Natural history of pulmonary complications in children after bone marrow transplantation

The Pathology of Pulmonary Disease After Pediatric Hematopoietic Stem Cell Transplantation

Pulmonary complications continue to cause significant morbidity and mortality in posthematopoietic stem cell transplantation (HSCT) settings. The histopathology of pulmonary diseases in the post-HSCT context is poorly characterized, especially in the pediatric population. We sought to characterize the pathologic spectrum of pulmonary disease post-HSCT in a pediatric cohort. Fifty-six specimens, including 53 biopsy specimens, corresponding to 53 patients, were identified. Biopsy slides were reviewed and assigned to diagnostic categories (infectious, graft-versus-host disease, vasculopathy, indeterminate, and others) by consensus among 3 pediatric pulmonary pathologists, taking into consideration pathologic, clinical, radiologic, and laboratory findings. The most common diagnostic category was infection (n=20). Vasculopathy, mostly in the form of fibromyxoid intimal expansion, was very common in the entire cohort (n=26) and was the sole finding in a small subset of patients (n=5), with particularly poor outcomes. A subset of biopsies remained indeterminate (n=10), and the findings in this cohort were dominated by acute lung injury. The latter group had a poor prognosis, with a short biopsy-to-death interval. The overall clinicopathologic concordance was 40%, most commonly agreeing in the infectious category. Finally, wedge biopsies led to a change in management in 69% of cases versus 23% of limited procedures (i.e., core needle biopsies). Our results suggest that while infectious complications continue to be common post-HSCT, other findings such as vasculopathy and acute lung injury portend a particularly poor prognosis and should be actively sought and reported.

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.

Pulmonary complications post allogeneic haematopoietic stem cell transplant in children

Objectives

Haematopoietic stem cell transplant (HCT) is a cellular therapy that, whilst curative for a child's underlying disease, carries significant risk of mortality, including because of pulmonary complications. The aims of this study were to describe the burden of pulmonary complications post-HCT in a cohort of Australian children and identify risk factors for the development of these complications.

Methods

Patients were identified from the HCT databases at two paediatric transplant centres in Australia. Medical records were reviewed, and demographics, HCT characteristics and pulmonary complications documented. Relative risk ratio was used to identify risk factors for developing pulmonary complications prior to first transplant episode, and survival analysis performed to determine hazard ratio.

Results

In total, 243 children underwent transplant during the study period, and pulmonary complications occurred in 48% (117/243) of children. Infectious complications were more common (55%) than non-infective complications (18%) and 26% of patients developed both. Risk factors for the development of pulmonary complications included the following: diagnoses of MPAL (RR 2.16, P = 0.02), matched unrelated donor (RR1.34, P = 0.03), peripheral blood (RR 1.36, P = 0.028) or cord blood (RR 1.73, P = 0.012) as the stem cell source and pre-existing lung disease (RR1.72, P < 0.0001). Children with a post-HCT lung complication had a significantly increased risk of mortality compared with those who did not (HR 3.9, P < 0.0001).

Conclusion

This study demonstrates pulmonary complications continue to occur frequently in children post-HCT and contribute significantly to mortality. Highlighting the need for improved strategies to identify patients at risk pre-transplant and enhanced treatments for those who develop lung disease.

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.

Clinical analysis of air-leak syndrome following allogeneic hematopoietic stem cell transplantation in pediatric patients

BACKGROUND

Air-leak syndrome (ALS) is considered as an independent risk factor for poor prognosis in adult patients who had received hematopoietic stem cell transplantation (HSCT), and the 5-year overall survival (OS) of ALS is less than 30%. However, the clinical features of ALS among post-transplant pediatric patients have rarely been explored.

PROCEDURES

We retrospectively reviewed 2206 pediatric patients who had received an allo-HSCT between January 2013 and December 2019 at the Hebei Yanda Lu Daopei Hospital, and analyzed the role of ALS in prognosis following HSCT.

RESULTS

In our research, ALS was divided into two categories: 15 cases of bronchiolitis obliterans syndrome (BOS) and 13 cases of idiopathic pneumonia syndrome (IPS). Following treatment of the ALS, 18 patients survived (18/28, 64.3%), and 10 patients died of respiratory failure or infection (10/28, 35.7%).

CONCLUSIONS

The OS of ALS in Hebei Yanda Lu Daopei Hospital is significantly higher than others, and they were cited to be related to early diagnosis and timely FAM treatment in previous reports.

Pulmonary Hemorrhage in Pediatric Hematopoietic Stem Cell Transplant Recipients: A Single-Center Retrospective Study

OBJECTIVES

Pulmonary hemorrhage (PH) is a serious complication posthematopoietic stem cell transplant (HSCT). In view of limited available pediatric data, we performed a retrospective study to describe epidemiology, management, and outcomes of PH post-HSCT in children in our national center.

DESIGN

Retrospective study.

SETTING

Academic children's hospital (2000-2015).

SUBJECTS

Children (< 18 yr) with PH and requiring PICU care post-HSCT.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The historical prevalence of PH in our center was 2.7% (31/1,148). Twenty patients had a concomitant infection, 15 had bacterial infection, 8 had viral infection, and 3 patients had a fungal infection. With a median follow-up time of 60 months, 7 of 31 patients were alive. Early PH (< 40 d post-HSCT) was associated with improved survival (6/15 vs 1/16, p = 0.035). Patients who received high-dose pulsed corticosteroid had improved survival when compared with those who did not (7/22 vs 0/9, p = 0.0012); this also applied to the subgroup of patients with a concomitant infection (5/15 vs 0, p = 0.001). None of the patients who survived had measurable respiratory sequelae.

CONCLUSIONS

PH is a rare but serious complication after HSCT. Corticosteroids were associated with improved survival even in patients with a concomitant infection.

Pulmonary Histopathologic Findings in Pediatric Patients After Hematopoietic Stem Cell Transplantation: An Autopsy Study

BACKGROUND

Pathologic characterization of pulmonary complications following hematopoietic stem cell transplantation (HSCT) is limited. We describe lung findings in pediatric patients who died following HSCT and attempt to identify potential clinical associations.

METHODS

Pathology databases at Texas Children's Hospital and the Children's Hospital of Philadelphia were queried (2013-2018 CHOP and 2017-2018 TCH). Electronic medical records and slides were reviewed.

