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4. ContentLungBOS6_3Increased total cell-free DNA early after lung transplantation is associated with baseline lung allograft dysfunction BOS6_5Comparison of plasma donor-derived cell-free DNA with LASHA scoring system in lung transplantation: A single centre experienceFG2_2Mitochondrial damage comparison between brain death donors and donors after circulatory death in lung transplantation: Prospective multicenter studyFG2_3A novel whole-body cooling system protects donor lungs from ischemia reperfusion injury: Targeting uncontrolled donation after circulatory death donorsFG2_4Not too warm, not too cold: Real-world multi-center outcomes with elevated hypothermic preservation of donor lungsOS7_1Utility of the banff human organ transplant panel in diagnosing antibody-mediated rejection in lung transplant biopsies

5. ContentLungOS7_2Using predicted indirectly recognizable HLA epitopes to investigate formation of de novo donor-specific HLA-antibodies after lung transplantationOS7_3Transcriptional co-activator BOB1 as the key regulator of pathogenic lymphocytic responses in chronic lung allograft dysfunctionOS7_4Validation of a blood gene signature to predict chronic allograft dysfunction in lung transplantation OS7_5Unsupervised analysis of lung transplant phenotypes using gene expression dataOS7_6Role of donor-derived cell-free DNA in chronic lung allograft dysfunction. A longitudinal studyOS7_7Donor-derived cell-free DNA and cell-free RNA levels using a cost-effective liquid biopsy technique monitoring lung allograft rejectionOS7_8Induction extracorporeal photopheresis stimulates beneficial immune modulation in cystic fibrosis patients undergoing lung transplantation

6. Increased total cell-free DNA early after lung transplantation is associated with baseline lung allograft dysfunctionZajacova A. et al., ESOT Congress 2023; BOS6_3BackgroundBLAD is the inability to achieve the forced expiratory volume in 1 second and forced vital capacity of 80% predicted on two consecutive measurements within the first year post LuTxThe underlying cause of BLAD is not yet fully understood, but early graft alteration has been identified as a risk factor16 patients who underwent bilateral LuTx between May 2021 and March 2022 were followed-up in a single centerBlood samples were collected monthly from 3 up to 6 months post-LuTx8 M8 FMedian age at the time of LuTx: 50.2 years (IQR 37.8-63.8) %ddcfDNA, ddcfDNA (cp/ml) and cfDNA (cp/ml) levels were obtained by the Prospera test and the results analysed by the Mann-Whitney testMethodsSamples obtained during rejection or infection were excludedAim: To determine if early levels of ddcfDNA and %ddcfDNA, which are biomarkers of graft damage, as well as total cfDNA levels, may have predictive value for the incidence of BLAD

7. Increased total cell-free DNA early after lung transplantation is associated with baseline lung allograft dysfunctionZajacova A. et al., ESOT Congress 2023; BOS6_3Results46 samples were analyzed (median 2.9 per patient) and 5 of 16 patients had BLAD (31.3%)GroupsMedian ddcfDNAddcfDNAMedian cfDNA%IQRp-valueAbsolute value (cp/ml)IQRp-valueAbsolute value (cp/ml)IQRp-valueNon-BLAD0.170.11-0.31p=0.2124.9218.1- 56.18p=0.0691413.461009.63-2101.32p=0.019BLAD0.310.22-0.6070.2939.17-297.262685.632046.48-4215.17ConclusionsIncreased total cfDNA levels obtained between 3rd-6th month after LuTx are associated with a higher risk of BLADAs 90% of cfDNA originates in white blood cells, a proinflammatory state might be a risk factor for BLAD incidence, but further investigation is requiredThe statistically non-significant trend for elevated ddcfDNA and %ddcfDNA in BLAD was observedComparison of 3rd-6th month median of %ddcfDNA, absolute ddcfDNA and total cfDNA between LuTx recipients with and without BLAD

