Uncovering the Unseen: Bordetella hinzii Emerges in a Lung Transplant Recipient.

Bordetella hinzii (B. hinzii), a Gram-negative bacillus commonly associated with respiratory infections in animals, has garnered attention for its sporadic cases in humans, particularly in immunocompromised individuals. Despite its opportunistic nature, there remains limited understanding regarding its pathogenicity, diagnostic challenges, and optimal treatment strategies, especially in the context of immunosuppression. Herein, we present the first documented case of acute bronchitis caused by B. hinzii in an immunocompromised patient following double-lung transplantation. The patient, a former smoker with sarcoidosis stage IV, underwent transplant surgery and subsequently developed a febrile episode, leading to the identification of B. hinzii in broncho-alveolar lavage samples. Antimicrobial susceptibility testing revealed resistance to multiple antibiotics, necessitating tailored treatment adjustments. Our case underscores the importance of heightened awareness among clinicians regarding B. hinzii infections and the imperative for further research to elucidate its epidemiology and optimal management strategies, particularly in immunocompromised populations.

Toxicity of immunotherapy combinations with chemotherapy across tumor indications: Current knowledge and practical recommendations.

Chemotherapy associated with Immune Checkpoint Inhibitors is currently the standard of care in several tumor indications. This combination approach improves progression free survival (PFS), overall survival (OS) and complete pathological response (pCR) in several cancer types both in the early and metastatic approaches. However, the distinct spectrum of toxicities between cytotoxic side effects and immune related adverse events (irAEs) with similar clinical presentations and different management strategies remains a challenge in daily practice for healthcare professionals. This review summarizes the most common toxicities reported in the randomized clinical trials that led to the subsequent FDA approval of these combinations, across tumor indications. We cite in particular: non-small cell lung cancer, small cell lung cancer, triple negative breast cancer, squamous cell carcinoma of the head and neck, gastric carcinoma, esophageal carcinoma, cervical carcinoma and biliary tract carcinoma. We found that the combination of chemotherapy and immunotherapy was associated with an increased incidence of all grade adverse events (RR 1.11 [1.09; 1.12]) without an excess in treatment related mortality when compared to chemotherapy alone. We report also an increase in the incidence of serious adverse events (grade ≥ 3) (RR 1.16 [1.10;1.24]); in particular: high grade diarrhea, dyspnea, fatigue, rash and elevated liver enzymes. Together with the collaboration of our institutional network of organ specialists with expertise in irAEs, we propose practical recommendations for physicians to enhance clinical care and management of patients undergoing treatment with combined ICI immunotherapy and chemotherapy.

Blood MMP-9 measured at 2 years after lung transplantation as a prognostic biomarker of chronic lung allograft dysfunction.

BACKGROUND: Long-term outcomes of lung transplantation (LTx) remain hampered by chronic lung allograft dysfunction (CLAD). Matrix metalloproteinase 9 (MMP-9) is a secretory endopeptidase identified as a key mediator in fibrosis processes associated with CLAD. The objective of this study was to investigate whether plasma MMP9 levels may be prognostic of CLAD development. METHODS: Participants were selected from the Cohort in Lung Transplantation (COLT) for which a biocollection was associated. We considered two time points, year 1 (Y1) and year 2 (Y2) post-transplantation, for plasma MMP-9 measurements. We analysed stable recipients at those time points, comparing those who would develop a CLAD within the 2 years following the measurement to those who would remain stable 2 years after. RESULTS: MMP-9 levels at Y1 were not significantly different between the CLAD and stable groups (230 ng/ml vs. 160 ng/ml, p = 0.4). For the Y2 analysis, 129 recipients were included, of whom 50 developed CLAD within 2 years and 79 remained stable within 2 years. MMP-9 plasma median concentrations were higher in recipients who then developed CLAD than in the stable group (230 ng/ml vs. 118 ng/ml, p = 0.003). In the multivariate analysis, the Y2 MMP-9 level was independently associated with CLAD, with an average increase of 150 ng/ml (95% CI [0-253], p = 0.05) compared to that in the stable group. The Y2 ROC curve revealed a discriminating capacity of blood MMP-9 with an area under the curve of 66%. CONCLUSION: Plasmatic MMP-9 levels measured 2 years after lung transplantation have prognostic value for CLAD.

