Extended ischemic time (>15 hours) using controlled hypothermic storage in lung transplantation: A multicenter experience.

Static ice storage has long been the standard-of-care for lung preservation, although freezing injury limits ischemic time (IT). Controlled hypothermic storage (CHS) at elevated temperature could safely extend IT. This retrospective analysis assesses feasibility and safety of CHS with IT > 15 hours. Three lung transplant (LuTx) centers (April-October 2023) included demographics, storage details, IT, and short-term outcome from 13 LuTx recipients (8 male, 59 years old). Donor lungs were preserved in a portable CHS device at 7 (5-9.3)°C. Indication was overnight bridging and/or long-distance transport. IT of second-implanted lung was 17.3 (15.1-22) hours. LuTx were successful, 4/13 exhibited primary graft dysfunction grade 3 within 72 hours and 0/13 at 72 hours. Post-LuTx mechanical ventilation was 29 (7-442) hours. Intensive care unit stay was 9 (5-28) and hospital stay 30 (16-90) days. Four patients needed postoperative extracorporeal membrane oxygenation (ECMO). One patient died (day 7) following malpositioning of an ECMO cannula. This multicenter experience demonstrates the possibility of safely extending IT > 15 hours by CHS.

Noncanonical mechanism of Nrf2 activation by diacylglycerol polyethylene glycol adducts in normal human epidermal keratinocytes.

Polyethylene glycol-23 glyceryl distearate (GDS-23), a diacylglycerol polyethylene glycol adduct, forms niosomes with a liposome-like structure and functions as an active ingredient in drug delivery systems. In addition, it upregulates antioxidant proteins such as heme oxygenase 1 and NAD(P)H-quinone dehydrogenase 1 in cells. However, the activation of nuclear factor E2-related factor-2 (Nrf2), which plays a role in inducing the expression of antioxidant proteins, and its protective effects induced by GDS-23 treatment against oxidative stress have not been elucidated. This study aimed at verifying the activation of Nrf2 by GDS-23 and clarifying its underlying mechanisms, and investigated whether GDS-23 protects against hydroquinone-induced cytotoxicity. Normal human epidermal keratinocytes were treated with GDS-23. Real-time reverse transcription-polymerase chain reaction, western blotting, and immunostaining were used to investigate the mechanism of Nrf2 activation, and neutral red assay was performed to evaluate cytotoxicity. GDS-23-treated cells showed an increase in antioxidant protein levels and stabilization of Nrf2 in the nucleus. During Nrf2 activation, p62, an autophagy-related adaptor protein, was phosphorylated at Ser349. Inhibition of the interaction between the phosphorylated p62 and Kelch-like ECH-associated protein 1 significantly suppressed the GDS-23-mediated induction of antioxidant protein expression. In addition, hydroquinone-induced cell toxicity was significantly attenuated by GDS-23. GDS-23 induced the intracellular antioxidant system by activating Nrf2 in a p62 phosphorylation-dependent manner without generating oxidative stress in the cells. GDS-23 may be applied as a multifunctional material for drug delivery system that enhances internal antioxidant systems.

Reduced Community-acquired Respiratory Virus Infection, but Not Non-virus Infection, in Lung Transplant Recipients During Government-mandated Public Health Measures to Reduce COVID-19 Transmission.

Community-acquired respiratory viruses (CARVs) are an important cause of morbidity and mortality in lung transplant (LTx) recipients. Despite routine mask-wearing, LTx patients remain at a higher risk of CARV infection than the general population. In 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of COVID-19 and a novel CARV, emerged leading federal and state officials to implement public health nonpharmaceutical interventions (NPIs) to curb its spread. We hypothesized that NPI would be associated with the reduced spread of traditional CARVs. Methods: A single-center, retrospective cohort analysis comparing CARV infection before a statewide stay-at-home order, during the stay-at-home order and subsequent statewide mask mandate, and during 5 mo following the elimination of NPI was performed. All LTx recipients followed by and tested at our center were included. Data (multiplex respiratory viral panels; SARS-CoV-2 reverse transcription polymerase chain reaction; blood cytomegalovirus and Epstein Barr virus polymerase chain reaction; blood and bronchoalveolar lavage bacterial and fungal cultures) were collected from the medical record. Chi-square or Fisher exact tests were utilized for categorical variables. A mixed-effect model was used for continuous variables. Results: Incidence of non-COVID CARV infection was significantly lower during the MASK period than during the PRE period. No difference was noted in airway or bloodstream bacterial or fungal infections, but cytomegalovirus bloodborne viral infections increased. Conclusions: Reductions in respiratory viral infections, but not bloodborne viral infections nor nonviral respiratory, bloodborne, or urinary infections, were observed in the setting of public health COVID-19 mitigation strategies, suggesting the effectiveness of NPI in preventing general respiratory virus transmission.

