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Immune rejection remains the major obstacle to long-term survival of allogeneic lung transplants. The expression of major histocompatibility complex molecules and minor histocompatibility antigens triggers allogeneic immune responses that can lead to allograft rejection. Transplant outcomes therefore depend on long-term immunosuppression, which is associated with severe side effects. To address this problem, we investigated the effect of genetically engineered transplants with permanently down-regulated swine leukocyte antigen (SLA) expression to prevent rejection in a porcine allogeneic lung transplantation (LTx) model. Minipig donor lungs with unmodified SLA expression (control group, n = 7) or with modified SLA expression (treatment group, n = 7) were used to evaluate the effects of SLA knockdown on allograft survival and on the nature and strength of immune responses after terminating an initial 4-week period of immunosuppression after LTx. Genetic engineering to down-regulate SLA expression was achieved during ex vivo lung perfusion by lentiviral transduction of short hairpin RNAs targeting mRNAs encoding β2-microglobulin and class II transactivator. Whereas all grafts in the control group were rejected within 3 months, five of seven animals in the treatment group maintained graft survival without immunosuppression during the 2-year monitoring period. Compared with controls, SLA-silenced lung recipients had lower donor-specific antibodies and proinflammatory cytokine concentrations in the serum. Together, these data demonstrate a survival benefit of SLA-down-regulated lung transplants in the absence of immunosuppression.

Objectives: Lack of organ donors demands transplantation of older lung allografts for recipients between 0 and 50 years. So far, it has not yet been investigated whether donor-recipient age mismatch affects long-term outcome., Methods: Records of patients aged between 0 and 50 years were retrospectively reviewed. Donor-recipient age mismatch was calculated subtracting recipient age from donor age. Multivariable Cox regression analyses was performed to assess donor-recipient age mismatch regarding the end points' overall patient mortality, mortality conditioned to hospital discharge, biopsy-confirmed rejection and chronic lung allograft dysfunction. Furthermore, we performed competing risk analysis to analyse if age mismatch affects biopsy-confirmed rejection and CLAD while death being a competing risk., Results: Between January 2010 and September 2021, out of 1363 patients who underwent lung transplantation at our institution, 409 patients fulfilled the eligibility criteria and were included. Age mismatch ranged between 0 and 56 years. Multivariable analysis revealed that donor-recipient age mismatch does not affect overall patient mortality (P = 0.19), biopsy-confirmed rejection (P = 0.68) and chronic lung allograft dysfunction (P = 0.42). There was no difference seen in CLAD (P = 0.166) and biopsy-confirmed rejection (P = 0.944) with the competing risk death (P = 0.765 and P = 0.851; respectively)., Conclusions: Age mismatch between recipients and donors of lung allografts does not affect long-term outcomes after lung transplantation., (© The Author(s) 2023. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)

Background: In spite of renal graft shortage and increasing waiting times for transplant candidates, simultaneous heart and kidney transplantation (HKTx) is an increasingly performed procedure established for patients with combined end-stage cardiac and renal failure. Although data on renal graft outcome in this setting is limited, reports on reduced graft survival in comparison to solitary kidney transplantation (KTx) have led to an ongoing discussion of adequate organ utilization., Methods: This retrospective study was conducted to evaluate prognostic factors and outcomes of 27 patients undergoing HKTx in comparison to a matched cohort of 27 patients undergoing solitary KTx between September 1987 and October 2019 in one of Europe's largest transplant centers., Results: Median follow-up was 100.33 (0.46-362.09) months. Despite lower five-year kidney graft survival (62.6% versus 92.1%; 111.73 versus 183.08 months; p = 0.189), graft function and patient survival (138.90 versus 192.71 months; p = 0.128) were not significantly inferior after HKTx in general. However, in case of prior cardiac surgery requiring sternotomy we observed significantly reduced early graft and patient survival (57.00 and 94.09 months, respectively) when compared to patients undergoing solitary KTx (183.08 and 192.71 months; p < 0.001, respectively) or HKTx without prior cardiac surgery (203.22 and 203.22 months; p = 0.016 and p = 0.019, respectively), most probably explained by the significantly increased rate of primary nonfunction (33.3%) and in-hospital mortality (25.0%)., Conclusions: Our data demonstrates the increased rate of early kidney graft loss and thus significantly inferior graft survival in high-risk patients undergoing HKTx. Thus, we advocate for a "kidney-after-heart" program in such patients to ensure responsible and reasonable utilization of scarce resources in times of ongoing organ shortage crisis., (© 2021. The Author(s).)