Outcomes of listing for lung and heart-lung transplantation in pulmonary hypertension: comparative experience in France and the UK.

Background: Lung or heart-lung transplantation (LT/HLT) for severe pulmonary hypertension (PH) as the primary disease indication carries a high risk of waiting list mortality and post-transplant complications. France and the UK both have coordinated PH patient services but with different referral pathways for accessing LT services. Methods: We conducted a comparative analysis of adult PH patients listed for LT/HLT in the UK and France. Results: We included 211 PH patients in France (2006-2018) and 170 in the UK (2010-2019). Cumulative incidence of transplant, delisting and waiting list death within 3 years were 81%, 4% and 11% in France versus 58%, 10% and 15% in the UK (p<0.001 for transplant and delisting; p=0.1 for death). Median non-priority waiting time was 45 days in France versus 165 days in the UK (p<0.001). High-priority listing occurred in 54% and 51% of transplanted patients respectively in France and the UK (p=0.8). Factors associated with achieving transplantation related to recipients' height, male sex, clinical severity and priority listing status. 1-year post-transplant survival was 78% in France and 72% in the UK (p= 0.04). Conclusion: Access to transplantation for PH patients is better in France than in the UK where more patients were delisted due to clinical deterioration because of longer waiting time. High rates of priority listing occurred in both countries. Survival for those achieving transplantation was slightly better in France. Ensuring optimal outcomes after transplant listing for PH patients is challenging and may involve early listing of higher risk patients, increasing donor lung utilisation and improving allocation rules for these specific patients.

Assessing the role of phosphorylated S6 ribosomal protein in the pathological diagnosis of pulmonary antibody-mediated rejection.

BACKGROUND: Pulmonary antibody-mediated rejection is still a challenging diagnosis as C4d immunostaining has poor sensitivity. Previous studies have indicated that the phosphorylated S6 ribosomal protein, a component of the mammalian target of rapamycin (mTOR) pathway, is correlated with de novo donor-specific antibodies in lung transplantation. The objective of this study was to evaluate the phosphorylation of S6 ribosomal protein as a surrogate for antibody-mediated rejection diagnosis in lung transplant patients. METHODS: This multicentre retrospective study analyzed transbronchial biopsies from 216 lung transplanted patients, 114 with antibody-mediated rejection and 102 without (19 with acute cellular rejection, 17 with ischemia/reperfusion injury, 18 with infection, and 48 without post-transplant complications). Immunohistochemistry was used to quantify phosphorylated S6 ribosomal protein expression in macrophages, endothelium, epithelium, and inter-pathologist agreement was assessed. RESULTS: Median phosphorylated S6 ribosomal protein expression values were higher in antibody-mediated rejection cases than in controls for all cell components, with the highest sensitivity in macrophages (0.9) and the highest specificity in endothelial expression (0.8). The difference was mainly significant in macrophages compared to other post-lung transplantation complications. Inter-pathologist agreement was moderate for macrophages and endothelium, with higher agreement when phosphorylated S6 ribosomal protein expression was dichotomized into positive/negative. The inclusion of phosphorylated S6 ribosomal protein in the diagnostic algorithm could have increased antibody-mediated rejection certainty levels by 25%. CONCLUSIONS: The study supports the role of the mTOR pathway in antibody-mediated rejection-related graft injury and suggests that tissue phosphorylation of S6 ribosomal protein could be a useful surrogate for a more accurate pathological diagnosis of lung antibody-mediated rejection.

Effect of antifibrotic agents on postoperative complications after lung transplantation for idiopathic pulmonary fibrosis.

BACKGROUND: Antifibrotic agents (AFAs) are now standard-of-care for idiopathic pulmonary fibrosis (IPF). Concerns have arisen about the safety of these drugs in patients undergoing lung transplantation (LTx). METHODS: We performed a multi-centre, nationwide, retrospective, observational study of French IPF patients undergoing LTx between 2011 and 2018 to determine whether maintaining AFAs in the peri-operative period leads to increased bronchial anastomoses issues, delay in skin healing and haemorrhagic complications. We compared the incidence of post-operative complications and the survival of patients according to AFA exposure. RESULTS: Among 205 patients who underwent LTx for IPF during the study period, 58 (28%) had received AFAs within 4 weeks before LTx (AFA group): pirfenidone in 37 (18.0%) and nintedanib in 21 (10.2%). The median duration of AFA treatment before LTx was 13.8 (5.6-24) months. The AFA and control groups did not significantly differ in airway, bleeding or skin healing complications (p = 0.91, p = 0.12 and p = 0.70, respectively). Primary graft dysfunction was less frequent in the AFA than control group (26% vs. 43%, p = 0.02), and the 90-day mortality was lower (7% vs. 18%, p = 0.046). CONCLUSIONS: AFA therapy did not increase airway, bleeding or wound post-operative complications after LTx and could be associated with reduced rates of primary graft dysfunction and 90-day mortality.

