Outcomes of liver transplantation for hepatopulmonary syndrome in patients with concomitant respiratory disease.

BACKGROUND & AIMS: Concomitant respiratory disease is a common finding in patients with hepatopulmonary syndrome (HPS). Among patients who underwent liver transplantation (LT) for HPS, we compared characteristics and outcome of patients with versus without concomitant respiratory disease. METHODS: This single center retrospective observational study included patients with HPS who underwent LT between 1999 and 2020. RESULTS: During the study period, 32 patients with HPS received a LT; nine (28%) with concomitant respiratory disease of whom one required a combined lung-liver transplantation. Patients with concomitant respiratory disease had higher PaCO2 (38 vs. 33 mm Hg, p = .031). The 30-day postoperative mortality was comparable, but the estimated cumulative probability of resolution of oxygen therapy after LT in HPS patients with versus those without concomitant respiratory disease was lower: 63% versus 91% at 12 months and 63% versus 100% at 18 months (HR 95% CI .140-.995, p = .040). In addition to the presence of concomitant respiratory disease (p = .040), history of smoking (p = .012), and high baseline 99mTcMAA shunt fraction (≥20%) (p = .050) were significantly associated with persistent need of oxygen therapy. The 5-year estimated cumulative probability of mortality in patients with concomitant respiratory disease was worse: 50% versus 23% (HR 95% CI .416-6.867, p = .463). CONCLUSIONS: The presence of a concomitant respiratory disease did not increase the short-term postoperative mortality after LT in patients with HPS. However, it resulted in a longer need for oxygen therapy.

Complications related to extracorporeal life support in lung transplantation: single-center analysis.

Background: Extracorporeal life support (ECLS) is not routinely used at our center during sequential single-lung transplantation (LTx), but is restricted to anticipate and overcome hemodynamic and respiratory problems occurring peri-operatively. In this retrospective descriptive cohort study, we aim to describe our single-center experience with ECLS in LTx, analyzing ECLS-related complications. Methods: All transplantations with peri-operative ECLS use [2010-2020] were retrospectively analyzed. Multi-organ and heart-lung transplantation were excluded. Demographics, support type and indications are described. Complications are categorized according to the underlying nature and type. Data are presented as median [interquartile range (IQR)]. Kaplan-Meier was used for survival analysis. Results: The overall use of ECLS was 22% (156/703 patients) with a mean age of 52 years (IQR, 36-59 years). Transplant indications in ECLS cohort were interstitial lung disease (38%; n=60), chronic obstructive pulmonary disease (COPD) (19%; n=29), cystic fibrosis (17%; n=26) and others (26%; n=41). Per indication, 94% (15/16) of pulmonary arterial hypertension patients required ECLS, whereas only 8% (29/382) of COPD patients did. In 16% (25/156) of supported patients, veno-venous extracorporeal membrane oxygenation was initiated, while 77% (120/156) required veno-arterial support, and 7% (11/156) cardiopulmonary bypass. Thirty-day mortality was 6% (9/156). Sixteen percent (25/156) of patients were bridged to transplantation on ECLS and 24% (37/156) required post-operative support. Main reasons to use ECLS were intra-operative hemodynamic instability (53%; n=82), ventilation/oxygenation problems (22%; n=34) and reperfusion edema (17%; n=26). Overall incidence of patients with at least one ECLS-related complication was 67% (n=104). Most common complications were hemothorax (25%; n=39), need for continuous renal replacement therapy (19%; n=30), and thromboembolism (14%; n=22). Conclusions: ECLS was required in 22% of LTxs, with a reported ECLS-related complication rate of 67%, of which the most common was hemothorax. Larger databases are needed to further analyze complications and develop tailored deployment strategies for ECLS-use in LTx.

The hemodynamic interplay between pulmonary ischemia-reperfusion injury and right ventricular function in lung transplantation: a translational porcine model.

