Investigating the "sex paradox" in pulmonary arterial hypertension: Results from the Pulmonary Hypertension Association Registry (PHAR)

BACKGROUND

Female sex is a significant risk factor for pulmonary arterial hypertension (PAH), yet males with PAH have worse survival - a phenomenon referred to as the "sex paradox" in PAH.

METHODS

All adult PAH patients in the Pulmonary Hypertension Association Registry (PHAR) with congruent sex and gender were included. Baseline differences in demographics, hemodynamics, functional parameters, and quality of life were assessed by sex. Kaplan-Meier survival analysis was used to evaluate survival by sex. Mediation analysis was conducted with Cox proportional hazards regression by comparing the unadjusted hazard ratios for sex before and after adjustment for covariates. The plausibility of collider-stratification bias was assessed by modeling how large an unmeasured factor would have to be to generate the observed sex-based mortality differences. Subgroup analysis was performed on idiopathic and incident patients.

RESULTS

Among the 1,891 patients included, 75% were female. Compared to men, women had less favorable hemodynamics, lower 6-minute walk distance, more PAH therapies, and worse functional class; however, sex-based differences were less pronounced when accounting for body surface area or expected variability by gender. On multivariate analysis, women had a 48% lower risk of death compared to men (Hazard Ratio 0.52, 95% Confidence interval 0.36 - 0.74, p < 0.001). Modeling found that under reasonable assumptions collider-stratification could account for sex-based differences in mortality.

CONCLUSIONS

In this large registry of PAH patients new to a care center, men had worse survival than women despite having more favorable baseline characteristics. Collider-stratification bias could account for the observed greater mortality among men.

Macrophage and CD8 T cell discordance are associated with acute lung allograft dysfunction progression

BACKGROUND

Acute lung allograft dysfunction (ALAD) is an imprecise syndrome denoting concern for the onset of chronic lung allograft dysfunction (CLAD). Mechanistic biomarkers are needed that stratify risk of ALAD progression to CLAD. We hypothesized that single cell investigation of bronchoalveolar lavage (BAL) cells at the time of ALAD would identify immune cells linked to progressive graft dysfunction.

METHODS

We prospectively collected BAL from consenting lung transplant recipients for single cell RNA sequencing. ALAD was defined by a ≥10% decrease in FEV1 not caused by infection or acute rejection and samples were matched to BAL from recipients with stable lung function. We examined cell compositional and transcriptional differences across control, ALAD with decline, and ALAD with recovery groups. We also assessed cell-cell communication.

RESULTS

BAL was assessed for 17 ALAD cases with subsequent decline (ALAD declined), 13 ALAD cases that resolved (ALAD recovered), and 15 cases with stable lung function. We observed broad differences in frequencies of the 26 unique cell populations across groups (p = 0.02). A CD8 T cell (p = 0.04) and a macrophage cluster (p = 0.01) best identified ALAD declined from the ALAD recovered and stable groups. This macrophage cluster was distinguished by an anti-inflammatory signature and the CD8 T cell cluster resembled a Tissue Resident Memory subset. Anti-inflammatory macrophages signaled to activated CD8 T cells via class I HLA, fibronectin, and galectin pathways (p < 0.05 for each). Recipients with discordance between these cells had a nearly 5-fold increased risk of severe graft dysfunction or death (HR 4.6, 95% CI 1.1-19.2, adjusted p = 0.03). We validated these key findings in 2 public lung transplant genomic datasets.

CONCLUSIONS

BAL anti-inflammatory macrophages may protect against CLAD by suppressing CD8 T cells. These populations merit functional and longitudinal assessment in additional cohorts.

CCR5 drives NK cell-associated airway damage in pulmonary ischemia-reperfusion injury

Primary graft dysfunction (PGD) limits clinical benefit after lung transplantation, a life-prolonging therapy for patients with end-stage disease. PGD is the clinical syndrome resulting from pulmonary ischemia-reperfusion injury (IRI), driven by innate immune inflammation. We recently demonstrated a key role for NK cells in the airways of mouse models and human tissue samples of IRI. Here, we used 2 mouse models paired with human lung transplant samples to investigate the mechanisms whereby NK cells migrate to the airways to mediate lung injury. We demonstrate that chemokine receptor ligand transcripts and proteins are increased in mouse and human disease. CCR5 ligand transcripts were correlated with NK cell gene signatures independently of NK cell CCR5 ligand secretion. NK cells expressing CCR5 were increased in the lung and airways during IRI and had increased markers of tissue residency and maturation. Allosteric CCR5 drug blockade reduced the migration of NK cells to the site of injury. CCR5 blockade also blunted quantitative measures of experimental IRI. Additionally, in human lung transplant bronchoalveolar lavage samples, we found that CCR5 ligand was associated with increased patient morbidity and that the CCR5 receptor was increased in expression on human NK cells following PGD. These data support a potential mechanism for NK cell migration during lung injury and identify a plausible preventative treatment for PGD.

Lung Transplantation for Pulmonary Arterial Hypertension

TOPIC IMPORTANCE

Even though patients with pulmonary arterial hypertension have multiple therapeutic options, the disease can be refractory despite appropriate management. In patients with end-stage pulmonary arterial hypertension, lung transplantation has the potential both to extend survival and improve health-related quality of life. Pulmonary arterial hypertension is the only major diagnostic indication for transplantation that is not a parenchymal pulmonary process, and thus the care of these patients is unique.

REVIEW FINDINGS

This review focuses on the complexities of lung transplantation for patients with pulmonary arterial hypertension, presents the updated referral and listing criteria, and discusses the inequities in the organ allocation process that impact this disease group and the strategies to optimize outcomes for patients with pulmonary arterial hypertension who require lung transplantation.