Thirty years of surgical management of pediatric pulmonary hypertension: Mid-term outcomes following reverse Potts shunt and transplantation.

BACKGROUND: Reverse Potts shunt (RPS) and lung or heart-lung transplantation are life-extending surgical interventions for pediatric patients with severe pulmonary arterial hypertension (PAH). Robust criteria for identifying patients who will benefit from these procedures remain elusive. Based on 30 years of experience, we sought to refine the surgical indications. METHODS: This single-center retrospective cohort study included 61 consecutive pediatric patients with PAH managed by RPS (2004-2020) or transplantation (1988-2020). Their mid-term outcomes were assessed. RESULTS: Compared with the 20 patients managed by RPS, the 41 transplant waitlist patients, of whom 28 were transplanted, were older (14.9 vs 8.0 years, P = .0001), had worse right ventricular impairment (tricuspid annular plane systolic excursion, 12.5 mm vs 18.0 mm, P = .03), and were managed later in the evolution of the disease (6.0 vs 1.7 years, P = .002). After implementation of a high-priority allocation program in 2007, waitlist mortality decreased from 52.6% to 13.6% (P = .02) and 5-year survival increased from 57.1% to 74.7% after RPS and 55.6% to 77.2% after transplantation. At a median follow-up of 8.6 years after RPS and 5.9 years after transplantation, functional capacity had improved significantly, and PAH-specific drug requirements had diminished markedly in the RPS group. Two patients successfully underwent double-lung transplant 6 and 9 years after RPS. CONCLUSIONS: In selected children with suprasystemic PAH, RPS is associated with functional capacity improvements and decreased pharmacotherapy needs over the midterm. RPS deserves consideration earlier in the course of pediatric PAH, with transplantation being performed in the event of refractory RV failure.

Molecular monitoring of lung allograft health: is it ready for routine clinical use?

Maintenance of long-term lung allograft health in lung transplant recipients (LTRs) requires a fine balancing act between providing sufficient immunosuppression to reduce the risk of rejection whilst at the same time not over-immunosuppressing individuals and exposing them to the myriad of immunosuppressant drug side-effects that can cause morbidity and mortality. At present, lung transplant physicians only have limited and rather blunt tools available to assist them with this task. Although therapeutic drug monitoring provides clinically useful information about single time point and longitudinal exposure of LTRs to immunosuppressants, it lacks precision in determining the functional level of immunosuppression that an individual is experiencing. There is a significant gap in our ability to monitor lung allograft health and therefore tailor optimal personalised immunosuppression regimens. Molecular diagnostics performed on blood, bronchoalveolar lavage or lung tissue that can detect early signs of subclinical allograft injury, differentiate rejection from infection or distinguish cellular from humoral rejection could offer clinicians powerful tools in protecting lung allograft health. In this review, we look at the current evidence behind molecular monitoring in lung transplantation and ask if it is ready for routine clinical use. Although donor-derived cell-free DNA and tissue transcriptomics appear to be the techniques with the most immediate clinical potential, more robust data are required on their performance and additional clinical value beyond standard of care.

Outcome of lung transplantation for adults with interstitial lung disease associated with genetic disorders of the surfactant system.

