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

Detection of Bronchiolitis Obliterans Syndrome after Pediatric Hematopoietic Stem Cell Transplantation: An Official American Thoracic Society Clinical Practice Guideline

Background: Many children undergo allogeneic hematopoietic stem cell transplantation (HSCT) for the treatment of malignant and nonmalignant conditions. Unfortunately, pulmonary complications occur frequently post-HSCT, with bronchiolitis obliterans syndrome (BOS) being the most common noninfectious pulmonary complication. Current international guidelines contain conflicting recommendations regarding post-HSCT surveillance for BOS, and a recent NIH workshop highlighted the need for a standardized approach to post-HSCT monitoring. As such, this guideline provides an evidence-based approach to detection of post-HSCT BOS in children. Methods: A multinational, multidisciplinary panel of experts identified six questions regarding surveillance for, and evaluation of, post-HSCT BOS in children. A systematic review of the literature was undertaken to answer each question. The Grading of Recommendations, Assessment, Development, and Evaluation approach was used to rate the quality of evidence and the strength of recommendations. Results: The panel members considered the strength of each recommendation and evaluated the benefits and risks of applying the intervention. In formulating the recommendations, the panel considered patient and caregiver values, the cost of care, and feasibility. Recommendations addressing the role of screening pulmonary function testing and diagnostic tests in children with suspected post-HSCT BOS were made. Following a Delphi process, new diagnostic criteria for pediatric post-HSCT BOS were also proposed. Conclusions: This document provides an evidence-based approach to the detection of post-HSCT BOS in children while also highlighting considerations for the implementation of each recommendation. Further, the document describes important areas for future research.

Diagnosis of Post-Hematopoietic Stem Cell Transplantation Bronchiolitis Obliterans Syndrome in Children: Time for a Rethink?

Hematopoietic stem cell transplantation (HSCT) is undertaken in children with the aim of curing a range of malignant and nonmalignant conditions. Unfortunately, pulmonary complications, especially bronchiolitis obliterans syndrome (BOS), are significant sources of morbidity and mortality post-HSCT. Currently, criteria developed by a National Institutes of Health (NIH) working group are used to diagnose BOS in children post-HSCT. Unfortunately, during the development of a recent American Thoracic Society (ATS) Clinical Practice Guideline on this topic, it became apparent that the NIH criteria have significant limitations in the pediatric population, leading to late diagnosis of BOS. Specific limitations include use of an outdated pulmonary function testing reference equation, a reliance on spirometry, use of a fixed forced expiratory volume in 1 second (FEV1) threshold, focus on obstructive defects defined by FEV1/vital capacity, and failure to acknowledge that BOS and infection can coexist. In this review, we summarize the evidence regarding the limitations of the current criteria. We also suggest potential evidence-based ideas for improving these criteria. Finally, we highlight a new proposed criteria for post-HSCT BOS in children that were developed by the authors of the recently published ATS clinical practice guideline, along with a pathway forward for improving timely diagnosis of BOS in children post-HSCT.

Late-onset pulmonary complications following allogeneic hematopoietic cell transplantation in pediatric patients: a prospective multicenter study

The primary objective of our multicenter prospective study was to describe the incidence of late-onset non-infectious pulmonary complications (LONIPCs) in children undergoing hematopoietic cell transplantation (HCT) using sensitive criteria for pulmonary function test (PFT) abnormalities including the non-specific pattern of airflow obstruction. Secondary objectives were to assess the factors associated with LONIPC occurrence and the sensitivity of the 2014 NIH-Consensus Criteria of bronchiolitis obliterans syndrome (BOS). PFT and clinical assessment were performed prior to HCT and at 6, 12, 24, and 36 months post-HCT. LONIPC diagnosis was validated by an Adjudication Committee. The study comprised 292 children from 12 centers. Thirty-two individuals (11%, 95% CI: 8-15%) experienced 35 LONIPCs: 25 BOS, 4 interstitial lung diseases, 4 organizing pneumonia and 2 pulmonary veno-occlusive diseases. PFT abnormalities were obstructive defects (FEV1/FVC z-score < -1.645; n = 12), restrictive defects (TLC < 80% predicted, FEV1 and FVC z-scores < -1.645; n = 7) and non-specific pattern (FEV1 and FVC z-score< -1.645, FEV1/FVC z-score > -1.645, and TLC > 80% predicted; n = 8). HCT for malignant disease was the only factor associated with LONIPC (P = 0.04). The 2014 NIH-Consensus Criteria would only diagnose 8/25 participants (32%) as having BOS. In conclusion, 11% of children experienced a LONIPC in a prospective design. Clinical Trials.gov identifier (NCT number): NCT02032381.

