A Unique Cellular Organization of Human Distal Airways and Its Disarray in Chronic Obstructive Pulmonary Disease.

Rationale: Remodeling and loss of distal conducting airways, including preterminal and terminal bronchioles (pre-TBs/TBs), underlie progressive airflow limitation in chronic obstructive pulmonary disease (COPD). The cellular basis of these structural changes remains unknown. Objectives: To identify biological changes in pre-TBs/TBs in COPD at single-cell resolution and determine their cellular origin. Methods: We established a novel method of distal airway dissection and performed single-cell transcriptomic profiling of 111,412 cells isolated from different airway regions of 12 healthy lung donors and pre-TBs of 5 patients with COPD. Imaging CyTOF and immunofluorescence analysis of pre-TBs/TBs from 24 healthy lung donors and 11 subjects with COPD were performed to characterize cellular phenotypes at a tissue level. Region-specific differentiation of basal cells isolated from proximal and distal airways was studied using an air-liquid interface model. Measurements and Main Results: The atlas of cellular heterogeneity along the proximal-distal axis of the human lung was assembled and identified region-specific cellular states, including SCGB3A2+ SFTPB+ terminal airway-enriched secretory cells (TASCs) unique to distal airways. TASCs were lost in COPD pre-TBs/TBs, paralleled by loss of region-specific endothelial capillary cells, increased frequency of CD8+ T cells normally enriched in proximal airways, and augmented IFN-γ signaling. Basal cells residing in pre-TBs/TBs were identified as a cellular origin of TASCs. Regeneration of TASCs by these progenitors was suppressed by IFN-γ. Conclusions: Altered maintenance of the unique cellular organization of pre-TBs/TBs, including loss of the region-specific epithelial differentiation in these bronchioles, represents the cellular manifestation and likely the cellular basis of distal airway remodeling in COPD.

Outcomes of Heller Myotomy for Esophageal Achalasia: Lessons From a 48-Year Prospective Experience With 4 Different Techniques.

OBJECTIVE: To provide information on long-term outcomes of Heller myotomy for esophageal achalasia with or without an antireflux fundoplication. BACKGROUND: Since the adoption of the Heller myotomy, surgeons have modified the original technique in order to balance the cure of dysphagia and the consequent cardial incontinence. METHODS: Totally, 470 patients underwent primary Heller myotomy between 1955 and 2020. A long abdominal myotomy (AM) was performed in 83 patients, the Ellis limited transthoracic myotomy (TM) in 30, the laparotomic Heller-Dor (L-HD) in 202, the videolaparoscopic Heller-Dor (VL-HD) in 155. The HD was performed under intraoperative manometric assessment. Starting on 1973 these patients underwent a prospective follow-up program of timed lifelong clinical, radiological, endoscopic evaluations. RESULTS: Median follow-up time was 23.06 years [interquantile range (IQR): 15.04-32.06] for AM, 29.22 years (IQR: 13.46-40.17) for TM, 14.85 years (IQR: 11.05-21.56) for L-HD and 7.51 years (IQR: 3.25-9.60) for VL-HD. In AM, relapse of dysphagia occurred in 25/71 (35.21%), in TM in 11/30 (36.66%), in LH-D in 10/201 (4.97%), in VL-HD in 3/155 (1.93%). Erosive-ulcerative esophagitis was diagnosed for AM in 28.16%, for TM in 30%, for L-HD in 8.45%, for VL-HD in 2.58%. Overall, the outcome was satisfactory in 52.11% for AM, 41.9% for TM, 89.05% for L-HD, 96.12% for VL-HD. CONCLUSIONS: The Dor fundoplication drastically reduces postmyotomy gastroesophageal reflux. The Heller-Dor operation is a competitive option for the cure of esophageal achalasia if this operation is performed according to the rules of surgical physiology learned by means of intraoperative manometry.