SUMMARY

Lung transplantation is an effective and lifesaving therapy for patients with end-stage lung disease. Sadly, patients with pulmonary arterial hypertension face many challenges as it relates to transplantation including higher perioperative risks, inequities in the allocation system, and less favorable long-term outcomes. This review covers the complexities of transplantation in patients with pulmonary vascular disease.

Development of the Lung Transplant Frailty Scale (LT-FS)

BACKGROUND

Existing measures of frailty developed in community dwelling older adults may misclassify frailty in lung transplant candidates. We aimed to develop a novel frailty scale for lung transplantation with improved performance characteristics.

METHODS

We measured the short physical performance battery (SPPB), fried frailty phenotype (FFP), Body Composition, and serum Biomarkers representative of putative frailty mechanisms. We applied a 4-step established approach (identify frailty domain variable bivariate associations with the outcome of waitlist delisting or death; build models sequentially incorporating variables from each frailty domain cluster; retain variables that improved model performance ability by c-statistic or AIC) to develop 3 candidate "Lung Transplant Frailty Scale (LT-FS)" measures: 1 incorporating readily available clinical data; 1 adding muscle mass, and 1 adding muscle mass and research-grade Biomarkers. We compared construct and predictive validity of LT-FS models to the SPPB and FFP by ANOVA, ANCOVA, and Cox proportional-hazard modeling.

RESULTS

In 342 lung transplant candidates, LT-FS models exhibited superior construct and predictive validity compared to the SPPB and FFP. The addition of muscle mass and Biomarkers improved model performance. Frailty by all measures was associated with waitlist disability, poorer HRQL, and waitlist delisting/death. LT-FS models exhibited stronger associations with waitlist delisting/death than SPPB or FFP (C-statistic range: 0.73-0.78 vs. 0.57 and 0.55 for SPPB and FFP, respectively). Compared to SPPB and FFP, LT-FS models were generally more strongly associated with delisting/death and improved delisting/death net reclassification, with greater improvements with increasing LT-FS model complexity (range: 0.11-0.34). For example, LT-FS-Body Composition hazard ratio for delisting/death: 6.0 (95%CI: 2.5, 14.2), SPPB HR: 2.5 (95%CI: 1.1, 5.8), FFP HR: 4.3 (95%CI: 1.8, 10.1). Pre-transplant LT-FS frailty, but not SPPB or FFP, was associated with mortality after transplant.

CONCLUSIONS

The LT-FS is a disease-specific physical frailty measure with face and construct validity that has superior predictive validity over established measures.

Design and implementation of a digital health home spirometry intervention for remote monitoring of lung transplant function

BACKGROUND

We developed an automated, chat-based, digital health intervention using Bluetooth-enabled home spirometers to monitor for complications of lung transplantation in a real-world application.

METHODS

A chat-based application prompted patients to perform home spirometry, enter their forced expiratory volume in 1 second (FEV1), answer symptom queries, and provided patient education. The program alerted patients and providers to substantial FEV1 decreases and concerning symptoms. Data was integrated into the electronic health record (EHR) system and dashboards were developed for program monitoring.

RESULT

Between May 2020 and December 2021, 544 patients were invited to enroll, of whom 427 were invited remotely and 117 were enrolled in-person. 371 (68%) participated by submitting ≥1 FEV1 values. Overall engagement was high, with an average of 197 unique patients submitting FEV1 data per month. In-person enrollees submitted an average of 4.6 FEV1 values per month and responded to 55% of scheduled chats. Home and laboratory FEV1 values correlated closely (rho = 0.93). There was an average of 133 ± 59 FEV1 decline alerts and 59 ± 23 symptom alerts per month. 72% of patients accessed education modules, and the program had a high net promoter score (53) amongst users.

CONCLUSIONS

We demonstrate that a novel, automated, chat-based, and EHR-integrated home spirometry intervention is well accepted, generates reliable assessments of graft function, and can deliver automated feedback and education resulting in moderately-high adherence rates. We found that in-person onboarding yields better engagement and adherence. Future work will aim to demonstrate the impact of remote care monitoring on early detection of lung transplant complications.

Subphenotypes of frailty in lung transplant candidates

Heterogeneous frailty pathobiology might explain the inconsistent associations observed between frailty and lung transplant outcomes. A Subphenotype analysis could refine frailty measurement. In a 3-center pilot cohort study, we measured frailty by the Short Physical Performance Battery, body composition, and serum biomarkers reflecting causes of frailty. We applied latent class modeling for these baseline data. Next, we tested class construct validity with disability, waitlist delisting/death, and early postoperative complications. Among 422 lung transplant candidates, 2 class model fit the best (P = .01). Compared with Subphenotype 1 (n = 333), Subphenotype 2 (n = 89) was characterized by systemic and innate inflammation (higher IL-6, CRP, PTX3, TNF-R1, and IL-1RA); mitochondrial stress (higher GDF-15 and FGF-21); sarcopenia; malnutrition; and lower hemoglobin and walk distance. Subphenotype 2 had a worse disability and higher risk of waitlist delisting or death (hazards ratio: 4.0; 95% confidence interval: 1.8-9.1). Of the total cohort, 257 underwent transplant (Subphenotype 1: 196; Subphenotype 2: 61). Subphenotype 2 had a higher need for take back to the operating room (48% vs 28%; P = .005) and longer posttransplant hospital length of stay (21 days [interquartile range: 14-33] vs 18 days [14-28]; P = .04). Subphenotype 2 trended toward fewer ventilator-free days, needing more postoperative extracorporeal membrane oxygenation and dialysis, and higher need for discharge to rehabilitation facilities (P ≤ .20). In this early phase study, we identified biological frailty Subphenotypes in lung transplant candidates. A hyperinflammatory, sarcopenic Subphenotype seems to be associated with worse clinical outcomes.