All That Wheezes Is Not Asthma

Wheezing is a high pitched, whistling sound generated when air flows through narrowed airways and is often equated with asthma. However, wheezing may be a presenting symptom of various other conditions including structural lesions of the airways, foreign body aspiration, pulmonary infections as well as cardiac causes. Underlying etiology of wheezing may also vary with age. Detailed history, physical examination, and laboratory investigations are often required to identify the underlying etiology of wheezing. Additional studies may sometimes be needed to accurately identify the underlying etiology such as pulmonary function test or spirometry, chest radiography (chest X-ray), and bronchoscopy. This review article discusses the common causes of wheezing encountered in clinical practice. [Pediatr Ann. 2024;53(5):e189-e194.].

Sleep-related breathing disorder in non-infectious pulmonary complications after pediatric allogeneic stem cell transplantation

BACKGROUND

Chronic lung problems are a rare but serious complication of allogeneic hematopoietic stem cell transplantation (HSCT). We studied clinical phenotypes and polysomnography appearance of breathing abnormality in late onset non-infectious pulmonary complications (NIPS).

METHODS

We reviewed Finnish national reference database between the years 1999 and 2016. We identified 12 children with most severely decreased pulmonary function and performed polysomnography and 24 aged-matched controls out of 325 performed pediatric allogeneic HSCTs.

RESULTS

All patients with NIPS had severely decreased pulmonary function already at 6 months post HSCT with median FEV₁ value 42% (interquartile range (IQR) 30-52%) of predicted normal values. Seven children had obstructive and five children more restrictive lung function. Children with obstructive lung function showed laborious breathing (7/7), decreased oxygenation and ventilation-to-perfusion mismatch (6/7), or REM-sleep-related hypoventilation (4/7) on polysomnography. Children with restrictive lung function (5/12) did not show sleep-related breathing disorder.

CONCLUSIONS

Children going through allogeneic HSCT who develop severe chronic obstructive lung function are more likely to present with sleep-related hypoxia and hypoventilation than children with restrictive lung function.

IMPACT

Children with severe obstructive lung function and chronic lung graft-versus-host disease following hematopoietic stem cell transplantation are more likely to present with sleep-related mild hypoxia and hypoventilation than children with restrictive lung disease. To our knowledge there are no reports on sleep-related breathing disorders and ventilatory function measured by polysomnography in children with pulmonary complications after allogeneic HSCT. Polysomnography may add to the differential diagnostics between patients with BOS and other non-infectious pulmonary complications.

Early pulmonary complications related to cancer treatment in children

In this review, we summarize early pulmonary complications related to cancer therapy in children and highlight characteristic findings on imaging that should be familiar to a radiologist reviewing imaging from pediatric cancer patients.

Pulmonary Complications in Children Following Hematopoietic Cell Transplantation: A Case Report and Review of the Diagnostic Approach

Pulmonary complications are common in children following hematopoietic cell transplantation (HCT) and contribute to their morbidity and mortality. Early diagnosis is essential for management and prevention of progression of lung injury and damage. In many cases, diagnosis can be challenging and may require diagnostic imaging and more invasive testing such as bronchoscopy and lung biopsy. We report the case of a 12-year-old girl who developed recurrent episodes of acute respiratory failure requiring intensive care unit admission in the post-HCT phase and describe the diagnostic and multidisciplinary approach for her management. In addition, we review the diagnostic approach of pulmonary complications post-HCT and highlight the utility and risks of bronchoscopy and lung biopsy in these children.

Declining mortality rates in children admitted to ICU following HCT

We aimed to assess short- and long-term mortality, including factors associated with mortality, for children referred to a pediatric intensive care unit (ICU) at Rigshospitalet, Denmark, following haematopoietic cell transplantation (HCT). Data regarding admission to ICU and mortality following HCT for children below 16 years of age between 2000 and 2017 were retrospectively analyzed. We identified 55 ICU admissions in 39 patients following 46 HCTs. The overall in-ICU, in-hospital, 3-month, and 1-year mortality rates were 33.3%, 43.6%, 46.2%, and 51.3%, respectively. Patients admitted from 2000 to 2010 had a 3-month mortality of 63.2% and 1-year mortality of 68.4%, compared to 30% and 35% (P = .040 and P = .039) for patients admitted from 2011 to 2017. The main reason for ICU admission was respiratory failure (78.2%). Mechanical ventilation (MV) was associated with a higher long-term mortality (P = .044), and use of inotropes or vasopressors was associated with increased mortality at all times (all P > .006). Extracorporeal life support, renal replacement therapy, longer ICU stay, and longer time with MV were not associated with increased mortality. Over the past two decades, mortality was significantly reduced in pediatric HCT patients admitted to the ICU. The cause is probably multifactorial and warrants further studies. Our findings support admissions of critically ill pediatric HCT patients to intensive care with encouraging outcomes of even long-term admissions.

