Topological Analysis of Functions on Arbitrary Grids: Applications to Quantum Chemistry.

Algorithms are presented for performing a topological analysis of an arbitrary function, evaluated on an arbitrary grid of points. These algorithms work strictly by post-processing the data and require no additional function evaluations. This is achieved by connecting the grid points with a neighborhood graph, allowing the topological analysis to be recast as a problem in the graph theory. The flexibility of the approach is demonstrated for various applications involving analysis of the charge and magnetically induced current densities in molecules, where features of the neighborhood graph are found to correspond to chemically relevant topographical properties, such as Bader charges. These properties converge using orders of magnitude fewer grid points than uniform-grid approaches while exhibiting an appealing O[N log(N)] scaling of the computational cost. The issue of grid bias is discussed in the context of graph-based algorithms and strategies for avoiding this bias are presented. Python implementations of the algorithms are provided.

Design Principles for High-Temperature Superconductors with a Hydrogen-Based Alloy Backbone at Moderate Pressure.

Hydrogen-based superconductors provide a route to the long-sought goal of room-temperature superconductivity, but the high pressures required to metallize these materials limit their immediate application. For example, carbonaceous sulfur hydride, the first room-temperature superconductor made in a laboratory, can reach a critical temperature (T_{c}) of 288 K only at the extreme pressure of 267 GPa. The next recognized challenge is the realization of room-temperature superconductivity at significantly lower pressures. Here, we propose a strategy for the rational design of high-temperature superconductors at low pressures by alloying small-radius elements and hydrogen to form ternary H-based superconductors with alloy backbones. We identify a "fluorite-type" backbone in compositions of the form AXH_{8}, which exhibit high-temperature superconductivity at moderate pressures compared with other reported hydrogen-based superconductors. The Fm3[over ¯]m phase of LaBeH_{8}, with a fluorite-type H-Be alloy backbone, is predicted to be thermodynamically stable above 98 GPa, and dynamically stable down to 20 GPa with a high T_{c}∼185 K. This is substantially lower than the synthesis pressure required by the geometrically similar clathrate hydride LaH_{10} (170 GPa). Our approach paves the way for finding high-T_{c} ternary H-based superconductors at conditions close to ambient pressures.

Diffusing capacity of the lung for carbon monoxide: association with long-term outcomes after lung transplantation in a 20-year longitudinal study.

RATIONALE: The diffusing capacity of the lung for carbon monoxide corrected for haemoglobin (D LCOcor) measures gas movement across the alveolar-capillary interface. We hypothesised that D LCOcor is a sensitive measure of injurious allograft processes disrupting this interface. OBJECTIVES: To determine the prognostic significance of the D LCOcor trajectory on chronic lung allograft dysfunction (CLAD) and survival. METHODS: A retrospective analysis was conducted of all bilateral lung transplant recipients at a single centre, between January 1998 and January 2018, with one or more D LCOcor measurements. Low baseline D LCOcor was defined as the failure to achieve a D LCOcor >75% predicted. Drops in D LCOcor were defined as >15% below recent baseline. RESULTS: 1259 out of 1492 lung transplant recipients were included. The median (range) time to peak D LCOcor was 354 (181-737) days and the mean±sd D LCOcor was 80.2±21.2% pred. Multivariable analysis demonstrated that low baseline D LCOcor was significantly associated with death (hazrd ratio (HR) 1.68, 95% CI 1.27-2.20; p<0.001). Low baseline D LCOcor was not independently associated with CLAD after adjustment for low baseline forced expiratory volume in 1 s or forced vital capacity. Any D LCOcor declines ≥15% were significantly associated with death, independent of concurrent spirometric decline. Lower percentage predicted D LCOcor values at CLAD onset were associated with shorter post-CLAD survival (HR 0.75 per 10%-unit change, p<0.01). CONCLUSION: Low baseline D LCOcor and post-transplant declines in D LCOcor were significantly associated with survival, independent of spirometric measurements. We propose that D LCOcor testing may allow identification of a subphenotype of baseline and chronic allograft dysfunction not captured by spirometry. There may be benefit in routine monitoring of D LCOcor after lung transplantation to identify patients at risk of poor outcomes.

Stochastic nodal surfaces in quantum Monte Carlo calculations.