The Lung Allocation Score Remains Inequitable for Patients with Pulmonary Arterial Hypertension, Even after the 2015 Revision

Rationale: The lung allocation score (LAS) was revised in 2015 to improve waiting list mortality and rate of transplant for patients with pulmonary arterial hypertension (PAH). Objectives: We sought to determine if the 2015 revision achieved its intended goals. Methods: Using the Standard Transplant Analysis and Research file, we assessed the impact of the 2015 LAS revision by comparing the pre- and postrevision eras. Registrants were divided into the LAS diagnostic categories: group A-chronic obstructive pulmonary disease; group B-pulmonary arterial hypertension; group C-cystic fibrosis; and group D-interstitial lung disease. Competing risk regressions were used to assess the two mutually exclusive competing risks of waiting list death and transplant. Cumulative incidence plots were created to visually inspect risks. Measurements and Main Results: The LAS at organ matching increased by 14.2 points for registrants with PAH after the 2015 LAS revision, the greatest increase among diagnostic categories (other LAS categories: Δ, -0.9 to +2.8 points). Before the revision, registrants with PAH had the highest risk of death and lowest likelihood of transplant. After the 2015 revision, registrants with PAH still had the highest risk of death, now similar to those with interstitial lung disease, and the lowest rate of transplant, now similar to those with chronic obstructive pulmonary disease. Conclusions: Although the 2015 LAS revision improved access to transplant and reduced the risk of waitlist death for patients with PAH, it did not go far enough. Significant differences in waitlist mortality and likelihood of transplant persist.

Echocardiographic estimation of pulmonary vascular resistance in advanced lung disease

Noninvasive assessment of pulmonary hemodynamics is often performed by echocardiographic estimation of the pulmonary artery systolic pressure (ePASP), despite limitations in the advanced lung disease population. Other noninvasive hemodynamic variables, such as echocardiographic pulmonary vascular resistance (ePVR), have not been studied in this population. We performed a retrospective analysis of 147 advanced lung disease patients who received both echocardiography and right heart catheterization for lung transplant evaluation. The ePVR was estimated by four previously described equations. Noninvasive and invasive hemodynamic parameters were compared in terms of correlation, agreement, and accuracy. The ePVR models strongly correlated with invasively determined PVR and had good accuracy with biases of <1 Wood units (WU), although with moderate precision and wide 95% limits of agreement varying from 5.9 to 7.8 Wood units. The ePVR models were accurate to within 1.9 WU in over 75% of patients. In comparison to the ePASP, ePVR models performed similarly in terms of correlation, accuracy, and precision when estimating invasive hemodynamics. In screening for pulmonary hypertension, ePVR models had equivalent testing characteristics to the ePASP. Mid-systolic notching of the right ventricular outflow tract Doppler signal identified a subgroup of 11 patients (7%) with significantly elevated PVR and mean pulmonary artery pressures without relying on the acquisition of a tricuspid regurgitation signal. Analysis of ePVR and determination of the notching pattern of the right ventricular outflow tract Doppler flow velocity envelope provide reliable insights into hemodynamics in advanced lung disease patients, although limitations in precision exist.

Palliative care referrals in patients with pulmonary arterial hypertension: The Pulmonary Hypertension Association Registry

BACKGROUND

Pulmonary arterial hypertension (PAH) is a life limiting disease with substantial symptom burden and healthcare utilization. Palliative care alleviates physical and emotional symptoms for patients with serious illness, and has been underutilized for these patients.

OBJECTIVE

To characterize patients with PAH referred to palliative care and identify predictors of referral.

METHODS

We conducted an observational study of adult patients enrolled in the Pulmonary Hypertension Association Registry from January 2015 through June 2021, performing descriptive statistics on patient characteristics at baseline for all patients and the subset referred to palliative care. These characteristics were modeled in a backwards elimination Cox regression with time to referral to palliative care as the primary outcome.

RESULTS

92 of 1,578 patients were referred to palliative care (5.8%); 43% were referred at their last visit prior to death. Referrals were associated with increasing age per decade (hazard ratio 1.35 [95% confidence interval 1.16-1.58]), lower body mass index (hazard ratio 0.97 [95% confidence interval 0.94-0.998]), supplemental oxygen use (hazard ratio 2.01 [95% confidence interval 1.28-3.16]), parenteral prostanoid use (hazard ratio 2.88 [95% confidence interval 1.84-4.51]), and worse quality of life, measured via lower physical (hazard ratio 0.97 [95% confidence interval 0.95-0.99]) and mental (hazard ratio 0.98 [95% confidence interval 0.96-0.995]) scores on the 12-item Short Form Health Survey.

CONCLUSION

Patients with PAH are infrequently referred to palliative care, even at centers of excellence. Referrals occur in sicker patients with lower quality of life scores, often close to the end of life.

NKG2D receptor activation drives primary graft dysfunction severity and poor lung transplantation outcomes

Clinical outcomes after lung transplantation, a life-saving therapy for patients with end-stage lung diseases, are limited by primary graft dysfunction (PGD). PGD is an early form of acute lung injury with no specific pharmacologic therapies. Here, we present a large multicenter study of plasma and bronchoalveolar lavage (BAL) samples collected on the first posttransplant day, a critical time for investigations of immune pathways related to PGD. We demonstrated that ligands for NKG2D receptors were increased in the BAL from participants who developed severe PGD and were associated with increased time to extubation, prolonged intensive care unit length of stay, and poor peak lung function. Neutrophil extracellular traps (NETs) were increased in PGD and correlated with BAL TNF-α and IFN-γ cytokines. Mechanistically, we found that airway epithelial cell NKG2D ligands were increased following hypoxic challenge. NK cell killing of hypoxic airway epithelial cells was abrogated with NKG2D receptor blockade, and TNF-α and IFN-γ provoked neutrophils to release NETs in culture. These data support an aberrant NK cell/neutrophil axis in human PGD pathogenesis. Early measurement of stress ligands and blockade of the NKG2D receptor hold promise for risk stratification and management of PGD.