Lung transplantation (LTx) is a challenging procedure. Following the process of ischemia-reperfusion injury, the transplanted pulmonary graft might become severely damaged, resulting in primary graft dysfunction. In addition, during the intraoperative window, the right ventricle (RV) is at risk of acute failure. The interaction of right ventricular function with lung injury is, however, poorly understood. We aimed to address this interaction in a translational porcine model of pulmonary ischemia-reperfusion injury. Advanced pulmonary and hemodynamic assessment was used, including right ventricular pressure-volume loop analysis. The acute model was based on clamping and unclamping of the left lung hilus, respecting the different hemodynamic phases of a clinical lung transplantation. We found that forcing entire right ventricular cardiac output through a lung suffering from ischemia-reperfusion injury increased afterload (pulmonary vascular resistance from baseline to end experiment P < 0.0001) and induced right ventricular failure (RVF) in 5/9 animals. Notably, we identified different compensation patterns in failing versus nonfailing ventricles (arterial elastance P = 0.0008; stroke volume P < 0.0001). Furthermore, increased vascular pressure and flow produced by the right ventricle resulted in higher pulmonary injury, as measured by ex vivo CT density (correlation: pressure r = 0.8; flow r = 0.85). Finally, RV ischemia as measured by troponin-T was negatively correlated with pulmonary injury (r = -0.76); however, troponin-T values did not determine RVF in all animals. In conclusion, we demonstrate a delicate balance between development of pulmonary ischemia-reperfusion injury and right ventricular function during lung transplantation. Furthermore, we provide a physiological basis for potential benefit of extracorporeal life support technology.NEW & NOTEWORTHY In contrast to the abundant literature of mechanical pulmonary artery clamping to increase right ventricular afterload, we developed a model adding a biological factor of pulmonary ischemia-reperfusion injury. We did not only focus on the right ventricular behavior, but also on the interaction with the injured lung. We are the first to describe this interaction while addressing the hemodynamic intraoperative phases of clinical lung transplantation.

Lung transplantation for COPD/pulmonary emphysema.

COPD and α-1 antitrypsin deficiency emphysema remain one of the major indications for lung transplantation. If all other treatment possibilities are exhausted or not possible (including rehabilitation, oxygen therapy, noninvasive ventilation, lung volume reduction), patients may qualify for lung transplantation. Strict selection criteria are implemented with a lot of relative and absolute contraindications. Because of an ongoing donor shortage, only a minority of endstage COPD patients will finally get transplanted. The procedure may involve a single or a double lung transplantation, dependent on the experience of the centre, the waiting list, the availability of donor lungs and the patient's risk-benefit ratio. In general, the life expectancy as well as the health-related quality of life after lung transplantation for COPD are usually increased, and may be somewhat better after double compared with single lung transplantation. Several specific complications can be encountered, such as the development of solid organ cancer and chronic lung allograft dysfunction, which develops in up to 50% of patients within 5 years of their transplant and has a major impact on long-term survival, because of the current inefficient treatment modalities.

Lung Transplant Outcome From Selected Older Donors (≥70 Years) Equals Younger Donors (<70 Years): A Propensity-matched Analysis.

OBJECTIVE: To describe our experience with lung transplantation (LTx) from donors ≥70 years and compare short and long-term outcomes to a propensity-matched cohort of donors <70 years. BACKGROUND: Although extended-criteria donors have been widely used to enlarge the donor pool, the experience with LTx from older donors (≥70 years) remains limited. METHODS: All single-center bilateral LTx between 2010 and 2020 were retrospectively analyzed. Matching (1:1) was performed for the donor (type, sex, smoking history, x-ray abnormalities, partial pressure of oxygen/fraction of inspired oxygen ratio, and time on ventilator) and recipient characteristics (age, sex, LTx indication, perioperative extracorporeal life support, and cytomegalovirus mismatch). Primary graft dysfunction grade-3, 5-year patient, and chronic lung allograft dysfunction-free survival were analyzed. RESULTS: Out of 647 bilateral LTx, 69 were performed from donors ≥70 years. The mean age in the older donor cohort was 74 years (range: 70-84 years) versus 49 years (range: 12-69 years) in the matched younger group. No significant differences were observed in the length of ventilatory support, intensive care unit, or hospital stay. Primary graft dysfunction-3 was 26% in the older group versus 29% in younger donor recipients ( P = 0.85). Reintervention rate was comparable (29% vs 16%; P = 0.10). Follow-up bronchoscopy revealed no difference in bronchial anastomotic complications ( P = 1.00). Five-year patient and chronic lung allograft dysfunction-free survivals were 73.6% versus 73.1% ( P = 0.72) and 51.5% versus 59.2% ( P = 0.41), respectively. CONCLUSIONS: LTx from selected donors ≥70 years is feasible and safe, yielding comparable short and long-term outcomes in a propensity-matched analysis with younger donors (<70 years).

