Human Serum Albumin Misfolding in Aging and Disease

Age-dependent conformational stability of human serum albumin was determined by the method of fluorescent bilayer liposome assay. After pre-heating at 80 °C, albumin in the sera of 74-year-old healthy subjects exhibited hydrophobic effects on liposomes and made liposomal membrane phospholipids more susceptible to hydrolysis by the lipolytic enzyme phospholipase A2. In contrast, albumin in the sera of 24-year-old individuals was stable at 80 °C and displayed no increased hydrophobic effects on liposomes. The results suggest that albumin in the sera of 74-year-old subjects is more easily converted to a misfolded form in which its protein structure is altered when compared to albumin in the sera of 24-year-old individuals. Misfolded albumin can lose its ability to carry out its normal homeostatic functions and may promote alterations in membrane integrity under inflammatory conditions. However, our investigation has limitations that include the lack of testing sera from large numbers of individuals across a broad range of age to validate our preliminary observations of age-dependent differences in albumin stability and its interactions with liposomes.

Long-term evaluation of the safety and efficacy of recombinant human pentraxin-2 (rhPTX-2) in patients with idiopathic pulmonary fibrosis (IPF): an open-label extension study

Background

Recombinant human pentraxin-2 (rhPTX-2) significantly decreased decline in percent predicted forced vital capacity (FVC) and stabilized 6-min walk distance (6MWD) in patients with idiopathic pulmonary fibrosis (IPF) during the 28-week, placebo-controlled, randomized period of the Phase II PRM-151–202 study. Interim (76-week) data from the open-label extension (OLE) demonstrated sustained safety and efficacy with rhPTX-2 treatment. Here, we present the entire long-term OLE safety and efficacy data to 128 weeks.

Methods

Patients who completed the randomized PRM-151–202 study period were eligible for the OLE, during which all patients received rhPTX-2, having started rhPTX-2 (i.e., crossed from placebo) or continued rhPTX-2 after Week 28. rhPTX-2 was administered in 28-week cycles, with 10 mg/kg intravenous infusions (60 min) on Days 1, 3, and 5 in the first week of each cycle, then one infusion every 4 weeks up to Week 128. The OLE primary objective was to assess the long-term safety and tolerability of rhPTX-2. Other outcomes included FVC, 6MWD, and patient-reported outcomes (descriptive analysis).

Results

All 111 patients who completed the randomized period entered the OLE (n = 37 started rhPTX-2; n = 74 continued rhPTX-2); 57 (51.4%) completed to Week 128. The treatment-emergent adverse event (TEAE) profile was consistent with the randomized period, with the majority of TEAEs graded mild or moderate. Serious TEAEs occurred in 47 patients (42.3%), most frequently IPF (n = 11; 9.9%), pneumonia (n = 7; 6.3%), and acute respiratory failure (n = 3; 2.7%). Three patients underwent lung transplantation. Most serious TEAEs (and all 14 fatal events) were considered unrelated to rhPTX-2 treatment. For patients starting vs continuing rhPTX-2, mean (95% confidence interval) changes from baseline to Week 128 were, respectively, − 6.2% (− 7.7; − 4.6) and − 5.7% (− 8.0; − 3.3) for percent predicted FVC and − 36.3 m (− 65.8; − 6.9) and − 28.9 m (− 54.3; − 3.6) for 6MWD; however, conclusions were limited by patient numbers at Week 128.

Conclusions

Long-term treatment (up to 128 weeks) with rhPTX-2 was well tolerated in patients with IPF, with no new safety signals emerging in the OLE. The limited efficacy data over 128 weeks may suggest a trend towards a treatment effect.

Trial registration NCT02550873; EudraCT 2014-004782-24.

Cryptogenic organising pneumonia: current understanding of an enigmatic lung disease

Organising pneumonia (OP) is currently recognised as a nonspecific lung injury response that is associated with a variety of imaging patterns obtained with high-resolution computed tomography (HRCT) of the chest and is characterised histopathologically by the presence of inflammatory cells and a connective tissue matrix within distal airspaces of the lungs. OP is associated with many conditions that include connective tissue disorders, various infections, drug reactions, hypersensitivity pneumonitis and aspiration. When OP cannot be linked to an associated condition and appears to be idiopathic, it is termed cryptogenic organising pneumonia.

ISHLT consensus document on lung transplantation in patients with connective tissue disease: Part I: Epidemiology, assessment of extrapulmonary conditions, candidate evaluation, selection criteria, and pathology statements

Patients with connective tissue disease (CTD) and advanced lung disease are often considered suboptimal candidates for lung transplantation (LTx) due to their underlying medical complexity and potential surgical risk. There is substantial variability across LTx centers regarding the evaluation and listing of these patients. The International Society for Heart and Lung Transplantation-supported consensus document on lung transplantation in patients with CTD standardization aims to clarify definitions of each disease state included under the term CTD, to describe the extrapulmonary manifestations of each disease requiring consideration before transplantation, and to outline the absolute contraindications to transplantation allowing risk stratification during the evaluation and selection of candidates for LTx.

Optimizing virus protection in lung transplant recipients: Don't drop the ball

Meyer and Avery comment on the implications of a study by Hostetler et al. (page 2864), in which screening of a large group of lung transplant candidates revealed that some lacked humoral immunity to measles, mumps, and varicella, especially younger patients and those with cystic fibrosis.