Anticoagulation in pulmonary arterial hypertension - association with mortality, healthcare utilization, and quality of life: The Pulmonary Hypertension Association Registry (PHAR)

BACKGROUND

Routine long-term anticoagulation in pulmonary arterial hypertension (PAH) is controversial. To date, anticoagulation has been found to be beneficial or neutral in idiopathic disease (IPAH) and neutral-to-harmful in connective tissue disease (CTD-PAH). We sought to examine the association between anticoagulation and mortality, healthcare utilization, and quality of life (QoL) in PAH.

METHODS

The PHAR is a prospective registry of PAH patients referred to 58 pulmonary hypertension care centers in the United States. We compared patients who received anticoagulation during enrollment (questionnaire documented) to those who did not. Cox proportional hazard models were used for mortality, Poisson multivariate regression models for healthcare utilization, and generalized estimating equations for QOL RESULTS: Of 1175 patients included, 316 patients were treated with anticoagulation. IPAH/hereditary PAH (HPAH) comprised 46% of the cohort and CTD-PAH comprised 33%. After adjustment for demographics, clinical characteristics, site and disease severity, anticoagulation was not associated with mortality in the overall population (HR, 1.00; 95% CI, 0.72-1.36), IPAH/HPAH (HR, 1.19; 95% CI, 0.74-1.94), or CTD-PAH (HR 0.87; 95% CI, 0.53-1.42). Anticoagulation was associated with an increased rate of emergency department visits (IRR: 1.41), hospitalizations (IRR: 1.30), and hospital days (IRR 1.33). QOL measured by emPHasis-10 score was worse in patients receiving anticoagulation (mean difference 1.74; 95% CI 0.40-3.09).

CONCLUSIONS

Anticoagulation is not associated with higher mortality, but is associated with increased healthcare utilization in the PHAR. PAH-specific QoL may be worse in patients receiving anticoagulation. The risks and benefits surrounding routine prescription of anticoagulation for PAH should be carefully considered.

Methamphetamine-associated pulmonary arterial hypertension

PURPOSE OF REVIEW

Methamphetamine use is increasing in popularity globally, and chronic users suffer from various drug toxicities, including the development of pulmonary arterial hypertension. Although it was previously thought to be a possible cause of pulmonary arterial hypertension, as of the sixth World Symposium on Pulmonary Hypertension, methamphetamine use is now recognized as a definite cause of pulmonary arterial hypertension. This review will discuss the history of methamphetamine use, the link between methamphetamine use and pulmonary arterial hypertension, and the clinical characteristics of patients with pulmonary hypertension from methamphetamine use.

RECENT FINDINGS

The mechanism by which methamphetamine abuse leads to pulmonary hypertension is unclear. However, recent studies have suggested that reduced expression of carboxylesterase 1 may be implicated due to maladaptation to the environmental injury of methamphetamine abuse. Based on the report of two recent cohort studies, patients with methamphetamine-associated pulmonary arterial hypertension have a worse functional class, less favorable hemodynamics, impaired health-related quality of life, increased health-care utilization, and attenuated survival, as compared to those with idiopathic pulmonary arterial hypertension.

SUMMARY

Future studies are needed to better understand the mechanism by which methamphetamine use leads to pulmonary arterial hypertension. Methamphetamine-associated pulmonary arterial hypertension likely represents a more advanced disease state than idiopathic pulmonary arterial hypertension, however, it is treated less aggressively in clinical practice.

Depressive symptoms in lung transplant recipients: trajectory and association with mortality and allograft dysfunction

OBJECTIVE

Most studies observing an association between depressive symptoms following lung transplantation and mortality are limited to depressive symptom measurement at a single time point, unrelated to allograft function. We aimed to test the association of depressive symptoms over multiple assessments with allograft dysfunction and with mortality.

METHODS

We assessed depressive symptoms before and serially up to 3 years after lung transplantation in lung transplant recipients. We quantified depressive symptoms with the Geriatric Depression Scale (GDS; range 0-15; minimally important difference (MID): 2). We quantified changes in GDS using linear mixed effects models and tested the association with mortality using Cox proportional hazards models with GDS as a time-dependent predictor. To determine if worsening in GDS preceded declines in lung function, we tested the association of GDS as a time-dependent predictor with the lagged outcome of FEV₁ at the following study visit.

RESULTS

Among 266 participants, depressive symptoms improved early after transplantation. Worsening in post-transplant GDS by the MID was associated with mortality (HR 1.25, 95% CI 1.05 to 1.50), and in lagged outcome analyses with decreased per cent predicted FEV₁ (Δ, -1.62%, 95% CI -2.49 to -0.76). Visual analyses of temporal changes in GDS demonstrated that worsening depressive symptoms could precede chronic lung allograft dysfunction.

CONCLUSIONS

Depressive symptoms generally improve after lung transplantation. When they worsen, however, there is an association with declines in lung function and mortality. Depression is one of the few, potentially modifiable, risk factors for chronic lung allograft dysfunction and death.

Screening Strategies for Pulmonary Hypertension in Patients With Interstitial Lung Disease: A Multidisciplinary Delphi Study

BACKGROUND

Pulmonary hypertension (PH) is a common complication of interstitial lung disease (ILD) and is associated with worse outcomes and increased mortality. Evaluation of PH is recommended in lung transplant candidates, but there are currently no standardized screening approaches. Trials have identified therapies that are effective in this setting, providing another rationale to routinely screen patients with ILD for PH.

RESEARCH QUESTION

What screening strategies for identifying PH in patients with ILD are supported by expert consensus?

STUDY DESIGN AND METHODS

The study convened a panel of 16 pulmonologists with expertise in PH and ILD, and used a modified Delphi consensus process with three surveys to identify PH screening strategies. Survey 1 consisted primarily of open-ended questions. Surveys 2 and 3 were developed from responses to survey 1 and contained statements about PH screening that panelists rated from -5 (strongly disagree) to 5 (strongly agree).