8. Comparison of plasma donor-derived cell-free DNA with LASHA scoring system in lung transplantation: A single centre experience Pezzuto F. et al., ESOT Congress 2023; BOS6_5Backgrounddd-cfDNA has been investigated as a non-invasive alternative approach to TBBs to evaluate LAI following transplantationAim: To compare the diagnostic yield of dd-cfDNA to scheduled TBBs systematically evaluated according to the LASHA templateTBBs are scored according to LASHA templateAlveolar macrophages, oedema, and mild capillary dilation with score <2 are considered nonspecific and classified as unremarkable if not associated with altered microbiological or immunological findingsImmunological evaluation BloodBALPlasmaMicrobiological/cytological evaluation % dd-cfDNA by NGSMethods21 recipients were prospectively enrolled between October and November 2022

9. Comparison of plasma donor-derived cell-free DNA with LASHA scoring system in lung transplantation: A single centre experience Pezzuto F. et al., ESOT Congress 2023; BOS6_5Resultsdd-cfDNA was under the threshold of 0.85% in 10 patientsIn 8 patients, TBB was negative or unremarkableNone showed immunological complicationsThe negative predictive value was 80%dd-cfDNA was over the threshold in 11 patientsThe positive predictive value was 82% ConclusionsPlasma dd-cfDNA is highly predictive of LAI, even after a granular histological evaluationFurther studies are needed to confirm the clinical validity of cfDNA, especially for the detection of specific or concomitant pathological lesions of LAISexAge(years)Months from Ltx CLADDSAAltered histological parameters in LASHA templateInfections in BALdd-cfDNA (%)Lung allograft injuryM66260-Unremarkable-0,08NoM3440-Negative+0,11YesM58170-Unremarkable-0,13No M6630-Negative-0,22NoF61210-Negative-0,24NoM5581-Negative-0,26NoF3320-Organizing pneumonia (I/R injury?)-0,26NoF26940-Negative-0,35NoF34520-Unremarkable-0,50NoM64150-Neutrophilic/cellular debris in alveolar septa -0,58Yes F2470-Unremarkable-0,86NoM6130-Neutrophils in alveolar septa +0,90Yes M65530+Unremarkable-1,27Yes F4050-Organizing pneumonia+1,28Yes F261811-Negative -1,68Yes F21170-A1B0- 2,03Yes M5640-A3B0+3,54Yes M6550-Negative+4,67Yes M461280-Unremarkable-4,75NoM36610+Unremarkable+5,40Yes F41632+ Neutrophilic/cellular debris in alveolar septa -6,85Yes

10. Mitochondrial damage comparison between brain death donors and donors after circulatory death in lung transplantation: Prospective multicenter studyBello I. et al., ESOT Congress 2023; FG2_2BackgroundThe warm ischemia time associated to cDCD may enhance the apoptosis process in lung tissue leading to post-mortem degradation of mtDNA into DAMPsMultiple observations suggest that the DAMPs could serve as sentinel marker to PGDAim: To compare the DAMPs observed in lung recipients from DBD and cDCDMethods80 adult lung recipients were prospectively enrolled in 4 Spanish transplant centres from July 2018 to July 201940 DBDPaired by lung transplantation indication and age40 cDCDBefore (E0) and during the retrieval process (E1) Blood samples collectionDonorBefore implant (R-1), after graft reperfusion (R0) and 72 hours after lung transplantation (R72)RecipientMitochondrial damage (DAMPs) is analysed and compared between groups12

11. Mitochondrial damage comparison between brain death donors and donors after circulatory death in lung transplantation: Prospective multicenter studyBello I. et al., ESOT Congress 2023; FG2_2ResultsDemographics of donors and recipients as well as transplant surgical procedure characteristics are similar between groups except for a higher rate of corticoid treatment and vaso-active support in DBD group and higher blood transfusion requirements in cDCD groupNo differences is found in mitochondrial damage between groups in E0, E1, E, R-1, R0 and R72 (Figure)PGD incidence and mortality do not have statistically differences between both groups (Table)ConclusionscDCD do not have higher mitochondrial damage and PGD incidence than DBD despite warm ischemic time in our cohortLung transplantation from cDCD is a safe alternative to increase the lung donor poolOutcomesDBD(n=40)cDCD(n=40)p-valuePrimary graft dysfunction, n (%) Of any grade Grade III 27 (67.5)14 (35) 26 (65)11 (27.5) 0.1000.469Post-operative mortality0 (0)2 (5)0.494Three-month mortality0 (0)2 (5)0.494mtDNA number of copies/µl plasma