Background: Interstitial lung disease associated with genetic disorders of the surfactant system is a rare entity in adults that can lead to lung transplantation. Our objective was to describe the outcome of these patients after lung transplantation. Methods: We conducted a retrospective, multicentre study, on adults who underwent lung transplantation for such disease in the French lung transplant centres network, from 1997 to 2018. Results: 20 patients carrying mutations in SFTPA1 (n=5), SFTPA2 (n=7) or SFTPC (n=8) were included. Median interquartile range (IQR) age at diagnosis was 45 (40-48) years, and median (IQR) age at lung transplantation was 51 (45-54) years. Median overall survival after transplantation was 8.6 years. Two patients had a pre-transplant history of lung cancer, and two developed post-transplant lung cancer. Female gender and a body mass index <25 kg·m-2 were significantly associated with a better prognosis, whereas transplantation in high emergency was associated with a worst prognosis. Conclusions: Lung transplantation in adults with interstitial lung disease associated with genetic disorders of surfactant system may be a valid therapeutic option. Our data suggest that these patients may have a good prognosis. Immunosuppressive protocol was not changed for these patients, and close lung cancer screening is needed before and after transplantation.

Changes in HCMV immune cell frequency and phenotype are associated with chronic lung allograft dysfunction.

Background: Human cytomegalovirus (HCMV) infection is common and often severe in lung transplant recipients (LTRs), and it is a risk factor associated with chronic lung allograft dysfunction (CLAD). The complex interplay between HCMV and allograft rejection is still unclear. Currently, no treatment is available to reverse CLAD after diagnosis, and the identification of reliable biomarkers that can predict the early development of CLAD is needed. This study investigated the HCMV immunity in LTRs who will develop CLAD. Methods: This study quantified and phenotyped conventional (HLA-A2pp65) and HLA-E-restricted (HLA-EUL40) anti-HCMV CD8+ T (CD8 T) cell responses induced by infection in LTRs developing CLAD or maintaining a stable allograft. The homeostasis of immune subsets (B, CD4T, CD8 T, NK, and γδT cells) post-primary infection associated with CLAD was also investigated. Results: At M18 post-transplantation, HLA-EUL40 CD8 T responses were less frequently found in HCMV+ LTRs (21.7%) developing CLAD (CLAD) than in LTRs (55%) keeping a functional graft (STABLE). In contrast, HLA-A2pp65 CD8 T was equally detected in 45% of STABLE and 47.8% of CLAD LTRs. The frequency of HLA-EUL40 and HLA-A2pp65 CD8 T among blood CD8 T cells shows lower median values in CLAD LTRs. Immunophenotype reveals an altered expression profile for HLA-EUL40 CD8 T in CLAD patients with a decreased expression for CD56 and the acquisition of PD-1. In STABLE LTRs, HCMV primary infection causes a decrease in B cells and inflation of CD8 T, CD57+/NKG2C+ NK, and δ2-γδT cells. In CLAD LTRs, the regulation of B, total CD8 T, and δ2+γδT cells is maintained, but total NK, CD57+/NKG2C+ NK, and δ2-γδT subsets are markedly reduced, while CD57 is overexpressed across T lymphocytes. Conclusions: CLAD is associated with significant changes in anti-HCMV immune cell responses. Our findings propose that the presence of dysfunctional HCMV-specific HLA-E-restricted CD8 T cells together with post-infection changes in the immune cell distribution affecting NK and γδT cells defines an early immune signature for CLAD in HCMV+ LTRs. Such a signature may be of interest for the monitoring of LTRs and may allow an early stratification of LTRs at risk of CLAD.

Intimal granulomatous angiitis in sarcoid pulmonary vasculitis: worth remembering.

Intimal granulomatous angiitis is a facet of pulmonary sarcoidosis vasculitis that has almost been forgotten. Its observation may offer new understanding of the various patterns of pulmonary hypertension associated with sarcoidosis. https://bit.ly/3g6Ms76.

mTOR Inhibition Impairs the Activation and Function of Belatacept-Resistant CD4+CD57+ T Cells In Vivo and In Vitro.

Calcineurin inhibitors have improved graft survival in solid-organ transplantation but their use is limited by toxicity, requiring a switch to another immunosuppressor in some cases. Belatacept is one option that has been shown to improve graft and patient survival despite being associated with a higher risk of acute cellular rejection. This risk of acute cellular rejection is correlated with the presence of belatacept-resistant T cells. We performed a transcriptomic analysis of in vitro-activated cells to identify pathways affected by belatacept in belatacept-sensitive cells (CD4+CD57-) but not in belatacept-resistant CD4+CD57+ T cells. mTOR was significantly downregulated in belatacept-sensitive but not belatacept-resistant T cells. The inhibition of mTOR strongly decreases the activation and cytotoxicity of CD4+CD57+ cells. In humans, the use of a combination of mTOR inhibitor and belatacept prevents graft rejection and decreases the expression of activation markers on CD4 and CD8 T cells. mTOR inhibition decreases the functioning of belatacept-resistant CD4+CD57+ T cells in vitro and in vivo. It could potentially be used in association with belatacept to prevent acute cellular rejection in cases of calcineurin intolerance.

