Hans Henrik Schultz

Long-term persistence of human donor alveolar macrophages in lung transplant recipients

Background Alveolar macrophages (AMFs) are critical regulators of lung function, and may participate in graft rejection following lung transplantation. Recent studies in experimental animals suggest that most AMFs are self-maintaining cells of embryonic origin, but knowledge about the ontogeny and life span of human AMFs is scarce. Methods To follow the origin and longevity of AMFs in patients with lung transplantation for more than 100 weeks, we obtained transbronchial biopsies from 10 gender-mismatched patients with lung transplantation. These were subjected to combined in situ hybridisation for X/Y chromosomes and immunofluorescence staining for macrophage markers. Moreover, development of AMFs in humanised mice reconstituted with CD34+ umbilical cord-derived cells was assessed. Results The number of donor-derived AMFs was unchanged during the 2 year post-transplantation period. A fraction of the AMFs proliferated locally, demonstrating that at least a subset of human AMFs have the capacity to self-renew. Lungs of humanised mice were found to abundantly contain populations of human AMFs expressing markers compatible with a monocyte origin. Moreover, in patients with lung transplantation we found that recipient monocytes seeded the alveoli early after transplantation, and showed subsequent phenotypical changes consistent with differentiation into proliferating mature AMFs. This resulted in a stable mixed chimerism between donor and recipient AMFs throughout the 2-year period. Conclusions The finding that human AMFs are maintained in the lung parenchyma for several years indicates that pulmonary macrophage transplantation can be a feasible therapeutic option for patients with diseases caused by dysfunctional AMFs. Moreover, in a lung transplantation setting, long-term persistence of donor AMFs may be important for the development of chronic graft rejection.

An association of particulate air pollution and traffic exposure with mortality after lung transplantation in Europe

Air pollution from road traffic is a serious health risk, especially for susceptible individuals. Single-centre studies showed an association with chronic lung allograft dysfunction (CLAD) and survival after lung transplantation, but there are no large studies. 13 lung transplant centres in 10 European countries created a cohort of 5707 patients. For each patient, we quantified residential particulate matter with aerodynamic diameter ≤10 µm (PM10) by land use regression models, and the traffic exposure by quantifying total road length within buffer zones around the home addresses of patients and distance to a major road or freeway. After correction for macrolide use, we found associations between air pollution variables and CLAD/mortality. Given the important interaction with macrolides, we stratified according to macrolide use. No associations were observed in 2151 patients taking macrolides. However, in 3556 patients not taking macrolides, mortality was associated with PM10 (hazard ratio 1.081, 95% CI 1.000–1.167); similarly, CLAD and mortality were associated with road lengths in buffers of 200–1000 and 100–500 m, respectively (hazard ratio 1.085– 1.130). Sensitivity analyses for various possible confounders confirmed the robustness of these associations. Long-term residential air pollution and traffic exposure were associated with CLAD and survival after lung transplantation, but only in patients not taking macrolides. Long-term residential air pollution/traffic exposure associated with CLAD and survival after lung transplantation http://ow.ly/Izxj304uA5k

Pulmonary hypertension as a risk factor of mortality after lung transplantation

Pulmonary hypertension (PH) is recognized as a risk factor in lung transplantation as reflected in the lung allocation score (LAS). We examined the impact of PH on outcome after lung transplantation, with special emphasis on pre‐ and post‐capillary PH.

The number of FoxP3+ cells in transbronchial lung allograft biopsies does not predict bronchiolitis obliterans syndrome within the first five years after transplantation

An important limitation to the success of lung transplantation is the development of bronchiolitis obliterans syndrome (BOS). It has been hypothesized that regulatory T lymphocytes (Tregs) are related to the risk of BOS. We aim to evaluate whether the number of forkhead box P3 (FoxP3+) cells/mm2 in lung allograft biopsies is a predictor of long‐term outcome.

Long-term outcomes of thoracic transplant recipients following conversion to everolimus with reduced calcineurin inhibitor in a multicenter, open-label, randomized trial.