RESULTS

Panelists reached consensus on several triggers for suspicion of PH including the following: symptoms, clinical signs, findings on chest CT scan or other imaging, abnormalities in pulse oximetry, elevations in brain natriuretic peptide (BNP) or N-terminal pro-brain natriuretic peptide (NT-proBNP), and unexplained worsening in pulmonary function tests or 6-min walk distance. Echocardiography and BNP/NT-proBNP were identified as screening tools for PH. Right heart catheterization was deemed essential for confirming PH.

INTERPRETATION

Many patients with ILD may benefit from early evaluation of PH now that an approved therapy is available. Protocols to evaluate patients with ILD often overlap with evaluations for pulmonary hypertension-interstitial lung disease and can be used to assess the risk of PH. Because standardized approaches are lacking, this consensus statement is intended to aid physicians in the identification of patients with ILD and possible PH, and provide guidance for timely right heart catheterization.

Inflammation on bronchoalveolar lavage cytology is associated with decreased chronic lung allograft dysfunction-free survival

BACKGROUND

Lung transplant recipients undergo bronchoalveolar lavage (BAL) to detect antecedents of chronic lung allograft dysfunction (CLAD), but routine assessment of BAL cytology is controversial. We hypothesized that inflammation on BAL cytology would predict CLAD-free survival.

METHODS

In a single-center retrospective cohort, associations between cytology results and clinical characteristics were compared using generalized-estimating equation-adjusted regression. The association between BAL inflammation and CLAD or death risk was assessed using time-dependent Cox models.

RESULTS

 In 3,365 cytology reports from 451 subjects, inflammation was the most common finding (6.2%, 210 cases), followed by fungal forms (5.3%, 178 cases, including 24 cases of suspected Aspergillus). Inflammation on BAL cytology was more common in procedures for symptoms (8.5%) versus surveillance (3.2%, P<0.001). Inflammation on cytology was associated with automated neutrophil and lymphocyte counts, acute cellular rejection, infection, and portended a 2.2-fold hazard ratio (CI 1.2-4.0, P = 0.007) for CLAD or death. However, inflammation by cytology did not inform CLAD-free survival risk beyond automated BAL cell counts (P = 0.57).

CONCLUSIONS

Inflammation on BAL cytology is clinically significant, suggesting acute rejection or infection and increased risk of CLAD or death. However, other indicators of allograft inflammation can substitute for much of the information provided by BAL cytology. This article is protected by copyright. All rights reserved.

The association of post-operative delirium with patient-reported outcomes and mortality after lung transplantation

Post-operative delirium after lung transplantation is common. Its associations with health-related quality of life (HRQL), depression, and mortality remains unknown. In 236 lung transplant recipients, HRQL and depressive symptoms were assessed as part of a structured survey battery before and after transplantation. Surveys included the Geriatric Depressive Scale (GDS) and Short Form 12 (SF12). Delirium was assessed throughout the post-operative intensive care unit (ICU) stay with Confusion Assessment Method for ICU. Delirium and mortality data were extracted from electronic medical records. We examined associations between delirium and changes in depressive symptoms and HRQL using linear mixed effects models and association between delirium and mortality with Cox-proportional hazard models. Post-operative delirium occurred in 34 participants (14%). Delirium was associated with attenuated improvements in SF12-PCS (difference ₋4.0; 95%CI: -7.4, -0.7) but not SF12-MCS (difference 2.2; 95%CI: -0.7,5.7) or GDS (difference ₋0.4; 95%CI: -1.5,0.7). Thirty-two participants died during the study period. Delirium was associated with increased adjusted hazard risk of mortality (HR 17.9, 95%CI: 4.4,72.5). Delirium after lung transplantation identifies a group at increased risk for poorer HRQL and death within the first post-operative year. Further studies should investigate potential causal links between delirium, and poorer HRQL and mortality risk after lung transplantation.

Pulmonary hypertension due to interstitial lung disease or chronic obstructive pulmonary disease: a patient experience study of symptoms and their impact on quality of life

Pulmonary hypertension resulting from chronic lung disease such as chronic obstructive pulmonary disease and interstitial lung disease is categorized by the World Health Organization as Group 3 pulmonary hypertension. To identify the symptoms and impacts of World Health Organization Group 3 pulmonary hypertension and to capture data related to the patient experience of this disease, qualitative research interviews were undertaken with 3 clinical experts and 14 individuals with pulmonary hypertension secondary to chronic obstructive pulmonary disease or interstitial lung disease. Shortness of breath, fatigue, cough, and swelling were the most frequently reported symptoms of pulmonary hypertension due to chronic obstructive pulmonary disease or interstitial lung disease, and shortness of breath was further identified as the single most bothersome symptom for most patients (71.4%). Interview participants also described experiencing a number of impacts related to pulmonary hypertension and pulmonary hypertension symptoms, including limitations in the ability to perform activities of daily living and impacts on physical functioning, family life, and social life as well as emotional impacts, which included frustration, depression, anxiety, isolation, and sadness. Results of these qualitative interviews offer an understanding of the patient experience of pulmonary hypertension due to chronic obstructive pulmonary disease or interstitial lung disease, including insight into the symptoms and impacts that are most important to patients in this population. As such, these results may help guide priorities in clinical treatment and assist researchers in their selection of patient-reported outcome measures for clinical trials in patients with pulmonary hypertension due to chronic obstructive pulmonary disease or interstitial lung disease.