Thoracic retransplantation: Does time to retransplantation matter?

OBJECTIVE: For some individuals, chronic allograft failure is best treated with retransplantation. We sought to determine if time to retransplantation impacts short- and long-term outcomes for heart or lung retransplant recipients with a time to retransplantation more than 1 year. METHODS: The United Network for Organ Sharing/Organ Procurement and Transplantation Network STAR file was queried for all adult, first-time heart (June 1, 2006, to September 30, 2020) and lung (May 1, 2005, to September 30, 2020) retransplantations with a time to retransplantation of at least 1 year. Patients were grouped according to the tertile of time to retransplantation (tertile 1: 1-7.7 years, tertile 2: 7.7-14.7 years, tertile 3: 14.7+ years; lung: tertile 1: 1-2.8 years, tertile 2: 2.8-5.6 years, tertile 3: 5.6+ years). The primary outcome was survival after retransplantation. Comparative statistics identified differences in groups, and Kaplan-Meier methods and a Cox proportional hazard model were used for survival analysis. RESULTS: After selection, 908 heart and 871 lung retransplants were identified. Among heart retransplant recipients, tertile 1 was associated with male sex, smoking history, higher listing status, and increased mechanical support pretransplant. Tertile 3 had the highest rate of concomitant kidney transplant; however, the incidence of morbidity and in-hospital mortality was similar among the groups. Unadjusted and adjusted analyses revealed no survival difference among all groups. Regarding lung retransplant recipients, tertile 1 was associated with increased lung allocation score, pretransplant hospitalization, and mechanical support. Unadjusted and adjusted survival analyses revealed decreased survival in tertile 1. CONCLUSIONS: Time to retransplant does not appear to affect heart recipients with a time to retransplantation of more than 1 year; however, shorter time to retransplantation for prior lung recipients is associated with decreased survival. Potential lung retransplant candidates with a time to retransplantation of less than 2.8 years should be carefully evaluated before retransplantation.

Donor and Recipient Hepatitis C Status Does Not Affect Rejection in Thoracic Transplantation.

BACKGROUND: Donors with hepatitis C virus (HCV) have expanded the donor pool for heart and lung transplantation, but concerns have arisen about rejection. We examined the incidence of rejection after heart and lung transplantation in recipients of HCV-positive donors as well as HCV-positive recipients. METHODS: Adults undergoing heart and lung transplantation from March 31, 2015 to December 31, 2019 were identified in the United Network for Organ Sharing/Organ Transplantation and Procurement Network Standard Transplant Analysis and Research file. Patients were stratified as donor-recipient HCV negative, donor positive, and recipient positive. Comparative statistics and a multilevel logistic regression model were used. RESULTS: Meeting the criteria were 10 624 heart transplant recipients. Donor-positive recipients were significantly associated with older age, blood group O, and shorter waitlist time. No significant differences existed with regards to treatment for rejection in the first year (negative, 19.5%; donor positive, 22.3%; recipient positive, 19.5%; P = .45) or other outcomes. On regression analysis HCV status was not associated with treated rejection; however center variability was significantly associated with treated rejection (median odds ratio, 2.18). Similarly, 9917 lung transplant recipients were identified. Donor-positive recipients were more commonly White and had obstructive disease and lower lung allocation scores. Both unadjusted (negative, 22.1%; donor positive, 23.0%; recipient positive, 18.6%; P = .43) and adjusted analyses failed to demonstrate a significant association between HCV status and treatment for rejection, whereas center variability remained significantly associated with treatment for rejection (median odds ratio, 2.41). CONCLUSIONS: Use of HCV donors has expanded the donor pool for heart and lung transplantation. HCV donor status was not associated with treatment for rejection in the first year, but center variability played a role in the incidence and treatment of rejection.