Lung Transplantation for Primary Ciliary Dyskinesia and Kartagener Syndrome: A Multicenter Study.

Primary ciliary dyskinesia, with or without situs abnormalities, is a rare lung disease that can lead to an irreversible lung damage that may progress to respiratory failure. Lung transplant can be considered in end-stage disease. This study describes the outcomes of the largest lung transplant population for PCD and for PCD with situs abnormalities, also identified as Kartagener's syndrome. Retrospectively collected data of 36 patients who underwent lung transplantation for PCD from 1995 to 2020 with or without SA as part of the European Society of Thoracic Surgeons Lung Transplantation Working Group on rare diseases. Primary outcomes of interest included survival and freedom from chronic lung allograft dysfunction. Secondary outcomes included primary graft dysfunction within 72 h and the rate of rejection ≥A2 within the first year. Among PCD recipients with and without SA, the mean overall and CLAD-free survival were 5.9 and 5.2 years with no significant differences between groups in terms of time to CLAD (HR: 0.92, 95% CI: 0.27-3.14, p = 0.894) or mortality (HR: 0.45, 95% CI: 0.14-1.43, p = 0.178). Postoperative rates of PGD were comparable between groups; rejection grades ≥A2 on first biopsy or within the first year was more common in patients with SA. This study provides a valuable insight on international practices of lung transplantation in patients with PCD. Lung transplantation is an acceptable treatment option in this population.

The Safety and Efficacy of Tracheostomy in Patients Diagnosed With COVID-19: An Analysis of 143 Patients at a Major NYC Medical Center.

OBJECTIVE: To determine the optimal surgical strategy for performing tracheostomy in COVID-19 patients. BACKGROUND: Many ventilated COVID-19 patients require prolonged ventilation. We do not know if tracheostomy will improve their care. Given the paucity of data on this topic, the optimal surgical approach has yet to be elucidated. METHODS: This is a cohort study of 143 ventilator dependent COVID-19 patients undergoing tracheostomy at an academic medical center from April 15th to May 15th, 2020, with follow up until June 1, 2020. We included adult patients admitted to a NYC medical center with COVID-19 who required invasive mechanical ventilation for greater than 2 weeks who were unable to be extubated and determined to have reasonable chance of recovery and fit defined tracheostomy candidate criteria. Patients underwent either a percutaneous tracheostomy (PT) or open surgical tracheostomy (ST) performed by 1 of 3 surgical services. RESULTS: One hundred forty-three patients underwent tracheostomy, 58 (41%) via a ST, and 85 (59%) via a PT. There were no significant differences in patient characteristics between the 2 groups, except that more patients who had a history of extracorporeal membrane oxygenation underwent PT (11% vs 2%, P = 0.049). There were no statistical differences observed between the PT and ST groups with regard to bleeding complications (3.5%vs 10.3%, P = 0.099), tracheostomy related complications (5.9% vs 8.6%, P = 0.528), inpatient death (12% vs 5%, P = 0.178), discharge from hospital (39% vs 36%, P = 0.751) or surgeon illness (0% vs 0%, P = 1). CONCLUSION AND RELEVANCE: The rapid formation of a multi-disciplinary team allows for the efficient evaluation and performance of a large volume of tracheostomies in a resource-limited setting. Bedside tracheostomy in COVID-19 does not cause additional harm to patients if performed after 2 weeks from intubation. It also seems to be safe for proceduralists to perform in this timeframe. The manner of tracheostomy does not change outcomes significantly if it is performed safely and efficiently.

Survival After Lung Transplantation for Chronic Hypersensitivity Pneumonitis: Results From a Large International Cohort Study.