Treatment of primary sjögren's syndrome-related interstitial lung disease: a retrospective cohort study

Background:

Interstitial lung disease (ILD) is a common complication of primary Sjögren’s syndrome (pSS). Because there is a paucity of literature on the management of pSS-associated ILD (pSS-ILD), this retrospective cohort study assessed the efficacy of azathioprine and mycophenolate therapy in adult patients with pSS-ILD.

Methods:

A retrospective cohort study was performed using electronic health records to identify adults meeting the 2016 American College of Rheumatology/European League Against Rheumatism classification criteria for pSS. The presence of pSS-ILD was confirmed by characteristic high-resolution computed tomography and/or histopathology findings. Sociodemographic, clinical, and pulmonary function test (PFT) data were abstracted for patients meeting the criteria and followed longitudinally from the date of their ILD diagnosis. PFT values were anchored on time of treatment start, and linear mixed-effects modeling was used to analyze changes in diffusion capacity for carbon monoxide (DLCO) and forced vital capacity (FVC) before and after treatment initiation.

Results:

We identified 19 subjects who had pSS-ILD, of whom seven were treated with azathioprine and seven were treated with mycophenolate. Within the azathioprine treated group, FVC% slope change trended toward improvement from a rate of -9.8% per month pre-treatment to 2.1% per month post-treatment (p = 0.13). Within the mycophenolate treated group, FVC% slope change improved from a rate of 1.5% per month pre-treatment to 4.3% per month post-treatment (p = 0.02) and DLCO% slope changed from a rate of -3.8% to –1.3% per month (p = 0.01) after therapy start.

Conclusions:

Mycophenolate treatment was associated with significant improvement in PFTs of pSS-ILD patients over time, and azathioprine treatment followed a similar non-significanttrend. Additional prospective studies are needed to further evaluate these findings. (Sarcoidosis Vasc Diffuse Lung Dis 2020; 37 (2): 136-147)

Aging-Related and Gender Specific Albumin Misfolding in Alzheimer's Disease

Aging-related protein misfolding and aggregation may play critical roles in the pathogenesis of numerous diseases. In the brain, extracellular aggregated amyloid-β (Aβ) is closely related to the death of neurons in individuals with Alzheimer’s disease (AD). Albumin-Aβ binding is important in preventing Aβ fibril aggregation. However, because albumin is the most abundant and important antioxidant in the circulation, aging-related oxidative stress could have a significant effect on the molecular conformation and binding capacities of albumin. To investigate the link between misfolded albumin and AD, we developed fluorescent assays to determine the effects of misfolded albumin on membrane integrity in the presence of a lipolytic, inflammatory response-like enzyme, secretory phospholipase A2 (sPLA2). We found that misfolded albumin increased degradation of phospholipids in highly fluid bilayer membranes in the presence of sPLA2 due to hydrophobic effects of misfolded albumin. High amounts of misfolded albumin were present in sera of elderly (average 74 years) versus young (average 24 years) subjects (p < 0.0001). Albumin in cerebrospinal fluid (CSF) of elderly subjects, though present in small concentrations, had a 2- to 3-fold increased capacity to promote sPLA2-catalyzed membrane phospholipid degradation as compared with the same amount of albumin in serum (p < 0.0001). In addition, the fatty acid binding capacity of albumin in CSF from female subjects was considerably lower than values obtained for men, especially for individuals diagnosed with AD (p = 0.0006). This study suggests that inflammation, misfolded albumin and/or other dysfunctional proteins, and changes in membrane fluidity could alter cell membrane integrity and homeostasis and contribute to the pathogenesis of aging-related dementia and AD.

Lung transplantation for pulmonary sarcoidosis

Although relatively few patients with pulmonary sarcoidosis develop advanced disease that progresses to respiratory insufficiency despite receiving best practice pharmacologic interventions, lung transplantation may be the only therapeutic option for such patients to both prolong survival and provide improved quality of life. Lung transplant can be successfully performed for patients with end-stage pulmonary sarcoidosis, and post-transplant survival is similar to that for other transplant indications such as idiopathic pulmonary fibrosis. However, appropriate timing of referral, comprehensive assessment of potential candidates for lung transplant, placement of patients on the lung transplant waiting list when within the transplant window as appropriate, choosing the best procedure (bilateral versus single lung transplant), and optimal peri-operative and post-transplant management are key to successful lung transplant outcomes for patients with sarcoidosis.

Specific Donor HLA-DR Types Correlate With Altered Susceptibility to Development of Chronic Lung Allograft Dysfunction

BACKGROUND

The greatest challenge to long-term graft survival is the development of chronic lung allograft dysfunction. Th17 responses to collagen type V (colV) predispose lung transplant patients to the severe obstructive form of chronic lung allograft dysfunction, known as bronchiolitis obliterans syndrome (BOS). In a previous study cohort (n = 54), pretransplant colV responses were increased in recipients expressing HLA-DR15, consistent with the high binding avidity of colV (α1) peptides for HLA-DR15, whereas BOS incidence, which was known to be strongly associated with posttransplant autoimmunity to colV, was higher in patients who themselves lacked HLA-DR15, but whose lung donor expressed it.

METHODS

To determine if this DR-restricted effect on BOS incidence could be validated in a larger cohort, we performed a retrospective analysis of outcomes for 351 lung transplant recipients transplanted between 1988 and 2008 at the University of Wisconsin. All subjects were followed until graft loss, death, loss to follow-up, or through 2014, with an average follow-up of 7 years. Comparisons were made between recipients who did or did not develop BOS. Grading of BOS followed the recommendations of the international society for heart and lung transplantation.

RESULTS

Donor HLA-DR15 was indeed associated with increased susceptibility to severe BOS in this population. We also discovered that HLA-DR7 expression by the donor or HLA-DR17 expression by the recipient decreased susceptibility.