Systems prediction of chronic lung allograft dysfunction: Results and perspectives from the Cohort of Lung Transplantation and Systems prediction of Chronic Lung Allograft Dysfunction cohorts.

Background: Chronic lung allograft dysfunction (CLAD) is the leading cause of poor long-term survival after lung transplantation (LT). Systems prediction of Chronic Lung Allograft Dysfunction (SysCLAD) aimed to predict CLAD. Methods: To predict CLAD, we investigated the clinicome of patients with LT; the exposome through assessment of airway microbiota in bronchoalveolar lavage cells and air pollution studies; the immunome with works on activation of dendritic cells, the role of T cells to promote the secretion of matrix metalloproteinase-9, and subpopulations of T and B cells; genome polymorphisms; blood transcriptome; plasma proteome studies and assessment of MSK1 expression. Results: Clinicome: the best multivariate logistic regression analysis model for early-onset CLAD in 422 LT eligible patients generated a ROC curve with an area under the curve of 0.77. Exposome: chronic exposure to air pollutants appears deleterious on lung function levels in LT recipients (LTRs), might be modified by macrolides, and increases mortality. Our findings established a link between the lung microbial ecosystem, human lung function, and clinical stability post-transplant. Immunome: a decreased expression of CLEC1A in human lung transplants is predictive of the development of chronic rejection and associated with a higher level of interleukin 17A; Immune cells support airway remodeling through the production of plasma MMP-9 levels, a potential predictive biomarker of CLAD. Blood CD9-expressing B cells appear to favor the maintenance of long-term stable graft function and are a potential new predictive biomarker of BOS-free survival. An early increase of blood CD4 + CD57 + ILT2+ T cells after LT may be associated with CLAD onset. Genome: Donor Club cell secretory protein G38A polymorphism is associated with a decreased risk of severe primary graft dysfunction after LT. Transcriptome: blood POU class 2 associating factor 1, T-cell leukemia/lymphoma domain, and B cell lymphocytes, were validated as predictive biomarkers of CLAD phenotypes more than 6 months before diagnosis. Proteome: blood A2MG is an independent predictor of CLAD, and MSK1 kinase overexpression is either a marker or a potential therapeutic target in CLAD. Conclusion: Systems prediction of Chronic Lung Allograft Dysfunction generated multiple fingerprints that enabled the development of predictors of CLAD. These results open the way to the integration of these fingerprints into a predictive handprint.

Circovirus Hepatitis Infection in Heart-Lung Transplant Patient, France.

In March 2022, a 61-year-old woman in France who had received a heart-lung transplant sought treatment with chronic hepatitis mainly characterized by increased liver enzymes. After ruling out common etiologies, we used metagenomic next-generation sequencing to analyze a liver biopsy sample and identified an unknown species of circovirus, tentatively named human circovirus 1 (HCirV-1). We found no other viral or bacterial sequences. HCirV-1 shared 70% amino acid identity with the closest known viral sequences. The viral genome was undetectable in blood samples from 2017-2019, then became detectable at low levels in September 2020 and peaked at very high titers (1010 genome copies/mL) in January 2022. In March 2022, we found >108 genome copies/g or mL in the liver and blood, concomitant with hepatic cytolysis. We detected HCirV-1 transcripts in 2% of hepatocytes, demonstrating viral replication and supporting the role of HCirV-1 in liver damage.

2022 Update of indications and contraindications for lung transplantation in France.

Lung transplantation (LTx) is a steadily expanding field. The considerable developments have been driven over the years by indefatigable work conducted at LTx centers to improve donor and recipient selection, combined with multifaceted efforts to overcome challenges raised by the surgical procedure, perioperative care, and long-term medical complications. One consequence has been a pruning away of contraindications over time, which has, in some ways, complicated the patient selection process. The Francophone Pulmonology Society (Société de Pneumology de Langue Française, SPLF) set up a task force to produce up-to-date working guidelines designed to assist pulmonologists in managing end-stage respiratory insufficiency, determining which patients may be eligible for LTx, and appropriately timing LTx-center referral. The task force examined the most recent literature and evaluated the risk factors that limit patient survival after LTx. Ideally, the objectives of LTx are to prolong life while also improving quality of life. The guidelines developed by the task force apply to a limited resource and are consistent with the ethical principles described below.

