Keller, Cesar A.

Background Acute cellular rejection (ACR) in lung transplant recipients requires demonstration of perivascular lymphocytic infiltration in alveolar tissue samples from transbronchial biopsies (TBBs). Probe-based confocal laser endomicroscopy (pCLE) allows in vivo observation of alveolar, vascular, and cellular microstructures in the lung with potential to identify ACR. The objective of our prospective, blinded, multicenter observational study was to identify pCLE findings in patients with ACR diagnosed histopathologically by TBB. Methods Lung transplant recipients undergoing diagnostic bronchoscopies within 1 year posttransplant for suspected ACR had pCLE video imaging obtained immediately prior to tissue sampling via TBB. Findings of 2 pCLE criteria, abundant alveolar cellularity and perivascular cellularity (PVC), were assessed by 4 investigators familiar with pCLE and compared with histopathologic criteria of ACR to derive sensitivity, specificity, area under the receiver operating characteristic curve, and accuracy. Interobserver agreement was assessed by calculating intraclass coefficient and Fleiss κ. Findings were analyzed before and after a consensus meeting of investigators on interpreting images. Results Thirty pCLE procedures were performed on 24 patients, 8 showing ACR in TBB. Diagnostic performance and interobserver agreement using pCLE to identify PVC were significantly higher than those of abundant alveolar cellularity (P < 0.01). The number of blood vessels identified with PVC on pCLE was significantly correlated with histopathologic activity grading of ACR (P < 0.01). Perivascular cellularity agreement among investigators significantly improved after consensus meeting (P < 0.01). Conclusions When found on pCLE, PVC is a feasible and reproducible criterion for assessment of ACR in vivo, but there is a learning curve for image interpretation.

Background. Lungs are allocated in the United States using the lung allocation score (LAS). We investigated the effect of LAS trends on lung transplant-related costs, healthcare utilization, and mortality. Methods. Utilization data from Mayo Clinic (Florida and Minnesota) from 2005 to 2015 were obtained from the electronic health records (N = 465). Costs were categorized as 1-year posttransplant or transplant episode and standardized using 2015 Medicare reimbursement and cost-to-charge ratios. Regression analysis was used to assess the relationship of LAS to length of stay (LOS), mortality, and cost of transplant. Results. The mean LAS at transplant increased from 45.7 to 58.3 during the study period, whereas the 1-year survival improved from 88.1% to 92.5% (P < 0.0001). The proportion of patients transplanted with LAS of 60 or greater increased from 16.9% to 33.3%. Posttransplant, overall, and intensive care unit LOS increased with increasing LAS. Patients with higher LAS had substantially higher transplant episode costs. An increase of LAS at transplant by 10 points increased inflation-adjusted costs by 12.0% (95% confidence interval, 9.3%–14.5%). Conclusions. The mean LAS at transplant has significantly increased over time associated with increases in LOS, resource utilization and cost. Lung allocation score has not jeopardized overall survival, but a high LAS (>60) at transplant is associated with increased mortality.

Goals: To assess the effect of unilateral versus bilateral lung transplantation (LTx) on esophageal motility and gastroesophageal reflux, and the association with the development of obstructive chronic lung allograft dysfunction (o-CLAD). Background: We have shown that esophagogastric junction outflow obstruction, incomplete bolus transit, and proximal reflux are all independent risk factors for the development of chronic allograft failure. However, it remains unclear whether these factors are influenced by the type of surgery and how this relates to allograft failure. Study: Patients post-LTx (n=48, 24 female; aged 20 to 73 y) completed high-resolution impedance manometry and 24-hour pH/impedance. Results: Patients who had undergone unilateral LTx were more likely to exhibit esophagogastric junction outflow obstruction (47% vs. 18%; P=0.046) and less likely to exhibit hypocontractility (0% vs. 21%; P=0.058) than those who had undergone bilateral LTx. Although the proportion of patients exhibiting gastroesophageal reflux was no different between groups (33% vs. 39%; P=0.505), those undergoing bilateral LTx were more likely to exhibit proximal reflux (8% vs. 37%; P=0.067). Univariate Cox proportion hazards regression analysis did not show a difference between unilateral versus bilateral LTx in the development of o-CLAD (hazard ratio=1.17; 95% confidence interval, 0.48-2.85; P=0.723). Conclusion: The type of LTx performed seems to lead to different risk factors for the development of o-CLAD. Physicians should be aware of these differences, as they may need to be taken into account when managing patient’s post-LTx.

Abstract Feasibility, tolerance, and safety of intravenous infusions of allogeneic mesenchymal stem cell (MSC) therapy in lung transplant recipients with bronchiolitis obliterans syndrome (BOS) are not well established. MSCs were manufactured, cryopreserved, transported to our facility, thawed, and infused into nine recipients with moderate BOS (average drop in forced expiratory volume in 1 second was 56.8% ± 3.2% from post-transplant peak) who were refractory to standard therapy and not candidates for retransplant. Cells were viable and sterile prior to infusion. Patients received a single infusion of either 1 (n = 3), 2 (n = 3), or 4 (n = 3) million MSCs per kg. Patients were medically evaluated before; during; and at 24 hours, 1 week, and 1 month after infusion for evidence of infusion-related adverse events and tolerance of therapy. Vital signs, pulmonary function test results, Borg Dyspnea Index, and routine laboratory data were recorded. Vital signs and O2 saturation did not significantly change during or up to 2 hours after MSC infusion. There were no significant changes in gas exchange variables, pulmonary function test results, or laboratory values at 1, 7, and 30 days postinfusion compared with preinfusion values. Infusion of MSCs in patients with BOS was feasible, safe, and well tolerated and did not produce any significant adverse changes in clinical, functional, or laboratory variables during or up to 30 days after infusion. Manufacturing, transport, and administration of intravenous, allogeneic bone marrow-derived MSCs in doses from 1 to 4 million MSCs per kg is safe in lung transplant recipients with BOS.