CONCLUSIONS

We show in this retrospective study that specific donor HLA class II types are important in lung transplantation, because they are associated with either protection from or susceptibility to development of severe BOS.

Mycophenolate therapy in interstitial pneumonia with autoimmune features: a cohort study

Objectives

International experts recently characterized interstitial pneumonia with autoimmune features (IPAF) as a provisional diagnosis for patients with interstitial lung disease who have characteristics of autoimmune disease but do not meet criteria for a specific autoimmune disease. We describe clinical characteristics of IPAF patients and examine responses to mycophenolate as a therapy for IPAF.

Methods

This retrospective cohort included adult patients meeting European Respiratory Society/American Thoracic Society classification criteria for IPAF. Sociodemographic, clinical, and pulmonary function test data were abstracted for patients with and without mycophenolate treatment and followed longitudinally from interstitial lung disease diagnosis for change in pulmonary function test results.

Results

We identified 52 patients who met criteria for IPAF. Of 52 IPAF patients, 24 did not receive mycophenolate and 28 did, with median time to mycophenolate treatment 22 months. Changes in FVC% and percentage predicted lung diffusion capacity for carbon monoxide (D_LCO%) between the mycophenolate-treated and untreated groups were not significantly different (FVC% change P=0.08, D_LCO% change P=0.17). However, there was a trend toward more rapid baseline decline of both FVC% and D_LCO% in the mycophenolate-treated cohort before vs after mycophenolate therapy. The slope of both FVC% and D_LCO% values improved after onset of mycophenolate exposure for the treated group, although this finding was not statistically significant.

Conclusion

Patients with IPAF might benefit from mycophenolate therapy. Larger prospective clinical trials are needed to evaluate the efficacy of mycophenolate for patients who meet criteria for IPAF.

Recent advances in lung transplantation

Lung transplantation can improve quality of life and prolong survival for individuals with end-stage lung disease, and many advances in the realms of both basic science and clinical research aspects of lung transplantation have emerged over the past few decades. However, many challenges must yet be overcome to increase post-transplant survival. These include successfully bridging patients to transplant, expanding the lung donor pool, inducing tolerance, and preventing a myriad of post-transplant complications that include primary graft dysfunction, forms of cellular and antibody-mediated rejection, chronic lung allograft dysfunction, and infections. The goal of this manuscript is to review salient recent and evolving advances in the field of lung transplantation.

Lung disease associated with occupational styrene exposure

Despite reports of pulmonary toxicity due to styrene, guidelines on acceptable styrene exposure levels have been based on risk of cancer and central nervous system and liver toxicity and not on respiratory effects. Many reports have linked exposure to styrene vapor in occupational settings to various forms of non-malignant pulmonary disorders including bronchiolitis, hypersensitivity pneumonitis, and occupational asthma. We report two cases in which the same tasks performed in a single workplace resulted in exposure to styrene vapor with subsequent development of acute respiratory symptoms associated with impaired gas exchange and imaging and histopathologic findings consistent with bronchiolitis and organizing pneumonia. Both patients gradually recovered once their workplace exposure to styrene was terminated. Clinicians, employers, and insurers should be aware of the potential for pulmonary toxicity from exposure to styrene.

Effect of Recombinant Human Pentraxin 2 vs Placebo on Change in Forced Vital Capacity in Patients With Idiopathic Pulmonary Fibrosis: A Randomized Clinical Trial

IMPORTANCE

Idiopathic pulmonary fibrosis (IPF) is a progressive fibrotic lung disease with poor prognosis. Approved therapies do not halt disease progression.

OBJECTIVE

To determine the effect of recombinant human pentraxin 2 vs placebo on change from baseline to week 28 in mean forced vital capacity (FVC) percentage of predicted value.

DESIGN, SETTING, AND PARTICIPANTS

Phase 2, randomized, double-blind, placebo-controlled trial conducted at 18 sites in 7 countries of eligible patients with IPF (N = 117; aged 40-80 years; FVC ≥50% and ≤90% predicted; ratio of forced expiratory volume in the first second/FVC >0.70; diffusing capacity for carbon monoxide [Dlco] ≥25% and ≤90% predicted; and distance of ≥150 m on the 6-minute walk test). Study period was August 2015-May 2017.

INTERVENTIONS

Patients were randomized to receive either recombinant human pentraxin 2 (10 mg/kg intravenous every 4 weeks, n = 77) or placebo (n = 39) for 24 weeks, and stratified by concurrent IPF treatment status.

MAIN OUTCOMES AND MEASURES

The primary end point was the least-squares mean change in FVC percentage of predicted value from baseline to week 28 (minimal clinically important difference, decline of 2%-6%). Secondary end points included mean change in lung volumes (total, normal, and interstitial lung abnormalities) on high-resolution computed tomography (HRCT) and 6-minute walk distance (minimal clinically important difference, 24-45 m).