RESULTS

Among 29 patients, 19 received HSCT for hematologic malignancy, 8 for non-malignant hematologic disorders, and 2 for metastatic solid tumors. Twenty-five patients (86%) showed 1 or more patterns of acute and organizing lung injury. Sixty-two percent had microvascular sclerosis, with venous involvement noted in most cases and not correlating with clinical history of pulmonary hypertension, clinical transplant-associated thrombotic microangiopathy, irradiation, or graft-versus-host disease. Features suggestive of graft-versus-host-disease were uncommon: 6 patients had lymphocytic bronchiolitis, and only 2 patients had evidence of bronchiolitis obliterans (both clinically unexpected), both with a mismatched unrelated donor transplant.

CONCLUSIONS

Acute and subacute alveolar injury (diffuse alveolar damage or organizing pneumonia) is common in pediatric patients who died following HSCT and is difficult to assign to a specific etiology. Microvascular sclerosis was frequent and did not correlate with a single distinct clinical feature.

Evaluation of Children with Malignancies for Blood and Marrow Transplantation: A Report from the ASTCT Committee on Practice Guidelines

Evaluation of a candidate for hematopoietic cell transplantation (HCT) is a complex process with substantial intercenter variability. Although literature providing guidance for evaluating the eligibility of adults is well established, similar guidance for children is lacking. To address gaps between adult recommendations and the specific needs of children, we convened a panel of pediatric HCT experts from a wide geographic range of American Society of Transplantation and Cellular Therapy (ASTCT) member institutions to offer recommendations for pediatric-focused pre-HCT evaluation. In this report from the ASTCT Committee on Practice Guidelines, we present a practical framework for evaluating children with malignancies who are candidates for HCT. We also highlight key differences from adults and emphasize areas of unmet need that require additional research to delineate best practices.

High-Dose Busulfan-Fludarabine Conditioning and Low Alveolar Volume as Predictors of Pulmonary Complications after Allogeneic Peripheral Blood Stem Cell Transplantation in Children

This study was conducted to investigate risk factors and predictors of infectious and noninfectious pulmonary complications (PCs) after allogeneic hematopoietic stem cell transplantation in children. We conducted a retrospective analysis of the post-transplantation PCs of 240 patients who underwent allogeneic peripheral blood stem cell transplantation (allo-PBSCT) between 2009 and 2018. Transplantation-related variables, pretransplantation baseline spirometry, body plethysmography, and CO diffusing capacity were analyzed for association with the development of infectious PCs (IPCs) and noninfectious PCs (NIPCs). Compared with the control group, the PC group had statistically significantly lower overall survival (50.6% versus 77.8%; P < .001), higher disease-related mortality (26.6% versus 54.4%; P < .001), and higher nonrelapse mortality (31.6% versus 5.9%; P < .001). A greater number of patients received pretransplantation conditioning with high-dose busulfan (520 mg/m²; Bu 520) and fludarabine (160 mg/m²; Flu 160) in both the IPC and NIPC groups. In the multivariate Cox hazard regression analysis, Bu 520 significantly increased the risk of NIPCs (hazard ratio [HR], 1.99; 95% confidence interval [CI], 1.13 to 3.49; P = .016), and Flu 160 was a predictor of IPCs (HR, 1.99; 95% CI, 1.13 to 3.49; P = .016). The Bu 520 + Flu 160 regimen was associated with a statistically significant increase in the risk of NIPC (HR, 1.92; 95% CI, 1.09 to 3.37; P = .023). In a multivariate analysis using pretransplantation baseline lung function, alveolar volume (VA) grades 3 and 4 and lung function score (LFS) VA categories III and IV were associated with increased risk for both IPCs and NIPCs. Our data identify receipt of the high-dose Bu-Flu conditioning regimen as an independent risk factor for NIPCs after allo-PBSCT. Impaired CO diffusing capacity before transplantation, especially VA reduction, contributes to the risk of post-transplantation pulmonary complications, and pretransplantation risk can be estimated by grading the degree of insufficiency of VA and LFS VA.

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.

Survival of pediatric patients requiring admission in the intensive care unit post hematopoietic stem cell transplantation: Prognostic factors associated with mortality

BACKGROUND

Although hematopoietic stem cell transplantation (HSCT) is the only curative option for some children with malignant and nonmalignant disorders, the procedure itself carries a high risk of complications. A proportion of children undergoing HSCT develop severe transplant-related complications requiring hospitalization in the pediatric intensive care unit (PICU).

METHODS

A retrospective cohort study included 793 children with malignant and nonmalignant diseases that underwent 963 HSCTs in two large pediatric hospitals over 15 years. Ninety-one patients needed 105 (11%) PICU admissions. The objective of the study was to analyze the risk factors associated with morbidity and mortality in children post HSCT who were admitted to the PICU.

RESULTS

Survival rate of a single PICU hospitalization was 43%. Long-term survival rate (classified as 1 year and 3 years) was 29.1% and 14.9% among PICU hospitalized patients compared with 74.6% and 53.3% among patients who had undergone HSCT and did not require PICU hospitalization. Factors found to have a significant negative association with PICU survival were respiratory failure as indication for PICU admission, neutropenia, graft-versus-host disease, mechanical ventilation, inotropic support, need for dialysis, and multiple-organ failure (MOF) with more than one systemic intensive intervention. The strongest prognostic factors associated with mortality were MOF (p < .001) and the need for inotropic support (p = .004).

CONCLUSIONS

Neutropenia was found to be negatively associated with survival, suggesting non-engraftment and late engraftment are important risk factors for HSCT patients hospitalized in PICU. MOF and inotropic support were found to be the main negatively associated predictive factors with survival.

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.

Pulmonary Complications After Pediatric Stem Cell Transplant

The number of disorders that benefit from hematopoietic stem cell transplantation (HSCT) has increased, causing the overall number of HSCT to increase accordingly. Disorders treated by HSCT include malignancy, benign hematologic disorders, bone marrow failure syndromes, and certain genetic diagnoses. Thus, understanding the complications, diagnostic workup of complications, and subsequent treatments has become increasingly important. One such category of complications includes the pulmonary system. While the overall incidence of pulmonary complications has decreased, the morbidity and mortality of these complications remain high. Therefore, having a clear differential diagnosis and diagnostic workup is imperative. Pulmonary complications can be subdivided by time of onset and whether the complication is infectious or non-infectious. While most infectious complications have clear diagnostic criteria and treatment courses, the non-infectious complications are more varied and not always well understood. This review article discusses pulmonary complications of HSCT recipients and outlines current knowledge, gaps in knowledge, and current treatment of each complication. This article includes some adult studies, as there is a significant paucity of pediatric data.

