Late-Onset Noninfectious Pulmonary Complications After Allogeneic Hematopoietic Stem Cell Transplantation

Meta-analysis on the efficacy of allogeneic hematopoietic stem cell transplantation to treat malignant lymphoma

The goal of the study involved the comparison of clinical efficacy of allogeneic hematopoietic stem cell transplantation (allo-HSCT) and autologous hematopoietic stem cell transplantation (auto-HSCT) in the treatment of malignant lymphoma (ML). The effectiveness of allo-HSCT versus auto-HSCT in the treatment of ML was compared by searching EMBASE, PubMed, Web of Science, and the Cochrane Library for relevant studies. The confidence intervals (CI) and odds ratio (OR) of the article's outcomes were described by a forest plot. Finally, 972 patients in seven articles were included. Overall survival (OS) did not differ significantly between allo-HSCT and auto-HSCT groups (OR  =  0.87, 95% CI: 0.66-1.14, P  =  0.31). Furthermore, there was no significant difference in adverse reactions (AR) between the two groups (OR  =  1.35, 95% CI: 0.81-2.24, P  =  0.25). We observed a significant difference in progression-free survival (PFS) between the two groups (OR  =  4.14, 95% CI: 2.93-5.35, P < 0.01). There was no evidence of publication bias in this meta-analysis. The incidence of OS and AR differ significantly between allo-HSCT and auto-HSCT, but the PFS was longer in ML patients who received allo-HSCT.

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

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

Noninfectious Pulmonary Complications after Hematopoietic Stem Cell Transplantation

Pulmonary complications after hematopoietic stem cell transplantation (HSCT) are important sources of morbidity and mortality. Improvements in infection-related complications have made noninfectious pulmonary complications an increasingly significant driver of transplantation-related mortality. Broadly, these complications can be characterized as either early or late complications, with idiopathic pneumonia syndrome and bronchiolitis obliterans syndrome the most prevalent early and late complications, respectively. Outcomes with historical treatment consisting mainly of corticosteroids are often poor, highlighting the need for a deeper understanding of these complications' underlying disease biology to guide the adoption of novel therapies that are being increasingly used in the modern era.

Thoracic air leak syndrome as the sole manifestation of chronic lung graft-versus-host disease: a case report

Background

Thoracic air leak syndrome (TALS) is a rare complication associated with chronic lung graft-versus-host disease (GVHD) and bronchiolitis obliterans syndrome (BOS). In the present case, TALS was the sole pulmonary manifestation of GVHD.

Case presentation

A 30-year-old woman presented with dyspnea on exertion and swelling of the neck and face after allogeneic stem cell transplantation for acute myeloid leukemia. She was found to have subcutaneous emphysema, and chest imaging suggested pneumomediastinum, with normal lung parenchyma. Her clinical and radiological findings indicated TALS. There were no other features suggestive of lung GVHD. Her condition improved with conservative management and increased immunosuppression. However, she subsequently had two relapses, developed severe infection and pneumothorax, and died.

Conclusions

The present case report illustrates a unique presentation of TALS, a rare complication of GVHD, in a post-stem cell transplant patient. It highlights the challenges in the diagnosis and management of this condition.

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.

Fibrotic Cystic Lung Disease Post Hematopoietic Stem Cell Transplant: Who is the Culprit?

Pulmonary complications post hematopoietic stem cell transplant (HSCT) are associated with poor outcomes and require extensive management depending on the etiology. They usually present in the form of bronchiolitis obliterans syndrome, interstitial pneumonitis, or drug toxicity that can lead to fibrosis. Scant data exists regarding diffuse cystic lung disease following HSCT, and the existing literature only mentions mild cystic changes. We present the case of a 25-year-old man with stage IVB Hodgkin's lymphoma post allogeneic HSCT, who developed progressive traction bronchiectasis, with the appearance of extensive pulmonary cysts that followed significant fibrotic changes and discuss the possible etiologies behind it.

A Systematic Review on Pulmonary Complications Secondary to Hematopoietic Stem Cell Transplantation

The main purpose of this systematic review was to identify and synthesize evidence about pulmonary complications following stem cell transplantation to raise awareness among physicians since it is a lesser-known topic. Studies that included targeted pulmonary complications that occurred after stem cell transplantation; in humans; and were randomized controlled trials, cohort studies, and case studies between January 2011 and 2021. Fifteen intervention features were identified and analyzed in terms of their association with successful or unsuccessful interventions. Fifteen of 15 studies that met inclusion criteria had positive results. Features that appeared to have the most consistent positive effects included relevant information consisting of clinical presentations and management of complications. 