The NOCTET study randomized 282 patients ≥1 year after heart or lung transplantation to continue conventional calcineurin inhibitor (CNI) therapy or to start everolimus with reduced‐exposure CNI. Last follow‐up, at ≥5 years postrandomization (mean: 5.6 years) was attended by 72/140 everolimus patients (51.4%) and 91/142 controls (64.1%). Mean measured GFR remained stable in the everolimus group from randomization (51.3 ml/min) to last visit (51.4 ml/min) but decreased in controls (from 50.5 ml/min to 45.3 ml/min) and was significantly higher with everolimus at last follow‐up (P = 0.004). The least squares mean (SE) change from randomization was −1.5 (1.7)ml/min with everolimus versus −7.2 (1.7)ml/min for controls (difference: 5.7 [95% CI 1.7; 9.6]ml/min; P = 0.006). The difference was accounted for by heart transplant patients (difference: 6.9 [95% 2.3; 11.5]ml/min; P = 0.004). Lung transplant patients showed no between‐group difference at last follow‐up. Rates of rejection, death, and major cardiac events were similar between groups, as was graft function. Pneumonia was more frequent with everolimus (18.3% vs. 6.4%). In conclusion, introducing everolimus in maintenance heart transplant patients, with reduced CNI, achieves a significant improvement in renal function which is maintained for at least 5 years, but an early renal benefit in lung transplant patients was lost. Long‐term immunosuppressive efficacy was maintained.

Cytomegalovirus Viral Load in Bronchoalveolar Lavage to Diagnose Lung Transplant Associated CMV Pneumonia.

Background The diagnostic yield for cytomegalovirus (CMV) polymerase chain reaction (PCR) viral load in bronchoalveolar lavage (BAL) or in plasma to diagnose CMV pneumonia in lung transplant recipients remains uncertain and was investigated in a large cohort of consecutive lung transplant recipients. Methods Bronchoscopies within the first year of lung transplantation with CMV detectable in BAL by PCR (ie, viral load, ≥273 IU/mL) were included (66 recipients; 145 bronchoscopies); at each bronchoscopy episode, 2 independent experts reviewed clinical and laboratory information to determine whether the patient at that time fulfilled the criteria for CMV pneumonia per current international recommendations. Corresponding plasma CMV PCR viral load determined at time of the bronchoscopy (n = 126) was also studied. Optimal CMV PCR viral load cutoff for CMV pneumonia diagnosis was determined using receiver operating characteristics. Results CMV was detected in BAL with CMV PCR in 145 episodes, and 34 (23%) of these episodes fulfilled the criteria for CMV pneumonia. The area under the curve-receiver operating characteristics for CMV in BAL was 90% at the optimum cutoff (4545 IU/mL) with a corresponding sensitivity of 91% and specificity of 77% (in plasma the corresponding values were 274 IU/mL, 63% and 76%, respectively). Conclusions CMV PCR viral load in BAL had a high performance to diagnose CMV pneumonia in lung transplant recipients; plasma CMV viral load did not reliably aid as a diagnostic tool.

Early extracellular matrix changes are associated with later development of bronchiolitis obliterans syndrome after lung transplantation

Background Chronic lung allograft dysfunction in the form of bronchiolitis obliterans syndrome (BOS) is the main cause of death beyond 1-year post-lung transplantation. The disease-initiating triggers as well as the molecular changes leading to fibrotic alterations in the transplanted lung are largely unknown. The aim of this study was to identify potential early changes in the extracellular matrix (ECM) in different compartments of the transplanted lung prior to the development of BOS. Methods Transbronchial biopsies from a cohort of 58 lung transplantation patients at the Copenhagen University hospital between 2005 and 2006, with or without development of BOS in a 5-year follow-up, were obtained 3 and 12 months after transplantation. Biopsies were assessed for total collagen, collagen type IV and biglycan in the alveolar and small airway compartments using Massons Trichrome staining and immunohistochemistry. Results A time-specific and compartment-specific pattern of ECM changes was detected. Alveolar total collagen (p=0.0190) and small airway biglycan (p=0.0199) increased between 3 and 12 months after transplantation in patients developing BOS, while collagen type IV (p=0.0124) increased in patients without BOS. Patients with early-onset BOS mirrored this increase. Patients developing grade 3 BOS showed distinct ECM changes already at 3 months. Patients with BOS with treated acute rejections displayed reduced alveolar total collagen (p=0.0501) and small airway biglycan (p=0.0485) at 3 months. Conclusions Patients with future BOS displayed distinct ECM changes compared with patients without BOS. Our data indicate an involvement of alveolar and small airway compartments in post-transplantation changes in the development of BOS.