Treating the fermionic ground state-problem as a constrained stochastic optimization problem, a formalism for fermionic quantum Monte Carlo is developed that makes no reference to a trial wave function. Exchange symmetry is enforced by nonlocal terms appearing in the Green's function corresponding to an additional walker propagation channel. Complemented by a treatment of diffusion that encourages the formation of a stochastic nodal surface, we find that an approximate long-range extension of walker cancellations can be employed without introducing significant bias, reducing the number of walkers required for a stable calculation. A proof-of-concept implementation is shown to give a stable fermionic ground state for simple harmonic and atomic systems.

Functional outcomes and quality of life after normothermic ex vivo lung perfusion lung transplantation.

BACKGROUND: Ex vivo lung perfusion (EVLP) is an effective method to assess and improve the function of otherwise unacceptable lungs, alleviating the shortage of donor lungs. The early results with EVLP have been encouraging, but longer-term results, including functional and patient-reported outcomes, are not well characterized. METHODS: This retrospective single-center study included all lung transplants performed between September 2008 and December 2012. We investigated whether survival or rate of chronic lung allograft dysfunction (CLAD) differed in recipients of EVLP-treated lungs compared with contemporaneous recipients of conventional donor lungs. We also studied functional (highest forced expiratory volume in 1 second predicted, change in 6-minute walk distance, number of acute rejection episodes) and quality of life outcomes. RESULTS: Of 403 lung transplants that were performed, 63 patients (15.6%) received EVLP-treated allografts. Allograft survival for EVLP and conventional donor lung recipients was 79% vs 85%, 71% vs 73%, and 58% vs 57% at 1, 3, and 5 years after transplant, respectively (log-rank p = not significant). Freedom from CLAD was also similar (log-rank p = 0.53). There were no significant differences in functional outcomes such as highest forced expiratory volume in 1 second predicted (76.5% ± 23.8% vs 75.8% ± 22.8%, p = 0.85), change in 6-minute walk distance (194 ± 108 meters vs 183 ± 126 meters, p = 0.57), or the number of acute rejection episodes (1.5 ± 1.4 vs 1.3 ± 1.3, p = 0.36). The EVLP and conventional donor groups both reported a significantly improved quality of life after transplantation, but there was no intergroup difference. CONCLUSION: EVLP is a safe and effective method of assessing and using high-risk donor lungs before transplantation and leads to acceptable long-term survival, graft function, and improvements of quality of life that are comparable with conventionally selected donor lungs.

Restrictive allograft syndrome post lung transplantation is characterized by pleuroparenchymal fibroelastosis.

We previously described restrictive allograft syndrome as a form of chronic lung allograft dysfunction, demonstrating restrictive pulmonary function decline. However, the histopathological correlates of restrictive allograft syndrome have yet to be satisfactorily described. We hypothesized that pulmonary pleuroparenchymal fibroelastosis, as has recently been described in bone marrow transplant recipients, may also be present in the lungs of patients with restrictive allograft syndrome. Retrospective review of 493 patients who underwent lung transplantation between 1 January 1996 and 30 June 2009, was conducted. Out of 47 patients with clinical features of restrictive allograft syndrome, 16 had wedge biopsy, re-transplant lung explant, or autopsy lung specimens available for review. All lungs showed varying degrees of pleural fibrosis. Fifteen of 16 showed parenchymal fibroelastosis, characterized by hypocellular collagen deposition with preservation and thickening of the underlying alveolar septal elastic network. The fibroelastosis was predominantly subpleural in distribution, with some cases also showing centrilobular and paraseptal distribution. A sharp demarcation was often seen between areas of fibroelastosis and unaffected lung parenchyma, with fibroblastic foci often present at this interface. Concurrent features of obliterative bronchiolitis were present in 14 cases. Another common finding was the presence of diffuse alveolar damage (13 cases), usually in specimens obtained <1 year after clinical onset of restrictive allograft syndrome. The single specimen in which fibroelastosis was not identified was obtained before the clinical onset of chronic lung allograft dysfunction, and showed features of diffuse alveolar damage. In conclusion, pleuroparenchymal fibroelastosis is a major histopathologic correlate of restrictive allograft syndrome, and was often found concurrently with diffuse alveolar damage. Our findings support a temporal sequence of diffuse alveolar damage followed by the development of pleuroparenchymal fibroelastosis in the histopathologic evolution of restrictive allograft syndrome.