Hematopoietic stem cell transplantation is a therapeutic method that has been introduced for various hematological diseases. Its main objective is to restore the hematopoietic function that has been eradicated or affected. The stem cell transplantation requires a period of administration of chemotherapeutic agents that may lead to infectious and/or non-infectious pulmonary complications that require follow-up.

Noninfectious pulmonary complications include bronchiolitis obliterans, alveolar hemorrhage, fibroelastosis, pulmonary hypertension, and infections. Bronchiolitis obliterans syndrome is an obstructive lung disease that affects the small airways, reducing lung function, and it’s the most frequent late-onset complication. Furthermore, diffuse pulmonary hemorrhage is a fatal adverse effect and the most common noninfectious pulmonary complication of acute leukemia, observed within the first weeks after the procedure. Pulmonary hypertension has multiple etiologies, mainly related to the pulmonary veno-occlusive disease. It carries a poor prognosis, with a 55% mortality rate. The area of hematology is very wide and prone to new development of treatments and procedures that could be available for new emerging diseases and improving survival rates. 

The ISHLT Chronic Lung Allograft Dysfunction Consensus Criteria is Applicable to Pulmonary Chronic Graft-versus-Host Disease

Pulmonary chronic graft-versus-host disease (PcGvHD) is a devastating complication of allogeneic hematopoietic stem cell transplant (HCT). The 2014 NIH chronic GvHD (cGvHD) Consensus Criteria (NIH Criteria) only captures bronchiolitis obliterans syndrome (BOS). In this study, we adapted the 2019 Criteria of chronic lung allograft dysfunction (CLAD) to define novel phenotypes of PcGvHD and compared the performance of this criteria with the NIH Criteria to identify high-risk PcGvHD patients. We reviewed consecutive patients in a cGvHD natural history protocol (NCT00092235) and adapted the 2019 CLAD Criteria (the Adapted Criteria) to define PcGvHD as post-HCT FEV1 <80% predicted value, with four phenotypes: obstructive, restrictive, mixed obstructive/restrictive and undefined. An independent adjudication committee evaluated subjects for diagnosis and phenotyping. We identified 166 (47.4%) patients who met the Adapted Criteria, including obstructive (n = 12, 3.4%), restrictive (n=67, 19.1%), mixed obstruction/restriction (n = 47, 13.4%) and undefined (n = 40, 11.4%). In these patients, less than half (n= 78) met the NIH criteria for BOS (NIH+), the rest (n=88) did not (NIH-). The NIH- subjects showed increased risk of death compared to those without PcGvHD (HR = 1.88, 95%CI = 1.20-2.95, p = 0.006) that was similar to NIH+ subjects (p = 0.678). Our study demonstrated the potential of the Adapted Criteria in identifying high risk PcGvHD patients that have been missed by the NIH Criteria. The Adapted Criteria could become a valuable tool to better phenotype and study lung disease in cGvHD.

Late-Onset, Noninfectious Pulmonary Complications following Allogeneic Hematopoietic Stem Cell Transplantation: A Nationwide Cohort Study of Long-Term Survivors

BACKGROUND

Survivors of allogeneic hematopoietic stem cell transplantation (allo-HSCT) are at risk for pulmonary adverse events. Data on late-onset noninfectious pulmonary complications in long-term adult survivors of allo-HSCT are limited and incomplete.

OBJECTIVES

This study aimed (1) to determine occurrence and degree of pulmonary sequelae in adult survivors of allo-HSCT and (2) to identify associations between pulmonary function, high-resolution CT (HRCT), and clinical characteristics.

METHOD

In a nationwide, single-center cross-sectional study, 103 survivors (aged median [range] 35 [17-58] years, 53% females) were examined 17 (6-32) years after allo-HSCT and compared with healthy controls (n = 105). Methods included pulmonary function tests and HRCT.