In this retrospective study, we analyzed the presence of any association of three CD4 + CD25 high regulatory T-cell subpopulations at 3 weeks after lung transplantation with the later incidence of chronic lung allograft dysfunction and graft survival. Among lung-transplanted patients between January 2009 and April 2018, only patients with sufficient T-cell measurements at 3 weeks after transplantation were included into the study. Putative regulatory T cells were defined as CD4 + CD25 high T cells, detected in peripheral blood and further analyzed for CD127 low , FoxP3 + , and CD152 + using fluorescence-activated cell sorting (FACS) analysis. Associations of regulatory T cells with chronic lung allograft dysfunction (CLAD) and graft survival were evaluated using Cox analysis. During the study period, 724 (71%) patients were included into the study. Freedom from chronic lung allograft dysfunction (CLAD) and graft survival amounted to 66% and 68% at 5 years. At the multivariable analysis, increasing frequencies of CD127 low were associated with better freedom from CLAD (hazard ratio for each 1% increase of %CD127 low , HR = 0.989, 95% CI = 0.981-0.996, P = 0.003) and better graft survival (HR = 0.991, 95% CI = 0.984-0.999, P = 0.026). A higher frequency of CD127 low regulatory T cells in peripheral blood early after lung transplantation estimated a protective effect against chronic lung allograft dysfunction, mortality, and re-transplantation., (© 2020 Steunstichting ESOT.)

This retrospective study presents our 4-year experience of preemptive treatment of early anti-HLA donor specific antibodies with IgA- and IgM-enriched immunoglobulins. We compared outcomes between patients with antibodies and treatment (case patients) and patients without antibodies (control patients). Records of patients transplanted at our institution between March 2013 and November 2017 were reviewed. The treatment protocol included one single 2 g/kg immunoglobulin infusion followed by successive 0.5 g/kg infusions for a maximum of 6 months, usually combined with a single dose of anti-CD20 antibody and, in case of clinical rejection or positive crossmatch, with plasmapheresis or immunoabsorption. Among the 598 transplanted patients, 128 (21%) patients formed the case group and 452 (76%) the control group. In 116 (91%) patients who completed treatment, 106 (91%) showed no antibodies at treatment end. Fourteen (13%) patients showed antibody recurrence thereafter. In case versus control patients and at 4-year follow-up, respectively, graft survival (%) was 79 versus 81 (P = .59), freedom (%) from biopsy-confirmed rejection 57 versus 53 (P = .34), and from chronic lung allograft dysfunction 82 versus 78 (P = .83). After lung transplantation, patients with early donor-specific antibodies and treated with IgA- and IgM-enriched immunoglobulins had 4-year graft survival similar to patients without antibodies and showed high antibody clearance., (© 2018 The American Society of Transplantation and the American Society of Transplant Surgeons.)

Objective: Owing to the improved long-term outcome after cardiac transplantation, cardiac allograft vasculopathy or valvular disease is developing late after heart transplantation in a growing number of patients. In this study, we evaluated our results of nonretransplant cardiac surgery in these patients and compared them with those after retransplantation., Methods: Since 1983, a total of 867 heart transplantations have been performed at our institution. Among them, 44 patients underwent nonretransplant cardiac surgery, 4 of them repeatedly. The procedures included 19 coronary artery revascularizations, 20 tricuspid valve procedures, 4 other valvular procedures, 4 aortic operations, and 1 right atrial thrombectomy. Long-term results of these patients were compared with those of 20 patients after late cardiac retransplantation., Results: Indications for nonretransplant surgery included cardiac allograft vasculopathy, tricuspid regurgitation, aortic and mitral valve insufficiency, as well as acute aortic dissection type A. Mean interval between heart transplantation and reoperation was 8.4 years. Mean follow-up was 5.8 years. Early mortality was 4.5% (2/44). The early deaths were caused by intracerebral bleeding and acute rejection. Actuarial survivals at 1, 5, and 7 years were 84%, 64%, and 58%, respectively. In comparison, early mortality in the retransplant group was 20% (4/20) and survivals at the same time points were 70%, 70%, and 47%, respectively., Conclusions: According to these results, we consider nonretransplant surgical options for cardiac allograft vasculopathy and valvular disease a safe and effective therapeutic approach with low early mortality and acceptable long-term results., (Copyright 2010 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.)

