Flexible bronchoscopy in pediatric lung transplantation.

Pediatric lung transplantation represents a treatment option for children with advanced lung disease or pulmonary vascular disorders who are deemed an appropriate candidate. Pediatric flexible bronchoscopy is an important and evolving field that is highly relevant in the pediatric lung transplant population. It is thus important to advance our knowledge to better understand how care for children after lung transplant can be maximally optimized using pediatric bronchoscopy. Our goals are to continually improve procedural skills when performing bronchoscopy and to decrease the complication rate while acquiring adequate samples for diagnostic evaluation. Attainment of these goals is critical since allograft assessment by bronchoscopic biopsy is required for histological diagnosis of acute cellular rejection and is an important contributor to establishing chronic lung allograft dysfunction, a common complication after lung transplant. Flexible bronchoscopy with bronchoalveolar lavage and transbronchial lung biopsy plays a key role in lung transplant graft assessment. In this article, we discuss the application of bronchoscopy in pediatric lung transplant evaluation including historical approaches, our experience, and future directions not only in bronchoscopy but also in the evolving pediatric lung transplantation field. Pediatric flexible bronchoscopy has become a vital modality for diagnosing lung transplant complications in children as well as assessing therapeutic responses. Herein, we review the value of flexible bronchoscopy in the management of children after lung transplant and discuss the application of novel techniques to improve care for this complex pediatric patient population and we provide a brief update about new diagnostic techniques applied in the growing lung transplantation field.

ECMO Bridge to Lung Transplant in Children with Idiopathic Pulmonary Arterial Hypertension.

Idiopathic pulmonary arterial hypertension (IPAH) represents an important clinical indication for lung transplant (LTx) in children. Recent trends show fewer children with IPAH are undergoing LTx nowadays compared to previous time periods, including those with most severe form of the disease. Using the UNOS Registry, we investigated if ECMO at the time of transplant impacts post-transplant survival in children with IPAH. A total of 74 LTx recipients while on ECMO at the time of transplant were identified (IPAH: N = 12). Children with IPAH who underwent LTx while on ECMO had shown comparable survival rates to those who were on ECMO for other conditions. This analysis provides encouraging results, supporting the potential expansion of LTx for this patient population. Given the low number of children undergoing LTx, we think there should be a consensus document to provide better guidance for referring and selecting the high-risk pediatric population with IPAH on ECMO for lung transplant.

Outcomes of Concomitant Cardiac Surgical Procedures Performed During Pediatric Lung Transplantation in the United States.

Data on concomitant cardiac surgery (CCS) performed during pediatric lung transplantation (LTx) is limited. Therefore, we conducted a multi-institutional analysis to identify the incidence and outcomes of CCS in pediatric (< 18 years) LTx recipients by merging data (2004-2023) from the United Network for Organ Sharing (UNOS) and Pediatric Health Information System (PHIS) databases. Of the total of 596 pediatric LTx recipients, 87 (15%) underwent CCS. The majority of these cardiac surgeries were atrial septal defect (ASD) closure (90%) followed by aortic arch/descending aortic repair (3%), atrial repair (3%), ventricular septal defect closure (2%), patent ductus arteriosus ligation (2%), and tricuspid valve repair (2%). The median age at LTx was 3 years (IQR: 0-12). Pulmonary hypertension (PHT) was the predominant indication for LTx (54%). Survival to discharge was 94% and 5-years survival was 64%. Our findings indicate CCS in children undergoing LTx has acceptable outcomes.

Lung Transplantation for Pulmonary Vascular Disease in Children: A United Network for Organ Sharing Analysis.