RESULTS

Of 117 randomized patients, 116 received at least 1 dose of study drug (mean age, 68.6 years; 81.0% men; mean time since IPF diagnosis, 3.8 years), and 111 (95.7%) completed the study. The least-squares mean change in FVC percentage of predicted value from baseline to week 28 in patients treated with recombinant human pentraxin 2 was -2.5 vs -4.8 for those in the placebo group (difference, +2.3 [90% CI, 1.1 to 3.5]; P = .001). No significant treatment differences were observed in total lung volume (difference, 93.5 mL [90% CI, -27.7 to 214.7]), quantitative parenchymal features on HRCT (normal lung volume difference, -1.2% [90% CI, -4.4 to 1.9]; interstitial lung abnormalities difference, 1.1% [90% CI, -2.2 to 4.3]), or measurement of Dlco (difference, -0.4 [90% CI, -2.6 to 1.7]). The change in 6-minute walk distance was -0.5 m for patients treated with recombinant human pentraxin 2 vs -31.8 m for those in the placebo group (difference, +31.3 m [90% CI, 17.4 to 45.1]; P < .001). The most common adverse events in the recombinant human pentraxin 2 vs placebo group were cough (18% vs 5%), fatigue (17% vs 10%), and nasopharyngitis (16% vs 23%).

CONCLUSIONS AND RELEVANCE

In this preliminary study, recombinant human pentraxin 2 vs placebo resulted in a slower decline in lung function over 28 weeks for patients with idiopathic pulmonary fibrosis. Further research should more fully assess efficacy and safety.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT02550873.

Peripheral Blood Gene Expression Changes Associated With Primary Graft Dysfunction After Lung Transplantation

Recipient responses to primary graft dysfunction (PGD) after lung transplantation may have important implications to the fate of the allograft. We therefore evaluated longitudinal differences in peripheral blood gene expression in subjects with PGD. RNA expression was measured throughout the first transplant year in 106 subjects enrolled in the Clinical Trials in Organ Transplantation-03 study using a panel of 100 hypothesis-driven genes. PGD was defined as grade 3 in the first 72 posttransplant hours. Eighteen genes were differentially expressed over the first year based on PGD development, with significant representation from innate and adaptive immunity genes, with most differences identified very early after transplant. Sixteen genes were overexpressed in the blood of patients with PGD compared to those without PGD within 7 days of allograft reperfusion, with most transcripts encoding innate immune/inflammasome-related proteins, including genes previously associated with PGD. Thirteen genes were underexpressed in patients with PGD compared to those without PGD within 7 days of transplant, highlighted by T cell and adaptive immune regulation genes. Differences in gene expression present within 2 h of reperfusion and persist for days after transplant. Future investigation will focus on the long-term implications of these gene expression differences on the outcome of the allograft.

Pulmonary fibrosis, part II: state-of-the-art patient management

INTRODUCTION

While many pharmacologic therapies for the treatment of idiopathic pulmonary fibrosis (IPF) have been evaluated via randomized, placebo-controlled clinical trials (RCTs) conducted over the past two decades, most therapies have been shown to be ineffective or even potentially harmful. However, a number of recently completed RCTs have shown significant efficacy for pirfenidone and nintedanib for the treatment of IPF. Areas covered: This manuscript reviews recent advances in the management of IPF and other forms of fibrosing interstitial lung disease (ILD) with an emphasis on IPF. The material upon which this discussion is based was obtained from various published texts and manuscripts identified via literature searching (e.g. PubMed). Expert commentary: Anti-fibrotic drugs are now available for clinical use and perceived as standard-of-care therapies that have the potential to blunt disease progression for many patients with IPF. However, these agents do not necessarily stop disease progression or have a significant impact on mortality, and more effective pharmacologic therapies are needed for patients with IPF. Additionally, whether anti-fibrotic agents can be effective therapies for other forms of pulmonary fibrosis, which often have radiologic and histopathologic manifestations that mimic IPF, is being evaluated in a number of RCTs.

Pulmonary fibrosis, part I: epidemiology, pathogenesis, and diagnosis

INTRODUCTION

Many forms of interstitial lung disease (ILD) can progress to extensive fibrosis and respiratory failure. Idiopathic pulmonary fibrosis (IPF), which generally has a poor prognosis, has been thoroughly studied over the past two decades, and many important discoveries have been made that pertain to genetic predisposition, epidemiology, disease pathogenesis, diagnosis, and management. Additionally, non-IPF forms of ILD can have radiologic and histopathologic manifestations that mimic IPF, and making an accurate diagnosis is key to providing personalized medicine to patients with pulmonary fibrosis. Areas covered: This manuscript discusses current knowledge pertaining to the genetics, epidemiology, pathogenesis, and diagnosis of pulmonary fibrosis with an emphasis on IPF. The material upon which this discussion is based was obtained from various published texts and manuscripts identified via literature searching (e.g. PubMed). Expert commentary: Many genetic variants have been identified that are associated with risk of developing pulmonary fibrosis, and an improved understanding of the influence of both genomic and epigenomic factors in the development of pulmonary fibrosis is rapidly evolving. Because many forms of fibrosing ILD can have similar radiologic and histopathologic patterns yet have different responses to therapeutic interventions, making an accurate diagnosis of specific forms of pulmonary fibrosis is increasingly important.

Role of pirfenidone in the management of pulmonary fibrosis

Pulmonary fibrosis is associated with a number of specific forms of interstitial lung disease (ILD) and can lead to progressive decline in lung function, poor quality of life, and, ultimately, early death. Idiopathic pulmonary fibrosis (IPF), the most common fibrotic ILD, affects up to 1 in 200 elderly individuals and has a median survival that ranges from 3 to 5 years following initial diagnosis. IPF has not been shown to respond to immunomodulatory therapies, but recent trials with novel antifibrotic agents have demonstrated lessening of lung function decline over time. Pirfenidone has been shown to significantly slow decline in forced vital capacity (FVC) over time and prolong progression-free survival, which led to its licensing by the United States Food and Drug Administration (FDA) in 2014 for the treatment of patients with IPF. However, pirfenidone has been associated with significant side effects, and patients treated with pirfenidone must be carefully monitored. We review recent and ongoing clinical research and experience with pirfenidone as a pharmacologic therapy for patients with IPF, provide a suggested approach to incorporate pirfenidone into a treatment algorithm for patients with IPF, and examine the potential of pirfenidone as a treatment for non-IPF forms of ILD accompanied by progressive pulmonary fibrosis.