Primary graft dysfunction attenuates improvements in health-related quality of life after lung transplantation, but not disability or depression

Disability, depressive symptoms, and impaired health-related quality of life (HRQL) are common among patients with life-threatening respiratory compromise. We sought to determine if primary graft dysfunction (PGD), a syndrome of acute lung injury, attenuates improvements in patient-reported outcomes after transplantation. In a single-center prospective cohort, we assessed disability, depressive symptoms, and HRQL before and at 3- to 6-month intervals after lung transplantation. We estimated the magnitude of change in disability, depressive symptoms, and HRQL with hierarchical segmented linear mixed-effects models. Among 251 lung transplant recipients, 50 developed PGD Grade 3. Regardless of PGD severity, participants had improvements in disability and depressive symptoms, as well as generic-physical, generic-mental, respiratory-specific, and health-utility HRQL, exceeding 1- to 4-fold the minimally clinically important difference across all instruments. Participants with PGD Grade 3 had a lower magnitude of improvement in generic-physical HRQL and health-utility than in all other participants. Among participants with PGD Grade 3, prolonged mechanical ventilation was associated with greater attenuation of improvements. PGD remains a threat to the 2 primary aims of lung transplantation, extending survival and improving HRQL. Attenuation of improvement persists long after hospital discharge. Future studies should assess if interventions can mitigate the impact of PGD on patient-reported outcomes.

Age-related differences in hemodynamics and functional status in pulmonary arterial hypertension: Baseline results from the Pulmonary Hypertension Association Registry

BACKGROUND

The age of patients with pulmonary arterial hypertension (PAH) has increased, with registries now reporting mean ages of 50 to 65 years old. Limited data exist on age-related differences in hemodynamic and functional assessments in PAH.

METHODS

Adults with PAH in the Pulmonary Hypertension Association Registry were divided into 3 groups (18-50, 51-65, and >65 years old). Analysis of variance and chi-square testing were used to assess for baseline differences. Linear regression was used to examine the association of age with continuous hemodynamic and functional variables.

RESULTS

A total of 769 patients with mean age of 56 ± 16 years were included. Older patients had more connective tissue disease-associated PAH and less drug-associated PAH. In linear regression models, each year of increased age was associated with shorter 6-minute walk distance (-3.37 meters; 95% CI, -3.97 to -2.76), lower mean pulmonary arterial pressure (-0.21 mm Hg; 95% CI, -0.27 to -0.15), and lower pulmonary vascular resistance (-0.06 Wood units; 95% CI, -0.09 to -0.04). Pulmonary arterial compliance, cardiac index, right ventricular stroke work index, and percent predicted 6-minute walk distance were unrelated to age; resistance-compliance time was negatively related to age (-3 milliseconds per year; 95% CI, -4 to -2).

CONCLUSIONS

Relative to their pulmonary vascular resistance, older patients have lower pulmonary artery compliance and worse right ventricular performance. Based on these findings, we suspect that age influences right ventricular loading conditions and the response of the right ventricle to increased afterload.

Tacrolimus trough monitoring guided by mass spectrometry without accounting for assay differences is associated with acute kidney injury in lung transplant recipients

PURPOSE

Tacrolimus is a nephrotoxic immunosuppressant historically monitored via enzyme-based immunoassay (IA). After 2011, the 2 largest laboratory companies in the United States implemented tacrolimus quantification by liquid chromatography-mass spectrometry (LC-MS); this method excludes metabolites, potentially resulting in lower quantified drug concentrations. We sought to determine if tacrolimus therapeutic drug monitoring via LC-MS, as performed using trough targets originally derived from IA values, influences clinical outcomes.

METHODS

In a single-center retrospective cohort study of lung transplant recipients, risks of acute kidney injury, acute renal failure, and new-onset diabetes after transplantation, as well as chronic lung allograft dysfunction-free survival, were compared in 82 subjects monitored by LC-MS and 102 subjects monitored by IA using Cox proportional hazard models adjusted for age, sex, baseline renal function, and race.

RESULTS

LC-MS-based monitoring was associated with a greater risk of acute kidney injury (adjusted hazard ratio, 1.65; 95% confidence interval, 1.02-2.67). No statistically significant differences in risks of acute renal failure and new-onset diabetes after transplantation were observed.

CONCLUSION

Although LC-MS provides a more accurate representation of the blood concentration of the parent compound tacrolimus exclusive of metabolite, established cut points for tacrolimus dosing may need to be adjusted to account for the increased risk of renal injury.

Frailty after lung transplantation is associated with impaired health-related quality of life and mortality

BACKGROUND

Lung transplantation and related medications are associated with pathobiological changes that can induce frailty, a state of decreased physiological reserve. Causes of persistent or emergent frailty after lung transplantation, and whether such transplant-related frailty is associated with key outcomes, are unknown.

METHODS

Frailty and health-related quality of life (HRQL) were prospectively measured repeatedly for up to 3 years after lung transplantation. Frailty, quantified by the Short Physical Performance Battery (SPPB), was tested as a time-dependent binary and continuous predictor. The association of transplant-related frailty with HRQL and mortality was evaluated using mixed effects and Cox regression models, respectively, adjusting for age, sex, ethnicity, diagnosis, and for body mass index and lung function as time-dependent covariates. We tested the association between measures of body composition, malnutrition, renal dysfunction and immunosuppressants on the development of frailty using mixed effects models with time-dependent predictors and lagged frailty outcomes.

RESULTS

Among 259 adults (56% male; mean age 55.9±12.3 years), transplant-related frailty was associated with lower HRQL. Frailty was also associated with a 2.5-fold higher mortality risk (HR 2.51; 95% CI 1.21 to 5.23). Further, each 1-point worsening in SPPB was associated, on average, with a 13% higher mortality risk (HR 1.13; 95% CI 1.04 to 1.23). Secondarily, we found that sarcopenia, underweight and obesity, malnutrition, and renal dysfunction were associated with the development of frailty after transplant.