Repeated exposure to antigens via inhalation is the primary cause of hypersensitivity pneumonitis, a form of interstitial pneumonia. The chronic form of hypersensitivity pneumonitis leads to progressive loss of respiratory function; lung transplantation is the only therapeutic option for chronically ill patients. The ESTS Lung Transplantation Working Group conducted a retrospective multicentred cohort study to increase the body of knowledge available on this rare indication for lung transplantation. Data were collected for every patient who underwent lung transplant for hypersensitivity pneumonitis in participating centres between December 1996 and October 2019. Primary outcome was overall survival; secondary outcome was freedom from chronic lung allograft dysfunction. A total of 114 patients were enrolled from 9 centres. Almost 90% of patients were diagnosed with hypersensitivity pneumonitis before transplantation, yet the antigen responsible for the infection was identified in only 25% of cases. Eighty per cent of the recipients received induction therapy. Survival at 1, 3, and 5 years was 85%, 75%, and 70%, respectively. 85% of the patients who survived 90 days after transplantation were free from chronic lung allograft dysfunction after 3 years. The given study presents a large cohort of HP patients who underwent lung transplants. Overall survival rate is higher in transplanted hypersensitivity pneumonitis patients than in those suffering from any other interstitial lung diseases. Hypersensitivity pneumonitis patients are good candidates for lung transplantation.

Risk Factors and Outcomes for Gastroparesis After Lung Transplantation.

BACKGROUND: Gastroparesis is common after lung transplantation and is associated with worse transplant outcomes, including the development of chronic lung allograft dysfunction (CLAD). This study sought to identify the prevalence, risk factors, and outcomes associated with a new diagnosis of gastroparesis after lung transplantation. METHODS: This was a single-center retrospective study of patients who underwent lung transplantation in 2008-2018. The primary outcome was a new diagnosis of gastroparesis within 3 years of transplant. Secondary outcomes included a new diagnosis of gastroesophageal reflux and the association between gastroparesis and both post-transplant survival and CLAD-free survival. Multivariable logistic regression was used to compare diagnosis of gastroparesis and gastroesophageal reflux, while multivariable Cox proportional hazards models were used to analyze gastroparesis and post-transplant outcomes. RESULTS: Of 616 patients with no prior history of gastroparesis, 107 (17.4%) were diagnosed with delayed gastric emptying within 3 years of transplant. On multivariable logistic regression, black race (OR 2.16, 95% CI 1.18-3.98, p = 0.013) was significantly associated with a new diagnosis of gastroparesis. Age, sex, history of diabetes, connective tissue disease, type of transplant, diagnosis group, renal function, and body mass index were not predictive of gastroparesis post-transplant. Gastroparesis was significantly associated with CLAD (HR 1.76, 95% CI 1.20-2.59, p = 0.004), but not with overall mortality (HR 1.16, p = 0.43). CONCLUSION: While gastroparesis is common after lung transplantation, it remains difficult to predict which patients will develop these complications post-transplant. Black patients were more likely to be diagnosed with gastroparesis after adjusting for relevant confounders. Gastroparesis is associated with increased risk of CLAD, and further studies are needed to assess whether early detection and treatment can reduce the incidence of CLAD.

Neoadjuvant atezolizumab and chemotherapy in patients with resectable non-small-cell lung cancer: an open-label, multicentre, single-arm, phase 2 trial.

