Longitudinal Forced Vital Capacity Monitoring as a Prognostic Adjunct after Lung Transplantation

The Lung Microbiome Predicts Mortality and Response to Azithromycin in Lung Transplant Recipients with Chronic Rejection

Rationale: Chronic lung allograft dysfunction (CLAD) is the leading cause of death after lung transplant, and azithromycin has variable efficacy in CLAD. The lung microbiome is a risk factor for developing CLAD, but the relationship between lung dysbiosis, pulmonary inflammation, and allograft dysfunction remains poorly understood. Whether lung microbiota predict outcomes or modify treatment response after CLAD is unknown. Objectives: To determine whether lung microbiota predict post-CLAD outcomes and clinical response to azithromycin. Methods: Retrospective cohort study using acellular BAL fluid prospectively collected from recipients of lung transplant within 90 days of CLAD onset. Lung microbiota were characterized using 16S rRNA gene sequencing and droplet digital PCR. In two additional cohorts, causal relationships of dysbiosis and inflammation were evaluated by comparing lung microbiota with CLAD-associated cytokines and measuring ex vivo P. aeruginosa growth in sterilized BAL fluid. Measurements and Main Results: Patients with higher bacterial burden had shorter post-CLAD survival, independent of CLAD phenotype, azithromycin treatment, and relevant covariates. Azithromycin treatment improved survival in patients with high bacterial burden but had negligible impact on patients with low or moderate burden. Lung bacterial burden was positively associated with CLAD-associated cytokines, and ex vivo growth of P. aeruginosa was augmented in BAL fluid from transplant recipients with CLAD. Conclusions: In recipients of lung transplants with chronic rejection, increased lung bacterial burden is an independent risk factor for mortality and predicts clinical response to azithromycin. Lung bacterial dysbiosis is associated with alveolar inflammation and may be promoted by underlying lung allograft dysfunction.

Results from randomized trial of pirfenidone in patients with chronic rejection (STOP-CLAD study)

BACKGROUND

Chronic lung allograft dysfunction (CLAD) is the leading long-term cause of poor outcomes after transplant and manifests by fibrotic remodeling of small airways and/or pleuroparenchymal fibroelastosis. This study evaluated the effect of pirfenidone on quantitative radiographic and pulmonary function assessment in patients with CLAD.

METHODS

We performed a single-center, 6-month, randomized, placebo-controlled trial of pirfenidone in patients with CLAD. Randomization was stratified by CLAD phenotype. The primary outcome for this study was change in radiographic assessment of small airways disease, quantified as percentage of lung volume using parametric response mapping analysis of computed tomography scans (PRMfSAD); secondary outcomes included change in forced expiratory volume in 1 second (FEV1), change in forced vital capacity (FVC), and change in radiographic quantification of parenchymal disease (PRMPD). Linear mixed models were used to evaluate the treatment effect on outcome measures.

RESULTS

The goal enrollment of 60 patients was not met due to the coronavirus disease of 2019 pandemic, with 23 patients included in the analysis. There was no significant difference over the study period between the pirfenidone vs placebo groups with regards to the observed change in PRMfSAD (+4.2% vs -0.4%; p = 0.22), FEV1 (-3.5% vs -3.6%; p = 0.97), FVC (-1.9% vs -4.6%; p = 0.41), or PRMPD (-0.6% vs -2.5%; p = 0.30). The study treatment tolerance and adverse events were generally similar between the pirfenidone and placebo groups.

CONCLUSIONS

Pirfenidone had no apparent impact on radiographic evidence of allograft dysfunction or pulmonary function decline in a single-center randomized trial of CLAD patients that did not meet enrollment goals but had an acceptable tolerance and side-effect profile.

Design of Lung Transplant Go (LTGO): A randomized controlled trial evaluating the efficacy of a telerehabilitation behavioral exercise intervention to improve physical activity, physical function, and blood pressure control after lung transplantation

Background

Lung transplantation is an established treatment option for persons with advanced lung disease. After transplantation, lung function typically returns to near normal levels, however exercise capacity remains low due to chronic deconditioning, limited physical function, and inactive lifestyles which undermine the intended benefits of the highly selective, resource-intensive transplant procedure. Pulmonary rehabilitation is recommended to improve fitness and activity tolerance, however due to multiple barriers, lung transplant recipients either never participate, or fail to complete, pulmonary rehabilitation programs.

Purpose

To describe the design of Lung Transplant Go (LTGO), a trial modified for the remote environment based on recommendations to preserve trial integrity during COVID. The aims are to evaluate a behavioral exercise intervention to improve physical function, physical activity, and blood pressure control in lung transplant recipients conducted safely and effectively using a telerehabilitation (telerehab) platform, and to explore the role of potential mediators and moderators of the relationship between LTGO and outcomes.

Methods

Single-site, 2-group randomized controlled trial with lung transplant recipients randomized 1:1 to either the LTGO intervention (a 2-phased, supervised, telerehab behavioral exercise program), or to enhanced usual care (activity tracking and monthly newsletters). All study activities, including intervention delivery, recruitment, consenting, assessment, and data collection, will be performed remotely.

Conclusion

If efficacious, this fully scalable and replicable telerehab intervention could be efficiently translated to reach large numbers of lung recipients to improve and sustain self-management of exercise habits by overcoming barriers to participation in existing, in-person pulmonary rehabilitation programs.

Alterations in Pulmonary Physiology with Lung Transplantation

Lung transplant is a treatment option for patients with end-stage lung diseases; however, survival outcomes continue to be inferior when compared to other solid organs. We review the several anatomic and physiologic changes that result from lung transplantation surgery, and their role in the pathophysiology of common complications encountered by lung recipients. The loss of bronchial circulation into the allograft after transplant surgery results in ischemia-related changes in the bronchial artery territory of the allograft. We discuss the role of bronchopulmonary anastomosis in blood circulation in the allograft posttransplant. We review commonly encountered complications related to loss of bronchial circulation such as allograft airway ischemia, necrosis, anastomotic dehiscence, mucociliary dysfunction, and bronchial stenosis. Loss of dual circulation to the lung also increases the risk of pulmonary infarction with acute pulmonary embolism. The loss of lymphatic drainage during transplant surgery also impairs the management of allograft interstitial fluid, resulting in pulmonary edema and early pleural effusion. We discuss the role of lymphatic drainage in primary graft dysfunction. Besides, we review the association of late posttransplant pleural effusion with complications such as acute rejection. We then review the impact of loss of afferent and efferent innervation from the allograft on control of breathing, as well as lung protective reflexes. We conclude with discussion about pulmonary function testing, allograft monitoring with spirometry, and classification of chronic lung allograft dysfunction phenotypes based on total lung capacity measurements. We also review factors limiting physical exercise capacity after lung transplantation, especially impairment of muscle metabolism. © 2023 American Physiological Society. Compr Physiol 13:4269-4293, 2023.