12. A novel whole-body cooling system protects donor lungs from ischemia reperfusion injury: Targeting uncontrolled donation after circulatory death donorsNiikawa H. et al., ESOT Congress 2023; FG2_3BackgroundLung transplantation using lungs from uDCD may increase lung donor poolA novel chest cooling system for uDCD donors without surgical intervention was developpedWe hypothesized that the system described as involving whole-body cooling using a proprietary material could improve pulmonary function of uDCD donors Aim: To verify whether the cooling system ameliorates the physiological parameters, compared to control using EVLPDCD groupCooling group55Lungs subjected to 90 min of WIT at room temperatureLungs cooled with the cooling system during WIT MethodsTen pigs divided into 2 groupsTracheal temperature is continuously measured during WITLungs are procured in a standard fashion and then perfused in 2 hours of Lund-type EVLP following 5 hours of cold preservationTransplant suitability is decided based on physiological parameters and visual findingsLung tissue samples are collected for measurement of wet to dry ratio

13. A novel whole-body cooling system protects donor lungs from ischemia reperfusion injury: Targeting uncontrolled donation after circulatory death donorsNiikawa H. et al., ESOT Congress 2023; FG2_3ResultsThe tracheal temperature in the cooling group gradually decreases during WIT and finally reaches 28.5°C, while there is no decrease in the temperature of the DCD group (Figure A)In EVLP evaluation, compared to control, the cooling group is significantly associated with:Higher PaO2/FiO2 ratio (412 ± 82 vs 261 ± 71 mmHg, p<0.05, Figure B)Lower peak inspiratory pressure (13 ± 2 v. 19 ± 4 cmH2O, p<0.05)Lower lung weight ratio (lung weight at 2 hour/lung weight at 0 hour, 109 ± 15 vs 166 ± 35%, p<0.05)Lower wet to dry ratio (5.35 ± 0.32 vs 6.35 ± 0.24, p<0.05)Higher rate of transplant suitability (100 vs 0%, p<0.05)Figure AFigure BConclusionsThese results demonstrated that the novel chest cooling system resulted in better pulmonary function in a pig lung uDCD model, suggesting that the new cooling system without surgical intervention may protect uDCD donor lungs from ischemia reperfusion injury and expand the lung donor pool

14. Not too warm, not too cold: Real-world multi-center outcomes with elevated hypothermic preservation of donor lungsHaney J. et al., ESOT Congress 2023; FG2_4BackgroundRecent reports highlight the potential clinical improvements from hypothermic preservation at elevated temperatures of donor lungs, avoiding risk of mitochondrial injury with standard ice storage (ICE) where lungs reach temperatures near or below 0°CThe LUNGguard Donor Lung Preservation System (LG) is the only FDA and CE cleared preservation technology which maintains donor lungs at controlled elevated hypothermic temperatures, potentially mitigating temperature-related tissue injuryAim: To present real-world experience of this preservation strategy on recipient outcomes as studied in the GUARDIAN-Lung Registry MethodsGUARDIAN Lung Registry (multicenter registry)Outcomes following lung transplants using LG, n=86Retrospective review of clinical outcomes was examined using summary statistics and Kaplan-Meyer survival analysisOutcomes following lung transplants using ICE, n=90Continued enrolment will allow updated data to be presentedVS

15. Not too warm, not too cold: Real-world multi-center outcomes with elevated hypothermic preservation of donor lungsHaney J. et al., ESOT Congress 2023; FG2_4ResultsTransplants in patients using LG vs ICE have similar baseline characteristics, except significantly more LG-preserved lungs are retrieved from DCD, 17.6% LG vs 6.7% ICE, p=0.025 (Table)The LG cohort has a clinically meaningful 54% reduction in primary graft dysfunction at 72 hours (p=0.058)