BACKGROUND: Approximately 25% of all patients with non-small-cell lung cancer present with resectable stage IB-IIIA disease, and although perioperative chemotherapy is the standard of care, this treatment strategy provides only modest survival benefits. On the basis of the activity of immune checkpoint inhibitors in metastatic non-small-cell lung cancer, we designed a trial to test the activity of the PD-L1 inhibitor, atezolizumab, with carboplatin and nab-paclitaxel given as neoadjuvant treatment before surgical resection. METHODS: This open-label, multicentre, single-arm, phase 2 trial was done at three hospitals in the USA. Eligible patients were aged 18 years or older and had resectable American Joint Committee on Cancer-defined stage IB-IIIA non-small-cell lung cancer, an Eastern Cooperative Oncology Group performance status of 0-1, and a history of smoking exposure. Patients received neoadjuvant treatment with intravenous atezolizumab (1200 mg) on day 1, nab-paclitaxel (100 mg/m2) on days 1, 8, and 15, and carboplatin (area under the curve 5; 5 mg/mL per min) on day 1, of each 21-day cycle. Patients without disease progression after two cycles proceeded to receive two further cycles, which were then followed by surgical resection. The primary endpoint was major pathological response, defined as the presence of 10% or less residual viable tumour at the time of surgery. All analyses were intention to treat. This study is registered with ClinicalTrials.gov, NCT02716038, and is ongoing but no longer recruiting participants. FINDINGS: Between May 26, 2016, and March 1, 2019, we assessed 39 patients for eligibility, of whom 30 patients were enrolled. 23 (77%) of these patients had stage IIIA disease. 29 (97%) patients were taken into the operating theatre, and 26 (87%) underwent successful R0 resection. At the data cutoff (Aug 7, 2019), the median follow-up period was 12·9 months (IQR 6·2-22·9). 17 (57%; 95% CI 37-75) of 30 patients had a major pathological response. The most common treatment-related grade 3-4 adverse events were neutropenia (15 [50%] of 30 patients), increased alanine aminotransferase concentrations (two [7%] patients), increased aspartate aminotransferase concentration (two [7%] patients), and thrombocytopenia (two [7%] patients). Serious treatment-related adverse events included one (3%) patient with grade 3 febrile neutropenia, one (3%) patient with grade 4 hyperglycaemia, and one (3%) patient with grade 2 bronchopulmonary haemorrhage. There were no treatment-related deaths. INTERPRETATION: Atezolizumab plus carboplatin and nab-paclitaxel could be a potential neoadjuvant regimen for resectable non-small-cell lung cancer, with a high proportion of patients achieving a major pathological response, and manageable treatment-related toxic effects, which did not compromise surgical resection. FUNDING: Genentech and Celgene.

Bile acids inhibit cholinergic constriction in proximal and peripheral airways from humans and rodents.

Duodenogastroesophageal reflux (DGER) is associated with chronic lung disease. Bile acids (BAs) are established markers of DGER aspiration and are important risk factors for reduced post-transplant lung allograft survival by disrupting the organ-specific innate immunity, facilitating airway infection and allograft failure. However, it is unknown whether BAs also affect airway reactivity. We investigated the acute effects of 13 BAs detected in post-lung-transplant surveillance bronchial washings (BW) on airway contraction. We exposed precision-cut slices from human and mouse lungs to BAs and monitored dynamic changes in the cross-sectional luminal area of peripheral airways using video phase-contrast microscopy. We also used guinea pig tracheal rings in organ baths to study BA effects in proximal airway contraction induced by electrical field stimulation. We found that most secondary BAs at low micromolar concentrations strongly and reversibly relaxed smooth muscle and inhibited peripheral airway constriction induced by acetylcholine but not by noncholinergic bronchoconstrictors. Similarly, secondary BAs strongly inhibited cholinergic constrictions in tracheal rings. In contrast, TC-G 1005, a specific agonist of the BA receptor Takeda G protein-coupled receptor 5 (TGR5), did not cause airway relaxation, and Tgr5 deletion in knockout mice did not affect BA-induced relaxation, suggesting that this receptor is not involved. BAs inhibited acetylcholine-induced inositol phosphate synthesis in human airway smooth muscle cells overexpressing the muscarinic M3 receptor. Our results demonstrate that select BAs found in BW of patients with lung transplantation can affect airway reactivity by inhibiting the cholinergic contractile responses of the proximal and peripheral airways, possibly by acting as antagonists of M3 muscarinic receptors.

COVID-19 in lung transplant recipients: A single center case series from New York City.