Abnormal one-year post-lung transplant spirometry is a significant predictor of increased mortality and chronic lung allograft dysfunction

BACKGROUND

The prognostic value of evaluating spirometry at a fixed time point using standardized population reference has not previously been evaluated. Our aim was to assess the association between spirometric phenotype at 12 months (Spiro_12M), survival and incidence of chronic lung allograft dysfunction (CLAD) in bilateral lung transplant recipients.

METHODS

We conducted a retrospective cohort study of bilateral lung transplant recipients transplanted between January 2003 and September 2012. We defined Spiro_12M as the mean of the 2 prebronchodilator FEV₁ measurements 12-month post-transplant. Normal spirometry was defined as FEV₁/FVC ≥0.7 and FEV1≥80% and FVC≥80% predicted population-based values for that recipient. Abnormal spirometry was defined as failure to attain normal function by 12-months. We used a Cox regression model to assess the association between Spiro_12M, survival, and CLAD. We used logistic regression to assess potential pretransplant donor and recipient factors associated with abnormal Spiro_12M RESULTS: One hundred and eleven (51%) lung transplant recipients normalized their Spiro_12M. Normal Spiro_12M was associated improved survival (hazard ratio [HR] 0.60, 95% confidence interval [CI] 0.41-0.88], p = 0.009. Each 10% decrement in FEV₁ increased the risk of death in a stepwise fashion. Additionally, CLAD was reduced in those with normal Spiro_12M (HR:0.65, 95%CI:0.46-0.92, p = 0.016). Donor smoking history (OR:2.93, 95% CI:1.21-7.09; p = 0.018) and mechanical ventilation time in hours (OR:1.03, 95% CI:1.004-1.05; p = 0.02) were identified as independent predictors of abnormal Spiro_12M.

CONCLUSIONS

Abnormal Spiro_12M is associated with increased mortality and the development of CLAD. The effect is dose dependent with increased dysfunction corresponding to increased risk. This assessment of phenotype at 12-months can easily be incorporated into standard of care.

Relationship between FEV1 decline and mortality in patients with bronchiolitis obliterans syndrome-a systematic literature review

BACKGROUND

Bronchiolitis obliterans syndrome (BOS) is one of the most severe complications and the leading cause of late mortality and morbidity after lung transplantation (LT) and allogeneic hematopoietic stem cell transplantation (allo-HSCT). No approved treatment for BOS is available. This review aimed to systematically identify and summarise the findings regarding the relationship between FEV₁ decline and mortality in patients who developed BOS following LT or allo-HSCT.

METHODS

A systematic literature search was performed in the Medline, Embase and Cochrane reviews databases. Of the 501 potential studies identified 25 met inclusion criteria and were analysed.

RESULTS

Overall, 13 studies reported a relationship between FEV₁ and mortality, and 12 studies reported both mortality and FEV₁ results but did not investigate the relationship between them. There was heterogeneity in the analyses, which investigated the relationship between FEV₁ decline and mortality across the studies in terms of levels of lung functioning, comparison to a control group, treatment, and statistical methodology; nevertheless, a clear and consistent increase in the risk of death associated with FEV₁ decrease was seen in the analysed studies.

CONCLUSIONS

The systematic literature review identified studies and findings that support a relationship between FEV₁ and mortality, with a decrease in FEV₁ being statistically associated with increased risk of death. Knowing that lower FEV₁ levels are associated with higher mortality rates may help assess the condition of a patient with BOS and monitor future treatment effectiveness. However, more evidence is needed to further investigate this relationship and to verify its clinical usefulness.

Radiographic Graft Surveillance in Lung Transplantation: Prognostic Role of Parametric Response Mapping

RATIONALE

Chronic lung allograft dysfunction (CLAD) results in significant morbidity following lung transplantation. Potential CLAD occurs when lung function declines to 80-90% of baseline. Better non-invasive tools to prognosticate at potential CLAD are needed.

OBJECTIVES

To determine if parametric response mapping (PRM), a CT voxel-wise methodology, applied to high resolution CT scans can identify patients at risk of progression to CLAD or death.

METHODS

Radiographic features and PRM-based CT metrics quantifying functional small airways disease (PRMfSAD) and parenchymal disease (PRMPD) were studied at potential CLAD (n=61). High PRMfSAD and high PRMPD were defined as ≥ 30%. Restricted mean modeling was performed to compare CLAD-free survival among groups.

MEASUREMENTS AND MAIN RESULTS

PRM metrics identified 3 unique signatures: high PRMfSAD (11.5%), high PRMPD (41%) and neither (PRMNormal; 47.5%). Patients with high PRMfSAD or PRMPD had shorter CLAD-free median survival times (0.46 years and 0.50 years) compared to patients with predominantly PRMNormal (2.03 years; p=0.004 and 0.007 compared to PRMfSAD and PRMPD groups, respectively). In multivariate modeling adjusting for single versus double lung transplant, age at transplant, BMI at potential CLAD, and time from transplant to CT, PRMfSAD or PRMPD ≥ 30% continue to be statistically significant predictors of shorter CLAD-free survival. Air trapping by radiologist interpretation was common (66%), similar across PRM groups, and was not predictive of CLAD-free survival. Ground glass opacities by radiologist read occurred in 16% of cases and was associated with decreased CLAD-free survival (p<0.001).

CONCLUSIONS

PRM analysis offers valuable prognostic information at potential CLAD, identifying patients most at risk of developing CLAD or death.

National Institutes of Health Consensus Development Project on Criteria for Clinical Trials in Chronic Graft-versus-Host Disease: IV. The 2020 Highly morbid forms report

Chronic graft-versus-host disease (GVHD) can be associated with significant morbidity, in part because of nonreversible fibrosis, which impacts physical functioning (eye, skin, lung manifestations) and mortality (lung, gastrointestinal manifestations). Progress in preventing severe morbidity and mortality associated with chronic GVHD is limited by a complex and incompletely understood disease biology and a lack of prognostic biomarkers. Likewise, treatment advances for highly morbid manifestations remain hindered by the absence of effective organ-specific approaches targeting "irreversible" fibrotic sequelae and difficulties in conducting clinical trials in a heterogeneous disease with small patient numbers. The purpose of this document is to identify current gaps, to outline a roadmap of research goals for highly morbid forms of chronic GVHD including advanced skin sclerosis, fasciitis, lung, ocular and gastrointestinal involvement, and to propose strategies for effective trial design. The working group made the following recommendations: (1) Phenotype chronic GVHD clinically and biologically in future cohorts, to describe the incidence, prognostic factors, mechanisms of organ damage, and clinical evolution of highly morbid conditions including long-term effects in children; (2) Conduct longitudinal multicenter studies with common definitions and research sample collections; (3) Develop new approaches for early identification and treatment of highly morbid forms of chronic GVHD, especially biologically targeted treatments, with a special focus on fibrotic changes; and (4) Establish primary endpoints for clinical trials addressing each highly morbid manifestation in relationship to the time point of intervention (early versus late). Alternative endpoints, such as lack of progression and improvement in physical functioning or quality of life, may be suitable for clinical trials in patients with highly morbid manifestations. Finally, new approaches for objective response assessment and exploration of novel trial designs for small populations are required.