Trends in Donation After Circulatory Death in Lung Transplantation in the United States: Impact Of Era.

Background: Use of lungs donated after circulatory death (DCD) has expanded, but changes in donor/recipient characteristics and comparison to brain dead donors (DBD) has not been studied. We examined the evolution of the use of DCD lungs for transplantation and compare outcomes to DBD lungs. Methods: The SRTR database was used to construct three 5-year intervals. Perioperative variables and survival were compared by era and for DCD vs. DBD. Geographic variation was estimated using recipient permanent address. Results: 728 DCD and 27,205 DBD lung transplants were identified. DCD volume increased from Era 1 (n = 73) to Era 3 (n = 528), representing 1.1% and 4.2% of lung transplants. Proportionally more DCD recipients were in ICU or on ECMO pre-transplant, and had shorter waitlist times. DCD donors were older, had lower PaO2/FiO2 ratios compared to DBD, more likely to be bilateral, had longer ischemic time, length of stay, post-op dialysis, and increased use of lung perfusion. There was no difference in overall survival. Geographically, use was heterogeneous. Conclusion: DCD utilization is low but increasing. Despite increasing ischemic time and transplantation into sicker patients, survival is similar, which supports further DCD use in lung transplantation. DCD lung transplantation presents an opportunity to continue to expand the donor pool.

Clinical Validation of a Plasma Donor-derived Cell-free DNA Assay to Detect Allograft Rejection and Injury in Lung Transplant.

Background: Lung transplant patients are vulnerable to various forms of allograft injury, whether from acute rejection (AR) (encompassing acute cellular rejection [ACR] and antibody-mediated rejection [AMR]), chronic lung allograft dysfunction (CLAD), or infection (INFXN). Previous research indicates that donor-derived cell-free DNA (dd-cfDNA) is a promising noninvasive biomarker for the detection of AR and allograft injury. Our aim was to validate a clinical plasma dd-cfDNA assay for detection of AR and other allograft injury and to confirm and expand on dd-cfDNA and allograft injury associations observed in previous studies. Methods: We measured dd-cfDNA fraction using a novel single-nucleotide polymorphism-based assay in prospectively collected plasma samples paired with clinical-pathologic diagnoses. dd-cfDNA fraction was compared across clinical-pathologic cohorts: stable, ACR, AMR, isolated lymphocytic bronchiolitis, CLAD/neutrophilic-responsive allograft dysfunction (NRAD), and INFXN. Performance characteristics were calculated for AR and combined allograft injury (AR + CLAD/NRAD + INFXN) versus the stable cohort. Results: The study included 195 samples from 103 patients. Median dd-cfDNA fraction was significantly higher for ACR (1.43%, interquartile range [IQR]: 0.67%-2.32%, P = 5 × 10-6), AMR (2.50%, IQR: 2.06%-3.79%, P = 2 × 10-5), INFXN (0.74%, IQR: 0.46%-1.38%, P = 0.02), and CLAD/NRAD (1.60%, IQR: 0.57%-2.60%, P = 1.4 × 10-4) versus the stable cohort. Area under the receiver operator characteristic curve for AR versus stable was 0.91 (95% confidence interval [CI]: 0.83-0.98). Using a ≥1% dd-cfDNA fraction threshold, sensitivity for AR was 89.1% (95% CI: 76.2%-100.0%), specificity 82.9% (95% CI: 73.3%-92.4%), positive predictive value, 51.9% (95% CI: 37.5%-66.3%), and negative predictive value, 97.3% (95% CI: 94.3%-100%). For combined allograft injury area under the receiver operator characteristic curve was 0.76 (95% CI: 0.66-0.85), sensitivity 59.9% (95% CI: 46.0%-73.9%), specificity 83.9% (95% CI: 74.1%-93.7%), positive predictive value, 43.6% (95% CI: 27.6%-59.6%), and negative predictive value, 91.0% (95% CI: 87.9%-94.0%). Conclusions: These results indicate that our dd-cfDNA assay detects AR and other allograft injury. dd-cfDNA monitoring, accompanied by standard clinical assessments, represents a valuable precision tool to support lung transplant health and is appropriate for further assessment in a prospective randomized-controlled study.