Background: This study was designed to analyze the role of postoperative donor cell chimerism for the induction and maintenance of transplantation tolerance in a porcine lung transplantation model., Methods: Left-sided single lung transplantation from major histocompatibility mismatched male donors was performed in 27 female minipigs. All received a 28-day course of pharmacologic immunosuppression using various agents, some in combination with preoperative irradiation. Groups for eventual analysis were strictly defined by outcome, that is, pigs with acute rejection before postoperative day 178 (n=16) were allocated into one group, long-term surviving animals (n=11) into the other. Peripheral blood chimerism was monitored by flow cytometry and real-time polymerase chain reaction. Intragraft chimerism was detected from bronchoalveolar lavage fluid (BALF) by fluorescent in situ hybridization., Results: Blood chimerism peaked 1 hour after transplantation and was significantly higher in the group of long-term survivors at that time. Thereafter chimerism rapidly decreased, but tended to remain higher in long-term survivors. In case of acute rejection donor cells were lost, but remained detectable for up to 36 postoperative months in tolerant animals. In BALF, the percentage of male nuclei was equally high under immunosuppression in both groups. Rejecting animals showed a rapid decrease of Y-bearing cells in BALF after drug withdrawal and an almost complete loss when acute rejection occurred. In tolerant pigs, intragraft chimerism remained detectable throughout the follow-up., Conclusions: This study demonstrates a clear correlation of donor leukocyte chimerism with long-term allograft survival in a porcine allogeneic lung transplantation model.

Background: A simplified conditioning protocol including single-dose preoperative thymic and low-dose whole body irradiation with or without subsequent donor bone marrow transplantation (BMTx) can be applied in porcine lung transplantation. We hypothesized that this protocol would prolong allograft survival., Methods: Left-sided single lung transplantation from major histocompatibility complex (MHC)-mismatched donors was performed in 27 minipigs. Recipients received whole body (1.5 Gy) and thymic irradiation (7 Gy) before transplantation (IRR group, n=6), intravenous immunosuppression with methylprednisolone, cyclosporine, and azathioprine for 27 postoperative days (IS group, n=5) or both (IRR+IS group, n=10). BMTx group recipients were treated with irradiation, immunosuppression and a donor bone marrow infusion on postoperative day 1. Peripheral blood leukocyte phenotype and donor cell chimerism were monitored by flow cytometry. Purified CD25+ T cells from long-term survivors or rejecting animals were used for in vitro MLR suppression assays., Results: Median graft survival was: IRR 12 days, IS 55 days, IRR+IS 239 days, and BMTx 80 days (P<0.0001). Early peripheral blood macrochimerism was substantial in both the IRR+IS and the BMTX group but was lost in all groups after day 80. The frequency and suppressive function of CD4+CD25+ T cells were enhanced in IRR+IS group long-term survivors., Conclusion: Although donor bone marrow infusion was not beneficial in our model, a substantial proportion of the animals treated with irradiation and a 28-day course of immunosuppression accepted their lung allografts long term. The mechanism involved in maintaining allograft tolerance may be based on peripheral T-cell regulation.