Pulmonary vascular disease (PVD) represents an important clinical indication for lung transplant (LTx) in infants, children, and adolescents. There is limited information on LTx outcomes in these patients. We explored LTx volumes and post-LTx survival in children with PVD compared to other diagnoses. The UNOS Registry was queried from 1989 to 2020 to identify first-time pediatric LTx recipients (< 18 yo). PVD was categorized as idiopathic pulmonary arterial hypertension (IPAH) and non-idiopathic arterial hypertension (non-IPAH) and compared to all other patients as other diagnoses. Univariate and multivariate regression models were performed. 984 pediatric LTx patients (593 before 2010 and 391 during/after 2010) were identified, of which 145 (14.7%) had PVD. There has been no significant change in annual rate of all LTxs over comparative eras. However, there has been a decrease in rate of LTxs for PVD patients. Children with PVD had similar survival to other LTx groups in the early era (p = 0.2) and the latter era (p = 0.9). Univariate Cox models, showed that LTx in patients with PVD was associated with a significantly less risk of mortality for children aged 6-11 years compared to younger and older cohorts (HR = 0.4 [0.17-0.98]; p = 0.045), whereas multivariate analysis showed a trend toward higher mortality in 11-17-year-olds (HR = 1.54 [0.97-2.45]; p = 0.06). For PVD patients, oxygen supplementation and ventilator support at LTx were associated with worse post-transplant survival (p = 0.029 and p = 0.01). There has been a decrease in LTx volume for pediatric patients with PVD in the modern era. Post-LTx outcomes for children with PVD are similar to those of other diagnoses in both eras, with children aged 6-11 years having the best survival. Given these findings, LTx should be considered for this patient population.

Extracorporeal membrane oxygenation bridge to pediatric lung transplantation: Modern era analysis.

BACKGROUND: Survival outcomes of children on extracorporeal membrane oxygenation (ECMO) at time of lung transplant (LTx) remain unclear. METHODS: Pediatric first-time LTx recipients transplanted between January 2000 and December 2020 were identified in the United Network for Organ Sharing Registry to compare post-transplant survival according to ECMO support at time of transplant. For a comprehensive analysis of the data, univariate analysis, multivariable Cox regression, and propensity score matching were performed. RESULTS: During the study period, 954 children under 18 years of age underwent LTx with 40 patients on ECMO. We did not identify a post-LTx survival difference between patients receiving ECMO when compared to those that did not. A multivariable Cox regression model (Hazard ratio = 0.83; 95% confidence interval: 0.47, 1.45; p = .51) did not demonstrate an increased risk for death post-LTx. Lastly, a propensity score matching analysis, retaining 33 ECMO and 33 non-ECMO patients, further confirmed no post-LTx survival difference comparing ECMO to no ECMO cohorts (Hazard ratio = 0.98; 95% confidence interval: 0.48, 2.00; p = .96). CONCLUSIONS: In this contemporary cohort of children, the use of ECMO at the time of LTx did not negatively impact post-transplant survival.

Changing racial and ethnic differences for lung transplantation in cystic fibrosis.

BACKGROUND: CFTR modulators, especially (elexacaftor/tezacaftor/ivacaftor), have positively impacted the CF population and quickly decreased LTx numbers. However, no study has investigated if this reduction is universal across all races/ethnicities. METHODS: Using the UNOS Registry, we explored the frequency/proportions of LTx in WNH and NW (Black, non-Hispanic/Hispanic-Latino/Asian-non Hispanic/American Indian-Alaskan Native-non-Hispanic/Native Hawaiian/Other Pacific Islander-non-Hispanic/Multiracial) in children and adults with CF in the US. RESULTS: Between 1990 and 2019, the annual mean (±SD) number of LTxs for children with CF was 23.2 (±7.7) compared to 5 in 2020 (p < .001) and in 2021 (p < .001). In adults from 1990 to 2019, the mean (±SD) number of LTxs performed was 144.9 (±73.5), which was significantly higher than 2020 (n = 73; p < .001) and 2021 (n = 45; p < .001). Comparing 1990-2019 to post-2019, the proportion of LTxs performed in both children and adults with CF has decreased from 50.5% (696/1378) to 16.4% (9/55) and from 12.1% (4773/39542) to 2.4% (118/5004), respectively. In WNH pediatric patients, the difference in the percentage of all LTx made up by CF patients between the two eras was 41.2% compared to NW patients where the difference was 11%. Similarly in adults, the difference between the two eras was 10.4% in WNH and 2.4% in NW patients. CONCLUSIONS: The recent reduction in LTx for the CF population has had less impact on the NW population in the US, so the continuation of optimal referrals for this group is needed.

Improved donor lung size matching by estimation of lung volumes based on chest X-ray measurements.