Molecular Profiling of Tissue Samples with Chronic Rejection from Patients with Chronic Lung Allograft Dysfunction: A Pilot Study in Cystic Fibrosis Patients.

Chronic rejection (CR) is the main culprit for reduced survival and quality of life in patients undergoing lung transplantation (Ltx). High-throughput approaches have been used to unveil the molecular pathways of CR, mainly in the blood and/or in bronchoalveolar lavage. We hypothesized that a distinct molecular signature characterizes the biopsies of recipients with clinically confirmed histological signs of CR. Eighteen cystic fibrosis patients were included in the study and RNA sequencing was performed in 35 scheduled transbronchial biopsies (TBBs): 5 with acute cellular rejection, 9 with CR, and 13 without any sign of post-LTx complication at the time of biopsy; 8 donor lung samples were used as controls. Three networks with 33, 26, and 36 differentially expressed genes (DEGs) were found in TBBs with CR. Among these, seven genes were common to the identified pathways and possibly linked to CR and five of them (LCN2, CCL11, CX3CL1, CXCL12, MUC4) were confirmed by real-time PCR. Immunohistochemistry was significant for LCN2 and MUC4. This study identified a typical gene expression pattern in TBBs with histological signs of CR and the LCN2 gene appeared to play a central role. Thus, it could be crucial in CR pathophysiology.

Radiologic and Histologic Correlates of Early Interstitial Lung Changes in Explanted Lungs.

Background Interstitial lung abnormalities (ILAs) reflect imaging features on lung CT scans that are compatible with (early) interstitial lung disease. Despite accumulating evidence regarding the incidence, risk factors, and prognosis of ILAs, the histopathologic correlates of ILAs remain elusive. Purpose To determine the correlation between radiologic and histopathologic findings in CT-defined ILAs in human lung explants. Materials and Methods Explanted lungs or lobes from participants with radiologically documented ILAs were prospectively collected from 2010 to 2021. These specimens were air-inflated, frozen, and scanned with CT and micro-CT (spatial resolution of 0.7 mm and 90 µm, respectively). Subsequently, the lungs were cut and sampled with core biopsies. At least five samples per lung underwent micro-CT and subsequent histopathologic assessment with semiquantitative remodeling scorings. Based on area-specific radiologic scoring, the association between radiologic and histopathologic findings was assessed. Results Eight lung explants from six donors (median age at explantation, 71 years [range, 60-83 years]; four men) were included (unused donor lungs, n = 4; pre-emptive lobectomy for oncologic indications, n = 2). Ex vivo CT demonstrated ground-glass opacification, reticulation, and bronchiectasis. Micro-CT and histopathologic examination demonstrated that lung abnormalities were frequently paraseptal and associated with fibrosis and lymphocytic inflammation. The histopathologic results showed varying degrees of fibrosis in areas that appeared normal on CT scans. Regions of reticulation on CT scans generally had greater fibrosis at histopathologic analysis. Vasculopathy and bronchiectasis were also often present at histopathologic examination of lungs with ILAs. Fully developed fibroblastic foci were rarely observed. Conclusion This study demonstrated direct histologic correlates of CT-defined interstitial lung abnormalities. © RSNA, 2022 Supplemental material is available for this article. See also the editorial by Jeudy in this issue.