Efficacy of three COVID-19 vaccine doses in lung transplant recipients: a multicentre cohort study.

QUESTION ADDRESSED BY THE STUDY: Do three coronavirus disease 2019 (COVID-19) vaccine doses induce a serological response in lung transplant recipients? METHODS: We retrospectively included 1071 adults (551 (52%) males) at nine transplant centres in France. Each had received three COVID-19 vaccine doses in 2021, after lung transplantation. An anti-spike protein IgG response, defined as a titre >264 BAU·mL-1 after the third dose (median (interquartile range (IQR)) 3.0 (1.7-4.1) months), was the primary outcome and adverse events were the secondary outcomes. Median (IQR) age at the first vaccine dose was 54 (40-63) years and median (IQR) time from transplantation to the first dose was 64 (30-110) months. RESULTS: Median (IQR) follow-up after the first dose was 8.3 (6.7-9.3) months. A vaccine response developed in 173 (16%) patients. Factors independently associated with a response were younger age at vaccination, longer time from transplantation to vaccination and absence of corticosteroid or mycophenolate therapy. After vaccination, 51 (5%) patients (47 non-responders (47/898 (5%)) and four (4/173 (2%)) responders) experienced COVID-19, at a median (IQR) of 6.6 (5.1-7.3) months after the third dose. No responders had severe COVID-19 compared with 15 non-responders, including six who died of the disease. CONCLUSIONS: Few lung transplant recipients achieved a serological response to three COVID-19 vaccine doses, indicating a need for other protective measures. Older age and use of mycophenolate or corticosteroids were associated with absence of a response. The low incidence of COVID-19 might reflect vaccine protection via cellular immunity and/or good adherence to shielding measures.

Multiparametric evaluation of right ventricular function in pulmonary arterial hypertension associated with congenital heart disease.

INTRODUCTION AND OBJECTIVES: Outcome in patients with congenital heart diseases and pulmonary arterial hypertension (PAH) is closely related to right ventricular (RV) function. Two-dimensional echocardiographic parameters, such as strain imaging or RV end-systolic remodeling index (RVESRI) have emerged to quantify RV function. METHODS: We prospectively studied 30 patients aged 48±12 years with pretricuspid shunt and PAH and investigated the accuracy of multiple echocardiographic parameters of RV function (tricuspid annular plane systolic excursion, tricuspid annular peak systolic velocity, RV systolic-to-diastolic duration ratio, right atrial area, RV fractional area change, RV global longitudinal strain and RVESRI) to RV ejection fraction measured by cardiac magnetic resonance. RESULTS: RV ejection fraction <45% was observed in 13 patients (43.3%). RV global longitudinal strain (ρ [Spearman's correlation coefficient]=-0.75; P=.001; R2=0.58; P=.001), right atrium area (ρ=-0.74; P <.0001; R2=0.56; P <.0001), RVESRI (ρ=-0.64; P <.0001; R2=0.47; P <.0001), systolic-to-diastolic duration ratio (ρ=-0.62; P=.0004; R2=0.47; P <.0001) and RV fractional area change (ρ=0.48; P=.01; R2=0.37; P <.0001) were correlated with RV ejection fraction. RV global longitudinal strain, RVESRI and right atrium area predicted RV ejection fraction <45% with the greatest area under curve (0.88; 95%CI, 0.71-1.00; 0.88; 95%CI, 0.76-1.00, and 0.89; 95%CI, 0.77-1.00, respectively). RV global longitudinal strain >-16%, RVESRI ≥ 1.7 and right atrial area ≥ 22 cm2 predicted RV ejection fraction <45% with a sensitivity and specificity of 87.5% and 85.7%; 76.9% and 88.3%; 92.3% and 82.4%, respectively. CONCLUSIONS: RVESRI, right atrial area and RV global longitudinal strain are strong markers of RV dysfunction in patients with pretricuspid shunt and PAH.

Inverted direct allorecognition triggers early donor-specific antibody responses after transplantation.