Lung transplantation for high-risk patients with idiopathic pulmonary fibrosis

BACKGROUND

Survival for patients with idiopathic pulmonary fibrosis (IPF) and high lung allocation score (LAS) values may be significantly reduced in comparison to those with lower LAS values.

OBJECTIVES

To evaluate outcomes for high-risk IPF patients as defined by LAS values ≥46 (N=42) versus recipients with LAS values <46 (N=89).

METHODS

We retrospectively reviewed records of 131 consecutive patients with IPF who received lung transplants at our institution between 1999 and 2013.

RESULTS

The mean LAS was significantly higher (59.5, interquartile range 43.9-75.9 vs. 39.3, interquartile range 37.7-44.3; p<0.01) for the high-risk cohort. The higher LAS cohort had significantly lower percent predicted forced vital capacity (FVC) versus recipients with LAS <46 (41.3±14.1% vs. 53.2±16.2%; p<0.01) and required more supplemental oxygen (7±5 vs. 4±2 L/min, p<0.01) prior to transplant versus recipients with LAS <46. Although the incidence of early post-LTX pulmonary complications was increased for the higher LAS group versus recipients with LAS <46, 30-day mortality and actuarial survival did not differ between the two cohorts.

CONCLUSIONS

Although lung transplantation in patients with IPF and high LAS values is associated with increased risk of early post-transplant complications, long-term post-transplant survival for our high-LAS cohort was equivalent to that for the lower LAS recipients.

Timing and Frequency of Unplanned Readmissions After Lung Transplantation Impact Long-Term Survival

BACKGROUND

Adverse events that require hospital readmission frequently occur long after lung transplantation (LT) that has been successfully performed. We sought to identify the causes and rate of unplanned readmissions after LT and to determine whether unplanned readmissions have a significant impact on post-LT survival.

METHODS

We retrospectively reviewed the outcomes in 174 LT recipients who underwent LT at our center from June 2005 to May 2014. The median follow-up period was 38 months (range, 17 to 72 months).

RESULTS

One hundred sixty (92%) of the 174 recipients were readmitted 854 times (5.3 times per patient). The median time to first readmission was 71 days (interquartile range [IQR], 28 to 240 days), and the median hospital length of stay at readmission was 3 days (IQR, 2 to 6 days). Freedom from first readmission was observed for 65% of patients at 1 month, 48% at 3 months, 43% at 6 months, and 26% at 12 months. Gender, lung allocation score, body surface area, year of transplantation, air leak longer than 5 days after operation, and allograft function were risk factors for readmission. The causes of readmission included infections (33%), respiratory adverse events (18%), rejection (15%), gastrointestinal events (15%), renal dysfunction (5%), and cardiac events (4%). Patients who died were found to have had early readmissions (p = 0.04) and more frequent readmissions (p = 0.001).

CONCLUSIONS

The first year after LT remains a high-risk period for unplanned readmissions regardless of pretransplantation diagnosis. Readmissions soon after discharge at index hospitalization and multiple readmissions are associated with an increased risk of mortality.

Acute fibrinous and organising pneumonia following lung transplantation is associated with severe allograft dysfunction and poor outcome: a case series

Acute fibrinous and organising pneumonia (AFOP) is a histopathologic variant of acute lung injury that has been associated with infection and inflammatory disorders and has been reported as a complication of lung transplantation. A retrospective chart review was performed for all patients transplanted at the University of Wisconsin Hospital and Clinics from January 1995 to December 2013 (n = 561). We identified 6 recipients whose clinical course was complicated by AFOP. All recipients were found to have AFOP on lung biopsy or at post-mortem examination, and 5 of the 6 patients suffered progressive allograft dysfunction that led to fatal outcome. Only 1 of the 6 patients stabilised with augmented immunosuppression and had subsequent improvement and stabilisation of allograft function. We could not clearly identify any specific cause of AFOP, such as drug toxicity or infection. Lung transplantation can be complicated by lung injury with an AFOP pattern on histopathologic examination of lung biopsy specimens. The presence of an AFOP pattern was associated with irreversible decline in lung function that was refractory to therapeutic interventions in 5 of our 6 cases and was associated with severe allograft dysfunction and death in these 5 individuals. AFOP should be considered as a potential diagnosis when lung transplant recipients develop progressive decline in lung function that is consistent with a clinical diagnosis of chronic lung allograft dysfunction.

The presence or severity of pulmonary hypertension does not affect outcomes for single-lung transplantation

Advanced lung disease (ALD) that requires lung transplantation (LTX) is frequently associated with pulmonary hypertension (PH). Whether the presence of PH significantly affects the outcomes following single-lung transplantation (SLT) remains controversial. Therefore, we retrospectively examined the outcomes of 279 consecutive SLT recipients transplanted at our centre, and the patients were split into four groups based on their mean pulmonary artery pressure values. Outcomes, including long-term survival and primary graft dysfunction, did not differ significantly for patients with versus without PH, even when PH was severe. We suggest that SLT can be performed safely in patients with ALD-associated PH.