RESULTS

Chronic graft-versus-host disease was diagnosed in 33% of survivors, including 12% with bronchiolitis obliterans syndrome (BOS). Mean lung volumes (TLC, FVC, and FEV1) and gas diffusing capacity were >80% of predicted for the survivors as a group, but significantly lower than in healthy controls. Pathological HRCT findings were detected in 48% of the survivors (71% airways disease, 35% interstitial lung disease, and 24% apical subpleural interstitial thickening). Air trapping (%) on HRCT correlated with % predicted FEV1, p < 0.001. In a multiple logistic regression model, both BOS and pathological findings on HRCT were associated with chemotherapy prior to allo-HSCT, p < 0.05.

CONCLUSIONS

Long-term allo-HSCT survivors had significantly lower pulmonary function than age- and gender-matched healthy controls and nearly half had pathological findings on HRCT. Longitudinal data will determine if pulmonary sequelae will remain stable or progress. We recommend lifelong monitoring of pulmonary function in allo-HSCT survivors. HRCT provides additional information, but is not suited for surveillance.

Pulmonary surveillance in pediatric hematopoietic stem cell transplant: A multinational multidisciplinary survey

Background

Hematopoietic Stem Cell Transplant (HSCT) is an established treatment for malignant and non‐malignant conditions and pulmonary disease is a leading cause of late term morbidity and mortality. Accurate and early detection of pulmonary complications is a critical step in improving long term outcomes. Existing guidelines for surveillance of pulmonary complications post‐HSCT contain conflicting recommendations.

Aim

To determine the breadth of current practice in monitoring for pulmonary complications of pediatric HSCT.

Methods

An institutional review board approved, online, anonymous multiple‐choice survey was distributed to HSCT and pulmonary physicians from the United States of America and Australasia using the REDcap platform. The survey was developed by members of the American Thoracic Society Working Group on Complications of Childhood Cancer, and was designed to assess patient management and service design.

Results

A total of 40 (34.8%) responses were received. The majority (62.5%) were pulmonologists, and 82.5% were from the United States of America. In all, 67.5% reported having a protocol for monitoring pulmonary complications and 50.0% reported adhering “well” or “very well” to protocols. Pulmonary function tests (PFTs) most commonly involved spirometry and diffusion capacity for carbon monoxide. The frequency of PFTs varied depending on time post‐HSCT and presence of complications. In all, 55.0% reported a set threshold for a clinically significant change in PFT.

Conclusions

These results illustrate current variation in surveillance for pulmonary complications of pediatric HSCT. The results of this survey will inform development of future guidelines for monitoring of pulmonary complications after pediatric HSCT.

Lung transplantation for late-onset non-infectious chronic pulmonary complications of allogenic hematopoietic stem cell transplant

Background

Late onset non-infectious pulmonary complications (LONIPCs) following allogenic hematopoietic stem cell transplantation (allo-HSCT) confer a significant mortality risk. Lung transplantation (LTx) has the potential to provide survival benefit but the impact of prior allo-HSCT on post-LTx outcomes is not well studied.

Methods

This retrospective, single-centre cohort study assessed the post-LTx outcomes of adults with LONIPCs of allo-HSCT. Outcomes of LTx for LONIPCs were compared to propensity-score matched LTx controls (n = 38, non-HSCT) and recipients of re-LTx (n = 70) for chronic lung allograft dysfunction (CLAD).

Results

Nineteen patients underwent DLTx for LONIPCs of allo-HSCT between 2003 and 2019. Post-LTx survival was 50% at 5-years. Survival to 1-year post-LTx was similar to matched controls (p = 0.473). Survival, conditional on 1-year survival, was lower in the allo-HSCT cohort (p = 0.034). An increased risk of death due to infection was identified in the allo-HSCT cohort compared to matched controls (p = 0.003). Compared to re-LTx recipients, the allo-HSCT cohort had superior survival to 1-year post-LTx (p = 0.034) but conditional 1-year survival was similar (p = 0.145).

Conclusion

This study identifies an increased risk of post-LTx mortality in recipients with previous allo-HSCT, associated with infection. It supports the hypothesis that allo-HSCT LTx recipients are relatively more immunosuppressed than patients undergoing LTx for other indications. Optimisation of post-LTx immunosuppressive and antimicrobial strategies to account for this finding should be considered.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-021-01699-8.