Exploring pulmonary function and physical function in childhood cancer: A systematic review

BACKGROUND

Children with cancer experience pulmonary and physical function side effects from the cancer itself and the medical interventions. This systematic review examines the known relationship between pulmonary function and physical function in childhood cancer and identifies gaps in the literature.

METHODS

A search of Ovid Medline, CINAHL (EbscoHost) and Embase to identify literature from 2009 to March 2020.

RESULTS

Fifty-seven studies met inclusion criteria. Thirty-seven studies reported impaired pulmonary function. Incidence of pulmonary dysfunction ranged from 45.5 % to 84.1 %. Eighteen studies reported impaired physical function. Three studies investigated the relationship between pulmonary function and physical function. No studies explored inspiratory muscle strength.

CONCLUSION

Pulmonary function and physical function are related and frequently impaired in children during and after cancer treatment. A literature gap was found in diaphragm function and its relationship with physical function. Future studies should focus on interventions that target the pulmonary mechanisms impacting physical function.

Pulmonary Manifestations of Hematologic and Oncologic Diseases in Children

Pulmonary complications are common in children with hematologic or oncologic diseases, and many experience long-term effects even after the primary disease has been cured. This article reviews pulmonary complications in children with cancer, after hematopoietic stem cell transplant, and caused by sickle cell disease and discusses their management.

Lung evaluation in 10 year survivors of pediatric allogeneic hematopoietic stem cell transplantation

There is little data on the long-term respiratory development of children after allogeneic hematopoietic stem cell transplantation (allo-HSCT). We describe the respiratory assessment 10 years after allo-HSCT of 35 children transplanted between 2000 and 2004. During this period, 90 children were transplanted at our center. Twenty-five children died, thirty were lost to follow-up, and thirty-five came to have a pulmonary investigation. The thirty-five participants answered a questionnaire asking if they had pulmonary symptoms, and pulmonary function tests (PFTs) were performed. The median age of these children 10 years after the transplant was 16 years old. Just over a third of them had pulmonary symptoms. Among them, 5/13 (38%) had bronchiolitis obliterans syndrome (BOS). The majority of children (62.8%) did not have respiratory symptoms. PFTs were abnormal in one-third of asymptomatic children, revealing restrictive lung disease that was always mild to moderate (p = 0.02).Conclusion: In the long term, research at the time of the medical examination for the presence of chronic cough, shortness of breath on exertion, or wheezing helps to guide the clinician as to the need for further lung exploration. Similarly, informing patients and their families about these symptoms, which can be underestimated, should allow for more specific management.What is Known:• Pulmonary complications are a major cause of hematopoietic stem cell transplantation (HSCT) morbidity and mortality.• A long time after allogeneic HSCT, pulmonary function tests abnormalities may occur in children, but it is not always related to symptoms.What is New:• The occurrence of respiratory symptoms: cough, dyspnea on exertion, chronic bronchitis, and wheezing should be systematically investigated in the follow-up of allografted patients, even at a distance.• The presence of respiratory symptoms should lead to a respiratory functional investigation to detect the presence of an obstructive syndrome.

Acute Respiratory Failure in Pediatric Hematopoietic Cell Transplantation: A Multicenter Study

OBJECTIVES

Acute respiratory failure is common in pediatric hematopoietic cell transplant recipients and has a high mortality. However, respiratory prognostic markers have not been adequately evaluated for this population. Our objectives are to assess respiratory support strategies and indices of oxygenation and ventilation in pediatric allogeneic hematopoietic cell transplant patients receiving invasive mechanical ventilation and investigate how these strategies are associated with mortality.

DESIGN

Retrospective, multicenter investigation.

SETTING

Twelve U.S. pediatric centers.