There are limited data describing COVID-19 in lung transplant recipients. We performed a single center, retrospective case series study of lung transplant patients followed by the Columbia Lung Transplant program who tested positive for SARS-CoV-2 between March 19 and May 19, 2020. Thirty-two lung transplant patients developed mild (16%), moderate (44%), or severe (41%) COVID-19. The median age of patients was 65 years, and the median time from lung transplant was 5.6 years. Symptoms included cough (66%), dyspnea (50%), fever (47%), and gastrointestinal upset (44%). Patients received hydroxychloroquine (84%), azithromycin (75%), augmented steroids (44%), tocilizumab (19%), and remdesivir (9%). Eleven patients (34%) died at a median time of 14 days from admission. Complications during admission included: acute kidney injury (63%), transaminitis (31%), shock (31%), acute respiratory distress syndrome (25%), neurological events (25%), arrhythmias (22%), and venous thromboembolism (9%). Compared to patients with moderate COVID-19, patients with severe COVID-19 had higher peak white blood cell counts (15.8 vs 7 × 103 /uL, P = .019), C-reactive protein (198 vs. 107 mg/L, P = .010) and D-dimer (8.6 vs. 2.1 ug/mL, P = .004) levels, and lower nadir lymphocyte counts (0.09 vs. 0.4 × 103 /uL, P = .006). COVID-19 is associated with severe illness and a high mortality rate in lung transplant recipients.

Donor surfactant protein A2 polymorphism and lung transplant survival.

PURPOSE: Gene polymorphisms of surfactant proteins, key players in lung innate immunity, have been associated with various lung diseases. The aim of this study was to investigate the potential association between variations within the surfactant protein (SP)-A gene of the donor lung allograft and recipient post-transplant outcome. METHODS: Lung-transplant patients (n=192) were prospectively followed-up with pulmonary function tests, bronchoscopies with bronchoalveolar lavage and biopsies. Donor lungs were assayed for SP-A1 (6An) and SP-A2 (1An) gene polymorphism using the pyrosequencing method. Unadjusted and adjusted stratified Cox survival models are reported. RESULTS: SP-A1 and SP-A2 genotype frequency and lung transplant recipient and donor characteristics as well as cause of death are noted. Recipients were grouped per donor SP-A2 variants. Individuals that received lungs from donors with the SP-A2 1A0 (n=102) versus 1A1 variant (n=68) or SP-A2 genotype 1A01A0 (n=54) versus 1A0A1 (n=38) had greater survival at 1 year (log-rank p<0.025). No significant association was noted for SP-A1 variants. Stratified adjusted survival models for 1-year survival and diagnosis showed a reduced survival for 1A1 variant and the 1A01A1 genotype. Furthermore, when survival was conditional on 1-year survival no significance was observed, indicating that the survival difference was due to the first year's outcome associated with the 1A1 variant. CONCLUSION: Donor lung SP-A gene polymorphisms are associated with post-transplant clinical outcome. Lungs from donors with the SP-A2 variant 1A1 had a reduced survival at 1 year. The observed donor genetic differences, via innate immunity relate to the post-transplant clinical outcome.

Minimally invasive central venoarterial extracorporeal membrane oxygenation for long-term ambulatory support as a bridge to heart-lung transplant.

Extracorporeal membrane oxygenation (ECMO) is becoming a key tool for bridge to heart, lung, or heart-lung transplantation, and ambulatory ECMO support offers many advantages to prepare the patients. We here present a case of successful en bloc heart and lung transplantation after long-term ambulatory support with a minimally invasive central venoarterial ECMO approach as bridge to transplant.

Geographic disparities in donor lung supply and lung transplant waitlist outcomes: A cohort study.