Revisiting the pathologic finding of diffuse alveolar damage after lung transplantation.

BACKGROUND: Diffuse alveolar damage (DAD) is a non-specific pathologic diagnosis frequently encountered after lung transplantation. We examined the relationship between DAD and different forms of chronic lung allograft dysfunction (CLAD). METHODS: We reviewed the results of 4,085 transbronchial biopsies obtained from 720 lung transplant recipients. DAD detected in biopsies within 3 months and newly detected DAD after 3 months were defined as early DAD and late new-onset DAD, respectively. Among patients with CLAD (FEV(1) <80% baseline), restrictive allograft syndrome (RAS) was defined by a decline in total lung capacity to <90% baseline and bronchiolitis obliterans syndrome (BOS) as CLAD without restrictive allograft syndrome (RAS). Kaplan-Meier analyses and multivariate proportional hazard models were used. RESULTS: DAD was observed in 320 of 720 (44.4%) patients at least once; early and late new-onset DAD were observed in 264 of 707 (37.3%) and 87 of 655 (13.3%) patients, respectively. Early DAD was associated with significantly higher 90-day mortality (20 of 264 [7.6%] vs 11 of 443 [2.5%]; p = 0.001). Moreover, among 502 bilateral lung transplant recipients who had sufficient pulmonary function tests to distinguish BOS and RAS, early DAD was associated with earlier BOS onset (hazard ratio [HR] 1.24; confidence interval [CI] 1.04 to 1.47; p = 0.017; median time of BOS onset: 2,902 vs 4,005 days). Conversely, treated as a time-varying covariate, late new-onset DAD was a significant risk factor for RAS in a Cox model (HR 36.8; CI 18.3 to 74.1; p < 0.0001). CONCLUSIONS: Early DAD is associated with early mortality and BOS, and late new-onset DAD increases the risk of RAS.

Impact of extracorporeal life support on outcome in patients with idiopathic pulmonary arterial hypertension awaiting lung transplantation.

BACKGROUND: Our management of patients with idiopathic pulmonary arterial hypertension (iPAH) awaiting lung transplantation changed in 2006 with the introduction of extracorporeal life support (ECLS) as an option to bridge these patients to transplantation (BTT). METHODS: To study the effect of this change on waiting list mortality and post-transplant outcome, 21 consecutive iPAH patients listed for lung transplantation between January 2006 and September 2010 (second cohort) were compared with 23 consecutive iPAH patients listed between January 1997 and December 2005 (first cohort). RESULTS: Between the first and second cohort, the number of patients admitted to the hospital as BTT increased from 4% (1 of 23) to 48% (10 of 21; p = 0.0009). Six patients were BTT with ECLS in the second cohort, including 4 with the Novalung device (Novalung GmbH, Hechingen, Germany) connected as a pumpless oxygenating right-to-left shunt between the pulmonary artery and left atrium. While on the waiting list, 5 patients (22%) died in the first cohort and none in the second cohort (p = 0.03). Time on the waiting list decreased from 118 ± 85 to 53 ± 40 days between the first and second cohort (p = 0.004). After lung transplantation, the 30-day mortality was 16.7% in the first cohort and 9.5% in the second cohort (p = 0.5). The postoperative intensive care unit stay increased from 17 ± 13 to 36 ± 30 days between the first and second cohort (p = 0.02). The long-term outcome after lung transplantation remained similar between both cohorts. CONCLUSIONS: Aggressive management with ECLS of iPAH patients awaiting lung transplantation could have a major impact to reduce the waiting list mortality. This may, however, be associated with longer intensive care unit stay after transplant.

Normothermic ex vivo lung perfusion in clinical lung transplantation.