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.

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 Function Predicts Outcome in Children With Obstructive Lung Disease After Hematopoietic Stem Cell Transplantation

Obstructive lung disease (OLD) that develops after hematopoietic stem cell transplantation (HSCT) has a significant impact on morbidity and mortality. We investigated the role of pulmonary function tests (PFTs) in the prediction of prognosis of OLD in children who have undergone HSCT. We retrospectively reviewed 538 patients who underwent allogenic HSCT in the Department of Pediatrics, Seoul St. Mary's Hospital, South Korea, from April 2009 to July 2017. OLD was identified on PFTs or chest computed tomography scans obtained from 3 months after HSCT onwards. OLD developed after HSCT in 46 patients (28 male individuals, median age: 11.2 y). The group that developed OLD with an unfavorable prognosis (n=23) had a lower forced vital capacity (FVC) (% of predicted, 78.53±24.00 vs. 97.71±16.96, P=0.01), forced expiratory volume in 1 second (FEV1) (% of predicted, 52.54±31.77 vs. 84.44±18.59, P=0.00), FEV1/FVC (%, 59.28±18.68 vs. 79.94±9.77, P=0.00), and forced expiratory flow at 25% to 75% of forced vital capacity (FEF25-75) (% of predicted, 30.95±39.92 vs. 57.82±25.71, P=0.00) at diagnosis than the group that developed OLD with a favorable prognosis (n=23). The group that developed OLD with an unfavorable prognosis had significant reductions in FVC, FEV1, FEV1/FVC, and FEF25-75 at 2 years after diagnosis. Children who develop OLD with an unfavorable prognosis after HSCT already have poor lung function at the time of diagnosis. Additional treatment should be considered in patients who develop OLD after HSCT according to their PFTs at diagnosis.

Outcome of Acute Respiratory Failure Secondary to Engraftment in Children After Hematopoietic Stem Cell Transplant

Introduction: Respiratory complications due to engraftment syndrome (ES) in the post-hematopoietic stem cell transplant (HSCT) setting can lead to acute respiratory failure (ARF). Outcomes of children developing ARF due to engraftment are unknown.

Methods: We conducted a retrospective analysis of 1,527 pediatric HSCT recipients and identified children who developed ARF due to ES over a 17-year period. Thirty patients that developed ARF and required invasive mechanical ventilation (IMV) due to ES were included in this study.

Results: The survival rate for our cohort was 80% [alive at intensive care unit (ICU) discharge]. The most common underlying primary disease was hematologic malignancy, and 67% of children underwent allogeneic HSCT. Further, 73% required vasopressor drips and 23% underwent dialysis. Survivors had a shorter median ICU length of stay than did non-survivors (15 vs. 40 days, respectively, p = 0.01). Survivors had a significantly lower median cumulative fluid overload % on days 4 and 5 after initiation of IMV than did non-survivors (2.8 vs. 14.0 ml/kg, p = 0.038 on day 4, and 1.8 vs. 14.9 ml/kg, p = 0.044 on day 5, respectively).

Conclusion: Our results suggest that children who develop ARF during engraftment have better ICU survival rates than do those with other etiologies of ARF post-HSCT. Furthermore, fluid overload contributes to mortality in these children; therefore, strategies to prevent and address fluid overload should be considered.

Respiratory pathogens associated with intubated pediatric patients following hematopoietic cell transplant

BACKGROUND

We describe organisms found in the respiratory tracts of a multicenter cohort of pediatric hematopoietic cell transplant (HCT) recipients with respiratory failure.

METHODS

Twelve centers contributed up to 25 pediatric allogeneic HCT recipients requiring mechanical ventilation for respiratory failure to a retrospective database. Positive respiratory pathogens and method of obtaining sample were recorded. Outcomes were assessed using Mann-Whitney U test or chi-squared analysis.

RESULTS

Of the 222 patients in the database, ages 1 month through 21 years, 34.6% had a positive respiratory culture. 105 pathogens were identified in 77 patients; of those, 48.6% were viral, 34.3% bacterial, 16.2% fungal, and 1% parasitic. PICU mortality with a respiratory pathogen was 68.8% compared to 54.9% for those without a respiratory pathogen (P = .045). Those with a positive respiratory pathogen had longer PICU length of stay, 20 days (IQR 14.0, 36.8) vs 15 (IQR 6.5, 32.0), P = .002, and a longer course of mechanical ventilation, 17 days (IQR 10, 29.5) vs 8 (3, 17), P < .0001. Method of pathogen identification, type of pathogen, and the presence of multiple pathogens were not associated with changes in PICU outcomes.

CONCLUSIONS

In this multicenter retrospective cohort of intubated pediatric post-HCT patients, there was high variability in the respiratory pathogens identified. Type of pathogen and method of detection did not affect PICU mortality. The presence of any organism leads to increased PICU mortality, longer PICU stay, and increased duration of mechanical ventilation suggesting that early detection and treatment of pathogens may be beneficial in this population.

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.

Therapeutic Impact and Complications Associated with Surgical Lung Biopsy after Allogeneic Hematopoietic Stem Cell Transplantation in Children

Hematopoietic stem cell transplantation (HSCT) in the pediatric population is associated with pulmonary complications in 25% of recipients. The role of surgical lung biopsy (SLB) remains unclear because of concerns about both the therapeutic impact and morbidity associated with the procedure. A retrospective review of consecutive allogeneic HSCT recipients at Dana-Farber and Boston Children's Hospital Cancer and Blood Disorders Center between 2006 and 2016 was performed. All recipients who underwent SLB during the study period were identified and charts reviewed for perioperative complications, histopathologic findings, and changes in therapy delivered. Pearson's chi-square test and Student's t-test (or appropriate nonparametric test) were used to evaluate the associations between perioperative complication and categorical and continuous variables, respectively. Five hundred fifty-five HSCTs were included, among which 48 SLBs (8.6%) were identified. Median follow-up time was 24 months (range, 0 to 139). Thirty-day postoperative morbidity was 16.7% and 30-day postoperative mortality 10.4% (n = 5). The overall 30-day postoperative complication rate (including mortality) was 20.8% (n = 10). No mortalities were directly attributable to SLB. Definitive diagnoses were identified in 70.8% of SLBs (n = 34), and therapeutic changes occurred in 79.2% (n = 38). Overall, 83.3% of SLBs (n = 40) either provided a diagnosis or led to a change in therapy. SLB has an acceptable risk of perioperative complications in this medically complicated and often severely ill population. In most HSCT patients, SLB aids in defining the etiology of pulmonary infiltrates and can inform therapeutic decisions in patients where noninvasive diagnostic modalities have failed to provide a definitive diagnosis.