PATIENTS

Pediatric allogeneic hematopoietic cell transplant recipients with respiratory failure.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Two-hundred twenty-two subjects were identified. PICU mortality was 60.4%. Nonsurvivors had higher peak oxygenation index (38.3 [21.3-57.6] vs 15.0 [7.0-30.7]; p < 0.0001) and oxygen saturation index (24.7 [13.8-38.7] vs 10.3 [4.6-21.6]; p < 0.0001), greater days with FIO2 greater than or equal to 0.6 (2.4 [1.0-8.5] vs 0.8 [0.3-1.6]; p < 0.0001), and more days with oxygenation index greater than 18 (1.4 [0-6.0] vs 0 [0-0.3]; p < 0.0001) and oxygen saturation index greater than 11 (2.0 [0.5-8.8] vs 0 [0-1.0]; p < 0.0001). Nonsurvivors had higher maximum peak inspiratory pressures (36.0 cm H2O [32.0-41.0 cm H2O] vs 30.0 cm H2O [27.0-35.0 cm H2O]; p < 0.0001) and more days with peak inspiratory pressure greater than 31 cm H2O (1.0 d [0-4.0 d] vs 0 d [0-1.0 d]; p < 0.0001). Tidal volume per kilogram was not different between survivors and nonsurvivors.

CONCLUSIONS

In this cohort of pediatric hematopoietic cell transplant recipients with respiratory failure in the PICU, impaired oxygenation and use of elevated ventilator pressures were common and associated with increased mortality.

Effect of reduced-intensity conditioning and the risk of late-onset non-infectious pulmonary complications in pediatric patients

OBJECTIVE

Late-onset non-infectious pulmonary complications (LONIPCs) contribute to higher morbidity and mortality after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Therefore, we investigated the risk factors of LONIPCs in pediatric patients.

METHOD

Between 2001 and 2011, 74 pediatric patients (range, 7 months to 22.7 years old; median 6.5 years old), including 29 with a primary immunodeficiency, underwent 80 allo-HSCTs at our institution. Sixty-seven patients who survived more than 3 months after allo-HSCT were analyzed retrospectively. The median follow-up period was 1 973 days (range, 126-5 145 days).

RESULTS

Nine patients (13.4%) developed LONIPCs between 90 and 3 578 days after allo-HSCT. A myeloablative conditioning (MAC) regimen and chronic GVHD were determined as significant risk factors of LONIPCs. None of 18 patients who received the reduced-intensity conditioning (RIC) regimen developed LONIPCs, although there was no difference in overall survival between the MAC and RIC regimen. Notably, two immunodeficient patients who received busulfan-based MAC regimen under 2 years old developed LONIPC with no history of chronic GVHD after 5 years and 10 years from SCT, respectively, suggesting the direct toxicity of busulfan.

CONCLUSION

Our study's findings indicate that the RIC regimen reduces the risk of LONIPCs in pediatric patients.

Clinical and radiological characteristics of patients with late-onset severe restrictive lung defect after hematopoietic stem cell transplantation

Background

Late-onset noninfectious pulmonary complications (LONIPCs), which occur more than 3 months after allogeneic hematopoietic stem cell transplantation (HSCT), are major causes of morbidity and mortality after transplantation. Among LONIPCs, we occasionally treat patients with late-onset severe restrictive lung defect after HSCT; however, its clinical features have not been fully elucidated.

Methods

A retrospective chart review of a single center on cases of late-onset severe restrictive lung defect after HSCT was performed. Among 453 patients who survived longer than 100 days after allogeneic HSCT with evaluable spirometry data, 12 patients (2.6%) developed late-onset severe restrictive lung defect (i.e., vital capacity percent of predicted less than 60%).

Results

Median duration from transplantation to diagnosis of late-onset severe restrictive lung defect cases was 44.5 months. Major computed tomography (CT) finding was pleuroparenchymal thickening with volume loss, an evidence of fibrosis, predominantly in upper lobes (n = 7), which was consistent with pleuroparenchymal fibroelastosis. The remaining patients showed unclassifiable interstitial pneumonia pattern (n = 2) and airway-predominant pattern (n = 3). The diffusing capacity for carbon oxide tended to decrease, while the residual volume/total lung capacity ratio tended to increase after HSCT. Of 12 patients, 8 patients died and the median month from diagnosis to death was 33.5 months. Seven patients died of pulmonary or systemic infection, and one patient died due to relapse of the primary disease.

Conclusion

Severe restrictive lung defect could develop in selected cases in the late-phase after HSCT and could be a unique clinical entity with specific radiographical findings.

Electronic supplementary material

The online version of this article (10.1186/s12890-017-0466-7) contains supplementary material, which is available to authorized users.

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.

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.

Stem cells in clinical practice: applications and warnings

Stem cells are a relevant source of information about cellular differentiation, molecular processes and tissue homeostasis, but also one of the most putative biological tools to treat degenerative diseases. This review focuses on human stem cells clinical and experimental applications. Our aim is to take a correct view of the available stem cell subtypes and their rational use in the medical area, with a specific focus on their therapeutic benefits and side effects. We have reviewed the main clinical trials dividing them basing on their clinical applications, and taking into account the ethical issue associated with the stem cell therapy.