BACKGROUND: More than 80% of donor lungs are potentially injured and therefore not considered suitable for transplantation. With the use of normothermic ex vivo lung perfusion (EVLP), the retrieved donor lung can be perfused in an ex vivo circuit, providing an opportunity to reassess its function before transplantation. In this study, we examined the feasibility of transplanting high-risk donor lungs that have undergone EVLP. METHODS: In this prospective, nonrandomized clinical trial, we subjected lungs considered to be high risk for transplantation to 4 hours of EVLP. High-risk donor lungs were defined by specific criteria, including pulmonary edema and a ratio of the partial pressure of arterial oxygen to the fraction of inspired oxygen (PO(2):FIO(2)) less than 300 mm Hg. Lungs with acceptable function were subsequently transplanted. Lungs that were transplanted without EVLP during the same period were used as controls. The primary end point was primary graft dysfunction 72 hours after transplantation. Secondary end points were 30-day mortality, bronchial complications, duration of mechanical ventilation, and length of stay in the intensive care unit and hospital. RESULTS: During the study period, 136 lungs were transplanted. Lungs from 23 donors met the inclusion criteria for EVLP; in 20 of these lungs, physiological function remained stable during EVLP and the median PO(2):FIO(2) ratio increased from 335 mm Hg in the donor lung to 414 and 443 mm Hg at 1 hour and 4 hours of perfusion, respectively (P<0.001). These 20 lungs were transplanted; the other 116 lungs constituted the control group. The incidence of primary graft dysfunction 72 hours after transplantation was 15% in the EVLP group and 30% in the control group (P=0.11). No significant differences were observed for any secondary end points, and no severe adverse events were directly attributable to EVLP. CONCLUSIONS: Transplantation of high-risk donor lungs that were physiologically stable during 4 hours of ex vivo perfusion led to results similar to those obtained with conventionally selected lungs. (Funded by Vitrolife; ClinicalTrials.gov number, NCT01190059.).

Restrictive allograft syndrome (RAS): a novel form of chronic lung allograft dysfunction.

BACKGROUND: Bronchiolitis obliterans syndrome (BOS) with small-airway pathology and obstructive pulmonary physiology may not be the only form of chronic lung allograft dysfunction (CLAD) after lung transplantation. Characteristics of a form of CLAD consisting of restrictive functional changes involving peripheral lung pathology were investigated. METHODS: Patients who received bilateral lung transplantation from 1996 to 2009 were retrospectively analyzed. Baseline pulmonary function was taken as the time of peak forced expiratory volume in 1 second (FEV(1)). CLAD was defined as irreversible decline in FEV(1) < 80% baseline. The most accurate threshold to predict irreversible decline in total lung capacity and thus restrictive functional change was at 90% baseline. Restrictive allograft syndrome (RAS) was defined as CLAD meeting this threshold. BOS was defined as CLAD without RAS. To estimate the effect on survival, Cox proportional hazards models and Kaplan-Meier analyses were used. RESULTS: Among 468 patients, CLAD developed in 156; of those, 47 (30%) showed the RAS phenotype. Compared with the 109 BOS patients, RAS patients showed significant computed tomography findings of interstitial lung disease (p < 0.0001). Prevalence of RAS was approximately 25% to 35% of all CLAD over time. Patient survival of RAS was significantly worse than BOS after CLAD onset (median survival, 541 vs 1,421 days; p = 0.0003). The RAS phenotype was the most significant risk factor of death among other variables after CLAD onset (hazard ratio, 1.60; confidential interval, 1.23-2.07). CONCLUSIONS: RAS is a novel form of CLAD that exhibits characteristics of peripheral lung fibrosis and significantly affects survival of lung transplant patients.

Deciding about lung transplantation: informational needs of patients and support persons.

CONTEXT: Information is essential for informed decision making. To date, the informational needs of patients and support persons making the lung transplant decision are unexplored; in addition, the role of support persons in the transplant decision is unknown. OBJECTIVE: To identify the informational needs of patients and support persons attending a transplant clinic for consultation on lung transplantation, and to identify the involvement of support persons in the decision. DESIGN: A qualitative descriptive study and qualitative content analysis. SETTING: Participants were recruited from the Toronto General Hospital Lung Transplant Program. PARTICIPANTS: Twenty-two patients (8 candidates, 14 recipients) and 16 support persons. RESULTS: Most patients made the lung transplant decision in collaboration with their support person and reported receiving adequate information to make an informed decision. Diverse learning needs were identified among and between patients and support persons. Many participants identified the need for more information on practical issues, life after transplantation, and the experiences of transplant recipients. CONCLUSION: Most patients attending a transplant clinic for consultation on lung transplantation felt they made an informed decision; however, modifications to the content, timing, and ways of providing information could enhance the decision-making process for patients and support persons. Specifically, the transplant team can provide information on core lung transplant topics with access to supplementary information to meet specific needs and use materials that vary in source, formats, and time points during the decision-making period.