16. Not too warm, not too cold: Real-world multi-center outcomes with elevated hypothermic preservation of donor lungsHaney J. et al., ESOT Congress 2023; FG2_4Results (cont.)LG is also associated with significantly improved one year Kaplan-Meier estimated survival, 95.0% vs 90.0%, p=0.02, LG vs ICE, respectively (Figure)ConclusionsUse of LUNGguard is associated with a reduction in PGD3 and enhanced 1-year survival compared to ICEThese data support growing evidence that avoiding donor lung near-freezing injury through controlled, elevated hypothermic preservation has a meaningful impact on post-transplant outcomes

17. Utility of the banff human organ transplant panel in diagnosing antibody-mediated rejection in lung transplant biopsiesSablik M. et al., ESOT Congress 2023; OS7_1BackgroundDiagnosing AMR in lung allografts is challengingWhile microarray-based rejection-related signatures have been published, the capacity of novel approaches to capture clinically relevant genes associated to pulmonary AMR remains to be demonstratedAim: To identify the molecular signature and capture the key functional pathways involved in pulmonary AMR using the B-HOT panelMethodsAMRn=42ACRn=50Non-rejectionn=29Sequenced using the B-HOT panelFormalin-fixed paraffin-embedded transbronchial biopsies from lung transplant recipientsn=121All non-AMR biopsiesClassified according to ISHLT guidelinesDifferential gene expression analysis AMRVS

18. Utility of the banff human organ transplant panel in diagnosing antibody-mediated rejection in lung transplant biopsiesSablik M. et al., ESOT Congress 2023; OS7_1ResultsA total of 295 genes are differentially expressedIncreased expression of genes associated with a cell injury-related profile and activation of immune cascades:Complement activation (C3AR1) Macrophage activation (MMP12, MS4A6A)Immune regulation (CD84, LILRB4, CTLA4, LAG3) and activation (JAK3, TNFRSF9, IL2RA) Chemokine signalling (CXCL13)Response to wounding (S100B, TNC, HIF1A, COL3A1, COL1A1)Decreased expression of genes associated with endothelial activation (CDH13, TEK, VEGFA, BMPER)Top associated pathways:Interleukin and interferon signallingLymphoid with non-lymphoid cell interactionsComplement system activationChemokine signallingConclusionsThis study shows that the B-HOT panel was able to identify the molecular profile of AMR in lung allograftsThis study aids in better understanding the disease state and the mechanisms involved in pulmonary humoral rejection

19. Using predicted indirectly recognizable HLA epitopes to investigate formation of de novo donor-specific HLA-antibodies after lung transplantationVorstandlechner M. et al., ESOT Congress 2023; OS7_2BackgroundHLA histocompatibility between organ donor and recipient can play a crucial role in the outcome after LuTXThe development of dnDSA can be a risk factor for graft failure and consequently have a negative impact on post-TX (graft-) survivalMismatches can be detected both directly and indirectly by the recipient’s immune systemAim: To predict dnDSA through the indirect pathway of antigen recognition by using the PIRCHE-II algorithm (predicted indirectly recognizable HLA epitopes)MethodsPatients who underwent LuTX from 2005 to 2018 Inclusion criteriaComplete clinical records regarding underlying disease and indication for TXSingle or double LuTXComplete donor and recipient class I and II HLA-typing (loci A, B, C, DR and DQ) prior to TX Regular post-TX-screenings for newly developed antibodiesFollow-up time of at least one year to assess long-term transplant success and monitor CLAD

20. Using predicted indirectly recognizable HLA epitopes to investigate formation of de novo donor-specific HLA-antibodies after lung transplantationVorstandlechner M. et al., ESOT Congress 2023; OS7_2ResultsOverall, a total of 585 patients is included in the study196 patients (33.7%) show signs of a repeatedly declining FEV1, eventually resulting in CLAD151 patients developed dnDSA. Among these patients, the incidence of CLAD and death due to graft failure were increased (p<0.0001; p=0.02)Of all dnDSA, HLA-DQ7 was the most common antibody and clearly associated with CLADThe mean PIRCHE-II-score was significantly higher in patients who died within the first year after LuTX. (survival < 1 year: 109.0 vs. survival > 1 year: 91.1; p=0.006)ConclusionsThe analysis of our data highlights the importance of immunological compatibility in transplantation. DnDSA increases the risk of CLAD and graft failure and can ultimately reduce survival chances after LuTX PIRCHE may be able to further optimize donor-recipient compatibility and help improve survival