RATIONALE: Organ size matching is an important determinant of successful allocation and outcomes in lung transplantation. While computed tomography (CT) is the gold standard, it is rarely used in an organ-donor context, and chest X-ray (CXR) may offer a practical and accurate solution in estimating lung volumes for donor and recipient size matching. We compared CXR lung measurements to CT-measured lung volumes and traditional estimates of lung volume in the same subjects. METHODS: Our retrospective study analyzed clinically obtained CXR and CT lung images of 250 subjects without evidence of lung disease (mean age 9.9 ± 7.8 years; 129 M/121F). From CT, each lung was semi-automatically segmented and total lung volumes were quantified. From anterior-posterior CXR view, each lung was manually segmented and areas were measured. Lung lengths from the apices to the mid-basal regions of each lung were measured from CXR. Quantified CT lung volumes were compared to the corresponding CXR lung lengths, CXR lung areas, height, weight, and predicted total lung capacity (pTLC). RESULTS: There are strong and significant correlations between CT volumes and CXR lung areas in the right lung (R2 = .89, p < .0001), left lung (R2 = .87, p < .0001), and combined lungs (R2 = .89, p < .0001). Similar correlations were seen between CT volumes and CXR measured lung lengths in the right lung (R2 = .79, p < .0001) and left lung (R2 = .81, p < .0001). This correlation between anatomical lung volume (CT) and CXR was stronger than lung-volume correlation to height (R2 = .66, p < .0001), weight (R2 = .43, p < .0001), or pTLC (R2 = .66, p < .0001). CONCLUSION: CXR measures correlate much more strongly with true lung volumes than height, weight, or pTLC. The ability to obtain efficient and more accurate lung volume via CXR has the potential to change our current listing practices of using height as a surrogate for lung size, with a case example provided.

CTOTC-08: A multicenter randomized controlled trial of rituximab induction to reduce antibody development and improve outcomes in pediatric lung transplant recipients.

We conducted a randomized, placebo-controlled, double-blind study of pediatric lung transplant recipients, hypothesizing that rituximab plus rabbit anti-thymocyte globulin induction would reduce de novo donor-specific human leukocyte antigen antibodies (DSA) development and improve outcomes. We serially obtained clinical data, blood, and respiratory samples for at least one year posttransplant. We analyzed peripheral blood lymphocytes by flow cytometry, serum for antibody development, and respiratory samples for viral infections using multiplex PCR. Of 45 subjects enrolled, 34 were transplanted and 27 randomized to rituximab (n = 15) or placebo (n = 12). No rituximab-treated subjects versus five placebo-treated subjects developed de novo DSA with mean fluorescence intensity >2000. There was no difference between treatment groups in time to the primary composite outcome endpoint (death, bronchiolitis obliterans syndrome [BOS] grade 0-p, obliterative bronchiolitis or listing for retransplant). A post-hoc analysis substituting more stringent chronic lung allograft dysfunction criteria for BOS 0-p showed no difference in outcome (p = .118). The incidence of adverse events including infection and rejection episodes was no different between treatment groups. Although the study was underpowered, we conclude that rituximab induction may have prevented early DSA development in pediatric lung transplant recipients without adverse effects and may improve outcomes (Clinical Trials: NCT02266888).

Extracorporeal Life Support for Respiratory Failure in Patients With Electronic Cigarette or Vaping Product Use-Associated Lung Injury.