Pulmonary Complications in Pediatric and Adolescent Patients Following Allogeneic Hematopoietic Cell Transplantation

Pulmonary complications after hematopoietic cell transplantation (HCT) can lead to significant morbidity and mortality. Limited evaluation of the true incidence of these complications in children and subsequent outcomes of these complications have not been evaluated recently. In April 2018, the National Heart, Lung, and Blood Institute; the Eunice Kennedy Shriver National Institute of Child Health and Human Development; and the National Cancer Institute cosponsored a meeting of experts to describe the status of pulmonary complications in children after HCT, identify critical gaps in knowledge, and explore avenues for research to advance care and optimize outcomes. The Center for International Blood and Marrow Transplant Research was used to evaluate the cumulative incidence of pulmonary complications in children and their respective survival. Of the 5022 children included in this analysis who received allogeneic HCT from 2010 to 2016, 606 developed pulmonary complications within the first year after HCT. Pneumonitis occurred in 388 patients, 125 patients developed pulmonary hemorrhage, and 200 patients had lung graft-versus-host disease (GVHD). For those developing pulmonary complications within 1 year, overall survival 100 days after diagnosis of pulmonary complications was 49% (95% confidence interval [CI], 43% to 54%) for patients with pneumonitis, 23% (95% CI, 16% to 31%) in patients with pulmonary hemorrhage, and 87% (95% CI, 81% to 91%) in patients with pulmonary GVHD. This study demonstrates the approximate incidence of these complications, as well as their significant effects on survival, and can serve as a baseline for future research.

Acute Respiratory Failure and Management

Acute respiratory failure is a common reason for admission to the pediatric intensive care unit in oncology patients. Acute respiratory complications are also common after pediatric hematopoietic stem cell transplant (HSCT), accounting for a high proportion of HSCT-related morbidity and mortality. Evaluation of these patients requires a thorough workup that includes identification and treatment of infectious etiologies, and treatment for noninfectious causes once infectious causes are ruled out. These patients should be closely monitored for development of pediatric acute respiratory distress syndrome (PARDS) with early escalation of respiratory support. Patients undergoing a trial of noninvasive ventilation (NIV) should be continuously monitored to ensure they are responding. Prolonged delay of endotracheal intubation in patients who do not improve or worsen on NIV could worsen their outcome. Optimal treatment of immunocompromised patients with acute lung failure requires early and aggressive lung protective ventilation, prevention of fluid overload, and rapid diagnosis of underlying causes to facilitate prompt disease-directed therapy.

Surgical lung biopsy in children after hematopoietic cell transplantation

BACKGROUND/PURPOSE

Pulmonary complications are some of the leading causes of morbidity and mortality in immunocompromised pediatric patients. We sought to assess the value of surgical lung biopsy (SLB) in hematopoietic cell transplantation (HCT) pediatric patients.

METHODS

A retrospective review of patients who underwent SLB within one year of HCT between 1999 and 2015 was performed.

RESULTS

Twenty-nine patients (15 females, 14 males) with a median age of 10years (range, 0.6-23) were identified. Median interval between HCT and SLB was 114.8days (range, 16-302). At surgery, 11 (38%) patients were intubated, and 7 (24%) were receiving supplemental oxygen. The most common histological finding was cryptogenic organizing pneumonia in 8 cases (27%), followed by infection in 7 (24%). Perioperative complications (17%) included bronchopleural fistula (n=2), splenic laceration from a trocar injury (n=2), and hemothorax (n=1). Changes in therapy occurred in 25 patients (86%). Twenty-four (83%) patients survived more than 30days post SLB, and the overall survival rate was 41% with a median follow-up of 8.5years (range, 1-13).

CONCLUSION

SLB appears to be safe and informative in pediatric patients after HCT and led to changes in therapy in most patients. However, long-term survival after this procedure was <50%, reinforcing the fact that pulmonary complications are some of the leading causes of mortality in these patients.

TYPE OF STUDY

Retrospective analysis.

LEVEL OF EVIDENCE

Level IV.

Dynamics of Sendai Virus Spread, Clearance, and Immunotherapeutic Efficacy after Hematopoietic Cell Transplant Imaged Noninvasively in Mice

There are no approved vaccines or virus-specific treatments for human parainfluenza viruses (HPIVs), which have recently been reclassified into the species Human respirovirus 1, Human respirovirus 3, Human rubulavirus 2, and Human rubulavirus 4 These viruses cause morbidity and mortality in immunocompromised patients, including those undergoing hematopoietic cell transplant (HCT). No small-animal models for noninvasive imaging of respiratory virus infection in the HCT host exist, despite the utility that such a system would offer to monitor prolonged infection, its clearance, and treatment options. We used a luciferase-expressing reporter virus to noninvasively image in mice the infection of murine respirovirus (strain Sendai virus [SeV]), the murine counterpart of HPIV1. Independent of disease severity, the clearance of infection began approximately 21 days after HCT, largely due to the recovery of CD8+ T cells. Immunotherapy with granulocyte colony-stimulating factor (G-CSF) and adoptive transfer of natural killer (NK) cells provided a limited therapeutic benefit. Treatment with a fusion (F) protein-specific monoclonal antibody arrested the spread of lung infection and reduced the disease severity even when treatment was delayed to up to 10 days postinfection but had little observable effect on upper respiratory tract infection. Adoptive transfer of virus-specific T cells at 10 days postinfection accelerated the clearance by 5 days, reduced the extent of infection throughout the respiratory tract, and reduced the disease severity. Overall, the results support investigation of the clinical treatment of respiratory virus infection in the HCT host with monoclonal antibodies and adoptive T-cell transfer; the imaging system should be extendable to other respiratory viruses, such as respiratory syncytial virus and influenza virus.IMPORTANCE Parainfluenza viruses are a major cause of disease and death due to respiratory virus infection in the immunocompromised host, including those undergoing bone marrow transplantation. There are currently no effective treatment measures. We noninvasively imaged mice that were undergoing a bone marrow transplant and infected with Sendai virus, a murine parainfluenza virus (respirovirus). For the first time, we show the therapeutic windows of adoptive T-cell therapy and treatment with a monoclonal antibody to the fusion (F) protein in clearing Sendai virus from the respiratory tract and reducing disease severity. Mice tolerated these treatments without any detectable toxicity. These findings pave the way for studies assessing the safety of T-cell therapy against parainfluenza virus in humans. Adoptive T-cell therapy against other blood-borne viruses in humans has been shown to be safe and effective. Our model of noninvasive imaging in mice that had undergone a bone marrow transplant may be well suited to track other respiratory virus infections and develop novel preventive and therapeutic strategies.