Can we attenuate ischaemia-reperfusion injury of allografts in a porcine left lung transplant models by adsorption of cytokines?

OBJECTIVES: Primary graft dysfunction resulting from ischaemia-reperfusion injury remains a major obstacle after lung transplantation (LTx) and is associated with morbidity and mortality. Continuous release of inflammatory cytokines, due to the process of ischaemia and reperfusion, triggers a complex cascade of apoptosis and necrosis resulting in graft dysfunction. Previous studies demonstrated successful graft improvement by cytokine filtration during ex vivo lung perfusion. We hypothesize that plasma cytokine filtration with CytoSorb® during in vivo graft perfusion immediately after implantation may attenuate ischaemia-reperfusion injury after left LTx in a porcine model. METHODS: Left porcine LTx was performed with allografts preserved for 24 h at 4°C. In the treatment group [T] (n = 7), a veno-venous shunt was created to insert the cytokine filter (CytoSorbents, Berlin, Germany). In the sham group [S] (n = 4), the shunt was created without the filter. Haemodynamic parameters, lung mechanics, blood gases and plasma cytokines were assessed during 6 h in vivo reperfusion. RESULTS: During 6 h of reperfusion, significant differences in plasma pro-inflammatory cytokine [interferon (IFN)-α, IFN-γ and interleukin (IL)-6] concentrations were observed between [T] and [S], but surprisingly with higher plasma levels in the [T] group. Plasma concentrations of other pro-inflammatory cytokines (IL-1ß, IL-12p40, IL-4, IL-6, IL-8, IFN-α, IFN-γ and tumour necrosis factor-α) and anti-inflammatory cytokines (IL-10) did not find any evidence for a difference. Furthermore, our study failed to show meaningful difference in haemodynamics and blood gases. Also, no statistically significant differences were found between [T] and [S] in biopsies and wet-to-dry ratio at the end of the experiment. CONCLUSIONS: In our porcine left LTx model cytokine filtration did not achieve the intended effect. This is in contrast to previous studies with CytoSorb use during ex vivo lung perfusion as a surrogate LTx model. Our findings might highlight the fact that the theoretical benefit of inserting an additional cytokine adsorber to improve graft function in clinical practice should be critically evaluated with further studies.

Bronchiolitis obliterans syndrome after lung or haematopoietic stem cell transplantation: current management and future directions.

Bronchiolitis obliterans syndrome (BOS) may develop after either lung or haematopoietic stem cell transplantation (HSCT), with similarities in histopathological features and clinical manifestations. However, there are differences in the contributory factors and clinical trajectories between the two conditions. BOS after HSCT occurs due to systemic graft-versus-host disease (GVHD), whereas BOS after lung transplantation is limited to the lung allograft. BOS diagnosis after HSCT is more challenging, as the lung function decline may occur due to extrapulmonary GVHD, causing sclerosis or inflammation in the fascia or muscles of the respiratory girdle. Treatment is generally empirical with no established effective therapies. This review provides rare insights and commonalities of both conditions, which are not well elaborated elsewhere in contemporary literature, and highlights the importance of cross disciplinary learning from experts in other transplant modalities. Treatment algorithms for each condition are presented, based on the published literature and consensus clinical opinion. Immunosuppression should be optimised, and other conditions or contributory factors treated where possible. When initial treatment fails, the ultimate therapeutic option is lung transplantation (or re-transplantation in the case of BOS after lung transplantation) in carefully selected candidates. Novel therapies under investigation include aerosolised liposomal cyclosporine, Janus kinase inhibitors, antifibrotic therapies and (in patients with BOS after lung transplantation) B-cell-directed therapies. Effective novel treatments that have a tangible impact on survival and thereby avoid the need for lung transplantation or re-transplantation are urgently required.

The MUC5B Promoter Polymorphism is Not Associated With Non-ILD Chronic Respiratory Diseases or Post-transplant Outcome.