Survival of lung transplant patients with cystic fibrosis harboring panresistant bacteria other than Burkholderia cepacia, compared with patients harboring sensitive bacteria.

BACKGROUND: The impact of panresistant bacteria, other than Burkholderia cepacia, on the survival after lung transplantation in patients with cystic fibrosis (CF) remains controversial. METHODS: To determine the impact of panresistant bacteria in CF patients on survival after lung transplantation a retrospective multicenter study was performed. All lung transplant recipients with a pre-transplant diagnosis of CF, at the University of Toronto (n = 53) and Duke University (n = 50), were included. Patients were included in the panresistant group if at least one specimen isolated from their respiratory secretions grew bacteria resistant or intermediate to all classes of antibiotics tested. Patients with sensitive or resistant B cepacia were excluded because of its adverse impact upon post-transplant survival. RESULTS: Forty-five of 103 (43.7%) patients harbored panresistant bacteria (43 had Pseudomonas aeruginosa, 1 had Stenotrophomonas maltophilia, and 1 had Achromobacter xylosoxidans). According to log-rank test, there was decreased survival in patients with panresistant bacteria compared to patients with sensitive bacteria (survival: 91.1 +/- 4.2% vs 98.3 +/- 1.7% at 3 months; 88.6 +/- 4.8% vs 96.6 +/- 2.4% at 1 year; 63.2 +/- 8.6% vs 90.7 +/- 4.0% at 3 years; 58.3 +/- 9.2% vs 85.6 +/- 5.2% at 5 years; p = 0.016). The results did not differ significantly between the two centers. Both groups had similar or better survival than CF patients as reported by the United Network of Organ Sharing (UNOS) registry (1-year, 86.0%; 3 years, 65.4%; 5 years, 49.6%). CONCLUSIONS: Patients with CF harboring panresistant bacteria have slightly decreased survival, but their survival is comparable to the results published by the UNOS registry.

Impact of donors aged 60 years or more on outcome after lung transplantation: results of an 11-year single-center experience.

OBJECTIVE: We examined the outcome of lung transplantation with the use of donors aged 60 years or more. METHODS: From May 1994 to May 2005, 467 lung transplants were performed at our institution. A total of 60 recipients received lungs from donors aged 60 years or more (range 60-77 years, median 65 years), whereas 407 recipients received lungs from younger donors (range 9-59, median 39 years). RESULTS: A total of 48 patients (10%) died within 30 days of surgery: 10 (17%) in the older donor group versus 38 (9%) in the younger donor group (P = .08). The operative mortality varied with the underlying lung disease and was higher in recipients presenting with pulmonary hypertension and pulmonary fibrosis than with emphysema or cystic fibrosis. A total of 210 patients died after a median follow-up of 25 months (range 0-136 months). The overall 5- and 10-year survivals were 57% and 38%, respectively. However, the 10-year survival tended to be worse in the older donor group (16% vs 39% in the younger donor group, P = .07). Bronchiolitis obliterans syndrome was the predominant cause of death in recipients of older donors who survived for more than 90 days after surgery (11/17, 65% vs 45/132, 34% in recipients of younger donors surviving for >90 days after surgery, P = .01). CONCLUSIONS: Given the lack of organ donors, lungs from donors aged 60 years or more should be considered for transplantation. However, the use of donors aged 60 years or more is associated with a lower 10-year survival, and bronchiolitis obliterans syndrome plays a significant role as the cause of late death.

Mycobacterium abscessus infections in lung transplant recipients: the international experience.

BACKGROUND: The clinical significance of Mycobacterium abscessus infection in the lung transplant population is not well understood. METHODS: An international survey was performed to determine the incidence and clinical outcomes of M abscessus infections before and after lung transplantation. RESULTS: Thirty-one (50%) of the 62 transplant centers affiliated with the International Society of Heart and Lung Transplantation responded to the survey. Of 5,200 transplants performed, 17 patients (0.33%) (M/F, 12:5) were identified with M abscessus after transplantation. Two patients had respiratory colonization before lung transplantation. Post-transplantation M abscessus infections occurred in the pulmonary allograft in 12, in skin/soft tissue in 3, or both in 2. Median time to diagnosis after transplantation was 18.5 months (range, 1-111 months). Therapies included multiple antibiotics in 16, surgical débridement in 2, interferon-gamma in 1, or no therapy owing to presumed colonization in 1. Eleven (73%) of 16 treated patients had a radiologic or microbiologic response to treatment. Concurrent infections were common, with Aspergillus (n = 8) and Pseudomonas aeruginosa (n = 5) most frequently seen. Death in 2 patients was attributed to M abscessus. Ten of 17 patients are alive and considered cured. CONCLUSIONS: M abscessus infection in the lung transplant recipient is uncommon and challenging; however, successful treatment can occur. Prolonged combination anti-microbial therapy is required for pulmonary involvement, and surgical débridement is recommended for cutaneous lesions. Concurrent infections are common and may contribute to mortality in this immunosuppressed population.