Positive psychological states and stress responses in caregivers of adults receiving an allogeneic bone marrow transplant: A study protocol

AIMS

This protocol directs a study that aims to: (a) describe the caregiver's experience over 8-12 weeks after an index adult patient's allogeneic bone marrow transplant (BMT) for advanced cancer using a case-oriented approach and mixed methods, with qualitative methods in the foreground; and (b) explore networks of relationships among psycho-neurological symptoms, positive psychological states and caregiver health.

DESIGN

Case-oriented longitudinal design using multiple data types and analytic approaches.

METHODS

Data will be collected from 10-12 caregivers. The sample will be recruited from a large public hospital in the southeastern United States using maximum variation sampling (e.g., caregiver race/ethnicity, relationship to patient, age, education, and number of caregiving roles). Participants will be asked to complete weekly surveys, have their blood drawn bi-weekly and participate in an interview each month during the study period (~100 days). Aim 1 analysis will include directed content analysis and case-oriented visual analysis. Aim 2 analysis will include symptom network estimation of psycho-neurological symptoms, positive psychological states, and caregiver health. Institutional review board approval was obtained August 2018.

DISCUSSION

Results will provide an in-depth description of caregivers' experiences in the 100 days after BMT. Findings will inform generation of hypotheses and identification of targets for interventions to improve caregiver's experiences after BMT.

IMPACT

This in-depth multi-method longitudinal study to describe caregivers of adult patients receiving an allogeneic BMT is an essential step in understanding caregivers' complex responses to chronic stress and the role of positive psychological states. The results from this study will inform future research on chronic stress processes, intense caregiving, and intervention development.

Determinants of cardiorespiratory fitness in very long-term survivors of allogeneic hematopoietic stem cell transplantation: a national cohort study

Purpose

Survivors of allogeneic hematopoietic stem cell transplantation (allo-HSCT) are at risk for cardiopulmonary adverse events. Data on long-term effects on cardiorespiratory fitness are limited. To address the gap in knowledge, we aimed to determine peak oxygen uptake (V̇O₂peak) and identify associations between cardiorespiratory fitness and clinical characteristics, self-reported physical activity, cardiac, and pulmonary function.

Methods

In a nationwide, single-center cross-sectional study, 90 survivors [aged median (range) 35 (17–54) years, 56% females] were examined, 17 (6–26) years after allo-HSCT. Myeloablative conditioning comprised busulfan/cyclophosphamide or cyclophosphamide only. Methods included pulmonary function tests, echocardiography, and cardiopulmonary exercise test.

Results

Chronic graft-versus-host disease (cGVHD) was found in 31% of the subjects, of whom 40% had bronchiolitis obliterans syndrome (BOS). Seventy-one percent of the survivors did not meet WHO recommendations for physical activity and 42% were overweight. Reduced gas diffusion (DL_CO) and systolic ventricular dysfunction (LVEF) were found in 44% and 31%, respectively. For the group, mean (95% CI), V̇O₂peak was 36.4 (34.7–38.0) mL/min/kg [89 (85–93)% of predicted]. V̇O₂peak was low at 43%. Cardiopulmonary factors and deconditioning were equally common limitations for exercise. In a multiple linear regression model, low V̇O₂peak was associated with low DL_CO, low LVEF, BOS, overweight, and inactivity.

Conclusion

Half of the survivors had reduced cardiorespiratory fitness median 17 years after allo-HSCT. Cardiopulmonary factors and deconditioning were equally common limitations to exercise. We encourage long-term cardiopulmonary monitoring of allo-HSCT survivors and targeted advice on modifiable lifestyle factors.

Electronic supplementary material

The online version of this article (10.1007/s00520-020-05644-1) contains supplementary material, which is available to authorized users.

Long-term Follow-up of Hematopoietic Stem Cell Transplant Survivors: A Focus on Screening, Monitoring, and Therapeutics