Twelve-month effects of everolimus on renal and lung function in lung transplantation: differences in chronic lung allograft dysfunction phenotypes

Background:

Chronic lung allograft dysfunction (CLAD), a complication affecting the survival of lung transplanted patients, includes two clinical phenotypes: bronchiolitis obliterans syndrome (BOS) and restrictive allograft syndrome (RAS). Everolimus is used in CLAD because of its antiproliferative mechanism. In lung transplant patients treated with everolimus, the clinical course of renal and lung function has not yet been assessed systematically in CLAD, BOS and RAS patients for more than 6 months.

Methods:

We retrospectively evaluated the 12-month follow-up of renal and lung function of lung-transplanted patients switched to everolimus and evaluated the reduction in immunosuppressant dosage (ISD) and mortality. Subgroups were based on indication for everolimus treatment: CLAD and non-CLAD patients, BOS and RAS among CLAD patients.

Results:

We included 26 patients, 17 with CLAD (10 BOS, seven RAS). After 1 year from the everolimus switch, we observed renal function improvement (serum creatinine −17%, estimated glomerular filtration rate +24%) and stable pulmonary function [forced expiratory volume in the first second (FEV₁) −0.5%, forced vital capacity (FVC) +0.05%]. RAS patients had progressive functional loss, whereas BOS patients had FEV₁ improvement and FVC stability. All-cause mortality was higher in the CLAD versus non-CLAD group (41% versus 11%), without differences between BOS and RAS patients (p > 0.05). All patients had significant and persistent ISD reduction.

Conclusion:

Lung transplant patients treated with everolimus had improvements in renal function and reduced ISD. We observed sustained improvements in lung function for CLAD related to BOS subgroup results, whereas RAS confirmed the 1-year worsening functional trend. Data seem to suggest one more piece of the puzzle in CLAD phenotyping.

Humoral immune responses mediate the development of a restrictive phenotype of chronic lung allograft dysfunction

Understanding the distinct pathogenic mechanisms that culminate in allograft fibrosis and chronic graft failure is key in improving outcomes after solid organ transplantation. Here, we describe an F1 → parent orthotopic lung transplant model of restrictive allograft syndrome (RAS), a particularly fulminant form of chronic lung allograft dysfunction (CLAD), and identify a requisite pathogenic role for humoral immune responses in development of RAS. B6D2F1/J (H2-b/d) donor lungs transplanted into the parent C57BL/6J (H2-b) recipients demonstrated a spectrum of histopathologic changes, ranging from lymphocytic infiltration, fibrinous exudates, and endothelialitis to peribronchial and pleuroparenchymal fibrosis, similar to those noted in the human RAS lungs. Gene expression profiling revealed differential humoral immune cell activation as a key feature of the RAS murine model, with significant B cell and plasma cell infiltration noted in the RAS lung allografts. B6D2F1/J lung allografts transplanted into μMt-/- (mature B cell deficient) or activation-induced cytidine deaminase (AID)/secretory μ-chain (μs) double-KO (AID-/-μs-/-) C57BL/6J mice demonstrated significantly decreased allograft fibrosis, indicating a key role for antibody secretion by B cells in mediating RAS pathology. Our study suggests that skewing of immune responses determines the diverse allograft remodeling patterns and highlights the need to develop targeted therapies for specific CLAD phenotypes.

Variability of forced vital capacity in progressive interstitial lung disease: a prospective observational study

Background

Fibrotic interstitial lung disease (ILD) is often associated with poor outcomes, but has few predictors of progression. Daily home spirometry has been proposed to provide important information about the clinical course of idiopathic pulmonary disease (IPF). However, experience is limited, and home spirometry is not a routine component of patient care in ILD. Using home spirometry, we aimed to investigate the predictive potential of daily measurements of forced vital capacity (FVC) in fibrotic ILD.

Methods

In this prospective observational study, patients with fibrotic ILD and clinical progression were provided with home spirometers for daily measurements over 6 months. Hospital based spirometry was performed after three and 6 months. Disease progression, defined as death, lung transplantation, acute exacerbation or FVC decline > 10% relative was assessed in the cohort.

Results

From May 2017 until August 2018, we included 47 patients (IPF n = 20; non-IPF n = 27). Sufficient daily measurements were performed by 85.1% of the study cohort. Among these 40 patients (IPF n = 17; non-IPF n = 23), who had a mean ± SD age of 60.7 ± 11.3 years and FVC 64.7 ± 21.7% predicted (2.4 ± 0.8 L), 12 patients experienced disease progression (death: n = 2; lung transplantation: n = 3; acute exacerbation: n = 1; FVC decline > 10%: n = 6). Within the first 28 days, a group of patients had high daily variability in FVC, with 60.0% having a variation ≥5%. Patients with disease progression had significantly higher FVC variability than those in the stable group (median variability 8.6% vs. 4.8%; p = 0.002). Cox regression identified FVC variability as independently associated with disease progression when controlling for multiple confounding variables (hazard ratio: 1.203; 95% CI:1.050–1.378; p = 0.0076).

Conclusions

Daily home spirometry is feasible in IPF and non-IPF ILD and facilitates the identification of FVC variability, which was associated with disease progression.

Longitudinal lung function measurements in single lung transplant recipients with chronic lung allograft dysfunction

BACKGROUND

Phenotyping chronic lung allograft dysfunction (CLAD) in single lung transplant (SLTX) recipients is challenging. The aim of this study was to assess the diagnostic and prognostic value of longitudinal lung function tests in SLTX recipients with CLAD.

METHODS

A total of 295 SLTX recipients were analyzed and stratified according to native lung physiology. In addition to spirometry, measurements of static lung volumes and lung capacities were used to phenotype patients and to assess their prognostic value. Outcome was survival after CLAD onset. Patients with insufficient clinical information were excluded (n = 71).