CONCLUSIONS

Transplant-related frailty is associated with lower HRQL and higher mortality in lung recipients. Abnormal body composition, malnutrition and renal dysfunction may contribute to the development of frailty after transplant. Confirming the role of these potential contributors and developing interventions to mitigate frailty may improve lung transplant success.

Heart-lung transplantation: A viable option for connective tissue diseases

BACKGROUND

While lung transplantation (LTx) has been effective for connective tissue disease (CTD) patients with pulmonary involvement, outcomes for heart-lung transplantation (HLTx) are less defined. The aim of this study is to evaluate HLTx in CTD patients utilizing the UNOS database.

METHODS

HLTx patients with CTD (HLTx-CTD) were compared to both LTx patients with CTD (LTx-CTD) and HLTx patients with all other indications (HLTx-OI) from 1999 to 2018. Primary outcome was 1- and 5-year graft survival. Secondary outcomes included freedom from first-year rejection and outcomes prior to transplant discharge.

RESULTS

1143/29 323 adults received first-time HLTx or LTx for CTD. Seventeen were HLTx-CTD (3.3% of total HLTx) and 1126 were LTx-CTD (3.9% of total LTx). There were 492 HLTx-OI. Transplant hemodynamic values including cardiac output, pulmonary capillary wedge pressure, and calculated pulmonary vascular resistance were significantly worse for HLTx-CTD vs LTx-CTD (4.2 vs 5.4 L/min, P = .005; 14 vs 10 mm Hg, P = .009; 439 vs 267 dynes, P = .007, respectively). Cardiac status 1 was more common for HLTx-CTD vs HLTx-OI (94% vs 56%, P < .001). HLTx-CTD 1 and 5-year graft survival was similar compared to LTx-CTD and HLTx-OI.

CONCLUSION

HLTx-CTD is a valid option for carefully selected patients with CTD cardiac and pulmonary involvement with similar morbidity and mortality compared to LTx-CTD and HLTx-OI.

A nonlinear relationship between visceral adipose tissue and frailty in adult lung transplant candidates

Frailty is a state of decreased physiologic reserve associated with poor outcomes before and after lung transplantation. Obesity, particularly central obesity characterized by excess proinflammatory visceral adipose tissue (VAT), is associated with incident frailty in middle-aged and older adults. The association between VAT and frailty in advanced lung disease, however, is unknown. In two, nonoverlapping multicenter cohorts of adults listed for lung transplantation, we measured VAT area on bioelectrical impedance assay (BIA) in one cohort and cross-sectional VAT and subcutaneous adipose tissue (SAT) areas on abdominal computed tomography (CT) in the other. We identified a nonlinear relationship between greater VAT by BIA and frailty. In fully adjusted piecewise regression models, every 20 cm² increase in VAT area was associated with 50% increased odds of frailty in subjects with high VAT (95% CI 1.2-1.9, P < .001), and 10% decreased odds of frailty (95% CI 0.7-1.04, P = .12) in subjects with low VAT. Compared to frail subjects with low VAT, those with high VAT were more likely to have low grip strength and less likely to have weight loss, suggesting that mechanisms of frailty may differ by VAT. Further investigation of mechanisms linking VAT and frailty may identify new targets for prevention and treatment.

Pirfenidone-Induced Sarcoid-Like Reaction: A Novel Complication

Idiopathic pulmonary fibrosis is the most common idiopathic interstitial pneumonia. Prognosis is poor with a median survival <3 years. Pirfenidone is one of two US Food and Drug Administration-approved medications that slow disease progression. We describe the development of lymphadenopathy or a sarcoid-like reaction following initiation of pirfenidone, a complication not previously reported.

Improvement in patient-reported outcomes after lung transplantation is not impacted by the use of extracorporeal membrane oxygenation as a bridge to transplantation

OBJECTIVE

Extracorporeal membrane oxygenation (ECMO) is increasingly used as a bridge to lung transplantation. The impact of preoperative ECMO on health-related quality of life (HRQL) and depressive symptoms after lung transplantation remains unknown, however.

METHODS

In a single-center prospective cohort study, we assessed HRQL and depressive symptoms before and at 3, 6, and 12 months after lung transplantation using the Short Form 12 Physical and Mental Component Scores (SF12-PCS and SF12-MCS), Airway Questionnaire 20-Revised (AQ20R), EuroQol 5D (EQ5D), and Geriatric Depression Scale (GDS). Changes in HRQL were quantified by segmented linear mixed-effects models controlling for age, sex, diagnosis, preoperative forced expiratory volume in 1 second, 6-minute walk distance, and Lung Allocation Score. We compared changes in HRQL among subjects bridged with ECMO, subjects hospitalized but not on ECMO, and subjects called in for transplantation as outpatients.

RESULTS

Out of 189 subjects, 17 were bridged to transplantation with ECMO. In all groups, improvements in HRQL following lung transplantation exceeded the minimally clinically important difference using the SF12-PCS, AQ20R, EQ5D, and GDS. HRQL defined by SF12-MCS did not change after transplantation. Improvements were generally similar among the groups, except for EQ5D, which showed a trend toward less benefit in the outpatients, possibly due to their better HRQL before lung transplantation.

CONCLUSIONS

Subjects ill enough to require ECMO as a bridge to lung transplantation appear to achieve similar improvements in HRQL and depressive symptoms as those who do not. It is reassuring to both providers and patients that lung transplantation provides substantial improvements in HRQL, even for those patients who are critically ill in the run up to transplantation.