Management of Idiopathic Pulmonary Fibrosis in the Elderly Patient: Addressing Key Questions

Idiopathic pulmonary fibrosis (IPF) is strongly associated with advanced age. Making an accurate diagnosis of IPF is critical, as it remains only one of many potential diagnoses for an elderly patient with newly recognized interstitial lung disease. Optimal management of IPF, especially in older-aged patients, hinges on such factors as balancing the application of standard-of-care measures with the patient's overall health status (robustness vs frailty) and considering the patient's wishes, desires, and expectations. IPF is known to be associated with certain comorbidities that tend to be more prevalent in the elderly population. Until recently, options for the pharmacologic management of IPF were limited and included therapies such as immunosuppressive agents, which may pose substantial risk to the elderly patient. However, the antifibrotic agents pirfenidone and nintedanib have now become commercially available in the United States for the treatment of IPF. The monitoring and treatment of patients with IPF, especially elderly patients with comorbid medical conditions, require consideration of adverse side effects, the avoidance of potential drug-drug interactions, treatment of comorbidities, and the timely implementation of supportive and palliative measures. Individualized counseling to guide decision-making and enhance quality of life is also integral to optimal management of the elderly patient with IPF.

An international ISHLT/ATS/ERS clinical practice guideline: diagnosis and management of bronchiolitis obliterans syndrome

Bronchiolitis obliterans syndrome (BOS) is a major complication of lung transplantation that is associated with poor survival. The International Society for Heart and Lung Transplantation, American Thoracic Society, and European Respiratory Society convened a committee of international experts to describe and/or provide recommendations for 1) the definition of BOS, 2) the risk factors for developing BOS, 3) the diagnosis of BOS, and 4) the management and prevention of BOS. A pragmatic evidence synthesis was performed to identify all unique citations related to BOS published from 1980 through to March, 2013. The expert committee discussed the available research evidence upon which the updated definition of BOS, identified risk factors and recommendations are based. The committee followed the GRADE (Grading of Recommendation, Assessment, Development and Evaluation) approach to develop specific clinical recommendations. The term BOS should be used to describe a delayed allograft dysfunction with persistent decline in forced expiratory volume in 1 s that is not caused by other known and potentially reversible causes of post-transplant loss of lung function. The committee formulated specific recommendations about the use of systemic corticosteroids, cyclosporine, tacrolimus, azithromycin and about re-transplantation in patients with suspected and confirmed BOS. The diagnosis of BOS requires the careful exclusion of other post-transplant complications that can cause delayed lung allograft dysfunction, and several risk factors have been identified that have a significant association with the onset of BOS. Currently available therapies have not been proven to result in significant benefit in the prevention or treatment of BOS. Adequately designed and executed randomised controlled trials that properly measure and report all patient-important outcomes are needed to identify optimal therapies for established BOS and effective strategies for its prevention.

Dysregulation of galectin-3. Implications for Hermansky-Pudlak syndrome pulmonary fibrosis

The etiology of Hermansky-Pudlak syndrome (HPS) pulmonary fibrosis (HPSPF), a progressive interstitial lung disease with high mortality, is unknown. Galectin-3 is a β-galactoside-binding lectin with profibrotic effects. The objective of this study was to investigate the involvement of galectin-3 in HPSPF. Galectin-3 was measured by ELISA, immunohistochemistry, and immunoblotting in human specimens from subjects with HPS and control subjects. Mechanisms of galectin-3 accumulation were studied by quantitative RT-PCR, Northern blot analysis, membrane biotinylation assays, and rescue of HPS1-deficient cells by transfection. Bronchoalveolar lavage galectin-3 concentrations were significantly higher in HPSPF compared with idiopathic pulmonary fibrosis or that from normal volunteers, and correlated with disease severity. Galectin-3 immunostaining was increased in HPSPF compared with idiopathic pulmonary fibrosis or normal lung tissue. Fibroblasts from subjects with HPS subtypes associated with pulmonary fibrosis had increased galectin-3 protein expression compared with cells from nonfibrotic HPS subtypes. Galectin-3 protein accumulation was associated with reduced Galectin-3 mRNA, normal Mucin 1 levels, and up-regulated microRNA-322 in HPSPF cells. Membrane biotinylation assays showed reduced galectin-3 and normal Mucin 1 expression at the plasma membrane in HPSPF cells compared with control cells, which suggests that galectin-3 is mistrafficked in these cells. Reconstitution of HPS1 cDNA into HPS1-deficient cells normalized galectin-3 protein and mRNA levels, as well as corrected galectin-3 trafficking to the membrane. Intracellular galectin-3 levels are regulated by HPS1 protein. Abnormal accumulation of galectin-3 may contribute to the pathogenesis of HPSPF.

Neutrophil elastase-mediated increase in airway temperature during inflammation

BACKGROUND

How elevated temperature is generated during airway infections represents a hitherto unresolved physiological question. We hypothesized that innate immune defence mechanisms would increase luminal airway temperature during pulmonary infection.

METHODS

We determined the temperature in the exhaled air of cystic fibrosis (CF) patients. To further test our hypothesis, a pouch inflammatory model using neutrophil elastase-deficient mice was employed. Next, the impact of temperature changes on the dominant CF pathogen Pseudomonas aeruginosa growth was tested by plating method and RNAseq.

RESULTS

Here we show a temperature of ~38°C in neutrophil-dominated mucus plugs of chronically infected CF patients and implicate neutrophil elastase:α1-proteinase inhibitor complex formation as a relevant mechanism for the local temperature rise. Gene expression of the main pathogen in CF, P. aeruginosa, under anaerobic conditions at 38°C vs 30°C revealed increased virulence traits and characteristic cell wall changes.