Incidence and prevalence of diabetes mellitus in patients with cystic fibrosis undergoing lung transplantation before and after lung transplantation.

Cystic fibrosis (CF) related diabetes mellitus (DM) occurs in 15% of adult pancreatic insufficient CF patients. Lung transplantation is a treatment option for end-stage CF. We hypothesized that the prevalence of DM increases after lung transplantation. The study population included adult patients undergoing lung transplantation from March 1988 to March 2002 for end-stage CF at the University of Toronto. Demographic data, exocrine pancreatic function, presence of DM before and after transplant, as well as timing of its development after transplant were collected. Eighty-six patients met the study criteria; 77 of 86 (89.5%) of patients were pancreatic insufficient and were further analyzed. Median follow-up post-transplant was 3.3 yr (interquartile range: 1.2-7.2). Their mean age was 29.7 +/- 8.1 yr and 46 of 77 (59.7%) were male. The prevalence of DM increased from 22 of 77 (28.6%) before transplant to 38 of 77 (49.4%) after transplant (p = 0.008). The median time of DM development after transplant was 80 d (range: 13-4352). Sixteen of 55 (29.1%) of pancreatic insufficient patients who were non-diabetic prior to transplant, developed DM after transplant. DM is common in CF patients undergoing lung transplantation and the prevalence increases after transplant.

Upper lobe fibrosis: a novel manifestation of chronic allograft dysfunction in lung transplantation.

BACKGROUND: Lung transplantation is an established treatment modality for a number of chronic lung diseases. Long-term survival after lung transplantation is limited by chronic allograft dysfunction, usually manifested by bronchiolitis obliterans syndrome. We describe a case series with upper lobe fibrosis, a novel presentation of chronic allograft dysfunction. METHODS: We reviewed lung transplants at the Toronto General Hospital and Duke University Hospital from 1990 to 2002 and identified patients with upper lobe fibrosis. RESULTS: Thirteen of 686 patients (6 women) developed upper lobe fibrosis (Toronto, 9; Duke, 4); 12 of 13 had bilateral transplants. The median age at diagnosis was 42 years (range, 19-70). Primary diagnoses were cystic fibrosis, 6; emphysema, 4; sarcoidosis, 1; and pulmonary fibrosis, 2 patients. Radiographic diagnosis was made at a median of 700 days post-transplant (range, 150-2,920). Pulmonary function tests demonstrated predominantly a progressively worsening restrictive pattern. Open lung biopsy specimens revealed dense interstitial fibrosis, with occasional features of obliterative bronchitis, bronchiolitis obliterans obstructive pneumonia, and aspiration. Nine patients died at a median follow-up of 2,310 days (range, 266-3,740), 8 due to respiratory failure. CONCLUSION: Upper lobe fibrosis is a novel presentation of chronic allograft dysfunction in lung transplant recipients and is differentiated from bronchiolitis obliterans syndrome on the basis of physiologic and radiologic findings.

Pre-transplant panel reactive antibody in lung transplant recipients is associated with significantly worse post-transplant survival in a multicenter study.