Despite the Final Rule mandate for equitable organ allocation in the United States, geographic disparities exist in donor lung allocation, with the majority of donor lungs being allocated locally to lower-priority candidates. We conducted a retrospective cohort study of 19 622 lung transplant candidates waitlisted between 2006 and 2015. We used multivariable adjusted competing risk survival models to examine the relationship between local lung availability and waitlist outcomes. The primary outcome was a composite of death and removal from the waitlist for clinical deterioration. Waitlist candidates in the lowest quartile of local lung availability had an 84% increased risk of death or removal compared with candidates in the highest (subdistribution hazard ratio [SHR]: 1.84, 95% confidence interval [CI]: 1.51-2.24, P < .001). The transplantation rate was 57% lower in the lowest quartile compared with the highest (SHR: 0.43, 95% CI: 0.39-0.47). The adjusted death or removal rate decreased by 11% with a 50% increase in local lung availability (SHR: 0.89, 95% CI: 0.85-0.93, P < .001) and the adjusted transplantation rate increased by 19% (SHR: 1.19, 95% CI: 1.17-1.22, P < .001). There are geographically disparate waitlist outcomes in the current lung allocation system. Candidates listed in areas of low local lung availability have worse waitlist outcomes.

Frailty phenotypes and mortality after lung transplantation: A prospective cohort study.

Frailty is associated with increased mortality among lung transplant candidates. We sought to determine the association between frailty, as measured by the Short Physical Performance Battery (SPPB), and mortality after lung transplantation. In a multicenter prospective cohort study of adults who underwent lung transplantation, preoperative frailty was assessed with the SPPB (n = 318) and, in a secondary analysis, the Fried Frailty Phenotype (FFP; n = 299). We tested the association between preoperative frailty and mortality following lung transplantation with propensity score-adjusted Cox models. We calculated postestimation marginalized standardized risks for 1-year mortality by frailty status using multivariate logistic regression. SPPB frailty was associated with an increased risk of both 1- and 4-year mortality (adjusted hazard ratio [aHR]: 7.5; 95% confidence interval [CI]: 1.6-36.0 and aHR 3.8; 95%CI: 1.8-8.0, respectively). Each 1-point worsening in SPPB was associated with a 20% increased risk of death (aHR: 1.20; 95%CI: 1.08-1.33). Frail subjects had an absolute increased risk of death within the first year after transplantation of 12.2% (95%CI: 3.1%-21%). In secondary analyses, FFP frailty was associated with increased risk of death within the first postoperative year (aHR: 3.8; 95%CI: 1.1-13.2) but not over longer follow-up. Preoperative frailty is associated with an increased risk of death after lung transplantation.

Adipose Gene Expression Profile Changes With Lung Allograft Reperfusion.

Obesity is a risk factor for primary graft dysfunction (PGD), a form of lung injury resulting from ischemia-reperfusion after lung transplantation, but the impact of ischemia-reperfusion on adipose tissue is unknown. We evaluated differential gene expression in thoracic visceral adipose tissue (VAT) before and after lung reperfusion. Total RNA was isolated from thoracic VAT sampled from six subjects enrolled in the Lung Transplant Body Composition study before and after allograft reperfusion and quantified using the Human Gene 2.0 ST array. Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed enrichment for genes involved in complement and coagulation cascades and Jak-STAT signaling pathways. Overall, 72 genes were upregulated and 56 genes were downregulated in the postreperfusion time compared with baseline. Long pentraxin-3, a gene and plasma protein previously associated with PGD, was the most upregulated gene (19.5-fold increase, p = 0.04). Fibronectin leucine-rich transmembrane protein-3, a gene associated with cell adhesion and receptor signaling, was the most downregulated gene (4.3-fold decrease, p = 0.04). Ischemia-reperfusion has a demonstrable impact on gene expression in visceral adipose tissue in our pilot study of nonobese, non-PGD lung transplant recipients. Future evaluation will focus on differential adipose tissue gene expression and the development of PGD after transplant.

Short Stature and Access to Lung Transplantation in the United States. A Cohort Study.

