respiratory symptoms. Prospective studies are required to evaluate the long term clinical consequences of these signs of small airway disease and the value of MBWN2 as an early marker of pulmonary cGvHD.

High Diagnostic Yield of Dedicated Pulmonary Screening before Hematopoietic Cell Transplantation in Children

Pulmonary complications are an important cause for treatment-related morbidity and mortality in hematopoietic cell transplantation (HCT) in children. The aim of this study was to investigate the yield of our pre-HCT pulmonary screening program. We also describe our management guidelines based on these findings and correlate them with symptomatic lung injury after HCT. Since 2008, all patients undergo a dedicated pulmonary screening consisting of pulmonary function test (PFT), chest high-resolution computed tomography (HRCT), and bronchial alveolar lavage (BAL) before HCT. We systematically evaluated the yield during the first 5 years of our screening program. We included 142 consecutive children. In 74% of patients, abnormalities were found. In 66% of patients, 1 or more PFT results were <80% of normal. Chest HRCT showed abnormalities in 55%; 19% of these abnormalities were considered "clinically significant." BAL was abnormal in 43% of patients; respiratory viruses (PCR) were found in 35 patients, fungi (antigen or culture) in 21, and bacteria (culture) in 22. All 3 screening tests contributed separately to clinically relevant information regarding pulmonary status in these pre-HCT children. In 46 patients (33%), screening results had diagnostic and/or therapeutic implications. We found an association between pre-SCT HRCT findings and lung injury after transplantation. Pre-HCT screening with the combination of 3 modalities, reflecting different domains of respiratory status (function, structure, and microbial colonization), reveals important abnormalities in a substantial number of patients. Whether this improves patient outcome requires further investigation.

Effectiveness of long-term routine pulmonary function surveillance following pediatric hematopoietic stem cell transplantation

INTRODUCTION

Pulmonary complications following hematopoietic stem cell transplantation (HSCT) are common and often subclinical. Thus, periodic pulmonary function testing (PFT) is mandatory. This study sought to evaluate the effectiveness of long-term PFT surveillance for children undergoing HSCT and identify potential risk factors.

METHODS

We reviewed long-term PFT for HSCT patients at a tertiary pediatric center. Inclusion criteria were PFT prior to and at least once following HSCT.

RESULTS

Fifty-seven patients performed 202 spirometry and 193 plethysmographic maneuvers; 41 were tested during the first year after HSCT, but only 29 were evaluated consistently long term (2-12 years). FVC and FEV(1) decreased gradually suggesting a restrictive ventilatory defect: FVC % predicted [mean ± SD] dropped from 91 ± 14% to 85 ± 17% after 0-24 months and 80 ± 19% beyond 2 years (P = 0.01) whereas FEV(1) dropped from 95 ± 16% to 88 ± 19% and 82 ± 20%, respectively (P = 0.002). A slight reduction in TLC was observed. Those undergoing allogeneic HSCT had a greater decline in FVC (P = 0.025) and FEV(1) (P = 0.025) as did those conditioned with radiation, regarding both FVC (P = 0.003) and FEV(1) (P = 0.002). Decline occurred earlier (≤2 years) after chemotherapy compared with radiation. Seven children had severe irreversible obstruction at >2 years despite therapeutic intervention.

CONCLUSIONS

Most survivors of childhood HSCT maintain almost normal pulmonary function although mild restrictive lung disease may develop, particularly following allogeneic HSCT and conditioning with radiation. Severe airways obstruction developed in a small minority. The surveillance protocol for PFT needs to be followed more stringently to enable intervention possibly before early subclinical changes progress and become irreversible.

Long-term follow-up and management guidelines in pediatric patients after allogenic hematopoietic stem cell transplantation

Over the past 50 years there has been considerable progress and success in the field of allogeneic hematopoietic stem cell transplant (HSCT) in children. In addition there has been significant improvement in transplant outcomes for both malignant and nonmalignant indications. These improved outcomes have resulted in many long-term survivors who are experiencing substantial long-term morbidities. There are limited data examining the long-term complications of transplant on the various organs. This issue is complicated by the fact that children receive their transplant at different stages of their growth and development (ie, infant, toddler, child, adolescent, and young adult). Each of these developmental stages has different sensitivities to treatment and can result in different sets of complications. We summarize the long-term side effects of allogeneic HSCT in children.