OBJECTIVES: Electronic cigarette or vaping product use-associated lung injury is a clinical entity that can lead to respiratory failure and death. Despite the severity of electronic cigarette or vaping product use-associated lung injury, the role of extracorporeal life support in its management remains unclear. Our objective was to describe the clinical characteristics and outcomes of patients with electronic cigarette or vaping product use-associated lung injury who received extracorporeal life support. DESIGN: We performed a retrospective review of records of electronic cigarette or vaping product use-associated lung injury patients who received extracorporeal life support. Standardized data were collected via direct contact with extracorporeal life support centers. Data regarding presentation, ventilatory management, extracorporeal life support details, and outcome were analyzed. SETTING: This was a multi-institutional, international case series with patients from 10 different institutions in three different countries. PATIENTS: Patients who met criteria for confirmed electronic cigarette or vaping product use-associated lung injury (based on previously reported diagnostic criteria) and were placed on extracorporeal life support were included. Patients were identified via literature review and by direct contact with extracorporeal life support centers. MEASUREMENTS AND MAIN RESULTS: Data were collected for 14 patients ranging from 16 to 45 years old. All had confirmed vape use within 3 months of presentation. Nicotine was the most commonly used vaping product. All patients had respiratory symptoms and radiographic evidence of bilateral pulmonary opacities. IV antibiotics and corticosteroids were universally initiated. Patients were intubated for 1.9 days (range, 0-6) prior to extracorporeal life support initiation. Poor oxygenation and ventilation were the most common indications for extracorporeal life support. Five patients showed evidence of ventricular dysfunction on echocardiography. Thirteen patients (93%) were placed on venovenous extracorporeal life support, and one patient required multiple rounds of extracorporeal life support. Total extracorporeal life support duration ranged from 2 to 37 days. Thirteen patients survived to hospital discharge; one patient died of septic shock. CONCLUSIONS: Electronic cigarette or vaping product use-associated lung injury can cause refractory respiratory failure and hypoxemia. These data suggest that venovenous extracorporeal life support can be an effective treatment option for profound, refractory respiratory failure secondary to electronic cigarette or vaping product use-associated lung injury.

Auto-inflammation and auto-immunity pathways are associated with emergence of BOS in pediatric lung transplantation.

BACKGROUND: Long-term survival after lung transplantation (LTx) is limited by chronic lung allograft dysfunction (CLAD). METHODS: We report an analysis of cytokine profiles in bronchoalveolar lavage samples collected during a prospective multicenter non-interventional trial primarily designed to determine the impact of community-acquired respiratory viral infections (CARV) in outcomes after pediatric LTx. In this analysis, we identify potential biomarkers of auto-inflammation and auto-immunity associated with survival and risk of bronchiolitis obliterans (BOS) after LTx with cytokine analysis of bronchoalveolar lavage fluid (BALF) from 61 pediatric recipients. RESULTS: Higher IL-23 (p = .048) and IL-31 (p = .035) levels were associated with the risk of BOS, and lower levels of epithelial growth factor (EGF) (p = .041) and eotaxin (EOX) (p = .017) were associated with BOS. Analysis using conditional inference trees to evaluate cytokines at each visit associated with survival identified soluble CD30 (p < .001), pro-inflammatory cytokine IL-23 (p = .02), and sTNFRI (p = .01) below cutoff levels as associated with BOS-free survival. CONCLUSIONS: Our results indicate that post-LTx survival in children may be linked to activation of alternate pathways of the immune system that affect airway remodeling in addition to activation of "classical" pathways that have been described in adult LTx recipients. These may indicate pathways to target for intervention.

Outpatient Respiratory Management of Infants, Children, and Adolescents with Post-Prematurity Respiratory Disease: An Official American Thoracic Society Clinical Practice Guideline.

Background: Premature birth affects millions of neonates each year, placing them at risk for respiratory disease due to prematurity. Bronchopulmonary dysplasia is the most common chronic lung disease of infancy, but recent data suggest that even premature infants who do not meet the strict definition of bronchopulmonary dysplasia can develop adverse pulmonary outcomes later in life. This post-prematurity respiratory disease (PPRD) manifests as chronic respiratory symptoms, including cough, recurrent wheezing, exercise limitation, and reduced pulmonary function. This document provides an evidence-based clinical practice guideline on the outpatient management of infants, children, and adolescents with PPRD. Methods: A multidisciplinary panel of experts posed questions regarding the outpatient management of PPRD. We conducted a systematic review of the relevant literature. The Grading of Recommendations, Assessment, Development, and Evaluation approach was used to rate the quality of evidence and the strength of the clinical recommendations. Results: The panel members considered the strength of each recommendation and evaluated the benefits and risks of applying the intervention. In formulating the recommendations, the panel considered patient and caregiver values, the cost of care, and feasibility. Recommendations were developed for or against three common medical therapies and four diagnostic evaluations in the context of the outpatient management of PPRD. Conclusions: The panel developed recommendations for the outpatient management of patients with PPRD on the basis of limited evidence and expert opinion. Important areas for future research were identified.

What Are the Factors Affecting Total Sleep Time During Video Polysomnography in Infants?