RESULTS

Of 224 lung transplant recipients, 105 (46.9%) developed CLAD. Time to CLAD onset (hazard ratio [HR]: 0.82, 95% CI: 0.74-0.90; p < 0.001), severity of CLAD at onset (HR: 0.97, 95% CI: 0.94-0.99; p = 0.009), and progression after onset of CLAD (HR: 1.03, 95% CI: 1.00-1.05; p = 0.023) were associated with outcome. Phenotypes at onset were bronchiolitis obliterans syndrome (BOS) (59.1%), restrictive allograft syndrome (RAS) (12.4%), mixed phenotype (6.7%), and undefined phenotype (21.9%). Survival estimates differed significantly between phenotypes (p = 0.004), with RAS and mixed phenotype being associated with the worst survival, followed by BOS and undefined phenotype. Finally, a higher hazard for mortality was noticed for RAS (HR: 2.34, 95% CI: 0.99-5.52; p = 0.054) and mixed phenotype (HR: 3.30, 95% CI: 1.20-9.11; p = 0.021) while controlling for time to CLAD onset and severity of CLAD at onset.

CONCLUSIONS

Phenotyping CLAD in SLTX remains challenging with a high number of patients with an undefined phenotype despite comprehensive lung function testing. However, phenotyping is of prognostic value. Furthermore, early, severe, and progressive CLADs are associated with worse survival.

Significance of Best Spirometry in the First Year After Bilateral Lung Transplantation: Association With 3-Year Outcomes

BACKGROUND

Spirometry is the cornerstone of monitoring allograft function after lung transplantation (LT). We sought to determine the association of variables on best spirometry during the first year after bilateral LT with 3-year posttransplant survival.

METHODS

We reviewed charts of patients who survived at least 3 months after bilateral LT (n = 157; age ± SD: 54 ± 13 y, male:female = 91:66). Best spirometry was calculated as the average of 2 highest measurements at least 3 weeks apart during the first year. Airway obstruction was defined as forced expiratory volume in 1-second (FEV1)/forced vital capacity (FVC) ratio <0.7. Survival was compared based on the ventilatory defect and among groups based on the best FEV1 and FVC measurements (>80%, 60%-80%, and <60% predicted). Primary outcome was 3-year survival.

RESULTS

Overall, 3-year survival was 67% (n = 106). Obstructive defect was uncommon (7%) and did not have an association with 3-year survival (72% versus 67%, P = 0.7). Although one-half patients achieved an FVC>80% predicted (49%), 1 in 5 (19%) remained below 60% predicted. Irrespective of the type of ventilatory defect, survival worsened as the best FVC (% predicted) got lower (>80: 80.8%; 60-80: 63.3%; <60: 40%; P < 0.001). On multivariate logistic regression analysis, after adjusting for age, gender, transplant indication, and annual bronchoscopy findings, best FVC (% predicted) during the first year after LT was independently associated with 3-year survival.

CONCLUSIONS

A significant proportion of bilateral LT patients do not achieve FVC>80% predicted. Although the type of ventilatory defect on best spirometry does not predict survival, failure to achieve FVC>80% predicted during the first year was independently associated with 3-year mortality.

Assessment of Quality of Life Among Patients After Lung Transplantation: A Single-Center Study

INTRODUCTION

Lung transplantation (LTx) is the only effective method of treatment to improve the health and quality of life (QoL) of patients with end-stage lung diseases. After LTx, medical examination accompanied by quality of life assessment should be performed on routine follow-up visits. The aim of the study was to assess the QoL of patients after LTx.

MATERIAL AND METHODS

The study group consisted of 60 patients (29 women and 31 men); 20 patients received single lung transplantation (SLT), and 40 received double lung transplantation (DLT). To determine the patient's QoL, the General Health Questionnaire (GHQ), the World Health Organization Quality of Life Test-BREF (WHOQOL-BREF), and the Saint George Respiratory Questionnaire (SGRQ) were used. Spirometry and the 6-minute walk test were analyzed to examine efficiency of transplanted organs.

RESULTS

In SGRQ there are differences between patients with cystic fibrosis and interstitial lung disease in symptom domain (20.28% vs 39.26%, P = .025) and total score (19.38% vs 32.47%, P = .028). As reported in the GHQ, men had worse overall results than women in sten scale (5.22 points vs 4.69 points). Patients after SLT achieved similar scores in every questionnaire.

CONCLUSION

Studies assessing QoL should be an important addition to lung function tests and an integral part of control during postoperative follow-up visits. This study is one of the important contributions to understanding of how essential QoL is after LTx. The authors of this study realize that their work does not cover the whole issue, and further studies in this area are warranted.

Long-term pulmonary function testing in pediatric bronchiolitis obliterans syndrome after hematopoietic stem cell transplantation

RATIONALE

Bronchiolitis obliterans syndrome (BOS) is a severe, chronic inflammation of the airways leading to an obstruction of the bronchioles. So far, there are only a few studies looking at the long-term development of pulmonary impairment in children with BOS.

OBJECTIVE

The objective of this study was to investigate the incidence and long-term outcome of BOS in children who underwent allogeneic hematopoietic stem cell transplantation (HSCT).

METHODS

Medical charts of 526 children undergoing HSCT in Frankfurt/Main, Germany between 2000 and 2017 were analyzed retrospectively and as a result, 14 patients with BOS were identified. A total of 271 lung functions (spirometry and body plethysmography), 26 lung clearance indices (LCI), and 46 chest high-resolution computed tomography (HRCT) of these 14 patients with BOS were evaluated.

RESULTS

Fourteen patients suffered from BOS after HSCT (2.7%), whereby three distinctive patterns of lung function impairment were observed: three out of 14 patients showed a progressive lung function decline; two died and one received a lung transplant. In five out of 14 patients with BOS persisted with a severe obstructive and secondarily restrictive pattern in lung function (forced vital capacity [FVC] < 60%, forced expiratory volume in 1 second [FEV1] < 50%, and FEV1/FVC < 0.7) and increased LCI (11.67-20.9), six out of 14 patients recovered completely after moderate lung function impairment and signs of BOS on HRCT. Long-term FVC in absolute numbers was increased indicating that the children still have lung growth.

CONCLUSION

Our results showed that the incidence of BOS in children is low. BOS was associated with high mortality and may lead to persistent obstructive lung disease; although, lung growth continued to exist.

A phase IIb, randomised, parallel-group study: the efficacy, safety and tolerability of once-daily umeclidinium in patients with asthma receiving inhaled corticosteroids

BACKGROUND

Patients with asthma uncontrolled on inhaled corticosteroids may benefit from umeclidinium (UMEC), a long-acting muscarinic antagonist.