21. Transcriptional co-activator BOB1 as the key regulator of pathogenic lymphocytic responses in chronic lung allograft dysfunctionYeremenko N. et al., ESOT Congress 2023; OS7_3BackgroundCLAD is the leading cause of mortality after lung transplantationBalance of effector and regulatory lymphocytic responses determines lung allograft outcomes favouring rejection or toleranceThe molecular mechanisms controlling these responses remain largely unknownThe expression of lymphocyte-specific transcriptional co-activator BOB1 in the lung recipients' blood predicts CLAD developmentAim: To explore the role of BOB1 in the pathophysiology of CLADMethods1Patients with CLAD Transbronchial biopsyStained with a panel of 36-heavy-metal-tagged antibodiesThe imaging mass cytometry2BOB1-specific inhibitors were developed through a classical medicinal chemistry approach via virtual library screening3B-cell proliferation, apoptosis, activation, and immunoglobulin production in the model of T-dependent B-cell differentiationB-cell regulatory capacity in the co-cultures with activated effector T cellsPrimary and secondary T-cell responseEffect of BOB1 targeting was assessed on

22. Transcriptional co-activator BOB1 as the key regulator of pathogenic lymphocytic responses in chronic lung allograft dysfunctionYeremenko N. et al., ESOT Congress 2023; OS7_3ResultsMultiple immune cell subsets are found in the lung allograft with a massive infiltration of plasma cells expressing high levels of BOB1Targeting BOB1 abrogates B-cell proliferation, activation and differentiation into antibody-secreting plasmablasts in vitroThis phenotype and the arrest of isotype-switched immunoglobulin production is accompanied by the down-modulation of plasma cell differentiation and class-switching genes, such as IRF4, PRDM1, AICDA, IgHG1, and IgHG3Targeting BOB1 suppresses proliferation and IL-17A production by T cells during recall responsesThe interference with BOB1 function do not affect the regulatory function of B cellsConclusionsThe presence of BOB1+ lymphocytes in CLAD lungs and the notion that attenuation of biological activity of BOB1 in vitro dampens activated lymphocytic responses without compromising the immunosuppressive potential, support the role of BOB1 in CLAD pathogenesis, laying a solid rationale for the investigation of its targeting in relevant experimental models in vivo

23. Validation of a blood gene signature to predict chronic allograft dysfunction in lung transplantationDanger R. et al., ESOT Congress 2023; OS7_4BackgroundSince CLAD is the major limitation to long-term survival after lung transplantation, identifying patients at risk of CLAD using non-invasive biomarkers would allow to prevent lung allograft damageThe B-cell related genes BLK, POU2AF1 and TCL1A are expressed in blood and associated with CLADAim: To validate this signature in an independent cohort of 293 lung transplanted recipientsMethodsBlood samples of lung transplanted patients of the multicenter COLT cohortCLAD n=56Patients with good graft function at least 5 years after transplantation n=102Blood from patients with lung infection at 12 months post-transplantationn=10Healthy volunteersn=10 BLK, POU2AF1 and TCL1A gene expression using quantitative PCR at 12, 18 or 24 months after transplantationControls

24. Validation of a blood gene signature to predict chronic allograft dysfunction in lung transplantationDanger R. et al., ESOT Congress 2023; OS7_4ResultsThe expression of the 3 genes measured during the second year post-transplantation is significantly decreased in blood from patients with CLAD occurring between 3 and 24 months after sample collection compared to patients with good graft function (p=0.041, 0.029 and 0.038 for BLK, POU2AF1 and TCL1A, respectively)Gene expression was not significantly affected by lung infectionThese results confirm the ability of these 3 genes to predict the development of CLAD in lung transplantationConclusionsThe downregulation of these three B cells-related genes suggests a B cell imbalance in favour of an alloimmune reactionCombined with clinical parameters, these genes may help identifying patients likely to develop CLAD and to benefit from therapy to prevent development of the pathology