The generation of antibodies against donor-specific major histocompatibility complex (MHC) antigens, a type of donor-specific antibodies (DSAs), after transplantation requires that recipient's allospecific B cells receive help from T cells. The current dogma holds that this help is exclusively provided by the recipient's CD4+ T cells that recognize complexes of recipient's MHC II molecules and peptides derived from donor-specific MHC alloantigens, a process called indirect allorecognition. Here, we demonstrated that, after allogeneic heart transplantation, CD3ε knockout recipient mice lacking T cells generate a rapid, transient wave of switched alloantibodies, predominantly directed against MHC I molecules. This is due to the presence of donor CD4+ T cells within the graft that recognize intact recipient's MHC II molecules expressed by B cell receptor-activated allospecific B cells. Indirect evidence suggests that this inverted direct pathway is also operant in patients after transplantation. Resident memory donor CD4+ T cells were observed in perfusion liquids of human renal and lung grafts and acquired B cell helper functions upon in vitro stimulation. Furthermore, T follicular helper cells, specialized in helping B cells, were abundant in mucosa-associated lymphoid tissue of lung and intestinal grafts. In the latter, more graft-derived passenger T cells correlated with the detection of donor T cells in recipient's circulation; this, in turn, was associated with an early transient anti-MHC I DSA response and worse transplantation outcomes. We conclude that this inverted direct allorecognition is a possible explanation for the early transient anti-MHC DSA responses frequently observed after lung or intestinal transplantations.

Lung transplantation for interstitial lung disease in idiopathic inflammatory myositis: A cohort study.

In patients with interstitial lung disease (ILD) complicating classical or amyopathic idiopathic inflammatory myopathy (IIM), lung transplantation outcomes might be affected by the disease and treatments. Here, our objective was to assess survival and prognostic factors in lung transplant recipients with IIM-ILD. We retrospectively reviewed data for 64 patients who underwent lung transplantation between 2009 and 2021 at 19 European centers. Patient survival was the primary outcome. At transplantation, the median age was 53 [46-59] years, 35 (55%) patients were male, 31 (48%) had classical IIM, 25 (39%) had rapidly progressive ILD, and 21 (33%) were in a high-priority transplant allocation program. Survival rates after 1, 3, and 5 years were 78%, 73%, and 70%, respectively. During follow-up (median, 33 [7-63] months), 23% of patients developed chronic lung allograft dysfunction. Compared to amyopathic IIM, classical IIM was characterized by longer disease duration, higher-intensity immunosuppression before transplantation, and significantly worse posttransplantation survival. Five (8%) patients had a clinical IIM relapse, with mild manifestations. No patient experienced ILD recurrence in the allograft. Posttransplantation survival in IIM-ILD was similar to that in international all-cause-transplantation registries. The main factor associated with worse survival was a history of muscle involvement (classical IIM). In lung transplant recipients with idiopathic inflammatory myopathy, survival was similar to that in all-cause transplantation and was worse in patients with muscle involvement compared to those with the amyopathic disease.

Sarcoid-like Granulomatosis Associated with Immune Checkpoint Inhibitors in Melanoma.

We aimed to review the clinical and biological presentation of granulomatosis associated with immune-checkpoint inhibitors (ICI) in patients with melanoma and to explore its association with classical sarcoidosis as well as with cancer response to ICI. To this end, a retrospective study on 18 melanoma patients with histologically proven ICI-induced granulomatosis over a 12-year period in a single center, as well as on 67 similar cases reported in the literature, was conducted. Results indicate ICI-induced granulomatosis is an early side effect (median time to onset: 2 months). Its clinical presentation, with predominant (90%) thoracic involvement, histopathological appearance and supposed underlying biology (involving the mTOR pathway in immune cells, Th17 polarization and TReg dysfunction) are indistinguishable from those of sarcoidosis. Moreover, it appears to be associated with ICI benefit (>65% objective response rate). Evolution is generally favorable, and symptomatic steroid treatment and/or ICI discontinuation are rarely necessary. ICI-associated granulomatosis is critical to explore for several reasons. Practically, it is essential to differentiate it from cancer progression. Secondly, this "experimental" sarcoidosis brings new elements that may help to address sarcoidosis origin and pathophysiology. Its association with ICI efficacy must be confirmed on a larger scale but could have significant impacts on patient management and biomarker definition.