METHODS

This Phase IIb, double-blind study included patients with reversible, uncontrolled/partially-controlled asthma for ≥6 months, receiving ≥100 mcg/day fluticasone propionate (or equivalent) for ≥12 weeks. Following a 2-week run-in on open-label fluticasone furoate (FF) 100 mcg, patients were randomised (1:1:1) to receive UMEC 31.25 mcg, UMEC 62.5 mcg or placebo on top of FF 100 mcg once-daily for 24 weeks. As-needed salbutamol was provided. Primary and secondary endpoints were change from baseline in clinic trough forced expiratory volume in 1 s (FEV₁) and clinic FEV₁ 3 h post-dose, respectively, at Week 24. Other endpoints included change from baseline in home daily spirometry (trough FEV₁, evening FEV₁, morning [pre-dose] and evening peak expiratory flow) over 24 weeks. Safety was assessed throughout the study.

RESULTS

The intent-to-treat population comprised 421 patients (UMEC 31.25 mcg: n =139, UMEC 62.5 mcg: n =139, placebo: n =143). UMEC 31.25 mcg and 62.5 mcg demonstrated significantly greater improvements from baseline in clinic trough FEV₁ at Week 24 (difference [95% CI]: 0.176 L [0.092, 0.260; p<0.001] and 0.184 L [0.101, 0.268; p<0.001], respectively), clinic FEV₁ 3 h post-dose at Week 24 (0.190 L [0.100, 0.279; p<0.001] and 0.198 L [0.109, 0.287; p<0.001], respectively) and mean change from baseline in daily home spirometry over 24 weeks versus placebo. No new safety signals were identified.

CONCLUSIONS

UMEC is a highly effective bronchodilator that leads to improved lung function when administered as a single bronchodilator on top of FF in subjects with fully reversible, uncontrolled/partially-controlled moderate asthma. These data support a favourable benefit/risk profile for UMEC (31.25 mcg and 62.5 mcg).

TRIAL REGISTRATION

GSK study ID: 205832; Clinicaltrials.gov ID: NCT03012061.

Fibroproliferation in chronic lung allograft dysfunction: Association of mesenchymal cells in bronchoalveolar lavage with phenotypes and survival

BACKGROUND

Chronic lung allograft dysfunction (CLAD), the primary cause of poor outcome after lung transplantation, arises from fibrotic remodeling of the allograft and presents as diverse clinical phenotypes with variable courses. Here, we investigate whether bronchoalveolar lavage (BAL) mesenchymal cell activity at CLAD onset can inform regarding disease phenotype, progression, and survival.

METHODS

Mesenchymal cell colony-forming units (CFUs) were measured in BAL obtained at CLAD onset (n = 77) and CLAD-free time post-transplant matched controls (n = 77). CFU counts were compared using Wilcoxon's rank-sum test. Cox proportional hazards and restricted means models were utilized to investigate post-CLAD survival.

RESULTS

Higher mesenchymal CFU counts were noted in BAL at the time of CLAD onset than in CLAD-free controls. Patients with restrictive allograft syndrome had higher BAL mesenchymal CFU count at CLAD onset than patients with bronchiolitis obliterans syndrome (p = 0.011). Patients with high mesenchymal CFU counts (≥10) at CLAD onset had worse outcomes than those with low (<10) CFU counts, with shorter average survival (2.64 years vs 4.25 years; p = 0.027) and shorter progression-free survival, defined as time to developing either CLAD Stage 3 or death (0.97 years vs 2.70 years; p < 0.001). High CFU count remained predictive of decreased overall survival and progression-free survival after accounting for the CLAD phenotype and other clinical factors in multivariable analysis.

CONCLUSIONS

Fulminant fibroproliferation with higher mesenchymal CFU counts in BAL is noted in restrictive allograft syndrome and is independently associated with poor survival after CLAD onset.

An update on chronic lung allograft dysfunction

Chronic lung allograft dysfunction (CLAD) remains a significant challenge and the major determinant of morbidity and mortality post lung transplantation (LTx). The definition of CLAD has evolved significantly over the last ten years, reflecting better understanding of pathophysiology and different phenotypes. While there is an agreed consensus approach to CLAD, questions remain regarding the limitations of lung function parameters as well as the role of imaging and histopathology. Here we present a current snapshot of the definition of CLAD, its evolution and future directions.

Variation in Time to Peak Values for Different Lung Function Parameters After Double Lung Transplantation

BACKGROUND

Establishment of baseline values for forced expiratory volume in the first second (FEV₁), forced vital capacity (FVC), or total lung capacity (TLC) is required when diagnosing and phenotyping chronic lung allograft dysfunction after lung transplant. It is generally accepted that the baseline (peak) values of these parameters occur simultaneously, but this assumption has not been substantiated for TLC.

METHODS

All lung function measurements in all double lung transplant recipients from a single center in the period from 1992-2014 were included. Time to baseline FEV₁ was assessed according to standards from the International Society for Heart and Lung Transplantation, and time to peak FVC, TLC, and diffusion capacity for carbon monoxide were evaluated.

RESULTS

A total of 288 double lung transplants surviving more than 3 months after transplant were included. Baseline FEV₁ occurred at a median of 0.77 years post transplant and was statistically different from median times to the peak FVC (1.02 years), to peak TLC (1.37 years), and to peak diffusion capacity for carbon monoxide 1.04 years post transplant (all log-rank P < .001). At the time of baseline FEV1, FVC, and TLC were at a mean of 96% and 95% of their peak values, respectively.

CONCLUSION

The peak lung function is reached at different time points for different parameters post transplant with FEV₁ baseline occurring first. For most patients values of FVC and TLC obtained at time for baseline FEV₁ is a good estimate of peak values, but in a small percentage of patients this procedure may jeopardize phenotyping of chronic lung allograft dysfunction based solely on lung function parameters.

Pulmonary Type B Niemann-Pick Disease Successfully Treated with Lung Transplantation

Background

Niemann-Pick Disease (NPD) type B is a rare autosomal recessive disease characterised by hepatosplenomegaly and pulmonary disease, highlighted by preserved volumes and diminished diffusion capacity of the lung for carbon monoxide (DLCO) on pulmonary function tests (PFTs). There is no current accepted treatment for the disease. We present a case of a successful bilateral lung transplant in a patient with a DLCO of 14%, and significant pulmonary changes attributable to NPD type B on computed tomography (CT) chest, and both microscopic and macroscopic assessment of the lung explant. To the author's knowledge this is only the third case of lung transplantation in a patient with NPD type B and is one of two current living patients post lung transplantation for NPD type B.