Lung transplantation in the septuagenarian can be successfully performed though long-term results impacted by diseases of aging.

BACKGROUND: Advanced age is considered a risk factor for lung transplantation (LTX). We sought to evaluate the long-term outcomes of LTX in the septuagenarian. METHODS: LTX recipients in the UNOS transplant registry (May 1, 2005-June 12, 2020) were stratified into 18-59, 60-69, and > = 70 years of age. Recipient and transplant characteristics were evaluated for survival, cause of death (COD), length of stay (LOS), and complications. A Kaplan-Meier analysis examined long-term survival for all patients stratified by age, specifically looking at cause of death. RESULTS: A total of 27 632 recipients were identified. As recipients aged, we found a decrease in proportion of cystic fibrosis and an increase in restrictive disease while obstructive disease peaked in the 60-69yo cohort (P < .001). Septuagenarians had higher rates of single LTX, male gender, and white race (P < .001). Older recipients had significantly longer donor recovery distances traveled with paradoxical shorter ischemic times, shorter hospital LOS and were transplanted at higher volume centers. There was no difference with in-hospital mortality among groups (P = .5). Acute rejection during initial hospitalization, rejection within 1 year, and post-transplant dialysis incidence decreased with age. Graft failure was a common COD in younger patients while malignancy and cardio/cerebrovascular diseases were common COD in > = 70yo. CONCLUSION: Select septuagenarian LTX candidates may be safely transplanted with relatively few complications. Immunosenescence and conditions of the aged are likely contributing factors to the decreased rejection and graft failure observations. Septuagenarians should not be excluded from LTX consideration based solely on age. Transplantation in septuagenarians should only be done in very selected patients (screened for malignancies and atherosclerotic disease) and these recipients should be carefully followed after transplantation because of these risk factors.

Insights into early postoperative acute kidney injury following lung transplantation.

BACKGROUND: Acute kidney injury (AKI) is a common complication after lung transplantation (LT) and is associated with higher cost and mortality. We sought to evaluate the incidence of postoperative AKI, defined as AKI within 14 days of transplant, and identify associated perioperative factors. METHODS: We conducted a single-center, retrospective review of 153 lung transplant recipients. Postoperative AKI was determined using the RIFLE (Risk, Injury, Failure, Loss, End Stage) criteria. Perioperative covariates and their association with postoperative AKI were analyzed using Cox proportional hazards. Kaplan-Meier survival curves were constructed to evaluate patient survival at 1 year and data finalization. A sub-analysis was performed evaluating factors associated with early AKI (within 48 h of transplant) and late AKI. RESULTS: Postoperative AKI occurred in 36.6% of patients with 51.8% of cases occurring within 48 h of LT. Recipient race, transplant type, cardiopulmonary support, and red blood cell administration were associated with postoperative AKI. Survival was significantly lower in patients with postoperative AKI following LT. CONCLUSIONS: Postoperative AKI within 2 weeks of lung transplant is associated with lower short- and long-term survival. Perioperative factors associated with postoperative AKI may be potential points of intervention to minimize AKI development in the future.

Looking Beyond the Allograft Survival: Long-Term, 5-Year Renal Outcome in Lung Transplant Recipients.