OBJECTIVE: The aim of the study is to investigate factors affecting total sleep time (TST) during infant polysomnography (PSG) and assess if <4 hours of TST is sufficient for accurate interpretation. STUDY DESIGN: Overall, 242 PSGs performed in 194 infants <6 months of chronological age between March 2013 and December 2015 were reviewed to identify factors that affect TST, including age of infant, location and timing of study, presence of medical complexity, and presence of nasal tubes. A continuum of apnea-hypopnea index (AHI) in relation to TST was reviewed. Data were examined in infants who had TST <4 hours and low AHI. RESULTS: Greater TST (p < 0.001) was noted among infants during nocturnal PSGs, at older chronological and post-menstrual ages, and without medical complexity. The presence of nasogastric/impedance probes reduced TST (p = 0.002). Elevated AHIs were identified even in PSGs with TST <4 hours. Short TST may have affected interpretation and delayed initial management in one infant without any inadvertent complications. CONCLUSION: Clinical factors such as PMA and medical complexity, and potentially modifiable factors such as time of day and location of study appeared to affect TST during infant PSGs. TST < 4 hours can be sufficient to identify high AHI allowing physician interpretation. KEY POINTS: · Less than 4 hours of TST is enough for interpretation of infant polysomnography.. · Shorter TST appears related to infant age, medical complexity, and higher apnea-hypopnea index.. · Modifiable factors seen with higher TST were time of day, environment, and presence of nasal tubes..

Remote intervention engagement and outcomes in the Clinical Trials in Organ Transplantation in Children consortium multisite trial.

Remote interventions are increasingly used in transplant medicine but have rarely been rigorously evaluated. We investigated a remote intervention targeting immunosuppressant management in pediatric lung transplant recipients. Patients were recruited from a larger multisite trial if they had a Medication Level Variability Index (MLVI) ≥2.0, indicating worrisome tacrolimus level fluctuation. The manualized intervention included three weekly phone calls and regular follow-up calls. A comparison group included patients who met enrollment criteria after the subprotocol ended. Outcomes were defined before the intent-to-treat analysis. Feasibility was defined as ≥50% of participants completing the weekly calls. MLVI was compared pre- and 180 days postenrollment and between intervention and comparison groups. Of 18 eligible patients, 15 enrolled. Seven additional patients served as the comparison. Seventy-five percent of participants completed ≥3 weekly calls; average time on protocol was 257.7 days. Average intervention group MLVI was significantly lower (indicating improved blood level stability) at 180 days postenrollment (2.9 ± 1.29) compared with pre-enrollment (4.6 ± 2.10), p = .02. At 180 days, MLVI decreased by 1.6 points in the intervention group but increased by 0.6 in the comparison group (p = .054). Participants successfully engaged in a long-term remote intervention, and their medication blood levels stabilized. NCT02266888.

To treat or not to treat: CFTR modulators after lung transplantation.

Evidence for the extrapulmonary benefits of (CFTR) modulators is rapidly expanding. The use of CFTR modulators in CF patients who have undergone lung transplantation is not clear without guidance published in the medical literature to assist clinicians in the care of these patients. We discuss the potential benefits of CFTR modulators and provide insight into their use based on our experience in a small cohort of CF LTx recipients. We present pros and cons of CFTR modulator therapy for LTx recipients with CF. CFTR modulators should be considered in CF patients after lung transplantation for the time being until further research defines how to best use these therapies in transplant recipients.

Vaping Associated Pulmonary Nontuberculous Mycobacteria.

INTRODUCTION: E-cigarette or vaping product use associated lung injury (EVALI) has been an important health risk in both children and adults. The pathophysiology of EVALI is not well understood. However, it is speculated that certain substances such as Vitamin E Acetate (VEA), particularly in marijuana containing vape cartridges may result in lung injury and lead to respiratory dysfunction. EVALI is often seen in the absence of infections, but it has been found to be associated with both fungal and bacterial infections. Like EVALI, nontuberculous mycobacteria (NTM) pulmonary disease is also on the rise, but is primarily reported in immunocompromised individuals. Here, we present three immunocompetent individuals wherein pulmonary NTM infection co-occurred with vaping. METHODS: Medical information including patient history, laboratory, and radiograph reports were abstracted from electronic medical records from participating institutions located in the Bronx, NY, Philadelphia, PA, and Lexington, KY. RESULTS: All three cases were otherwise immunocompetent individuals with a significant history of vaping either nicotine and/or marijuana containing products. The pathogens isolated include Mycobacterium avium complex, M. xenopi, and M. gordonae. All three patients were treated for NTM. CONCLUSION: There is little reported on the association between vaping and NTM. It is possible that vaping may have rendered these individuals to be more susceptible to NTM colonization and infection. The possible mechanisms of vaping lung injury and pulmonary NTM are discussed.