Open in new tab Download slide OBJECTIVES Total ischaemic time (IT) is considered a limiting factor in lung transplantation. In this retrospective study, we investigate effects of IT and disease burden on outcomes after bilateral lung transplantation. METHODS A total of 1298 patients undergoing bilateral lung transplantation between January 2010 and May 2022 (follow-up 100%, median 54 months) were included. Pre-transplant diseases' severity (recipient body mass index, recipient age, previous lung transplantation, Tacrolimus immunosuppression, preoperative recipient extracorporeal membrane oxygenation support, lung volume reduction) for graft failure was individually calculated and—as IT—categorized. Vice versa adjusted Cox models were calculated. Considering competing risks, we assessed cumulative incidences of airway obstructive complications and chronic lung allograft dysfunction with death as competing risk factors for primary graft dysfunction were assessed by binary logistic regression. RESULTS Higher disease burden significantly accelerated chronic lung allograft dysfunction and death occurrence (P  < 0.001); IT did not. IT-adjusted disease burden strata showed 50% graft survival differences at 11 years after transplantation (range 24–74%), disease burden-adjusted IT strata 18% for all and 6% (54–60%) among those above 7 h. All significant primary graft dysfunction risk factors were diagnoses related, IT was not significantly important and odds ratios did not increase with IT. CONCLUSIONS The eventual graft survival disadvantage that results from an IT between 7 and at least 11 h is negligible in contrast to frequent recipients' disease-based risk levels. [ABSTRACT FROM AUTHOR]

Introduction: For end-stage lung diseases, double lung transplantation (DLTx) is the ultimate curative treatment option. However, acute and chronic rejection and chronic dysfunction are major limitations in thoracic transplantation medicine. Thus, a better understanding of the contribution of immune responses early after DLTx is urgently needed. Passenger cells, derived from donor lungs and migrating into the recipient periphery, are comprised primarily by NK and T cells. Here, we aimed at characterizing the expression of killer cell immunoglobulin-like receptors (KIR) on donor and recipient NK and T cells in recipient blood after DLTx. Furthermore, we investigated the functional status and capacity of donor vs. recipient NK cells. Methods: Peripheral blood samples of 51 DLTx recipients were analyzed pre Tx and at T0, T24 and 3wk post Tx for the presence of HLA-mismatched donor NK and T cells, their KIR repertoire as well as activation status using flow cytometry. Results: Within the first 3 weeks after DLTx, donor NK and T cells were detected in all patients with a peak at T0. An increase of the KIR2DL/S1-positive subset was found within the donor NK cell repertoire. Moreover, donor NK cells showed significantly higher frequencies of KIR2DL/S1-positive cells (p<0.01) 3wk post DLTx compared to recipient NK cells. This effect was also observed in donor KIR+ T cells 3wk after DLTx with higher proportions of KIR2DL/S1 (p<0.05) and KIR3DL/S1 (p<0.01) positive T cells. Higher activation levels of donor NK and T cells (p<0.001) were detected compared to recipient cells via CD25 expression as well as a higher degranulation capacity upon activation by K562 target cells. Conclusion: Higher frequencies of donor NK and T cells expressing KIR compared to recipient NK and T cells argue for their origin in the lung as a part of a highly specialized immunocompetent compartment. Despite KIR expression, higher activation levels of donor NK and T cells in the periphery of recipients suggest their pre-activation during the ex situ phase. Taken together, donor NK and T cells are likely to have a regulatory effect in the balance between tolerance and rejection and, hence, graft survival after DLTx. [ABSTRACT FROM AUTHOR]

Open in new tab Download slide Open in new tab Download slide OBJECTIVES A combined lung and liver transplant in patients with cystic fibrosis (CF) is an uncommon procedure. The goal of this study was to compare long-term outcomes between patients with CF who underwent either a combined lung-liver or a lung-only transplant. METHODS This is a retrospective single-centre study of patients with CF who underwent a lung transplant between January 2005 and May 2020. Since 2006, our preference for a combined lung-liver transplant was to transplant the liver first and then the lung. Outcomes were compared using the Kaplan–Meier analysis and the log-rank test. Median follow-up was 53 (23–97) months. RESULTS During the study period, among 357 patients with CF who underwent a lung transplant, 14 (4%) required a lung-liver transplant whereas 343 (96%) had a lung-only transplant. Lung cold ischaemic time was longer in the lung-liver transplant group, but no patient in this group showed primary graft dysfunction at 72 h after the transplant. Prevalence of anti-human leucocyte antigen donor-specific antibodies was 7.1% vs 13.7% in the lung-liver versus the lung-only transplant group (P  = 0.42). At 5 years, lung graft survival (78% vs 69%) and freedom from chronic lung allograft dysfunction (79% vs 62%) did not differ between the lung-liver versus the lung-only groups (P  = 0.45 and P  = 0.55, respectively). Freedom from lung biopsy-confirmed rejection was significantly higher in patients undergoing a lung-liver transplant (91% vs 50%; P  = 0.027). CONCLUSIONS A lung-liver transplant did not impair lung graft function. The lower prevalence of donor-specific antibodies and the better freedom from lung biopsy-confirmed rejection suggest tolerogenic effects of the liver graft. [ABSTRACT FROM AUTHOR]