Case Report

A 64-year-old male patient underwent bilateral lung transplantation for NPD type B. Preoperative PFTs demonstrated preserved volumes with significantly decreased DLCO, with imaging showing a diffuse reticular interstitial pattern, typical of chronic fibrotic lung disease. The patient suffered from primary graft dysfunction type 3 in the postoperative period as well as rejection managed with methylprednisolone and intravenous immunoglobulin. The patient improved steadily and was discharged 80 days post-transplantation.

Conclusions

This case is only the third reported case of lung transplantation in a patient with NPD type B and the second case of a patient with NPD type B currently living post-transplantation, being at postoperative day (POD) 267 at the time of manuscript drafting. It demonstrates that lung transplantation, although hazardous, is a viable strategy for treatment in patients with NPD type B who have significant pulmonary involvement.

Evolution of Functional Exercise Capacity in Lung Transplant Patients With and Without Bronchiolitis Obliterans Syndrome: A Longitudinal Case-Control Study

INTRODUCTION

Bronchiolitis Obliterans Syndrome (BOS) is a debilitating disease with limited treatment options that threatens both the quality of life and long-term survival of lung transplant (LTx) recipients. This retrospective longitudinal case-control study was performed to compare the long-term functional evolution of LTx recipients with and without BOS.

METHODS

Twenty-four LTx recipients with BOS (BOS=Cases) and 24 without BOS (NON-BOS=Controls) were selected and individually matched according to age, gender, diagnosis and LTx characteristics. Measurements of 6-minute walking distance (6MWD), symptoms of dyspnea (BORG CR-10 scale), and comprehensive pulmonary function testing were performed before LTx and at annual follow-up assessments after LTx.

RESULTS

Peak FEV₁ after LTx was similar in both groups [FEV₁ (% predicted) 101±25 vs. 101±31, p=0.96] and BOS diagnosis in cases was established 3.6±2.5 years after LTx. At the final follow-up assessment (6.5±3.2 years after LTx) FEV₁ (% predicted) was 86±34 in NON-BOS vs. 44±17 in BOS (p<0.001). Evolution of 6MWD was different between groups (group by time interaction: p=0.002). Borg dyspnea scores were also significantly different between groups at the final evaluation (NON-BOS 3.3±1.7 vs. BOS 5.0±2.2; p=0.024).

CONCLUSIONS

We observed gradual reductions in functional exercise capacity and increasing symptoms of dyspnea in patients who developed BOS after LTx. As such, prospective studies seem warranted to explore whether rehabilitative interventions might be useful to improve symptoms and slow down deterioration of exercise capacity in these patients from the onset of BOS.

Prognostic significance of early pulmonary function changes after onset of chronic lung allograft dysfunction

BACKGROUND

Chronic lung allograft dysfunction (CLAD), including the phenotypes of bronchiolitis obliterans syndrome (BOS) and restrictive CLAD (R-CLAD), represents the leading cause of late death after lung transplantation. Little is known, however, regarding the natural history or prognostic significance of pulmonary function changes after the onset of these conditions. We examined changes in forced expiratory volume in 1 second (FEV₁) and forced vital capacity (FVC) over the first 18 months after CLAD. We also sought to determine whether lung function changes occurring early after CLAD impact longer term outcomes.

METHODS

We performed a retrospective analysis of 216 bilateral lung recipients with CLAD, which included those with R-CLAD (n = 65) or BOS (n = 151). The course of FEV₁ and FVC after CLAD was described. Cox proportional hazards models were used to evaluate the impact of a ≥10% decline in FEV₁ or FVC within the first 6 months of CLAD on graft loss after that time.

RESULTS

Lung recipients with CLAD, whether BOS or R-CLAD, had the largest decreases in FEV₁ and FVC within the first 6 months after onset. Moreover, a decline in FEV₁ or FVC of ≥10% within the first 6 months after CLAD was associated with a significantly increased hazard for graft loss after that time (hazard ratio [HR] = 3.17, 95% confidence interval [CI] 1.56 to 6.42, p = 0.001, and HR = 2.80, 95% CI 1.66 to 4.70, p ≤ 0.001, respectively), an effect observed in both BOS and R-CLAD patients.

CONCLUSIONS

Early physiologic changes after CLAD were independently associated with graft loss. This suggests lung function changes after CLAD, specifically a ≥10% decline in FEV₁ or FVC, could be a surrogate measure of graft survival.

Multiple breath washout in pediatric patients after lung transplantation

Forced expiratory volume in 1 second (FEV₁ ) from spirometry is the most commonly used parameter to detect early allograft dysfunction after lung transplantation (LTx). There are concerns regarding its sensitivity. Nitrogen-multiple breath washout (N₂ -MBW) is sensitive at detecting early global (lung clearance index [LCI]) and acinar (S_acin ) airway inhomogeneity. We investigated whether N₂ -MBW indices indicate small airways pathology after LTx in children with stable spirometry. Thirty-seven children without bronchiolitis obliterans syndrome [BOS] at a median of 1.6 (0.6-3.0) years after LTx underwent N₂ -MBW and spirometry, 28 of those on 2 occasions (≤6 months apart) during clinically stable periods. Additional longitudinal data (11 and 8 measurements, respectively) are provided from 2 patients with BOS. In patients without BOS, LCI and S_acin were significantly elevated compared with healthy controls. LCI was abnormal at the 2 test occasions in 81% and 71% of patients, respectively, compared with 30% and 39% of patients with abnormal FEV₁ /forced vital capacity (FVC). Correlations of LCI with FEV₁ /FVC (r = 0.1, P = .4) and FEV₁ (r = -0.1, P = .6) were poor. N₂ -MBW represents a sensitive and reproducible tool for the early detection of airways pathology in stable transplant recipients. Moreover, indices were highly elevated in both patients with BOS. Spirometry and LCI showed poor correlation, indicating distinct and complementary physiologic measures.

Lung Function Trajectory in Bronchiolitis Obliterans Syndrome after Allogeneic Hematopoietic Cell Transplant

RATIONALE

The natural history of lung function in patients with bronchiolitis obliterans syndrome (BOS) after allogeneic hematopoietic cell transplant is poorly characterized. Understanding the trajectory of lung function is necessary for prompt clinical recognition and treatment and also for the rational design of prospective studies.

OBJECTIVES

To describe the longitudinal trajectory of lung function parameters, including FEV₁, in patients with BOS after hematopoietic cell transplant.