Voriconazole increases the risk for cutaneous squamous cell carcinoma after lung transplantation

Lung transplant recipients (LTR) are at high risk of cutaneous squamous cell carcinoma (SCC). Voriconazole exposure after lung transplant has recently been reported as a risk factor for SCC. We sought to study the relationship between fungal prophylaxis with voriconazole and the risk of SCC in sequential cohorts from a single center. We evaluated 400 adult LTR at UCLA between 7/1/2005 and 12/22/2012. On 7/1/2009, our center instituted a protocol switch from targeted to universal antifungal prophylaxis for at least 6 months post-transplant. Using Cox proportional hazards models, time to SCC was compared between targeted (N = 199) and universal (N = 201) prophylaxis cohorts. Cox models were also used to assess SCC risk as a function of time-dependent cumulative exposure to voriconazole and other antifungal agents. The risk of SCC was greater in the universal prophylaxis cohort (HR 2.02, P < 0.01). Voriconazole exposure was greater in the universal prophylaxis cohort, and the cumulative exposure to voriconazole was associated with SCC (HR 1.75, P < 0.01), even after adjustment for other important SCC risk factors. Voriconazole did not increase the risk of advanced tumors. Exposure to other antifungal agents was not associated with SCC. Voriconazole should be used cautiously in this population.

Prevalence and risk factors for hypertension in hemophilia

Hypertension (HTN) is a major risk factor for intracranial hemorrhage. We, therefore, investigated the prevalence, treatment, and control of HTN in adult patients with hemophilia (PWH). PWH≥18 years (n=458) from 3 geographically different cohorts in the United States were evaluated retrospectively for HTN and risk factors. Results were compared with the nationally representative sample provided by the contemporary National Health and Nutrition Examination Survey (NHANES). PWH had a significantly higher prevalence of HTN compared with NHANES. Overall, the prevalence of HTN was 49.1% in PWH compared with 31.7% in NHANES. At ages 18 to 44, 45 to 64, 65 to 74, and ≥75 years, the prevalence of HTN for PWH was 31.8%, 72.6%, 89.7%, and 100.0% compared with 12.5%, 41.2%, 64.1%, and 71.7% in NHANES, respectively. Of treated hypertensive PWH, only 27.1% were controlled, compared with 47.7% in NHANES (all P<0.05). Age, body mass index, diabetes mellitus, and renal function were independently associated with HTN. Among patients with moderate or severe hemophilia there was a trend (≈1.5-fold) for higher odds of having HTN compared with patients with mild hemophilia. On the basis of these results, new care models for adult PWH and further studies for the causes of HTN in hemophilia are recommended.

BRAF mutations in cutaneous melanoma are independently associated with age, anatomic site of the primary tumor, and the degree of solar elastosis at the primary tumor site

Oncogenic BRAF mutations are more frequent in cutaneous melanoma occurring at sites with little or moderate sun-induced damage than at sites with severe cumulative solar ultraviolet (UV) damage. We studied cutaneous melanomas from geographic regions with different levels of ambient UV radiation to delineate the relative effects of cumulative UV damage, age, and anatomic site on the frequency of BRAF mutations. We show that BRAF-mutated melanomas occur in a younger age group on skin without marked solar elastosis and less frequently affect the head and neck area, compared to melanomas without BRAF mutations. The findings indicate that BRAF-mutated melanomas arise early in life at low cumulative UV doses, whereas melanomas without BRAF mutations require accumulation of high UV doses over time. The effect of anatomic site on the mutation spectrum further suggests regional differences among cutaneous melanocytes.

Upstream transcription factor 1 influences plasma lipid and metabolic traits in mice

Upstream transcription factor 1 (USF1) has been associated with familial combined hyperlipidemia, the metabolic syndrome, and related conditions, but the mechanisms involved are unknown. In this study, we report validation of Usf1 as a causal gene of cholesterol homeostasis, insulin sensitivity and body composition in mouse models using several complementary approaches and identify associated pathways and gene expression network modules. Over-expression of human USF1 in both transgenic mice and mice with transient liver-specific over-expression influenced metabolic trait phenotypes, including obesity, total cholesterol level, LDL/VLDL cholesterol and glucose/insulin ratio. Additional analyses of trait and hepatic gene expression data from an F2 population derived from C57BL/6J and C3H/HeJ strains in which there is a naturally occurring variation in Usf1 expression supported a causal role for Usf1 for relevant metabolic traits. Gene network and pathway analyses of the liver gene expression signatures in the F2 population and the hepatic over-expression model suggested the involvement of Usf1 in immune responses and metabolism, including an Igfbp2-centered module. In all three mouse model settings, notable sex specificity was observed, consistent with human studies showing differences in association with USF1 gene polymorphisms between sexes.

Association of stearoyl-CoA desaturase 1 activity with familial combined hyperlipidemia

OBJECTIVE

Stearoyl-CoA desaturase 1 (SCD1) is the rate-limiting enzyme involved in the synthesis of monounsaturated fatty acids, and in mice SCD1 activity is associated with plasma triglyceride levels. We used the fatty acid desaturation index (the plasma ratio of 18:1/18:0) as a marker of SCD1 activity to investigate the relationship of SCD1 to familial combined hyperlipidemia (FCHL).

METHODS AND RESULTS

The fatty acid desaturation index was measured in 400 individuals from 18 extended FCHL pedigrees. FCHL-affected individuals exhibited increased SCD1 activity when compared to unrelated controls (P < 0.0001). The fatty acid desaturation index was found to be highly heritable (h(2) = 0.48, P = 2.2 x 10(-11)) in this study sample. QTL analysis in 346 sibling pairs from 18 FCHL families revealed suggestive linkage of the desaturation index to chromosomes 3p26.1 to 3p13 (z = 2.7, P = 0.003), containing the peroxisome proliferator-activated receptor gamma (PPARgamma) gene, and 20p11.21 to 20q13.32 (z = 1.7, P = 0.04), containing the hepatocyte nuclear factor 4, alpha (HNF4alpha) gene. A specific haplotype of HNF4alpha was found to be associated with the desaturation index in these FCHL families (P = 0.002).

CONCLUSIONS

Our results demonstrate that the fatty acid desaturation index is a highly heritable trait that is associated with the dyslipidemia observed in FCHL.