25. Unsupervised analysis of lung transplant phenotypes using gene expression dataSablik M. et al., ESOT Congress 2023; OS7_5BackgroundNon-specific histopathologic findings and a lack of accurately defined phenotypes pose a barrier in diagnosing rejection in lung allograftsAim: To identify new rejection phenotypes using probabilistic unsupervised analysis of gene expression dataMethodsAMRn=42ACRn=50Non-rejectionn=29Sequenced using the B-HOT panelFormalin-fixed paraffin-embedded transbronchial biopsies from lung transplant recipientsn=121Classified according to ISHLT guidelinesArchetypal analysis is applied to normalized gene countsArchetype 2Archetype 1VSArchetype 3VSVSArchetype 4Differential gene expression analysis (each archetype vs. all other archetypes)

26. Unsupervised analysis of lung transplant phenotypes using gene expression dataSablik M. et al., ESOT Congress 2023; OS7_5Results4 distinct histological, immunological and molecular archetypes are identified (Figure):Archetype 1 (n=21 biopsies) is characterized by capillary lesions and circulating anti-HLA DSADifferentially expressed genes captured B- and T-cells activation and interferon signalling Archetype 2 (n=46) is predominantly defined by perivascular mononuclear cell infiltratesUpregulated transcripts are associated with cell-extracellular matrix interactions and cell injury Archetype 3 (n=35) and archetype 4 (n=18) are histologically similar but molecularly differ: Archetype 3: Top transcripts involved in cellular processes Archetype 4: Top transcripts capture anti-inflammatory responses and interferon signallingConclusionsUnsupervised archetypal analysis of gene expression data identifies lung allograft phenotypes with distinct histological, immunological and molecular profilesThis approach has the potential to refine rejection-related diagnoses in lung allografts and improve the shortcoming of the current diagnostic classification systemFigure. Volcano plots of differentially expressed genes associated with each archetype. Dots represent individual transcripts. Red dots indicate differentially expressed genes after applying a threshold of 0.05 to false discovery rate corrected p-values.

27. Role of donor-derived cell-free DNA in chronic lung allograft dysfunction. A longitudinal studyPeris M. A.. et al., ESOT Congress 2023; OS7_6BackgroundSurvival after LT is hampered by the development of CLADThere is no treatment available to reverse CLAD once diagnosed, but early intervention could modify the progressive lung function declineThus, biomarkers are needed for early detection of CLADHigh levels of ddcfDNA have been described to precede acute cellar rejection and antibody mediated rejection diagnosisAim: To assess if there is any association between ddcfDNA and CLADMethodsM0M36Plasma collectionLTn=100 LT recipientsLongitudinal study M3M6M9M12M24Real-time PCR is performed to detect an informative INDEL polymorphism for each donor/recipient pairLevels of ddcfDNA are determined by quantifying the informative INDEL by digital PCR Clinical data was collected during a three years follow-up to determine infections, antibody mediated and acute cellular rejection, and CLAD12

28. Role of donor-derived cell-free DNA in chronic lung allograft dysfunction. A longitudinal studyPeris M. A.. et al., ESOT Congress 2023; OS7_6ResultsUpward trend of ddcfDNA levels at 1, 2 and 3 years of follow-up when referred to 3 monthsLevels of ddcfDNA are compared between CLAD and no CLAD patients at different time points, and a cut-off value of 1.86% at 12 months could identify those patients with higher probability of developing CLAD (Figure)ConclusionsDetermining ddcfDNA levels in plasma could be a useful non-invasive biomarker for CLAD prediction