Lung transplantation for scleroderma lung disease: An international, multicenter, observational cohort study

BACKGROUND Due to its multisystemic nature, scleroderma is considered a relative contraindication to lung transplantation at many centers. However, recent studies suggest similar post-transplant outcomes in patients with scleroderma compared to those with other causes of interstitial lung disease (ILD). Furthermore, it remains unknown whether scleroderma-associated pulmonary arterial hypertension (PAH) influences post-transplant outcomes. Our objective in this study was to assess the indications, survival, and prognostic factors of lung or heart-lung transplantation for scleroderma lung disease. METHODS We retrospectively reviewed the data of 90 patients with scleroderma who underwent lung or heart-lung transplantation between 1993 and 2016 at 14 European centers. International criteria were used to diagnose scleroderma. Pulmonary hypertension (PH) was diagnosed during right heart catheterization based on international guidelines. RESULTS Survival rates after 1, 3, and 5 years were 81%, 68%, and 61%, respectively. By univariate analysis, borderline-significant associations with poorer survival were found for female gender (hazard ratio 2.11; 95% confidence interval [CI] 0.99 to 4.50; p = 0.05) and PAH as the reason for transplantation (hazard ratio 1.90; 95% CI 0.96 to 3.92; p = 0.06). When both these factors were present in combination, the risk of death was 3-fold that in males without PAH. The clinical and histologic presentation resembled veno-occlusive disease in 75% of patients with PAH. CONCLUSIONS Post-transplant survival rates and freedom from chronic lung allograft dysfunction in patients with scleroderma were similar to those in patients with other reasons for lung transplantation. Female sex and PAH in combination was associated with lower survival.

Urgent lung allocation system in the Scandiatransplant countries

BACKGROUND Throughout the world, the scarcity of donor organs makes optimal allocation systems necessary. In the Scandiatransplant countries, organs for lung transplantation are allocated nationally. To ensure shorter wait time for critically ill patients, the Scandiatransplant urgent lung allocation system (ScULAS) was introduced in 2009, giving supranational priority to patients considered urgent. There were no pre-defined criteria for listing a patient as urgent, but each center was granted only 3 urgent calls per year. This study aims to explore the characteristics and outcome of patients listed as urgent, assess changes associated with the implementation of ScULAS, and describe how the system was utilized by the member centers. METHODS All patients listed for lung transplantation at the 5 Scandiatransplant centers 5 years before and after implementation of ScULAS were included. RESULTS After implementation, 8.3% of all listed patients received urgent status, of whom 81% were transplanted within 4 weeks. Patients listed as urgent were younger, more commonly had suppurative lung disease, and were more often on life support compared with patients without urgent status. For patients listed as urgent, post-transplant graft survival was inferior at 30 and 90 days. Although there were no pre-defined criteria for urgent listing, the system was not utilized at its maximum. CONCLUSIONS ScULAS rapidly allocated organs to patients considered urgent. These patients were younger and more often had suppurative lung disease. Patients with urgent status had inferior short-term outcome, plausibly due to the higher proportion on life support before transplantation.

Lung Ultrasound – A Novel Diagnostic Tool To Phenotype Chronic Lung Allograft Dysfunction?

Lung transplantation (LTx) is a well-established treatment in a number of end-stage lung diseases that increases quality of life and survival corresponding to a one-, five-, and ten-year survival rate of 90 %, 60–70 %, and 40–50 %, respectively. Most patients die of chronic lung allograft dysfunction (CLAD) which affects approximately 50 % of all lung transplant recipients after five years. Since 2010 growing attention has been paid to the phenotyping of CLAD as bronchiolitis obliterans syndrome (BOS) and restrictive CLAD (rCLAD). BOS is defined as a persistent decline in forced expiratory volume in one second (FEV1) of 20 % compared to the average of the two best post-transplant values, whereas rCLAD is defined as a combined decline in FEV1 and total lung capacity (TLC) of more than 10 % compared to the best post-transplant baseline values (Sato M et al. J Heart Lung Transplant. 2011;30:735-42). BOS may respond well to pharmacological treatment, whereas there is not yet any documented rCLAD treatment. Also, in contrast to BOS, rCLAD is associated with pleuroparenchymal fibroelastosis (PPFE) on high-resolution computed tomography (HRCT) and has an inferior survival rate compared to BOS (Verleden SE et al. J Heart Lung Transplant. 2014;33:270-7). Identification of pleura pathology and fibrosis in interstitial lung diseases, such as idiopathic PPFE, can be identified using lung ultrasound (LUS) in the presence of pleural thickening and the so-called interstitial syndrome (IS), which, in accordance Case Report