Objective To observe the effect of naloxone on the lung function of potential lung transplant donors with neurogenic pulmonary edema. Design and Interventions Donors aged 16 to 55 years without any factors to contraindicate lung donation (pneumonia, pulmonary contusion, etc) were included. Ventilator settings were standardized to a tidal volume of 10 to 12 mL/kg, an FiO 2 of 0.40, and a respiratory rate that kept PCO 2 between 35 and 45 mm Hg. Chest physiotherapy, nebulizer treatments, and frequent suctioning were undertaken. Baseline arterial blood gas analysis and an oxygen challenge were performed. The patients were then given 8 to 10 mg of naloxone. Oxygen challenges and arterial blood gas analyses were repeated every 4 to 6 hours. The data were analyzed by using a paired t test, and each patient served as his or her own control. Setting These interventions were performed on the 19 LifeQuest donors who met the set criteria from July 2002 to July 2004. Results The PaO 2 on the oxygen challenge immediately after administration of naloxone increased from 329 (SD 177) to 363 (SD 191) mm Hg, although the increase from baseline was not significant. The PaO 2 from the second oxygen challenge (median time, 7 hours after administration of naloxone) increased to 413 (SD 177) mm Hg ( P < .01).

AbstractBackgroundConcomitant administration of the triazole antifungals, voriconazole or itraconazole, with tacrolimus can result in significant drug interaction in the transplant recipient. Limited published information exists regarding tacrolimus dosing when transitioning from voriconazole to itraconazole. The objective of this study was to evaluate the extent of the drug interaction with antifungal prophylaxis using voriconazole followed by a change to itraconazole in lung transplant recipients receiving tacrolimus.MethodsThis prospective study included lung transplant recipients receiving antifungal prophylaxis with voriconazole followed by a switch to itraconazole. Patients were followed from the time of transplant until two months after converting to itraconazole. All patients received standard immunosuppression with tacrolimus, mycophenolate mofetil, and a corticosteroid. Tacrolimus dose normalized concentrations using concentration/dose ratio were compared while receiving voriconazole versus itraconazole.ResultsTwenty lung transplant recipients were included in the final analysis. No difference was found with the tacrolimus dose normalized concentrations on voriconazole 254 ± 28 (ng/mL)/(mg/kg) compared with itraconazole 234 ± 34 (ng/mL)/(mg/kg), p = 0.65.ConclusionTacrolimus dosage adjustments were not necessary when converting from voriconazole to itraconazole. Validation in a larger population is needed to confirm these findings.

AbstractIntroductionSolid organ transplant recipients have a higher frequency of tuberculosis (TB) than the general population, with mortality rates of approximately 30%. Although donor‐derived TB is reported to account for <5% of TB in solid organ transplants, the source of Mycobacterium tuberculosis infection is infrequently determined.MethodsWe report 3 new cases of pulmonary TB in lung transplant recipients attributed to donor infection, and review the 12 previously reported cases to assess whether cases could have been prevented and whether any cases that might occur in the future could be detected and investigated more quickly. Specifically, we evaluate whether opportunities existed to determine TB risk on the basis of routine donor history, to expedite diagnosis through routine mycobacterial smears and cultures of respiratory specimens early post transplant, and to utilize molecular tools to investigate infection sources epidemiologically.FindingsOn review, donor TB risk was present among 7 cases. Routine smears and cultures diagnosed 4 asymptomatic cases. Genotyping was used to support epidemiologic findings in 6 cases.ConclusionValidated screening protocols, including microbiological testing and newer technologies (e.g., interferon‐gamma release assays) to identify unrecognized M. tuberculosis infection in deceased donors, are warranted.

BackgroundRight heart failure is an important cause of morbidity and mortality in primary pulmonary hypertension. In a recent prospective, randomized study of severely symptomatic patients, treatment with prostacyclin (epoprostenol) produced improvements in hemodynamics, quality of life, and survival. This article describes the echocardiographic characteristics of participants in this trial; the relationships of echocardiographic variables to hemodynamic parameters, exercise capacity, and quality of life; and the echocardiographic changes associated with prostacyclin therapy.Methods and ResultsThe 81 patients enrolled in this multicenter trial were randomized to treatment with a long-term infusion of prostacyclin in addition to conventional therapy (n=41) or conventional therapy alone (n=40) for 12 weeks. Echocardiograms and assessments of hemodynamics, exercise capacity, and quality of life were performed before and after the treatment phase. On baseline evaluation, patients had marked right ventricular dilatation and dysfunction, abnormal septal curvature, and significant tricuspid regurgitation with a high regurgitant velocity. Pericardial effusions were common. More pronounced abnormalities in right heart structure and function were associated with higher pulmonary arterial and mean right atrial pressures, lower cardiac index, and impaired exercise capacity but had no predictable relationship to quality-of-life indicators. The 12-week infusion of prostacyclin had beneficial effects on right ventricular size, curvature of the interventricular septum, and maximal tricuspid regurgitant jet velocity.ConclusionsThe echocardiographic manifestations of severe primary pulmonary hypertension reflect abnormalities in hemodynamics and exercise capacity. Prostacyclin has beneficial effects on right heart structure and function that may contribute to the clinical improvement and prolonged survival observed with this drug.