RATIONALE: Anecdotally, short lung transplant candidates suffer from long waiting times and higher rates of death on the waiting list compared with taller candidates. OBJECTIVES: To examine the relationship between lung transplant candidate height and waiting list outcomes. METHODS: We conducted a retrospective cohort study of 13,346 adults placed on the lung transplant waiting list in the United States between 2005 and 2011. Multivariable-adjusted competing risk survival models were used to examine associations between candidate height and outcomes of interest. The primary outcome was the time until lung transplantation censored at 1 year. MEASUREMENTS AND MAIN RESULTS: The unadjusted rate of lung transplantation was 94.5 per 100 person-years among candidates of short stature (<162 cm) and 202.0 per 100 person-years among candidates of average stature (170-176.5 cm). After controlling for potential confounders, short stature was associated with a 34% (95% confidence interval [CI], 29-39%) lower rate of transplantation compared with average stature. Short stature was also associated with a 62% (95% CI, 24-96%) higher rate of death or removal because of clinical deterioration and a 42% (95% CI, 10-85%) higher rate of respiratory failure while awaiting lung transplantation. CONCLUSIONS: Short stature is associated with a lower rate of lung transplantation and higher rates of death and respiratory failure while awaiting transplantation. Efforts to ameliorate this disparity could include earlier referral and listing of shorter candidates, surgical downsizing of substantially oversized allografts for shorter candidates, and/or changes to allocation policy that account for candidate height.

Frailty Phenotypes, Disability, and Outcomes in Adult Candidates for Lung Transplantation.

RATIONALE: Frailty is associated with morbidity and mortality in abdominal organ transplantation but has not been examined in lung transplantation. OBJECTIVES: To examine the construct and predictive validity of frailty phenotypes in lung transplant candidates. METHODS: In a multicenter prospective cohort, we measured frailty with the Fried Frailty Phenotype (FFP) and Short Physical Performance Battery (SPPB). We evaluated construct validity through comparisons with conceptually related factors. In a nested case-control study of frail and nonfrail subjects, we measured serum IL-6, tumor necrosis factor receptor 1, insulin-like growth factor I, and leptin. We estimated the association between frailty and disability using the Lung Transplant Valued Life Activities disability scale. We estimated the association between frailty and risk of delisting or death before transplant using multivariate logistic and Cox models, respectively. MEASUREMENTS AND MAIN RESULTS: Of 395 subjects, 354 completed FFP assessments and 262 completed SPPB assessments; 28% were frail by FFP (95% confidence interval [CI], 24-33%) and 10% based on the SPPB (95% CI, 7-14%). By either measure, frailty correlated more strongly with exercise capacity and grip strength than with lung function. Frail subjects tended to have higher plasma IL-6 and tumor necrosis factor receptor 1 and lower insulin-like growth factor I and leptin. Frailty by either measure was associated with greater disability. After adjusting for age, sex, diagnosis, and transplant center, both FFP and SPPB were associated with increased risk of delisting or death before lung transplant. For every 1-point worsening in score, hazard ratios were 1.30 (95% CI, 1.01-1.67) for FFP and 1.53 (95% CI, 1.19-1.59) for SPPB. CONCLUSIONS: Frailty is prevalent among lung transplant candidates and is independently associated with greater disability and an increased risk of delisting or death.

Body composition and mortality after adult lung transplantation in the United States.