With the increased incidence and survival of lung transplant (LTx) recipients, the risk for chronic sequelae such as chronic kidney disease (CKD) is on the rise. Data on the long-term renal outcome are scarce. We performed a retrospective chart review of 171 adults with LTx from January 1, 2014, to January 1, 2019. Primary outcomes were prevalence of CKD/end-stage renal disease, acute kidney injury (AKI) as a risk factor for future CKD, and all-cause mortality in recipients with CKD compared with the non-CKD group. Secondary outcomes were frequency of utilization of modalities for CKD (urinalysis, imaging, biopsy, nephrology consultations). Baseline median creatinine and estimated glomerular filtration rate (eGFR) were 0.8 mg/dL and 90 mL/min/1.73 m2, respectively. Of the participants, 60% (96 of 161), 67% (102 of 153), 79% (37 of 47), 86% (10 of 12) had CKD at the end of 6, 12, 36, and 60 months, respectively, and 16% were on dialysis at the end of the study period; 3% received a subsequent renal transplant, and 27% mortality was noted over a 5-year follow-up period. The odds of CKD development in patients with an AKI during index hospitalization vs no AKI was 6.22 (2.87 to 13.06, P < .0001). The odds ratio of all-cause mortality in patients with CKD compared with non-CKD was 3.36 (95% confidence interval, 1.44-8.64, P = .005). Measurement of hematuria/proteinuria, imaging, and renal biopsy were infrequently used. Given the high prevalence of AKI and CKD in this population, a multidisciplinary team approach with an early nephrology consultation will be key to improve the overall and renal outcomes in LTx recipients.

SARS-CoV-2 Infections among Recent Organ Recipients, March-May 2020, United States.

We conducted public health investigations of 8 organ transplant recipients who tested positive for severe acute respiratory syndrome coronavirus 2 infection. Findings suggest the most likely source of transmission was community or healthcare exposure, not the organ donor. Transplant centers should educate transplant candidates and recipients about infection prevention recommendations.

Effectiveness of short vs long-course perioperative antibiotics in lung transplant recipients with donor positive respiratory cultures.

Lung transplant recipients are at increased risk for infection in the early postoperative phase, thus perioperative antibiotics are employed. This retrospective study evaluated the efficacy of short- vs long-course perioperative antibiotics in lung transplant patients. Lung transplant patients with donor positive cultures between August 2013 and September 2019 were evaluated, excluding those with cystic fibrosis, death within 14 days and re-transplants. The primary outcome was 30-day freedom from donor-derived respiratory infection. A total of 147 patients were included (57 short vs 90 long-course). Median perioperative antibiotic duration was 6 days in the short-course vs 14 days in the long-course group (P < .0001). Thirty-day freedom from donor-derived respiratory infection was present in 56 (98%) patients in the short-course vs 85 (94%) patients in the long-course group (P = .41). There was no difference in development of Clostridioides difficile infections (P = .41), while cumulative ventilator time and time to post-op extubation were longer in the long-course group (P = .001 and .004, respectively). Among lung transplant recipients with positive donor respiratory cultures, short-course perioperative antibiotics were as effective as long-course antibiotics in preventing donor-derived bacterial respiratory infections.

International Society for Heart and Lung Transplantation consensus statement for the standardization of bronchoalveolar lavage in lung transplantation.

Bronchoalveolar lavage (BAL) is a key clinical and research tool in lung transplantation (LTx). However, BAL collection and processing are not standardized across LTx centers. This International Society for Heart and Lung Transplantation-supported consensus document on BAL standardization aims to clarify definitions and propose common approaches to improve clinical and research practice standards. The following 9 areas are covered: (1) bronchoscopy procedure and BAL collection, (2) sample handling, (3) sample processing for microbiology, (4) cytology, (5) research, (6) microbiome, (7) sample inventory/tracking, (8) donor bronchoscopy, and (9) pediatric considerations. This consensus document aims to harmonize clinical and research practices for BAL collection and processing in LTx. The overarching goal is to enhance standardization and multicenter collaboration within the international LTx community and enable improvement and development of new BAL-based diagnostics.

Early COVID-19 infection after lung transplantation.

COVID-19, the clinical syndrome caused by the novel coronavirus, SARS-CoV-2, continues to rapidly spread, leading to significant stressors on global healthcare infrastructure. The manifestations of COVID-19 in solid organ transplant recipients are only beginning to be understood with cases reported to date in transplant recipients on chronic immunosuppression. Herein, we report the first case of COVID-19 in a lung transplant recipient in the immediate posttransplant period, and we describe the epidemiologic challenges in identifying the source of infection in this unique situation.

Flavivirus Nonstructural Protein NS5 Dysregulates HSP90 to Broadly Inhibit JAK/STAT Signaling.