Early predictors of mortality in children with pulmonary complications after haematopoietic stem cell transplantation

PC are a main cause of death following HSCT in children. We aimed to evaluate early predictors of mortality in paediatric recipients with PCs. A retrospective observational study of 35 patients with 49 episodes of PI on chest radiography (of 124 patients) who had undergone HSCT at a tertiary university hospital between January 2011 and December 2012 was performed. During follow-up (median 26.1 months), 15 episodes led to death (30.6%). An aetiologic diagnosis was made by non-invasive tests in 24 episodes (49.0%) and by adding bronchoalveolar lavage and/or lung biopsy in 7 episodes with diagnostic yield (77.8%, P = .001). Thus, a specific diagnosis was obtained in 63.3% of the episodes. Aetiology identification and treatment modification after diagnosis did not decrease mortality (P = .057, P = .481). However, the number of organ dysfunctions at the beginning of PI was higher in the mortality group, compared to the survivor group (1.7 ± 1.2 vs 0.32 ± 0.59; P = .001). Hepatic dysfunction (OR, 11.145; 95% CI, 1.23 to 101.29; P = .032) and neutropaenia (OR, 10.558; 95% CI, 1.07 to 104.65; P = .044) were independently associated with risk of mortality. Therefore, hepatic dysfunction and neutropaenia are independent early predictors of mortality in HSCT recipients with PCs.

Recovery of Pulmonary Function after Allogeneic Hematopoietic Cell Transplantation in Children is Associated with Improved Survival

Abnormal pulmonary function is prevalent in survivors of allogeneic hematopoietic cell transplantation (HCT). Post-transplantation recovery of pulmonary function, and its effect on survival, in children are not known. This retrospective cohort study of 308 children followed for 10 years after HCT at a single institution included 2 groups of patients. Group 1 comprised 188 patients with 3 or more pulmonary function test (PFT) results, of which at least 1 was abnormal, and group 2 comprised 120 patients with 3 or more PFTs, all of which were normal. Pulmonary function normalized post-transplantation in 51 patients (27%) in group 1. Obstructive lung disease, restrictive lung disease, mixed lung disease, and normal pattern were seen in 43%, 25%, 5%, and 27% of patients, respectively, at a median of 5 years (range, 0.5 to 11.9 years) post-transplantation. Lung volumes recovered better than spirometric indices. Pulmonary complications were seen in 80 patients (43%) in group 1. Patients who recovered pulmonary function had better overall survival (P = .006), which did not differ significantly from that in patients in group 2 with normal lung function post-transplantation (P = .80). After adjusting for duration of follow-up, pulmonary complications (P = .01), and lower pretransplantation forced vital capacity z-scores (P = .01) were associated with poor recovery. T cell depletion (P < .001), lower pretransplantation forced expired volume in 1 second z-scores (P = .006), and chronic graft-versus-host disease (P < .001) increased the risk for pulmonary complications. Nonrecovery of lung function with pulmonary complications (P = .03), acute graft-versus-host disease (P = .004), and mechanical ventilation (P < .001) were risk factors for nonrelapse mortality. Normalization of pulmonary function is possible in long-term survivors of allogeneic HCT. Strategies to decrease the risk of pulmonary complications may improve outcomes.

Glutathione-S-transferase P1 may predispose children to a decline in pulmonary function after stem cell transplant

RATIONALE

Pulmonary complications after hematopoietic stem cell transplant (SCT) are associated with increased mortality. Genetic markers for those at risk for pulmonary impairment post-SCT have not been widely investigated.

METHODS

Forty-nine patients were retrospectively selected from a single institution's biorepository with linked clinical data. All subjects performed pre-SCT PFTs. Genotyping was conducted using the Infinium Exome-24 BeadChip. Four single nucleotide polymorphisms (SNPs) were selected (rs1800871, rs1695, rs1800629, rs12477314) and evaluated for association with PFT parameters as change over time from baseline. Associations between SNPs and PFT parameters were assessed and adjusted for the following confounding variables: age, gender, and race.

RESULTS

Using the recessive genetic model, patients with one or two minor alleles for the glutathione S-transferase P1 (GSTP1) SNP rs1695 had a lower decline in FEV₁ and FEF_25-75 at 1-year post-SCT compared to patients who were homozygous for the ancestral allele (adjusted P-values <0.01 and 0.02, respectively). No other SNPs were significantly associated with other PFT parameters.

CONCLUSIONS

Our findings suggest that GSTP1 genotype may be associated with lung function during the first year post-SCT. Identifying and investigating genes that predispose patients to pulmonary complications after SCT may allow for more personalized patient management based on pre-emptive genetic testing. The glutathione S-transferase gene merits further investigation.

Diagnostic yield of bronchoalveolar lavage in immunocompromised children with malignant and non-malignant disorders

BACKGROUND

The diagnostic yield of bronchoalveolar lavage (BAL) in the Immunocompromised pediatric population has ranged from 28% to 68%. We hypothesized that the diagnostic yield of BALs would be higher in more recent years due to new diagnostic assays.

METHODS

A retrospective case series was performed among immunocompromised children ≤18 years old who underwent BALs from 2001 to 2012, to assess the yield of microbiologic diagnostic studies and to determine the impact of BAL findings on antimicrobial management.

RESULTS

In all, 123 subjects underwent 174 BALs (mean age 9.9 years). Underlying diagnoses included both malignant (n = 79) and non-malignant (n = 44) disorders, and 75 (61.0%) subjects were hematopoietic stem cell transplant (HSCT) recipients. Fifty-four (31.0%) of 174 BAL were positive for ≥1 potential pathogen (n = 58 microorganisms). The diagnostic yield of BALs performed from 2001 to 2006 versus2007-2012 was similar (40.5% vs. 26.6%, respectively, P = 0.07). Most subjects (86.2%) were on ≥1 antimicrobial at the time of BAL. Most (65.8%) negative BALs were associated with narrowing antimicrobial therapy, while most (74.1%) positive BALs were associated with continuing or changing to targeted antimicrobial therapy.