Annually, ~50,000 patients undergo hematopoietic stem cell transplantation (HCT) worldwide with almost 22,000 of these patients receiving HCT in the United States. HCT is a curative option for a wide range of hematologic malignancies, and advances in transplantation medicine have resulted in an increase in HCT survivors. It is anticipated that the number of HCT survivors will more than double from 242,000 in 2020 to ~500,000 in 2030. Survivors of HCT are at an increased risk of developing late complications due to exposure to chemotherapy and/or radiation in the pre-, peri-, and post-HCT phases and these cumulative exposures have the potential to damage normal tissue. This tissue damage leads to the early onset of chronic health conditions resulting in premature mortality in HCT survivors, who have a 15-year cumulative incidence of severe or life-threatening chronic health conditions exceeding 40%. Due to the significant burden of morbidity in HCT survivors and the delay in the development of long-term complications, this delicate patient population requires life-long monitoring due to the risk for neuropsychological, cardiac, pulmonary, renal, hepatic, ocular, skeletal, cardiac, endocrine, fertility, and sexual health complications, as well as secondary neoplasms. This review will focus on recent advances in screening, monitoring, and therapeutics for late-occurring or long-term complications in HCT survivors.

Clinical and imaging characteristics of hematologic disease complicated by air leak syndrome: A STROBE-compliment observational study

There are limited systematic studies on hematologic disease complicated by air leak syndrome (ALS). Physicians in radiology departments and hematology departments have a limited awareness of ALS.The aim of this study was to explore the similarities and differences in clinical data between the clinical group and imaging group in patients with hematologic disease complicated by ALS.Clinical and CT data for 59 patients with hematologic disease complicated by ALS in our hospital were retrospectively reviewed. Patients were assessed by clinical grouping and image grouping. Data were compared between groups, and P < .05 was considered statistically significant.Dyspnea occurred more often in the allo-HSCT (allogeneic hematopoietic stem cell transplantation) group than that in the non-allo-HSCT group (68.8% vs 4.7%, P < .001), there were statistically significant differences in inducing factors between groups, and differences in other aspects were not statistically significant. Chest tightness and dyspnea occurred more often in the allo-HSCT with BO/BOOP (bronchiolitis Obliteran/bronchiolitis obliterans organizing pneumonia) group than those in the allo-HSCT without BO/BOOP group (80.0% vs 9.1%, P = .013), and differences in other aspects were not statistically significant. Chest pain occurred more often in the HPT (hydropneumothorax) group than that in the other 3 groups (pure pneumothorax [PT], pulmonary interstitial emphysema [PIE], complex ALS) (71.4% vs 11.1%, 0.0%, and 26.5%, P = .005); ALS thickness in the HPT group was greater than that in the other 2 groups (PIE and complex ALS) (19.7 vs 3.5 cm and 9.5 cm, P = .001); catheter drainage occurred more often in the HPT group than that in the other three groups (PT, PIE, complexALS) (64.3% vs 22.2%, 0.0%, and 2.9%, P = .001).ALS is a high risk in male patients who have a low BMI, have leukemia as a basic disease, and have basic lung diseases (eg, BO/BOOP). CT types are mainly complex ALS, HPT, and pure PT. In addition, clinical symptoms for patients in the HPT group are severe, and there is a high prevalence of catheter drainage.

Late Noninfectious Pulmonary Complications in Hematopoietic Stem Cell Transplantation

Hematopoietic stem cell transplantation (HSCT) is an established therapeutic modality for a number of malignant and nonmalignant conditions. Pulmonary complications following HSCT are associated with increased mortality and morbidity. These complications may be classified into infectious versus noninfectious, and early versus late based on the time of occurrence post-transplant. Thus, exclusion of infectious etiologies is the first step in the diagnoses of pulmonary complications. Late onset noninfectious pulmonary complications typically occur 3 months post-transplant. Bronchiolitis obliterans is the major contributor to late-onset pulmonary complications, and its clinical presentation, pathogenesis, and current therapeutic approaches are discussed. Idiopathic pneumonia syndrome is another important complication which usually occurs early, although its onset may be delayed. Organizing pneumonia is important to recognize due to its responsiveness to corticosteroids. Other late onset noninfectious pulmonary complications discussed here include pulmonary venoocclusive disease, pulmonary cytolytic thrombi, pleuroparenchymal fibroelastosis, thoracic air leak syndrome, and posttransplant lymphoproliferative disorders.