Cystic Fibrosis and Pseudomonas aeruginosa: the Host-Microbe Interface.

In human pathophysiology, the clash between microbial infection and host immunity contributes to multiple diseases. Cystic fibrosis (CF) is a classical example of this phenomenon, wherein a dysfunctional, hyperinflammatory immune response combined with chronic pulmonary infections wreak havoc upon the airway, leading to a disease course of substantial morbidity and shortened life span. Pseudomonas aeruginosa is an opportunistic pathogen that commonly infects the CF lung, promoting an accelerated decline of pulmonary function. Importantly, P. aeruginosa exhibits significant resistance to innate immune effectors and to antibiotics, in part, by expressing specific virulence factors (e.g., antioxidants and exopolysaccharides) and by acquiring adaptive mutations during chronic infection. In an effort to review our current understanding of the host-pathogen interface driving CF pulmonary disease, we discuss (i) the progression of disease within the primitive CF lung, specifically focusing on the role of host versus bacterial factors; (ii) critical, neutrophil-derived innate immune effectors that are implicated in CF pulmonary disease, including reactive oxygen species (ROS) and antimicrobial peptides (e.g., LL-37); (iii) P. aeruginosa virulence factors and adaptive mutations that enable evasion of the host response; and (iv) ongoing work examining the distribution and colocalization of host and bacterial factors within distinct anatomical niches of the CF lung.

Differences in airway microbiome and metabolome of single lung transplant recipients.

BACKGROUND: Recent studies suggest that alterations in lung microbiome are associated with occurrence of chronic lung diseases and transplant rejection. To investigate the host-microbiome interactions, we characterized the airway microbiome and metabolome of the allograft (transplanted lung) and native lung of single lung transplant recipients. METHODS: BAL was collected from the allograft and native lungs of SLTs and healthy controls. 16S rRNA microbiome analysis was performed on BAL bacterial pellets and supernatant used for metabolome, cytokines and acetylated proline-glycine-proline (Ac-PGP) measurement by liquid chromatography-high-resolution mass spectrometry. RESULTS: In our cohort, the allograft airway microbiome was distinct with a significantly higher bacterial burden and relative abundance of genera Acinetobacter & Pseudomonas. Likewise, the expression of the pro-inflammatory cytokine VEGF and the neutrophil chemoattractant matrikine Ac-PGP in the allograft was significantly higher. Airway metabolome distinguished the native lung from the allografts and an increased concentration of sphingosine-like metabolites that negatively correlated with abundance of bacteria from phyla Proteobacteria. CONCLUSIONS: Allograft lungs have a distinct microbiome signature, a higher bacterial biomass and an increased Ac-PGP compared to the native lungs in SLTs compared to the native lungs in SLTs. Airway metabolome distinguishes the allografts from native lungs and is associated with distinct microbial communities, suggesting a functional relationship between the local microbiome and metabolome.

Advanced spray dried proliposomes of amphotericin B lung surfactant-mimic phospholipid microparticles/nanoparticles as dry powder inhalers for targeted pulmonary drug delivery.