CONCLUSIONS

In this study population, the diagnostic yield of BAL was similar to that previously described and unchanged in more recent years. Both negative and positive BALs were associated with changes in antimicrobial management.

SUMMARY

A 10-year retrospective review of bronchoalveolar lavage in 123 immunocompromised children determined that the rate of isolation of potential pathogens was 31% in this population. The majority of BAL was associated with a change in antimicrobial therapy. Pediatr Pulmonol. 2017;52:820-826. © 2017 Wiley Periodicals, Inc.

Blood transfusions and pulmonary complications after hematopoietic cell transplantation

BACKGROUND

Transfusion of blood products is an essential component of the hematopoietic cell transplantation (HCT) process. Blood transfusion carries several risks including, but not limited to, lung injury. The effect of transfusions on lung complications after HCT has not been previously investigated.

STUDY DESIGN AND METHODS

We retrospectively studied 215 adult allogeneic HCT recipients at the University of Minnesota and examined the association between transfusion of blood components and development of lung complications after HCT. Patients without lung complications were used as the control group.

RESULTS

A total of 113 (58%) of the patients developed lung injury events before Day 180 after HCT. Six-month survival was significantly lower in the lung event group (52%) versus the controls (78%; p = 0.01). Patients who eventually developed lung events received more transfusion episodes per week in the first month after HCT (median, 4.3 vs. 2.7 for controls), platelet units per week (3.5 vs. 2.0), and RBC units per week (1.8 vs. 1.4; p < 0.01) for all. In a multivariable analysis, each additional transfusion before Day +30 was associated with a 2.7% higher risk of lung complication (95% confidence interval, 0.8-4.8; p = 0.01), adjusting for time to engraftment, conditioning intensity, and donor type. Blood utilization increased after the lung event and remained high for several months relative to controls.

CONCLUSION

Our data suggest that transfusion of blood products is associated with and may further complicate lung complications after HCT. Cautious use of blood components in the post HCT period is recommended.

A Critical Care and Transplantation-Based Approach to Acute Respiratory Failure after Hematopoietic Stem Cell Transplantation in Children

Acute respiratory failure contributes significantly to nonrelapse mortality after allogeneic hematopoietic stem cell transplantation. Although there is a trend of improved survival over time, mortality remains unacceptably high. An understanding of the pathophysiology of early respiratory failure, opportunities for targeted therapy, assessment of the patient at risk, optimal use of noninvasive positive pressure ventilation, strategies to improve alveolar recruitment, appropriate fluid management, care of the patient with chronic lung disease, and importantly, a team approach between critical care and transplantation services may improve outcomes.

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Outcomes from acute respiratory failure after hematopoietic stem cell transplantation remain unacceptably high.

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The review focuses on strategies to improve these outcomes.

Pre-hematopoietic stem cell transplant lung function and pulmonary complications in children

RATIONALE

Pulmonary complications are a significant cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation.

OBJECTIVES

The relationship between pretransplant pulmonary function tests (PFTs) and development of post-transplant pulmonary complications in children was studied.

METHODS

This is a retrospective single institution cohort study of 410 patients who underwent pretransplant PFT and were monitored to 10 years posttransplant.

MEASUREMENTS AND MAIN RESULTS

Pulmonary complications were observed in 174 (42%) patients. Children with pulmonary complications had significantly lower forced expiratory flow at 25-75% of vital capacity (P = 0.02) derived using conventional predicted equations for age, and the Global Lung Initiative-2012 predicted equations (P = 0.01). T-cell depletion (P = 0.001), acute grade 3-4 graft-versus-host disease (P = 0.008), and chronic graft-versus-host disease (P = 0.01) increased risk for pulmonary complications. Patients who had pulmonary complications had a 2.8-fold increased risk of mortality (P < 0.0001). The cumulative incidence of death due to pulmonary complications was significantly higher in children who had low lung volumes, FRC less than 50% (P = 0.005), TLC less than 50% (P = 0.0002), residual volume less than 50% (P = 0.007), and T-cell depletion (P = 0.01). Lower FEV1 (P = 0.0005), FVC (P = 0.0005), TLC (P  <  0.0001), residual volume less than 50% (P = 0.01), and restrictive lung disease (P = 0.01) predicted worse overall survival.

CONCLUSIONS

Abnormal pretransplant PFT significantly increased risk after transplant. These patients may benefit from modified transplant strategies to reduce morbidity and mortality.

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.

Bronchoalveolar lavage and lung biopsy in patients with cancer and hematopoietic stem-cell transplantation recipients: a systematic review and meta-analysis

PURPOSE

The objective of this study was to describe the diagnostic yield and complication rate of bronchoalveolar lavage (BAL) and lung biopsy in the evaluation of pulmonary lesions in patients with cancer and recipients of hematopoietic stem-cell transplantation (HSCT).

METHODS

We conducted a systematic literature review and performed electronic searches of Ovid MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials. Studies were included if patients had cancer or were recipients of HSCT, and if they underwent BAL or lung biopsy for the evaluation of pulmonary lesions. Only English language publications were included.

RESULTS

In all, 14,148 studies were screened; 72 studies of BAL and 31 of lung biopsy were included. The proportion of procedures leading to any diagnosis was similar by procedure type (0.53 v 0.54; P = .94) but an infectious diagnosis was more common with BAL compared with lung biopsy (0.49 v 0.34; P < .001). Lung biopsy more commonly led to a noninfectious diagnosis (0.43 v 0.07; P < .001) and was more likely to change how the patient was managed (0.48 v 0.31; P = .002) compared with BAL. However, complications were more common with lung biopsy (0.15 v 0.08; P = .006), and procedure-related mortality was four-fold higher for lung biopsy (0.0078) compared with BAL (0.0018).

CONCLUSION

BAL may be the preferred diagnostic modality for the evaluation of potentially infectious pulmonary lesions because of lower complication and mortality rates; thus, choice of procedure depends on clinical suspicion of infection. Guidelines to promote consistency in the approach to the evaluation of lung infiltrates may improve clinical care of patients.