CONCLUSION

Neutrophil elastase mediates increase in airway temperature, which may contribute to P. aeruginosa selection during the course of chronic infection in CF.

Immunosuppressive agents and interstitial lung disease: what are the risks?

Idiopathic pulmonary fibrosis is unlikely to respond to immunosuppressive therapies, and patients with idiopathic pulmonary fibrosis may be harmed by such therapy. In contrast, some forms of interstitial lung disease can respond well to treatment with immunosuppressive drug therapies. Such agents can, however, be associated with significant risk of adverse effects such as infection, diabetes, osteoporosis, myopathy, bone marrow suppression, hepatitis, urinary tract injury, and drug-induced pneumonitis. Treating clinicians must be aware of potential adverse reactions to any immunosuppressive drug that they prescribe for their patients, and they should implement appropriate pre-therapy screening (e.g., tuberculosis, hepatitis, renal insufficiency) and monitoring that is recommended to avoid/minimize risk during the treatment period. Some disorders (e.g., cellular non-specific interstitial pneumonia, organizing pneumonia, or sarcoidosis) may respond very well to immunosuppressive therapies including corticosteroids as monotherapy, and the use of steroid-sparing agents can minimize corticosteroid side effects and may enhance treatment efficacy for disorders such as sarcoidosis or connective tissue disease-associated forms of interstitial lung disease.

Diagnosis and management of interstitial lung disease

The complex tasks of making a confident diagnosis of a specific form of interstitial lung disease (ILD) and formulating a patient-centered, personalized management plan in an attempt to achieve remission or stabilization of the disease process can pose formidable challenges to clinicians. When patients are evaluated for suspected ILD, an accurate diagnosis of the specific form of ILD that a patient has developed must be made to provide the patient with useful prognostic information and to formulate an appropriate management plan that can relieve symptoms and restore or significantly improve quality of life. A well-performed patient history and physical examination provides invaluable information that can be combined with appropriate laboratory testing, imaging, and, if needed, tissue biopsy to reach a confident ILD diagnosis, and high-resolution computed tomography (HRCT) of the thorax is usually a key component of the diagnostic evaluation. If treatment is indicated, many forms of ILD can respond significantly to immunosuppressive anti-inflammatory therapies. However, ILD accompanied by extensive fibrosis may be difficult to treat, and the identification of an effective pharmacologic therapy for idiopathic pulmonary fibrosis (IPF) has remained elusive despite the completion of many phase 3 clinical trials over the past decade. Nonetheless, patients with IPF or advanced forms of non-IPF ILD can benefit significantly from detection and treatment of various co-morbid conditions that are often found in patients (especially the elderly patient), and supportive care (oxygen therapy, pulmonary rehabilitation) can have a beneficial impact on quality of life and symptom palliation. Finally, lung transplantation is an option for patients with progressive, advanced disease that does not respond to other therapies, but only a relatively small subset of patients with end-stage ILD are able to meet wait listing requirements and eventually undergo successful lung transplantation.

A new classification system for chronic lung allograft dysfunction

Although survival after lung transplantation has improved significantly during the last decade, chronic rejection is thought to be the major cause of late mortality. The physiologic hallmark of chronic rejection has been a persistent fall in forced expiratory volume in 1 second associated with an obstructive ventilatory defect, for which the term bronchiolitis obliterans syndrome (BOS) was defined to allow a uniformity of description and grading of severity throughout the world. Although BOS was generally thought to be irreversible, recent evidence suggests that some patients with BOS may respond to azithromycin with > 10% improvement in their forced expiratory volume in 1 second. In addition, a restrictive form of chronic rejection has recently been described that does not fit the strict definition of BOS as an obstructive defect. Hence, the term chronic lung allograft dysfunction (CLAD) has been introduced to cover all forms of graft dysfunction, but CLAD has yet to be defined. We propose a definition of CLAD and a flow chart that may facilitate recognition of the different phenotypes of CLAD that can complicate the clinical course of lung transplant recipients.

Lung Transplantation for Idiopathic Pulmonary Fibrosis

Despite advances in the development of novel pharmaceutical agents to treat idiopathic pulmonary fibrosis (IPF), there are no medical therapies known to resolve fibrosis or improve lung function in IPF. Therefore, lung transplantation remains the only life-saving therapy available to treat patients with IPF. However, a shortage of suitable donor organs limits the number of affected individuals who can undergo this procedure, and this shortage highlights the need to allocate donor lungs to those who are in the greatest need of a life-saving therapy yet ensure that those who undergo transplantation will have a reasonable expectation of long-term survival. Still, outcomes remain relatively poor for many patients after lung transplantation, although a sizable minority of patients can enjoy long-term survival after lung transplantation.

Barriers to optimal palliative care of lung transplant candidates

BACKGROUND

The provision of effective palliative care is of great importance to patients awaiting lung transplantation. Although the prospect of lung transplantation provides hope to patients and their families, these patients are usually very symptomatic from their underlying disease.

METHODS

An e-mail questionnaire was sent to members of the American College of Chest Physicians' Transplant NetWork and the Pulmonary Council of the International Society for Heart and Lung Transplantation (ISHLT). The survey included questions about barriers to providing palliative care, the availability of palliative care services, and recommended strategies to improve palliative care for lung transplant candidates.