The purpose of this study was to design, develop and characterize inhalable proliposomal microparticles/nanoparticles of Amphotericin B (AmB) with synthetic phospholipids, dipalmitoylphosphatidylcholine (DPPC) and dipalmitoylphosphatidylglycerol (DPPG) which are lung surfactant-mimic phospholipids. Organic solutions of AmB and phospholipids, were co-spray dried using an advanced closed-mode system and a high performance cyclone. Scanning electron microscopy (SEM) was employed to visualize the surface structure, morphology, and particles size. The residual water content of the proliposomes was quantified by Karl Fisher coulometric titration (KFT). Degree of crystallinity/non-crystallinity was measured by X-ray powder diffraction (XRPD). Phase behavior was measured by differential scanning calorimetry. The chemical composition by molecular fingerprinting was established using attenuated total reflectance (ATR)-Fourier-transform infrared (FTIR) spectroscopy. The amount of AmB loaded into the proliposomes was quantified using UV-VIS spectroscopy. The in vitro aerosol dispersion performance was conducted using the Next Generation Impactor (NGI) and the human dry powder inhaler (DPI) (Handihaler®) that is FDA-approved. Different human lung cell lines were employed to demonstrate in vitro safety as a function of dose and formulation. Smooth, spherical microparticles/nanoparticles were formed at medium and high spray drying pump rates and had low residual water content. A characteristic peak in the XRPD diffraction pattern as well as an endotherm in DSC confirmed the presence of the lipid bilayer structure characteristic in the DPPC/DPPG proliposomal systems. Superior in vitro aerosol performance was achieved with engineered microparticles/nanoparticles demonstrating suitability for targeted pulmonary drug delivery as inhalable dry powders. The in vitro cellular studies demonstrated that the formulated proliposomes are safe. These AmB proliposomes can be a better option for targeted treatment of severe pulmonary fungal infections.

Epidemiology and persistence of rhinovirus in pediatric lung transplantation.

BACKGROUND: Infection with rhinovirus (HRV) occurs following pediatric lung transplantation. Prospective studies documenting frequencies, persistence, and progression of HRV in this at-risk population are lacking. METHODS: In the Clinical Trials in Organ Transplant in Children prospective observational study, we followed 61 lung transplant recipients for 2 years. We quantified molecular subtypes of HRV in serially collected nasopharyngeal (NP) and bronchoalveolar lavage (BAL) samples and correlated them with clinical characteristics. RESULTS: We identified 135 community-acquired respiratory infections (CARV) from 397 BAL and 480 NP samples. We detected 93 HRV events in 42 (68.8%) patients, 22 of which (23.4%) were symptomatic. HRV events were contiguous with different genotypes identified in 23 cases, but symptoms were not preferentially associated with any particular species. Nine (9.7%) HRV events persisted over multiple successive samples for a median of 36 days (range 18-408 days). Three persistent HRV were symptomatic. When we serially measured forced expiratory volume in one second (FEV1) in 23 subjects with events, we did not observe significant decreases in lung function over 12 months post-HRV. CONCLUSION: In conjunction with our previous reports, our prospectively collected data indicate that molecularly heterogeneous HRV infections occur commonly following pediatric lung transplantation, but these infections do not negatively impact clinical outcomes.

County Rankings Have Limited Utility When Predicting Liver Transplant Outcomes.

BACKGROUND: Evidence of geographical differences in liver transplantation (LT) outcomes has been proposed as a reason to include community characteristics in risk adjustment of transplant quality metrics. However, consistency and utility of rankings in LT outcomes for counties have not been demonstrated. AIMS: We sought to evaluate the utility of county rankings (county socioeconomic status (SES) or county health scores (CHS)) on outcomes after LT. METHODS: Using the United Network for Organ Sharing Registry, adults ≥ 18 years of age undergoing LT between 2002 and 2014 were identified. County-specific 1-year survival was calculated using the Kaplan-Meier method for counties with ≥ 5 LT performed during this period. Agreement between high-risk designation by 1-year mortality rate and county ranking was calculated using the Spearman correlation coefficient. RESULTS: The analysis included 47,769 LT recipients in 1092 counties. County 1-year mortality rates were not correlated with county CHS (Spearman ρ = 0.01, p = 0.694) or county SES (Spearman ρ = - 0.01, p = 0.734). After controlling for individual-level covariates, a statistically significant variability in mortality hazards across counties (p < 0.001) persisted. Although both CHS and SES measures improved the model fit (p = 0.004 and p = 0.048, respectively), an unexplained residual variation in mortality hazard across counties continued. CONCLUSIONS: There is poor agreement between county rankings on various socioeconomic indicators and LT outcomes. Although there is variability in outcomes across counties, this appears not to be due to county-level socioeconomic indices.