: Paediatric lung transplantation poses unique management challenges. Experience regarding indications and outcome is scarce, especially in younger children. The primary aim of this study was to investigate outcome after first lung transplantation in children <12 years of age in comparison to adolescents (12-17 years old). : Records of patients <18 years who underwent first lung transplantation between 01/2005 and 01/2021 were retrospectively reviewed, and compared between children <12 years old and adolescents. Median (IQR) follow-up was 51 (23-91) months. Of the 117 patients underwent first lung transplantation at our institution, of whom 42 (35.8%) patients were <12 years and 75 (64.2%) ≥12 years old. Compared to adolescents, children were more often transplanted for interstitial lung disease (33.3% vs 12%, p = 0.005) and precapillary pulmonary hypertension (28.6% vs 12%, p = 0.025), and required more often intraoperative cardiopulmonary bypass (31% vs 14.7%, p = 0.036) and postoperative ECMO support (47.6% vs 13.3%, p < 0.001). Postoperatively, children required longer ventilation times (78 vs 18 hours, p = 0.009) and longer ICU stay (9.5 vs 3 days, p < 0.001) compared to their older counterparts. Primary graft dysfunction grade 3 at 72 hours (9.5% vs 9.3%, p = 0.999), in-hospital mortality (2.4% vs 6.7%, p = 0.418), graft survival (80% vs 62%, p = 0.479) and freedom from chronic lung allograft dysfunction (76% vs 59%, p = 0.41) at 8-year follow-up did not differ between groups. : Lung transplantation in children under 12 years is challenging due to underlying medical conditions and operative complexity. Nevertheless, outcomes are comparable to those in older children. [ABSTRACT FROM AUTHOR]

Over the past decade, extracorporeal membrane oxygenation (ECMO) has replaced cardiopulmonary bypass (CPB) for cardiopulmonary support during lung transplantation at our institution. In this study, we present our experience using intraoperative ECMO in isolated lung transplantation and evaluate its impact on long-term graft function and survival. All patients undergoing isolated lung transplantation with or without ECMO support between January 2010 and June 2019 were evaluated. Patients transplanted using CPB were excluded. Peri-operative and follow-up results from our database and patient charts were analyzed. Follow-up continued until September 1, 2019 (median, 3.34 years). In total, 311 of 1,161 lung transplant recipients (27%) received intraoperative ECMO, with 24 (2%) patients further requiring CPB. None of the remaining 826 (71%) patients required intraoperative cardiopulmonary support. ECMO patients exhibited higher pre-transplant surgical risk profiles and endured more complicated early post-operative courses than those without ECMO (in-hospital mortality, 10.9% vs 2.3%; p < 0.001). Inevitably, this resulted in poorer overall graft survival among ECMO recipients (p = 0.0025). However, correcting for patients surviving to hospital discharge, no difference in survival between groups was observed (5-year survival, 71% vs 72%; p = 0.56). Similarly, freedom from chronic lung allograft dysfunction, biopsy-confirmed cellular rejection, or need for pulsed-steroid therapy did not differ between the groups (p = 0.99, p = 0.78, and p = 0.93, respectively). Compared with patients not requiring cardiopulmonary support, ECMO recipients endured a more complicated peri-operative and early post-operative course. However, among those surviving to hospital discharge, no differences in long-term complications or outcomes were observed. [ABSTRACT FROM AUTHOR]