RESULTS

The 158 respondents represented approximately 65% of transplant programs in the ISHLT registry. Respondents were in practice a mean of 11.3 (± 9) years, 70% were pulmonologists, 17% were surgeons, and 13% were other care providers. Barriers were classified into domains including patient factors, family factors, physician factors, and institutional/transplant program/lung allocation system factors. Significant patient/family barriers included unrealistic patient/family expectations about survival, unwillingness to plan end-of-life care, concerns about abandonment or inappropriate care after enrollment in a palliative care program, and family disagreements about care goals. For institutional/program/allocation system barriers, only the requirement for weight loss or gain to meet program-specific BMI requirements was identified. Significant physician barriers included competing time demands and the seemingly contradictory goals of transplant vs palliative care. Strategies recommended to improve palliative care included routine advance care planning for patients awaiting transplantation, access to palliative care specialists, training of transplant physicians in symptom management, and regular meetings among transplant physicians, nurses, patients, and families.

CONCLUSIONS

Physicians providing care to lung transplant candidates reported considerable barriers to the delivery and acceptance of palliative care and identified specific strategies to improve palliative care for lung transplant candidates.

Lung transplantation

Lung transplantation may be the only intervention that can prolong survival and improve quality of life for those individuals with advanced lung disease who are acceptable candidates for the procedure. However, these candidates may be extremely ill and require ventilator and/or circulatory support as a bridge to transplantation, and lung transplantation recipients are at risk of numerous post-transplant complications that include surgical complications, primary graft dysfunction, acute rejection, opportunistic infection, and chronic lung allograft dysfunction (CLAD), which may be caused by chronic rejection. Many advances in pre- and post-transplant management have led to improved outcomes over the past decade. These include the creation of sound guidelines for candidate selection, improved surgical techniques, advances in donor lung preservation, an improving ability to suppress and treat allograft rejection, the development of prophylaxis protocols to decrease the incidence of opportunistic infection, more effective therapies for treating infectious complications, and the development of novel therapies to treat and manage CLAD. A major obstacle to prolonged survival beyond the early post-operative time period is the development of bronchiolitis obliterans syndrome (BOS), which is the most common form of CLAD. This manuscript discusses recent and evolving advances in the field of lung transplantation.

Surgical lung biopsy for the diagnosis of interstitial lung disease: a review of the literature and recommendations for optimizing safety and efficacy

Making an accurate diagnosis of a specific type of interstitial lung disease (ILD) requires a structured and comprehensive approach that includes a complete patient history, careful physical examination, appropriate laboratory testing, and thoracic imaging. If invasive procedures are required, bronchoscopy with bronchoalveolar lavage (BAL) and/or endoscopic lung biopsy (ELB) can frequently establish a confident diagnosis. However, surgical lung biopsy (SLB) may be required to make a confident diagnosis. Because SLB may be associated with a significant risk of morbidity and mortality, we performed a comprehensive literature review of all available literature published in the English language that reported outcomes of surgical lung biopsy performed for the diagnosis of ILD. The overall 30-day mortality for open lung biopsy (OLB) was 4.3% versus 2.1% for video-assisted thorascopic surgery (VATS) biopsy, and non-lethal complications appeared to occur more frequently with OLB (18.1%) vs. VATS (9.6%) procedures. In addition to presenting the results of our comprehensive literature review on SLB for the diagnosis of ILD, we suggest an approach that minimizes risks to patients and optimizes the diagnostic utility of SLB when SLB must be performed to obtain a confident ILD diagnosis.

Safety of and cellular response to segmental bronchoprovocation in allergic asthma

Rationale

Despite its incorporation into research studies, the safety aspects of segmental allergen bronchoprovocation and differences in cellular response among different allergens have received limited consideration.

Methods

We performed 87 segmental challenges in 77 allergic asthma subjects. Allergen dose was based on each subject’s response to whole lung allergen challenge. Bronchoalveolar lavage was performed at 0 and 48 hours. Safety indicators included spirometry, oxygen saturation, heart rate, and symptoms.

Results

Among subjects challenged with ragweed, cat dander, or house dust mite, there were no differences in safety indicators. Subjects demonstrated a modest oxygen desaturation and tachycardia during the procedure that returned to normal prior to discharge. We observed a modest reduction in forced vital capacity and forced expiratory volume in one second following bronchoscopy. The most common symptoms following the procedure were cough, sore throat and fatigue. Total bronchoalveolar lavage fluid cell numbers increased from 13±4 to 106±108×10⁴ per milliliter and eosinophils increased from 1±2 to 44±20 percent, with no significant differences among the three allergens.

Conclusions

In mild allergic asthma, segmental allergen bronchoprovocation, using individualized doses of aeroallergens, was safe and yielded similar cellular responses.

Bronchiolitis Obliterans Syndrome and Chronic Lung Allograft Dysfunction: Evolving Concepts and Nomenclature

Bronchiolitis obliterans syndrome (BOS) eventually occurs in the majority of lung transplant recipients who survive beyond 1 year, can greatly impair quality of life, and is, directly or indirectly, the major cause of delayed allograft dysfunction and recipient death. A number of associated events or conditions are strongly associated with the risk for developing BOS; these include acute rejection, gastroesophageal reflux, infections, and autoimmune reactions that can occur in the setting of alloimmune responses to the lung allograft as recipients are given intense immunosuppression to prevent allograft rejection. The term chronic lung allograft dysfunction (CLAD) is being increasingly used to refer to recipients with late allograft dysfunction that meets the spirometric criteria for the diagnosis of BOS, but clinicians should recognize that such dysfunction can occur for a variety of reasons other than BOS. The recently identified entity of restrictive allograft syndrome, which is now recognized as a relatively distinct phenotype of CLAD, has features that differentiate it from classic obstructive BOS. A number of other entities that can also significantly affect allograft function must also be considered when significant allograft dysfunction is encountered following lung transplantation.