A comparison of bronchoalveolar lavage versus lung biopsy in pediatric recipients after stem cell transplantation

Bronchoalveolar lavage (BAL) has been a useful initial diagnostic tool in the evaluation of pulmonary complications after hematopoietic stem cell transplantation (HSCT); however, the diagnostic sensitivity, prevalence, and outcome after BAL versus lung biopsy (LB) in pediatric HSCT patients remains to be determined. We reviewed 193 pediatric HSCT recipients who underwent a total of 235 HSCTs. Sixty-five patients (34%) underwent a total of 101 BALs for fever, respiratory distress, and/or pulmonary infiltrates on chest radiograph and/or computed tomography scan. The 1-year probability of undergoing BAL was 43.0% after allogeneic stem cell transplantation (alloSCT) and 8.5% after autologous stem cell transplantation (autoSCT) (P = .001). Sixteen of the 193 patients (8%) patients underwent 19 LBs. The probability of undergoing LB at 1 year after HSCT was 9.3%. No grade III or IV adverse events related to either procedure were observed. Of the 101 BALs performed, 40% (n = 40) were diagnostic, with a majority revealing a bacterial pathogen. Among the 19 LBs performed, 94% identified an etiology. In multivariate analysis, myeloablative conditioning alloSCT conferred the highest risk of requiring a BAL (hazard ratio [HR],8.5; P = .0002). The probability of 2-year overall survival was 20.2% in patients who underwent BAL, 17.5% for patients who underwent biopsy, and 67.4% for patients who had neither procedure. In multivariate analysis, only the requirement of a BAL was independently associated with an increased risk of mortality (HR, 2.96; P < .0001). In summary, in this cohort of pediatric HSCT recipients, BAL and LB were used in approximately 35% and 8% of pediatric HSCTs with diagnostic yields of approximately 40% and 94%, respectively, and were both associated with poor long-term outcomes.

Severe lung injury and lung biopsy in children post-hematopoietic stem cell transplantation: The differences between allogeneic and autologous transplantation

To review outcome of children post-allogeneic (allo) and autologous (auto) SCT with severe lung injury who had lung biopsy and to determine whether the diagnoses provided by lung biopsy had an impact on outcome. Retrospective study was carried out from January 2000 to June 2010. Nine hundred and eighteen children (0-18 yr) received SCT (allo 476, auto 442), and 59 biopsies were performed in 48 patients. Most common result of lung biopsy was non-infectious inflammation and recurrent disease in allo- and autorecipients, respectively. In a multivariate analysis, survival of allorecipients who had management change was inferior (p = 0.002; HR: 3.12). These patients were extremely sick, and management change was the last attempt to stabilize their respiratory status. There was a trend toward superior survival for children who had biopsy after 100 days following SCT (p = 0.09; HR: 0.55) and a trend toward inferior survival for those with proven infections within two wk of biopsy (p = 0.07; HR: 2.14). Only 31% of allorecipients and 25% of autorecipients survived. There were no biopsy-related complications. Lung biopsy itself appears to be well tolerated, although requiring a biopsy seems to carry a poor prognosis; this seems to be due to different causes, auto (relapse), allo (non-infectious inflammation).

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.

Lung function before and after pediatric allogeneic hematopoietic stem cell transplantation: a predictive role for DLCOa/VA

BACKGROUND

Pre-allogeneic hematopoietic stem cell transplantation (aHSCT) and post-aHSCT lung function of 41 eligible patients at Riley Hospital for Children were assessed to identify risk factors for post-aHSCT morbidity and mortality.

OBSERVATIONS

One year post-aHSCT pulmonary function tests were significantly lower compared with baseline. These findings recovered at 2 years post-aHSCT. Refractory disease before aHSCT correlated with lower pulmonary function tests after aHSCT. Graft-versus-host disease was significantly associated with higher post-aHSCT residual volume. Importantly, low pre-aHSCT carbon monoxide diffusing capacity adjusted for hemoglobin and alveolar volume was predictive of death.

CONCLUSIONS

Among survivors, lung function improves over time after pediatric aHSCT. Measurement of carbon monoxide diffusing capacity adjusted for hemoglobin and alveolar volume before pediatric aHSCT should be further investigated as a predictor of pulmonary dysfunction and mortality.

Lethal pulmonary complications after pediatric allogeneic hematopoietic stem cell transplantation

INTRODUCTION

Hematopoietic stem cell transplantation (HSCT) in children is accompanied by a transplant-related mortality of 10% to 30%, which is the result of lethal pulmonary complications (LPCs) in many cases.

METHODS

We retrospectively assessed prevalence and risk factors of LPC following 234 allogeneic HSCTs in 228 patients for malignant or nonmalignant diseases at a single institution.

RESULTS

Pulmonary complications (PCs) were observed following 81 of 234 transplants (35%). LPCs were observed in 4% of HSCT within 100 days and in 14% within 5 years after HSCT. Late PCs after day 100 were lethal in 56% (22/39) of the patients with PCs, who are 11% (22/202) of all evaluable patients still alive after day +100. Causes of LPC after day 100 were viral (10 cases), bacterial (1 case), fungal (5 cases) pulmonary infection, or noninfectious (6 cases) PCs. Abnormal pretransplant pulmonary function test was not associated with an increased risk of LPC. Children older than 10 years and those undergoing a second HSCT had an increased incidence of overall LPC. T-cell depletion and mismatched donor HSCT (P = 0.001), but not age, were associated with an increased risk of lethal viral pneumonia.

CONCLUSIONS

Transplant-related mortality up to 5 years after HSCT in children was associated with LPC in 14%. There were more late (>100 days) than early LPCs, predominantly due to infectious etiologies and affecting children >10 years of age.

Pulmonary outcomes in survivors of childhood cancer: a systematic review

BACKGROUND

The purpose of this article is to summarize the literature that documents the long-term impact of cancer treatment modalities on pulmonary function among survivors of cancer and to identify potential areas for further research.

METHODS

Systematic reviews of clinical trials, observational studies, case series, and review articles were conducted. Articles were limited to the studies that discussed pulmonary toxicity or late effects among pediatric cancer survivors and to follow-up investigations that were conducted a minimum of 2 years after completion of cancer-related treatment or 1 year after hematopoietic stem cell transplant.

RESULTS

Sixty publications (51 clinical studies/reports and nine reviews) published from January 1970 to June 2010 in PubMed met the inclusion criteria. Data showed an association between radiotherapy, alkylating agents, bleomycin, hematopoietic stem cell transplant, and thoracic surgery and pulmonary toxicity, as well as possible interactions among these modalities.

CONCLUSIONS

Pulmonary toxicity is a common long-term complication of exposure to certain anticancer therapies in childhood and can vary from subclinical to life threatening. Pulmonary function and associated loss of optimal exercise capacity may have adverse effects on long-term quality of life in survivors. Lung function diminishes as a function of normal aging, and the effects of early lung injury from cancer therapy may compound these changes. The information presented in this review is designed to provide a stimulus to promote both observational and interventional research that expands our knowledge and aids in the design of interventions to prevent or ameliorate pulmonary late effects among survivors of childhood cancer.