RATIONALE: Obesity and underweight are contraindications to lung transplantation based on their associations with mortality in studies performed before implementation of the lung allocation score (LAS)-based organ allocation system in the United States Objectives: To determine the associations of body mass index (BMI) and plasma leptin levels with survival after lung transplantation. METHODS: We used multivariable-adjusted regression models to examine associations between BMI and 1-year mortality in 9,073 adults who underwent lung transplantation in the United States between May 2005 and June 2011, and plasma leptin and mortality in 599 Lung Transplant Outcomes Group study participants. We measured body fat and skeletal muscle mass using whole-body dual X-ray absorptiometry in 142 adult lung transplant candidates. MEASUREMENTS AND MAIN RESULTS: Adjusted mortality rates were similar among normal weight (BMI 18.5-24.9 kg/m(2)), overweight (BMI 25.0-29.9), and class I obese (BMI 30-34.9) transplant recipients. Underweight (BMI < 18.5) was associated with a 35% increased rate of death (95% confidence interval, 10-66%). Class II-III obesity (BMI ≥ 35 kg/m(2)) was associated with a nearly twofold increase in mortality (hazard ratio, 1.9; 95% confidence interval, 1.3-2.8). Higher leptin levels were associated with increased mortality after transplant surgery performed without cardiopulmonary bypass (P for interaction = 0.03). A BMI greater than or equal to 30 kg/m(2) was 26% sensitive and 97% specific for total body fat-defined obesity. CONCLUSIONS: A BMI of 30.0-34.9 kg/m(2) is not associated with 1-year mortality after lung transplantation in the LAS era, perhaps because of its low sensitivity for obesity. The association between leptin and mortality suggests the need to validate alternative methods to measure obesity in candidates for lung transplantation. A BMI greater than or equal to 30 kg/m(2) may no longer contraindicate lung transplantation.

Changing patterns in lung transplant for respiratory failure due to COVID-19 in the U.S.

Many patients with severe COVID-19 have been affected by acute respiratory distress syndrome, which has been associated with increased mortality, and up to 31% of these survivors had persistent interstitial lung abnormalities with impaired lung function and quality of life even after 6 to 24 months after initial disease. Lung transplantation quickly emerged as a viable therapy for select patients with respiratory failure due to COVID-19 by mid-2020. In this report, we identified 477 patients who underwent lung transplantation for COVID-19 in the U.S. between March 2020 and December 2022. The number of patients waitlisted and undergoing lung transplantation for COVID-19 increased steadily in the early part of the pandemic with a peak of 97 patients waitlisted between October and December 2021, before steadily decreasing since. Notably, the procedure is now increasingly being done for survivors of COVID-19 with pulmonary fibrosis, rather than for refractory ARDS patients. The 1-year post-transplant mortality was 13.7%.

The Secondary Pulmonary Hypertension Diagnosis is Not Useful in Lung Allocation.

BACKGROUND: In lung transplant, the United Network for Organ Sharing (UNOS) contains a diagnosis of secondary pulmonary hypertension (SPH). SPH and pulmonary arterial hypertension are treated the same in the allocation scoring system. It is not clear whether utilizing the SPH diagnosis instead of the primary diagnosis is helpful to patients or providers. METHODS: Analysis of UNOS data from May 2005 through July 2021, comparing patients listed under the SPH diagnosis with patients listed under COPD and interstitial lung disease (ILD) who met criteria for PH (COPD-PH and ILD-PH, respectively), as well as patients listed under pulmonary arterial hypertension (primary pulmonary hypertension, PPH). Competing-risk analysis examined waitlist and post-transplant outcomes. An exploratory analysis of UNOS spirometry data was performed. RESULTS: Compared to patients listed under the SPH diagnosis, patients with ILD-PH were more likely to undergo transplantation (adjusted HR: 1.34, 95% confidence interval: 1.16-1.54, P < .001), with no significant difference comparing the SPH diagnosis to PPH or to COPD-PH. Waitlist mortality did not vary between groups. Post-transplant survival was lower in patients with PPH (adjusted HR: 1.35, 95% confidence interval: 1.04-1.75, P = .025), with no significant difference comparing the SPH diagnosis to COPD-PH or ILD-PH. Spirometry failed to demonstrate a clear phenotype within the SPH diagnosis. CONCLUSION: In an adjusted analysis, patients with advanced lung disease and secondary PH were more likely to undergo transplantation when listed for ILD than when listed under the SPH diagnosis. The SPH diagnosis is too clinically heterogeneous to be useful in predictive models and should be considered for removal from UNOS.