High probability of follow-up termination among AYA survivors after allogeneic hematopoietic cell transplantation

The need for long-term follow-up (LTFU) after allogeneic hematopoietic cell transplantation (HCT) has been increasingly recognized for managing late effects such as subsequent cancers and cardiovascular events. A substantial population, however, has already terminated LTFU at HCT centers. To better characterize follow-up termination, we analyzed the Japanese transplant registry database. The study cohort included 17 980 survivors beyond 2 years who underwent their first allogeneic HCT between 1974 and 2013. The median patient age at HCT was 34 years (range, 0-76 years). Follow-up at their HCT center was terminated in 4987 patients. The cumulative incidence of follow-up termination was 28% (95% confidence interval [CI], 27%-29%) at 10 years, increasing to 67% (95% CI, 65%-69%) at 25 years after HCT. Pediatric patients showed the lowest probability of follow-up termination for up to 16 years after HCT, whereas adolescent and young adult (AYA) patients showed the highest probability of follow-up termination throughout the period. Follow-up termination was most often made by physicians based on the patient's good physical condition. Multivariate analysis identified 6 factors associated with follow-up termination: AYA patients, female patients, standard-risk malignancy or nonmalignant disease, unrelated bone marrow transplantation, HCT between 2000 and 2005, and absence of chronic graft-versus-host disease. These results suggest the need for education of both physicians and patients about the importance of LTFU, even in survivors with good physical condition. The decreased risk for follow-up termination after 2005 may suggest the increasing focus on LTFU in recent years.

Managing pulmonary complications in allogeneic hematopoietic stem cell transplantation

Introduction: Progress in allogeneic hematopoietic stem cell transplantation (HSCT) procedures has been associated with improved survival in HSCT recipients. However, they have also brought to light organ-specific complications, especially pulmonary complications. In this setting, pulmonary complications are consistently associated with poor outcomes, and improved management of these complications is required. Areas covered: We review the multiple infectious and noninfectious lung complications that occur both early and late after allogeneic HSCT. This includes the description of these complications, risk factors, diagnostic approach and outcome. A literature search was performed using PubMed-indexed journals. Expert commentary: Multiple lung complications after allogeneic HSCT can be diagnosed concomitantly and require a multidisciplinary approach. A specific clinical evaluation including a precise analysis of a lung CT scan is necessary. Management of these lung complications, especially the noninfectious ones, is impaired by the lack of prospective, randomized control trials, suggesting preventive strategies should be developed.

Thoracic Air-Leak Syndrome Complicating Allogeneic Hematopoietic Stem-Cell Transplantation

We report a case of thoracic air-leak syndrome, an extremely rare complication developed after an episode of organizing pneumonia due to graft-vs-host disease in a 19-year-old male. This unusual non-infectious pulmonary complication occurred 527 days after allogeneic HSCT and led to the patient's death within 1 month due to cardio-respiratory failure. Herein, we highlight chest-imaging aspects which are typical. Early detection by high-resolution chest CT could improve patient management.

Pulmonary Complications After Solid Organ Transplantation: An Autopsy Perspective

Pulmonary complications following solid organ transplantation are common and often infectious in nature. Articles describing noninfectious pulmonary complications overwhelmingly rely on clinical and radiographic data. There are a limited number of studies with companion histology delineating the clinical diagnoses of pulmonary complications. This contrasts with blood and bone marrow transplantations. Using a retrospective cohort approach, the current study aimed to assess antemortem and postmortem pulmonary findings in solid organ transplantation recipients. Medical records and autopsy materials from 92 solid organ transplantation recipients were reviewed. Pulmonary complications were identified in 70 patients (76%). For patients with pulmonary complications at autopsy the mean survival posttransplantation was 3.48 years as compared to 7.29 years for patients without pulmonary complications at autopsy (P = .01). Twenty-eight infectious complications (fungal pneumonia, n = 20; cytomegalovirus pneumonia, n = 7; bacterial pneumonia, n = 1) and 113 noninfectious pulmonary complications were identified. The most common noninfectious findings were diffuse alveolar damage (n = 32), organizing pneumonia (n = 31), and pulmonary thromboemboli (n = 26). Disseminated infections and respiratory failure were the most common immediate causes of death (n = 24 and n = 23, respectively). Most noninfectious complications were not diagnosed antemortem.

Lung histopathology of non-infectious pulmonary complications after allogeneic haematopoietic stem cell transplantation

AIMS

Non-infectious pulmonary complications (NIPCs) occur frequently following allogeneic haematopoietic stem cell transplantation (HSCT). As there is no consensus on the description of the related pulmonary pathological lesions, pathologist reports and clinical conclusions are largely inconsistent in routine practice. The aim of our study was to provide an accurate overview of post-allogeneic HSCT NIPCs from a large number of lung biopsies.