BACKGROUND: The presence of antibodies to human leukocyte antigens (HLA) prior to transplantation has been linked to worse post-transplant outcomes in many solid organ transplants. The effect of these antibodies is less clear in lung transplant recipients, although previous studies have suggested an increased incidence of allograft dysfunction. METHODS: A retrospective study of all first lung transplant recipients from the University of Toronto (November 1983-July 2001, n = 380) and Duke University (April 1992-June 2000, n = 276) was performed. Demographic data, survival information, and level of last pre-transplant panel reactive antibody (PRA) were collected. PRA level was measured by the complement-dependent cell cytotoxicity assay at both centers. Survival analysis was performed using the Kaplan-Meier method, and groups were compared with the Wilcoxon rank sum test. RESULTS: Of 656 lung transplant recipients, 101 (15.4%) had a PRA greater than 0, 37 (5.6%) had a PRA greater than 10%, and 20 (3.0%) had a PRA greater than 25%. Patients with a PRA greater than 25% had decreased median survival than did the rest of the patients (1.5 vs 5.2 years) and at 1 month (70% vs 90%), 1 year (65% vs 76%), and 5 years (31% vs 50%), respectively (p = 0.006, Wilcoxon's rank sum test) test). CONCLUSION: Significant elevation of PRA prior to lung transplantation is associated with worse survival, especially in the early post-transplant period. This may be due to a direct effect of anti-HLA antibodies on the allograft. The effectiveness of treatments such as plasmapheresis and intravenous immunoglobulin prior to transplantation needs to be evaluated.

Bile acid aspiration and the development of bronchiolitis obliterans after lung transplantation.

BACKGROUND: Aspiration of gastroesophageal refluxate may contribute to lung transplant bronchiolitis obliterans syndrome (BOS). We investigated bile acids in bronchoalveolar lavage fluid (BALF) and studied its role in BOS. MATERIALS AND METHODS: Surveillance pulmonary function tests and BALF were evaluated in 120 lung recipients. BOS-(0p-3) was diagnosed after 6 months' survival. BOS was defined as "early" if diagnosed within 12 months after a transplant. BALF was assayed for differential cell count, bile acids, and interleukins 8 and 15. Bile acids were considered elevated if greater than normal serum levels ( or =8 micromol/L). RESULTS: Elevated BALF bile acids were measured in 20 (17%) of 120 patients. BOS was diagnosed in 36 (34%) of 107 patients and judged "early" in 21 (57%) of 36. Median BALF bile acid values were 1.6 micromol/L (range, 0-32 micromol/L) in BOS patients and 0.3 micromol/L (range, 0-16 micromol/L) in non-BOS patients ( P = .002); 2.6 micromol/L (range, 0-32 micromol/L) in early BOS patients and 0.8 micromol/L (range, 0-4.6 micromol/L) in late BOS patients, ( P = .02). Bile acids correlated with BALF IL-8 and alveolar neutrophilia (r = 0.3, P = .0004, and r = 0.3, P = .004, respectively), but not with IL-15. Freedom from BOS was significantly shortened in patients with elevated BALF bile acids (Cox-Mantel test, P = .0001). CONCLUSIONS: Aspiration of duodenogastroesophageal refluxate is prevalent after lung transplantation and is associated with the development of BOS. Elevated BALF bile acids may promote early BOS development via an inflammatory process, possibly mediated by IL-8 and alveolar neutrophilia.

Role of lung transplantation in the treatment of bronchogenic carcinomas for patients with end-stage pulmonary disease.

PURPOSE: To determine the role of lung transplantation in the treatment of patients presenting with bronchogenic carcinoma and end-stage lung disease. METHODS: An international survey was conducted to determine the outcome of patients with bronchogenic carcinoma in the explanted lung at the time of transplantation. A group of 69 patients was collected from 33 centers. RESULTS: Twenty-six patients underwent 29 lung transplantations for advanced multifocal bronchioloalveolar carcinoma (BAC) as the primary indication for transplantation, and 13 developed a recurrence, with an overall 5-year actuarial survival of 39%. Incidental bronchogenic carcinomas classified as stage I (n = 22), II (n = 12), and III (n = 2), or as incidental multifocal BAC (n = 7), were found in the explanted lung of the remaining 43 patients. The 5-year actuarial survival was 51% in patients with stage I carcinomas, and was significantly better than for patients with stage II and III carcinomas (survival of 14%) or with incidental multifocal BAC (survival of 23%). Time from transplantation to recurrence and from recurrence to death was significantly longer in patients with multifocal BAC than in patients with other types of bronchogenic carcinoma. In addition, the site of recurrence was limited to the transplanted lung in 88% of the patients with multifocal BAC, whereas it was always widespread in patients with other types of bronchogenic carcinoma. CONCLUSION: This study demonstrates that long-term survival can be achieved after lung transplantation in patients with stage I bronchogenic carcinoma or with advanced multifocal BAC.