Emergent Complications in the Pediatric Hematopoietic Stem Cell Transplant Patient

Hematopoietic cell transplantation is the only potentially curative option for a variety of pediatric malignant and nonmalignant disorders. Despite advances in transplantation biology and immunology as well as in posttransplant management that have contributed to improved survival and decreased transplant-related mortality, hematopoietic cell transplantation does not come without significant risk of complications. When patients who have undergone hematopoietic cell transplantation present to the emergency department, it is important to consider a variety of therapy-related complications to optimize management and outcome. In this article, we use clinical cases to highlight some of the more common emergent complications after hematopoietic cell transplantation.

Risk factors and outcome of pulmonary complications after autologous hematopoietic stem cell transplant

BACKGROUND

Most reports addressing pulmonary complications (PCs) in hematopoietic stem cell transplant (HSCT) recipients have focused on allogeneics. This study describes the PCs, their risk factors, and the impact on mortality in autologous recipients.

METHODS

We reviewed the medical records of 1,243 adult autologous HSCT recipients. We collected pretransplant and posttransplant data and data on PC after transplant and long-term mortality.

RESULTS

Four hundred eighty-seven PC developed in 343 patients (27.6%): 173 infectious (13.9%), 127 noninfectious (10.2%), and 43 both infectious and noninfectious (3.5%). Bacterial, fungal, and viral pneumonias were the most common infectious complications. The main noninfectious complications were acute pulmonary edema (APE) (59 [4.7%]), diffuse alveolar hemorrhage (DAH) (26 [2.1%]), peri-engraftment respiratory distress syndrome (PERDS) (31 [2.5%]), and idiopathic pneumonia syndrome (IPS) (12 [1.0%]). Independent factors associated with PC included diffusing capacity of lung for carbon monoxide and indications for transplant. Factors associated with mortality included sex, history of pulmonary disease, disease status at the time of transplant, FVC, Karnofsky score, and underlying diagnosis. A Cox proportional hazards regression model with separate time-dependent predictors for the first 1 month, 1 to 2 months, 2 to 6 months, and 6 or more months showed an association with mortality at hazard ratios (HRs) of 32.39, 10.13, 4.29, and 0.98, respectively, compared with persons without PC.

CONCLUSIONS

More than 25% of autologous HSCT recipients develop PCs within 1 year of transplant. Most of the complications are infections. The most common noninfectious complications are APE, DAH, PERDS, and IPS. PCs increase the risk of death, with HR as high as 32.

Outcome of children requiring intensive care following haematopoietic SCT for primary immunodeficiency and other non-malignant disorders

Haematopoietic SCT (HSCT) is curative for many children with primary immunodeficiencies or other non-malignant conditions. Outcome for those admitted to intensive care following HSCT for oncology diagnoses has historically been very poor. There is no literature available specifically regarding the outcome for children with primary immunodeficiency requiring intensive care following HSCT. We reviewed our post-HSCT admission to intensive care over a 5-year period. A total of 111 children underwent HSCT. Median age at transplant was 1 year 4 months. The most common diagnosis was SCID. In all, 35% had at least one intensive care admission and 44% survived to be discharged from intensive care. Also, 73% of admission episodes requiring invasive ventilation but no inotropes or renal replacement therapy resulted in survival to discharge. Children undergoing HSCT for immunological diagnoses had a high rate of admission to intensive care. No factors were identified that could predict the need for admission. Invasive ventilation alone has a much better outcome than that in historical series. However, the need for multi-organ system support was still associated with a poor outcome. This information is useful when counselling families of children that have deteriorated and been admitted to intensive care during the HSCT procedure.

Strong association between respiratory viral infection early after hematopoietic stem cell transplantation and the development of life-threatening acute and chronic alloimmune lung syndromes

Alloimmune lung syndromes (allo-LS), including idiopathic pneumonia syndrome, bronchiolitis obliterans syndrome, and bronchiolitis obliterans organizing pneumonia, are severe complications after hematopoietic stem cell transplantation (HSCT). In our cohort of 110 pediatric patients, 30 had allo-LS (27.3%), 18 with idiopathic pneumonia syndrome and 12 with bronchiolitis obliterans syndrome. Multivariate analysis showed that respiratory viral infection early after HSCT is an important predictor for the development of allo-LS (P <.0001). This was true for all viruses tested. In multivariate analysis, allo-LS was the only predictor for higher mortality (P = .04). Paradoxically, prolonged administration of immunosuppressive agents because of acute graft-versus-host disease had a protective effect on the development of allo-LS (P = .004). We hypothesize that early infection of the respiratory tract with a common cold virus makes the lungs a target for alloimmunity.

Airway reactivity in children before and after stem cell transplantation

Stem cell transplantation (SCT) is associated with pulmonary complications. We encountered several children post-SCT with a clinical picture suggestive of airway hyper-reactivity (AHR) and evidence of reversible airway obstruction that was not reported pre-transplant.We evaluated the possibility of increased AHR as assessed by methacholine challenge test (MCT) following the course of SCT, and assessed a possible correlation between AHR and pulmonary complications.This was a prospective study evaluating consecutive patients referred for SCT to the Department of Pediatric Hemato-Oncology. Evaluation included pulmonary function test and MCT before and after SCT, and assessment of pulmonary complications.Twenty-one of 33 patients completed the study. The mean PC(20) was 14.3 +/- 4.1 mg/ml prior to SCT; afterward the mean PC(20) decreased to 11.2 +/- 5.6 mg/ml (P = 0.018). The number of patients with airway reactivity (PC(20) < or = 8 mg/ml) increased from 2/21 patients before SCT to 8/21 patients after SCT (P = 0.043; McNemar test with Yates correction). Pulmonary complications and hospitalization were recorded in 33.3% of the patients (7/21 patients): 62.5% of the patients (5 patients) with AHR compared to 15.4% (2 patients) in the group without AHR (P = 0.041; Fisher exact test). There were 10 hospitalizations among the 8 patients with positive MCT compared to 2 hospitalizations in 13 patients with negative MCT (median 1 vs. 0, P = 0.045; Mann-Whitney U-test).Increased airway reactivity was observed in our study following the course of SCT. Positive MCT after SCT may be associated with increased risk of pulmonary complications. Larger prospective studies are needed to evaluate the possible mechanisms responsible for increased AHR and the clinical importance of these findings.