The MUC5B promoter polymorphism (rs35705950) has been associated with interstitial lung disease (ILD) and with prolonged pre-transplant survival in idiopathic pulmonary fibrosis (IPF), but no information is available regarding its prevalence in other respiratory diseases and its influence on post-transplant outcome. We included the Leuven lung transplantation cohort between 1991 and 2015 (n = 801). We assessed the minor allele frequency (MAF) of the MUC5B variant in the entire study cohort and investigated the influence of recipient MUC5B promoter polymorphism on post-transplant outcome in patients who were transplanted after 2004. MUC5B was successfully genotyped in 746 patients. The MAF was significantly higher in ILD (17.6%) compared to chronic obstructive pulmonary disease (COPD)/emphysema (9.3%), cystic fibrosis (CF)/bronchiectasis (BRECT) (7.5%) and pulmonary hypertension (PHT) (7.4%) (p < 0.001). No association was observed between rs35705950 and chronic lung allograft dysfunction (CLAD)/graft loss in the ILD population [CLAD: HR 1.37 95% CI (0.70-2.68); graft loss: HR 1.02 95% CI (0.55-1.89)], nor the entire study cohort [CLAD: HR 0.96 95% CI (0.69-1.34); graft loss: HR 0.97 95% CI (0.70-1.35)]. The MUC5B promoter polymorphism is a very specific predictive factor for the presence of pulmonary fibrosis as it is only associated with pulmonary fibrosis and not with other chronic respiratory diseases. While the MUC5B promoter variant is associated with better pre-transplant survival among IPF patients, recipient MUC5B promoter variant does not play a role in post-transplant outcome.

Azole-Induced Myositis after Combined Lung-Liver Transplantation.

Lung transplant recipients experience a high rate of invasive pulmonary aspergillosis infections, for which voriconazole is the treatment of choice. We report a patient who developed voriconazole-induced myositis that relapsed after one dose of isavuconazole. Our patient was a 38-year-old man who received a single sequential lung transplantation and liver transplantation because of end-stage cystic fibrosis. He presented to our emergency room with acute pain in both forearms at 3 weeks after voriconazole was initiated for invasive pulmonary aspergillosis infection. Levels of voriconazole were normal during the course of therapy. After stopping voriconazole, the symptoms decreased but relapsed after one dose of isavuconazole. Other causes of muscle pain and inflammation were excluded. Magnetic resonance imaging of both arms showed muscle edema in both arms, including involvement of the fascia, consistent with myositis. There were no signs of necrosis. Isavuconazole was discontinued, and the corticosteroid dose was temporarily increased, with rapid resolution of all complaints. Our patient is the fourth reported case of voriconazole-induced myositis, and the first whose symptoms relapsed after initiating isavuconazole.

Novel biomarkers of chronic lung allograft dysfunction: is there anything reliable?

PURPOSE OF REVIEW: Chronic lung allograft dysfunction (CLAD) remains a major barrier preventing long-term survival following lung transplantation. As our clinical knowledge regarding its definition and presentation has significantly improved over the last years, adequate biomarkers to predict development of CLAD, phenotype of CLAD or prognosis post-CLAD diagnosis are definitely needed. RECENT FINDINGS: Radiological and physiological markers are gradually entering routine clinical practice. In-depth investigation of biological samples including broncho-alveolar lavage, biopsy and serum has generated potential biomarkers involved in fibrogenesis, airway injury and inflammation but none of these are universally accepted or implemented although progress has been made, specifically regarding donor-derived cell-free DNA and donor-specific antibodies. SUMMARY: Although a lot of promising biomarkers have been put forward, a very limited number has made it to routine clinical practice. Nevertheless, a biomarker that leads to earlier detection or more adequate disease phenotyping would advance the field enormously.

Once daily tacrolimus conversion in lung transplantation: A prospective study on safety and medication adherence.