29. Donor-derived cell-free DNA and cell-free RNA levels using a cost-effective liquid biopsy technique monitoring lung allograft rejectionTisekar O. et al., ESOT Congress 2023; OS7_7Backgrounddd-cfDNA and cell-free RNA are non-invasive tests that look for donor-specific DNA/RNA markers in recipient plasmaNGS, ddPCR, and mmPCR platforms are currently available to diagnose allograft rejection, but are not economically viable in developing countries Aim: To create a real-time PCR-based dd-cfDNA and dd-cfRNA assayMethods123 plasma samples from 60 lung transplant recipientsdd-cfDNA and dd-cfRNA measured by PCRDiagnosis of acute rejectionPreoperative, intraoperative, and postoperative risk factors are subjected to regression analysis12

30. Donor-derived cell-free DNA and cell-free RNA levels using a cost-effective liquid biopsy technique monitoring lung allograft rejectionTisekar O. et al., ESOT Congress 2023; OS7_7Results61.2% of the patients are male, with a mean age of 47.37 years (range: 14-72 years) and a BMI of 22.84 (range: 14.1-33.7)The most common pre-transplant diagnosis is idiopathic pulmonary fibrosis (35.8%), followed by chronic hypersensitivity pneumonitis (15.4%) and connective tissue-related interstitial disease (8.9%)When compared to the stable organ (median 8.3, IQR: 0.0-40.65 ng/mL), the dd-cfDNA level is higher in acute rejection (median 21.7 ng/L, IQR: -0.0-95.65 ng/L)The dd-cfRNA level is higher in acute rejection (median 13.75 ng/L, IQR: -0.0-46.8 ng/L) than in stable organ (median 2.3 ng/L, IQR: -0.0-17.3 ng/L)Data analysis of dd-cfDNA levels reveals a rejection sensitivity of 56.7% and specificity of 79.7%, whereas dd-cfRNA levels reveals a rejection sensitivity of 33% and specificity of 77.1%. However, the positive predictive values for dd-cfDNA and dd-cfRNA ae only 28.8% and 33%, respectively, while the negative predictive values are 89.68% and 87.1%, respectivelyUsing multinomial logistic regression, only donor ischaemia time have a statistically significant impact on dd-cfDNA or dd-cfRNA levelsConclusionsdd-cfRNA, like dd-cfDNA, has good negative predictive values in detecting rejection that histopathology may have missed

31. Induction extracorporeal photopheresis stimulates beneficial immune modulation in cystic fibrosis patients undergoing lung transplantationRighi I. et al., ESOT Congress 2023; OS7_8BackgroundCR is the leading cause of late morbidity and mortality upon LuTxECP has emerged as a promising immunomodulatory treatment against rejectionAim: To perform an in-depth investigation of the immunological effects of induction ECP in LuTx recipients with a diagnosis of CFMethodsPilot clinical trial enrolled 20 CF LuTx patients randomly allocated in 2 armsStandard immunosuppressive therapy alone Standard immunosuppressive therapy plus ECPD0LuTxD3M31 cycle 5 cycles Functional activation of T and NK subpopulations as well as mRNA expression and cytokine secretion profiling are evaluated in peripheral blood and in BAL before the first cycle and 48 hours after the end of each cycle and up to 12 months after LuTxClinical parameters, including respiratory volumes (e.g. FEV1), rejection episodes and infections, are analyzed 123

32. Induction extracorporeal photopheresis stimulates beneficial immune modulation in cystic fibrosis patients undergoing lung transplantationRighi I. et al., ESOT Congress 2023; OS7_8ResultsECP was well tolerated with no complications nor opportunistic infectionsRejection rate was comparable in the two groupsNotably, a significantly better FEV1 was observed in the ECP group overtimeTreg lymphocytes and IL10-producing NKs were significantly increased, while Th17 cells were significantly reduced in the ECP group compared to the controlCytokine profile showed that ECP reduced pro-inflammatory cytokines (e.g. IL1b, IL6) production, increasing that of anti-inflammatory cytokines (e.g. IL10, IL1RA) both in plasma and BALConclusionsInduction ECP is associated with immune modulation resulting in improved patients’ respiratory performanceMore extensive studies and longer follow-up are needed to verify if ECP-induced immune modulation will have a beneficial effect of organ rejection as well