METHODS AND RESULTS

We reviewed 61 lung biopsies in patients with an NIPC, including 51 surgical lung biopsies, four post-mortem biopsies and six lung explants. We found both bronchiolar (n = 59) and alveolar/interstitial pathologies (n = 27). We describe two types of bronchiolar lesions: bronchiolectasies (n = 37) and fibrous and cellular lesions with luminal narrowing (n = 43). We found a wide spectrum of airway/interstitial pathologies that were labelled using the terminology of the 2013 American Thoracic Society and European Respiratory Society (ATS/ERS) classification of idiopathic interstitial pneumonias (IIPs), including the following: organising pneumonia (OP, n = 8), non-specific interstitial pneumonia (NSIP, n = 9), diffuse alveolar damage (DAD, n = 6), lymphoid interstitial pneumonia (LIP, n = 1) and pleuroparenchymal fibroelastosis (PPFE, n = 2), as well as one instance of associated PPFE and NSIP.

CONCLUSIONS

Interstitial pathology was associated with bronchiolar lesions in 41% of the cases reviewed (n = 25). Lung airway and interstitial inflammation was still present in lung explants from patients who underwent lung transplantation for post-allogeneic HSCT end-stage respiratory insufficiency. Herein, we describe a wide spectrum of pathological lung lesions encountered in post-allogeneic HSCT NIPCs.

Noninfectious lung complications after allogeneic haematopoietic stem cell transplantation

Epidemiological data on late-onset noninfectious pulmonary complications (LONIPCs) following allogeneic haematopoietic stem cell transplantation (HSCT) are derived exclusively from retrospective studies and are conflicting. We aimed to evaluate prospectively the incidence, risk factors and outcomes for LONIPCs.All consecutive patients scheduled to receive allogeneic HSCT between 2006 and 2008 at a university teaching hospital in France were screened for inclusion in the study. Eligible patients were those surviving at day 100. Among 243 screened patients, 198 patients were included in the analysis. The median (interquartile range) follow-up was 72.3 (15.2-88.5) months. 55 LONIPCs were diagnosed in 43 patients. Bronchiolitis obliterans syndrome (n=22) and interstitial lung disease (n=12) were the most common LONIPCs. At 36 months after inclusion, the estimated cumulative incidence of LONIPCs was 19.8% (95% CI 14.2-25.3%). The estimated median survival after the diagnosis of LONIPCs was 78.5 months (95% CI 20.0-not reached). Based on a multivariate Cox model, a history of chest irradiation anytime prior to HSCT, a history of pneumonia within 100 days post-HSCT and a low mean forced expiratory flow at 25-75% of forced vital capacity at day 100 were associated with the development of LONIPCs.Our data provide clues to identify patients at high risk of developing LONIPCs. These patients should be targeted for close monitoring to provide earlier LONIPC treatment or prophylactic treatment.

Lung transplantation after allogeneic stem cell transplantation: a pan-European experience

Late-onset noninfectious pulmonary complications (LONIPCs) affect 6% of allogeneic stem cell transplantation (SCT) recipients within 5 years, conferring subsequent 5-year survival of 50%. Lung transplantation is rarely performed in this setting due to concomitant extrapulmonary morbidity, excessive immunosuppression and concerns about recurring malignancy being considered contraindications. This study assesses survival in highly selected patients undergoing lung transplantation for LONIPCs after SCT.

SCT patients undergoing lung transplantation at 20 European centres between 1996 and 2014 were included. Clinical data pre- and post-lung transplantation were reviewed. Propensity score-matched controls were generated from the Eurotransplant and Scandiatransplant registries. Kaplan–Meier survival analysis and Cox proportional hazard regression models evaluating predictors of graft loss were performed.

Graft survival at 1, 3 and 5 years of 84%, 72% and 67%, respectively, among the 105 SCT patients proved comparable to controls (p=0.75). Sepsis accounted for 15 out of 37 deaths (41%), with prior mechanical ventilation (HR 6.9, 95% CI 1.0–46.7; p<0.001) the leading risk factor. No SCT-specific risk factors were identified. Recurring malignancy occurred in four patients (4%). Lung transplantation <2 years post-SCT increased all-cause 1-year mortality (HR 7.5, 95% CI 2.3–23.8; p=0.001).