Pathogenic flaviviruses antagonize host cell Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling downstream of interferons α/ß. Here, we show that flaviviruses inhibit JAK/STAT signaling induced by a wide range of cytokines beyond interferon, including interleukins. This broad inhibition was mapped to viral nonstructural protein 5 (NS5) binding to cellular heat shock protein 90 (HSP90), resulting in reduced Janus kinase-HSP90 interaction and thus destabilization of unchaperoned JAKs (and other kinase clients) of HSP90 during infection by Zika virus, West Nile virus, and Japanese encephalitis virus. Our studies implicate viral dysregulation of HSP90 and the JAK/STAT pathway as a critical determinant of cytokine signaling control during flavivirus infection.

Lung T-Cell Profile Alterations are Associated with Bronchiolitis Obliterans Syndrome in Cystic Fibrosis Lung Transplant Recipients.

The contribution of T-cells after lung transplant (LTx) remains controversial with no current consensus of their role concerning chronic lung allograft dysfunction. Using flow cytometry to assess T-cell subsets of bronchoalveolar lavage fluid (BALF) in 16 cystic fibrosis (CF) LTx recipients, we identified a decline in CD4+ T-cell frequency and an increase in CD8+ T-cell frequency in patients who developed severe bronchiolitis obliterans syndrome (BOS) (N = 10) when comparing baseline (6 months post-LTx) and follow-up (most recent bronchoscopy-clinical or surveillance per protocol). Comparing BOS to No BOS cohorts, significant differences were found in CD4+ T-cell frequency [17.4 (12.5, 28.2) vs 46.6 (44.4, 48.4), p = 0.003] and CD8+ T-cell frequency [65.6 (62.8, 75.3) vs 39.2 (32.2, 43.3), p = 0.014], respectively. The mean difference of the CD4:CD8 ratio was 0.87 units lower (95% CI - 1.44 to - 0.30, p = 0.006) than patients without BOS, while the median difference of the CD4:CD8 ratio was 0.92 units lower (95% CI - 1.83 to - 0.009, p = 0.048). Therefore, our results suggest that T-cell profiles measured through flow cytometry of BALF in the CF LTx population are associated with the development of severe BOS. Further work is needed in larger patient populations to validate our findings and to determine if this is useful for recipients who underwent LTx for other indications.

Optimizing Nutrition Assessment to Create Better Outcomes in Lung Transplant Recipients: A Review of Current Practices.

Lung transplantation offers patients with end-stage lung disease an opportunity for a better quality of life, but with limited organ availability it is paramount that selected patients have the best opportunity for successful outcomes. Nutrition plays a central role in post-surgical outcomes and, historically, body mass index (BMI) has been used as the de facto method of assessing a lung transplant candidate's nutritional status. Here, we review the historical origins of BMI in lung transplantation, summarize the current BMI literature, and review studies of alternative/complementary body composition assessment tools, including lean psoas area, creatinine-height index, leptin, and dual x-ray absorptiometry. These body composition measures quantify lean body mass versus fat mass and may provide a more comprehensive analysis of a patient's nutritional state than BMI alone.

Smoking is associated with quantifiable differences in the human lung DNA virome and metabolome.

BACKGROUND: The role of commensal viruses in humans is poorly understood, and the impact of the virome on lung health and smoking-related disease is particularly understudied. METHODS: Genetic material from acellular bronchoalveolar lavage fluid was sequenced to identify and quantify viral members of the lower respiratory tract which were compared against concurrent bronchoalveolar lavage bacterial, metabolite, cytokine and cellular profiles, and clinical data. Twenty smoker and 10 nonsmoker participants with no significant comorbidities were studied. RESULTS: Viruses that infect bacteria (phages) represented the vast majority of viruses in the lung. Though bacterial communities were statistically indistinguishable across smokers and nonsmokers as observed in previous studies, lung viromes and metabolic profiles were significantly different between groups. Statistical analyses revealed that changes in viral communities correlate most with changes in levels of arachidonic acid and IL-8, both potentially relevant for chronic obstructive pulmonary disease (COPD) pathogenesis based on prior studies. CONCLUSIONS: Our assessment of human lung DNA viral communities reveals that commensal viruses are present in the lower respiratory tract and differ between smokers and nonsmokers. The associations between viral populations and local immune and metabolic tone suggest a significant role for virome-host interaction in smoking related lung disease.