METHODS

Subjects with BOS defined by National Institutes of Health consensus guidelines criteria from a recent multicenter prospective trial of combination treatment with fluticasone, azithromycin and montelukast and a retrospective cohort from Fred Hutchinson Cancer Research Center were included. Longitudinal change in FEV₁ for each patient was calculated on the basis of available pulmonary function tests in three periods: pre-BOS, from BOS diagnosis to 6 months, and 6-18 months after diagnosis. The effect of treatment on FEV₁ trajectory was analyzed by univariate and multivariate linear regression. The Kaplan-Meier method was used to estimate survival.

MEASUREMENTS AND MAIN RESULTS

The FEV₁ percent predicted value at diagnosis was 46% (interquartile range, 35-57%) for trial participants and 53% (interquartile range, 41-64%) for the retrospective cohort. There was a concomitant mild reduction in FVC, as well as a marked reduction in forced expiratory flow, midexpiratory phase, at diagnosis. While there was individual heterogeneity, the overall FEV₁ trajectory was characterized by a marked decline within 6 months prior to BOS diagnosis, followed by stability of FEV₁ early after diagnosis and a slow rate of decline beyond 6 months. The effect of the trial medications on FEV₁ trajectory after BOS diagnosis was a mean rate of change of 0.92% predicted per month (95% confidence interval, -0.53 to 2.37) compared with the retrospective cohort, but this was not statistically significant. Two-year overall survival rates were 76% and 72% for the study participants and the retrospective cohort patients, respectively. Earlier time to diagnosis after hematopoietic cell transplant and severity of FVC at diagnosis were significantly associated with reduced survival.

CONCLUSIONS

The FEV₁ trajectory in patients with BOS after hematopoietic cell transplant in a contemporary era of management follows a predominant pattern of rapid FEV₁ decline in the 6 months prior to diagnosis, followed by FEV₁ stabilization after diagnosis.

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.

Parametric Response Mapping as an Imaging Biomarker in Lung Transplant Recipients

RATIONALE

The predominant cause of chronic lung allograft failure is small airway obstruction arising from bronchiolitis obliterans. However, clinical methodologies for evaluating presence and degree of small airway disease are lacking.

OBJECTIVES

To determine if parametric response mapping (PRM), a novel computed tomography voxel-wise methodology, can offer insight into chronic allograft failure phenotypes and provide prognostic information following spirometric decline.

METHODS

PRM-based computed tomography metrics quantifying functional small airways disease (PRM^fSAD) and parenchymal disease (PRM^PD) were compared between bilateral lung transplant recipients with irreversible spirometric decline and control subjects matched by time post-transplant (n = 22). PRM^fSAD at spirometric decline was evaluated as a prognostic marker for mortality in a cohort study via multivariable restricted mean models (n = 52).

MEASUREMENTS AND MAIN RESULTS

Patients presenting with an isolated decline in FEV₁ (FEV₁ First) had significantly higher PRM^fSAD than control subjects (28% vs. 15%; P = 0.005), whereas patients with concurrent decline in FEV₁ and FVC had significantly higher PRM^PD than control subjects (39% vs. 20%; P = 0.02). Over 8.3 years of follow-up, FEV₁ First patients with PRM^fSAD greater than or equal to 30% at spirometric decline lived on average 2.6 years less than those with PRM^fSAD less than 30% (P = 0.004). In this group, PRM^fSAD greater than or equal to 30% was the strongest predictor of survival in a multivariable model including bronchiolitis obliterans syndrome grade and baseline FEV_1% predicted (P = 0.04).

CONCLUSIONS

PRM is a novel imaging tool for lung transplant recipients presenting with spirometric decline. Quantifying underlying small airway obstruction via PRM^fSAD helps further stratify the risk of death in patients with diverse spirometric decline patterns.

Lung volumes predict survival in patients with chronic lung allograft dysfunction

Identification of disease phenotypes might improve the understanding of patients with chronic lung allograft dysfunction (CLAD). The aim of the study was to assess the impact of pulmonary restriction and air trapping by lung volume measurements at the onset of CLAD.

A total of 396 bilateral lung transplant recipients were analysed. At onset, CLAD was further categorised based on plethysmography. A restrictive CLAD (R-CLAD) was defined as a loss of total lung capacity from baseline. CLAD with air trapping (AT-CLAD) was defined as an increased ratio of residual volume to total lung capacity. Outcome was survival after CLAD onset. Patients with insufficient clinical information were excluded (n=95).

Of 301 lung transplant recipients, 94 (31.2%) developed CLAD. Patients with R-CLAD (n=20) and AT-CLAD (n=21), respectively, had a significantly worse survival (p<0.001) than patients with non-R/AT-CLAD. Both R-CLAD and AT-CLAD were associated with increased mortality when controlling for multiple confounding variables (hazard ratio (HR) 3.57, 95% CI 1.39–9.18; p=0.008; and HR 2.65, 95% CI 1.05–6.68; p=0.039). Furthermore, measurement of lung volumes was useful to identify patients with combined phenotypes.

Measurement of lung volumes in the long-term follow-up of lung transplant recipients allows the identification of patients who are at risk for worse outcome and warrant special consideration.

Comparison of extracorporeal photopheresis and alemtuzumab for the treatment of chronic lung allograft dysfunction

BACKGROUND

Survival after lung transplantation is limited by chronic lung allograft dysfunction (CLAD). Immunomodulatory therapies such as extracorporeal photopheresis (ECP) and alemtuzumab (AL) have been described for refractory CLAD, but comparative outcomes are not well defined.

METHODS

We retrospectively reviewed spirometric values and clinical outcomes after therapy with ECP, AL, or no treatment (NT) in patients with CLAD who underwent transplant between January 2005 and December 2014. We used inverse probability-weighted regression adjustment (IPWRA) to adjust for potential confounders affecting treatment choice.

RESULTS

Of 267 patients, 31 received immunomodulatory therapies for CLAD, and 78 received NT. The slope of forced expiratory volume in 1 second (FEV₁) decline significantly improved after treatment with AL and with ECP compared with pre-treatment FEV₁ slope; however, there was no significant change in slope of forced vital capacity (FVC). Comparison with NT was limited because of clinical differences in treatment groups. After IPWRA, we found no significant difference in mean difference of FEV₁ slope (ml/month) when comparing treatment with NT, suggesting stabilization of lung function in the treatment group. We found no difference between the 2 immunomodulatory therapies 1, 3, and 6 months post-treatment (-49.9 [95% CI -581.8, +482.0], p = 0.85; +27.7 [95% CI -167.6, +223.0], p = 0.78; -9.6 [95% CI -167.5, +148.2], p = 0.91). We found no difference in mean FVC slope or differences between ECP and AL in infection rates or survival after treatment.

CONCLUSIONS

Immunomodulatory therapy for CLAD with ECP or AL was associated with a significant change in FEV₁ slope post-treatment compared with pre-treatment slope, with minimal effect on FVC. There was no difference between the 2 therapies in their effect on pulmonary function.