Severe gammaherpesvirus-induced pneumonitis and fibrosis in syngeneic bone marrow transplant mice is related to effects of transforming growth factor-β

Pulmonary infections and pneumonitis occur frequently after hematopoietic stem cell transplantation. Using a syngeneic mouse model of bone marrow transplantation (BMT), we have previously demonstrated that BMT mice are more susceptible to acute gammaherpesvirus 68 (MHV-68) replication at day 7 after infection. By day 21, the virus is latent in lungs of BMT and control mice, and there is no difference in viral load. Despite similar latent viral load, BMT mice develop severe pneumonitis associated with reduced oxygen saturation, fibrosis, peripheral inflammation, hyaline membranes, and foamy alveolar macrophages, a phenotype that persists for 7 weeks after infection. BMT mice demonstrate increased bronchoalveolar lavage (BAL) cells, and this population is enriched in neutrophils and T cells. Alternatively, activated macrophages appear earlier than do classically activated macrophages. BAL fluid from BMT mice at day 21 after infection contains increased levels of hydrogen peroxide, nitrite, and transforming growth factor-β (TGF-β). Mice expressing the dominant-negative transgene dn-TGFβRII in multiple cell types were used as BMT donors. BMT mice with T-cell dnTGFβRII are largely protected from the pneumonitis phenotype, whereas mice with CD11c-dnTGFβRII BMT mice are only modestly protected from pneumonitis. Protection in BMT mice with T-cell dnTGFβRII is associated with decreased TGF-β derived from parenchymal cells in the BAL fluid, lower nitrite levels, and reduced apoptosis, whereas alternatively activated macrophage markers are unchanged.

Bronchiolitis obliterans after allo-SCT: clinical criteria and treatment options

Bronchiolitis obliterans (BO) following allogeneic haematopoietic SCT (HSCT) is a serious complication affecting 1.7-26% of the patients, with a reported mortality rate of 21-100%. It is considered a manifestation of chronic graft-versus-host disease, but our knowledge of aetiology and pathogenesis is still limited. Diagnostic criteria are being developed, and will allow more uniform and comparable research activities between centres. At present, no randomised controlled trials have been completed that could demonstrate an effective treatment. Steroids in combination with other immunosuppressive drugs still constitute the backbone of the treatment strategy, and results from our and other centres suggest that monthly infusions of high-dose pulse i.v. methylprednisolone (HDPM) might stabilise the disease and hinder progression. This article provides an overview of the current evidence regarding treatment options for BO and presents the treatment results with HDPM in a paediatric national HSCT-cohort.

Pulmonary complications in survivors of childhood hematological malignancies: single-center experience

Children treated for cancer face the risk of complications later in life, including pulmonary dysfunction. The objective of this study was to evaluate frequency and severity of pulmonary complications in survivors of childhood leukemia and lymphoma treated with chemotherapy alone or combined with radiotherapy. Seventy cancer survivors of hematological malignancies were evaluated for pulmonary complications through history taking, chest examination, high-resolution computed tomography (HRCT) chest, and pulmonary function testing (PFTs). Although most survivors were not clinically compromised, the spectrum of impaired PFTs included obstructive pattern (14.3%), restrictive pattern (5.7%), and mixed pattern (20%). Significant pulmonary dysfunction was seen in children older than 10 years of age (P = .003), and in patients treated with combined chemotherapy and radiotherapy (72.7%) compared with those treated with chemotherapy alone (25%) (P = .001). Cumulative dose of bleomycin was significantly associated with abnormal PFTs (P = .04). Multivariate analysis revealed methotrexate therapy as significant predictor of abnormal PFTs (P = .002). Male patients who received combined therapy showed higher frequency of restrictive, obstructive lung disease, abnormal respiratory reactance, and peripheral airway disease (P = .007, P = .04, P = .002, P = .003, P = .05, respectively). Those with abnormal CT findings (n = 14) had lower forced vital capacity (FVC%), forced expiratory volume in 1 second (FEV(1)%), and peak expiratory flow (PEF%) when compared to cases with normal CT (P = .001, P < 0.001, P = .001, respectively). Subclinical pulmonary function abnormalities are found in survivors of childhood hematological malignancies previously treated and off therapy. Pulmonary dysfunction is more evident with combined chemotherapy and radiotherapy, bleomycin, and methotrexate are the most incriminated chemotherapeutic agents, and males are at higher risk than females; therefore a specific and extended follow-up is warranted.

Clinical features of late onset non-infectious pulmonary complications following pediatric allogeneic hematopoietic stem cell transplantation

BACKGROUND

Late onset non-infectious pulmonary complications (LONIPCs) are major causes of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (allo-HSCT). We evaluated the incidence and the outcomes of LONIPCs in children who underwent allo-HSCT.

METHODS

Data for 143 children who underwent allo-HSCT at Asan Medical Center between April 2002 and April 2009 were reviewed, and the 127 who survived more than three months were enrolled.

RESULTS

Eleven (8.7%) developed LONIPCs at a median eight months (range 3-14 months) after allo-HSCT, presenting with cough and dyspnea. Six had bronchiolitis obliterans and five had idiopathic pneumonia syndrome. FVC declined more significantly in LONIPC than in non-LONIPC patients three months after HSCT. A significant risk factor for the development of LONIPCs was chronic graft-versus-host disease (GVHD) (p = 0.002). At a median follow-up of 36 months, the three-yr overall survival rate in LONIPC patients was significantly lower than that of non-LONIPC patients (37.4% vs. 72.7%, p = 0.02). The major cause of death was respiratory failure.

CONCLUSIONS

Along with chronic GVHD, deterioration of pulmonary function at three months after HSCT may help in the early identification of patients at risk of subsequent LONIPCs. Considering the poor prognosis of LONIPC, strategies should be aimed at their prevention.