BACKGROUND: Lung transplantation (LTx) requires a calcineurin inhibitor-based immunosuppressive regimen. A once daily (QD) tacrolimus regimen was developed to increase medication adherence. However, data concerning its safety and efficacy in LTx are lacking. METHODS: In this prospective study, stable LTx patients were consecutively converted from twice daily (BID) tacrolimus to QD tacrolimus on a 1 mg:1 mg basis. Trough level (Cmin), renal function, cholesterol, fasting glucose, potassium and lung function were monitored six months before and up to one year after conversion. Adherence and its barriers were assessed by self-reported questionnaires (Basel Assessment of Adherence to Immunosuppressive Medications Scale (BAASIS) and Identification of Medication Adherence Barriers questionnaire (IMAB)) and blood-based assays (mean Cmin and coefficient of variation (CV)). RESULTS: We included 372 patients, in whom we observed a decrease in tacrolimus Cmin of 18.5% (p < 0.0001) post-conversion, requiring subsequent daily dose adaptations in both cystic fibrosis (CF) (n = 72) and non-CF patients (n = 300). We observed a small decrease in eGFR one year post-conversion (p = 0.024). No significant changes in blood creatinine, potassium, fasting glucose, cholesterol or rate of lung function decline were observed. In a subgroup of 166 patients, significantly fewer patients missed doses (8.4% vs. 19.3%, p = 0.016) or had irregular intake post-conversion (19.3% vs. 32.5%, p = 0.019). Mean Cmin and CV, as well as the total number of barriers, also decreased significantly post-conversion. CONCLUSIONS: In LTx, conversion from BID to QD tacrolimus (1 mg:1 mg) requires close monitoring of tacrolimus Cmin. QD tacrolimus after transplantation is safe with respect to renal function, metabolic parameters and allograft function and improves LTx recipient adherence.

Diagnostic Yield of 18F-FDG PET After Lung Transplantation: A Single-center, Retrospective Cohort Study.

BACKGROUND: To investigate the diagnostic yield of 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) in lung transplant recipients. METHODS: A single-center, retrospective cohort study including 234 18F-FDG PET examinations in 199 lung transplant recipients. Indication for PET referral, 18F-FDG PET diagnosis/findings and final clinical diagnosis were classified into 3 groups: malignancy, infection/inflammation not otherwise specified, and chronic lung allograft dysfunction with restrictive allograft syndrome phenotype. Sensitivity/specificity analysis was performed to determine accuracy of 18F-FDG PET in each group. RESULTS: Sensitivity of 18F-FDG PET for malignancy was 91.4% (95% confidence interval, 82.5%-96.0%) and specificity was 82.3% (95% confidence interval, 74.5%-88.1%). Infection/inflammation not otherwise specified and restrictive allograft syndrome as indication for 18F-FDG PET comprised relatively small groups (14 and 31 cases, respectively). In addition, 18F-FDG PET revealed clinically relevant incidental findings in 15% of cases. CONCLUSIONS: Referral for 18F-FDG PET after lung transplantation mainly occurred to confirm or rule out malignancy. In this specific setting, 18F-FDG PET has a high diagnostic yield. Accuracy of 18F-FDG PET for other indications is less clear, given small sample sizes. Clinically relevant diagnoses, unrelated to the primary indication for 18F-FDG PET, are found relatively often in this immunocompromised cohort.

Case Report: An Unusual Course of Angiosarcoma After Lung Transplantation.

A 35-year-old woman underwent bilateral lung transplantation for primary ciliary dyskinesia and developed vascular tumors over a slow time course. Initial presentation of non-specific vascular tumors in the lungs and liver for up to 6 years after transplantation evolved toward bilateral ovarian angiosarcoma. Tumor analysis by haplotyping and human leukocyte antigen typing showed mixed donor chimerism, proving donor origin of the tumoral lesions. In retrospect, the donor became brain dead following neurosurgical complications for a previously biopsy-proven cerebral hemangioma, which is believed to have been a precursor lesion of the vascular malignancy in the recipient. Donor-transmitted tumors should always be suspected in solid organ transplant recipients in case of uncommon disease course or histology, and proper tissue-based diagnosis using sensitive techniques should be pursued.