Phenotyping Chronic Lung Allograft Dysfunction Using Body Plethysmography and Computed Tomography

Restrictive subtype of chronic lung allograft dysfunction (CLAD) was recently described after lung transplantation. This study compares different definitions of a restrictive phenotype in CLAD patients and impact on survival. Eighty-nine CLAD patients out of 1191 screened patients (September 1987 to July 2012) were included as complete longitudinal lung volume measurements and chest computed tomography (CT) after CLAD onset was available. CT findings and lung volumes were quantified and survival was calculated for distinctive groups and predictive factors for worse survival were investigated. Graft survival in patients with total lung capacity (TLC) between 90% and 81% of baseline (BL) (n = 13, 15%) in CLAD course was similar to those with TLC >90% BL (n = 64, 56%; log-rank test p = 0.9). Twelve patients (13%) developed a TLC ≤80% BL and 10 (11%) had significant parenchymal changes on CT, of whom 6 (46%) also had TLC ≤80% BL. CT changes correlated with TLC ≤80% BL (Φ-coefficient = 0.48, p = 0.001). Patients with either TLC ≤80% or significant CT changes (n = 16, 18%) had a significantly reduced survival (log-rank p < 0.001). Forced vital capacity loss at CLAD onset was associated with poorer survival but did not correlate with the TLC or CT changes. A restrictive subtype of CLAD may be defined by either TLC ≤80% BL or severe parenchymal changes on chest CT.

Daily Home Spirometry: An Effective Tool for Detecting Progression in Idiopathic Pulmonary Fibrosis

RATIONALE

Recent clinical trial successes have created an urgent need for earlier and more sensitive endpoints of disease progression in idiopathic pulmonary fibrosis (IPF). Domiciliary spirometry permits more frequent measurement of FVC than does hospital-based assessment, which therefore affords the opportunity for a more granular insight into changes in IPF progression.

OBJECTIVES

To determine the feasibility and reliability of measuring daily FVC in individuals with IPF.

METHODS

Subjects with IPF were given handheld spirometers and instruction on how to self-administer spirometry. Subjects recorded daily FEV1 and FVC for up to 490 days. Clinical assessment and hospital-based spirometry was undertaken at 6 and 12 months, and outcome data were collected for 3 years.

MEASUREMENTS AND MAIN RESULTS

Daily spirometry was recorded by 50 subjects for a median period of 279 days (range, 13-490 d). There were 18 deaths during the active study period. Home spirometry showed excellent correlation with hospital-obtained readings. The rate of decline in FVC was highly predictive of outcome and subsequent mortality when measured at 3 months (hazard ratio [HR], 1.040; 95% confidence interval [CI], 1.021-1.062; P ≤ 0.001), 6 months (HR, 1.024; 95% CI, 1.014-1.033; P < 0.001), and 12 months (HR, 1.012; 95% CI, 1.007-1.016; P = 0.001).

CONCLUSIONS

Measurement of daily home spirometry in patients with IPF is highly clinically informative and is feasible to perform for most of these patients. The relationship between mortality and rate of change of FVC at 3 months suggests that daily FVC may be of value as a primary endpoint in short proof-of-concept IPF studies.

Comprehensive Care of the Lung Transplant Patient

Lung transplantation has evolved into a life-saving treatment with improved quality of life for patients with end-stage respiratory failure unresponsive to other medical or surgical interventions. With improving survival rates, the number of lung transplant recipients with preexisting and posttransplant comorbidities that require attention continues to increase. A partnership between transplant and nontransplant care providers is necessary to deliver comprehensive and optimal care for transplant candidates and recipients. The goals of this partnership include timely referral and assistance with transplant evaluation, optimization of comorbidities and preparation for transplantation, management of common posttransplant medical comorbidities, immunization, screening for malignancy, and counseling for a healthy lifestyle to maximize the likelihood of a good outcome. We aim to provide an outline of the main aspects of the care of candidates for and recipients of lung transplants for nontransplant physicians and other care providers.

Predictors of survival in restrictive chronic lung allograft dysfunction after lung transplantation

BACKGROUND

Chronic lung allograft dysfunction (CLAD) is the main factor limiting long-term survival after lung transplantation. Besides bronchiolitis obliterans syndrome, a restrictive phenotype of CLAD (rCLAD) exists, which is associated with poor prognosis after diagnosis. However, survival determinants for rCLAD remain to be elucidated. Our aim in this study was to establish parameters predicting survival in patients with rCLAD.

METHODS

All patients diagnosed with rCLAD in 2 lung transplant centers were assessed in a retrospective manner. Various clinical parameters [demography, pulmonary function, bronchoalveolar lavage (BAL), histopathology, radiology and blood differentials] at rCLAD diagnosis were correlated with graft survival using unadjusted and adjusted analysis.

RESULTS

A total of 53 patients with rCLAD were included with a median graft survival after diagnosis of 1.1 years. Univariate analysis demonstrated that lower-lobe-dominant or diffuse infiltrates on chest computed tomography, presence of an identifiable trigger before rCLAD onset, lymphocytic bronchiolitis, increased BAL neutrophilia, increased BAL eosinophilia and increased blood eosinophils were associated with inferior graft survival after rCLAD diagnosis. Multivariate analysis confirmed the association of location of infiltrates and blood eosinophilia on graft survival.

CONCLUSION

In this study we have identified parameters associated with graft survival after rCLAD diagnosis that may be useful to predict prognosis.

Chronic lung allograft dysfunction: evolving practice

PURPOSE OF REVIEW

Chronic lung allograft dysfunction (CLAD) was recently introduced as an overarching term covering different phenotypes of chronic allograft dysfunction, including obstructive CLAD (bronchiolitis obliterans syndrome), restrictive CLAD (restrictive allograft syndrome) and graft dysfunction due to causes not related to chronic rejection. In the present review, we will highlight the latest insights and current controversies regarding the new CLAD terminology, underlying pathophysiologic mechanisms, diagnostic approach and possible treatment options.

RECENT FINDINGS

Different pathophysiological mechanisms are clearly involved in clinically distinct phenotypes of chronic rejection, as is reflected by differences in histology, allograft function and imaging. Therefore, not all CLAD patients may equally benefit from specific therapies.

SUMMARY

The recent introduction of CLAD importantly changed the clinical practice in lung transplant recipients. Given the relative low accuracy of the current diagnostic tools, future research should focus on specific biomarkers, more sensitive pulmonary function parameters and imaging techniques for timely CLAD diagnosis and phenotyping. Personalized or targeted therapeutic options for adequate prevention and treatment of CLAD are required.