Lung transplantation outcomes following SCT were comparable to other end-stage diseases. Lung transplantation should be considered feasible in selected candidates. No SCT-specific factors influencing outcome were identified within this carefully selected patient cohort.

Bronchiolitis Obliterans Syndrome and Other Late Pulmonary Complications After Allogeneic Hematopoietic Stem Cell Transplantation

As more individuals survive their hematologic malignancies after allogeneic hematopoietic stem cell transplantation (HSCT), there is growing appreciation of the late organ complications of this curative procedure for malignant and nonmalignant hematologic disorders. Late noninfectious pulmonary complications encompass all aspects of the bronchopulmonary anatomy. There have been recent advances in the diagnostic recognition and management of bronchiolitis obliterans syndrome, which is recognized as a pulmonary manifestation of chronic graft-versus-host disease. Organizing pneumonia and other interstitial lung diseases are increasingly recognized. This article provides an update on these entities as well as pleural and pulmonary vascular disease after allogeneic HSCT.

Effect of Azithromycin on Airflow Decline-Free Survival After Allogeneic Hematopoietic Stem Cell Transplant: The ALLOZITHRO Randomized Clinical Trial

IMPORTANCE

Bronchiolitis obliterans syndrome has been associated with increased morbidity and mortality after allogeneic hematopoietic stem cell transplant (HSCT). Previous studies have suggested that azithromycin may reduce the incidence of post-lung transplant bronchiolitis obliterans syndrome.

OBJECTIVE

To evaluate if the early administration of azithromycin can improve airflow decline-free survival after allogeneic HSCT.

DESIGN, SETTING, AND PARTICIPANTS

The ALLOZITHRO parallel-group trial conducted in 19 French academic transplant centers and involving participants who were at least 16 years old, had undergone allogeneic HSCT for a hematological malignancy, and had available pretransplant pulmonary function test results. Enrollment was from February 2014 to August 2015 with follow-up through April 26, 2017.

INTERVENTIONS

Patients were randomly assigned to receive 3 times a week either 250 mg of azithromycin (n = 243) or placebo (n = 237) for 2 years, starting at the time of the conditioning regimen.

MAIN OUTCOMES AND MEASURES

The primary efficacy end point was airflow decline-free survival at 2 years after randomization. Main secondary end points were overall survival and bronchiolitis obliterans syndrome at 2 years.

RESULTS

Thirteen months after enrollment, the independent data and safety monitoring board detected an unanticipated imbalance across blinded groups in the number of hematological relapses, and the treatment was stopped December 26, 2016. Among 480 randomized participants, 465 (97%) were included in the modified intention-to-treat analysis (mean age, 52 [SD, 14] years; 75 women [35%]). At the time of data cutoff, 104 patients (22%; 54 azithromycin vs 50 placebo) had experienced an airflow decline; 138 patients (30%) died (78 azithromycin vs 60 placebo). Two-year airflow decline-free survival was 32.8% (95% CI, 25.9%-41.7%) with azithromycin and 41.3% (95% CI, 34.1%-50.1%) with placebo (unadjusted hazard ratio [HR], 1.3; 95% CI, 1.02-1.70; P = .03). Of the 22 patients (5%) who experienced bronchiolitis obliterans syndrome, 15 (6%) were in the azithromycin group and 7 (3%) in the placebo group (P = .08). The azithromycin group had increased mortality, with a 2-year survival of 56.6% (95% CI, 50.2%-63.7%) vs 70.1% (95% CI, 64.2%-76.5%) in the placebo group (unadjusted HR, 1.5; 95% CI, 1.1-2.0; P = .02). In a post hoc analysis, the 2-year cumulative incidence of hematological relapse was 33.5% (95% CI, 27.3%-39.7%) with azithromycin vs 22.3% (95% CI, 16.4%-28.2%) with placebo (unadjusted cause-specific HR, 1.7; 95% CI, 1.2-2.4; P = .002).

CONCLUSIONS AND RELEVANCE

Among patients undergoing allogeneic HSCT for hematological malignancy, early administration of azithromycin resulted in worse airflow decline-free survival than did placebo; these findings are limited by early trial termination. The potential for harm related to relapse requires further investigation.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01959100.