Effects of drug abuse, smoking and alcohol on donor hearts and lungs

Prediction of Donor Heart Acceptance for Transplant and Its Clinical Implications: Results From The Donor Heart Study

BACKGROUND

Despite a shortage of potential donors for heart transplant in the United States, most potential donor hearts are discarded. We evaluated predictors of donor heart acceptance in the United States and applied machine learning methods to improve prediction.

METHODS

We included a nationwide (2005-2020) cohort of potential heart donors in the United States (n=73 948) from the Scientific Registry of Transplant Recipients and a more recent (2015-2020) rigorously phenotyped cohort of potential donors from DHS (Donor Heart Study; n=4130). We identified predictors of acceptance for heart transplant in both cohorts using multivariate logistic regression, incorporating time-interaction terms to characterize their varying effects over time. We fit models predicting acceptance for transplant in a 50% training subset of DHS using logistic regression, least absolute shrinkage and selection operator, and random forest algorithms and compared their performance in the remaining 50% (test) of the subset.

RESULTS

Predictors of donor heart acceptance were similar in the nationwide and DHS cohorts. Among these, older age (P value for time interaction, 0.0001) has become increasingly predictive of discard over time while other factors, including those related to drug use, infection, and mild cardiac diagnostic abnormalities, have become less influential (P value for time interaction, <0.05 for all). A random forest model (area under the curve, 0.908; accuracy, 0.831) outperformed other prediction algorithms in the test subset and was used as the basis of a novel web-based prediction tool.

CONCLUSIONS

Predictors of donor heart acceptance for transplantation have changed significantly over the last 2 decades, likely reflecting evolving evidence regarding their impact on posttransplant outcomes. Real-time prediction of donor heart acceptance, using our web-based tool, may improve efficiency during donor management and heart allocation.

Epithelial barrier hypothesis: Effect of the external exposome on the microbiome and epithelial barriers in allergic disease

Environmental exposure plays a major role in the development of allergic diseases. The exposome can be classified into internal (e.g., aging, hormones, and metabolic processes), specific external (e.g., chemical pollutants or lifestyle factors), and general external (e.g., broader socioeconomic and psychological contexts) domains, all of which are interrelated. All the factors we are exposed to, from the moment of conception to death, are part of the external exposome. Several hundreds of thousands of new chemicals have been introduced in modern life without our having a full understanding of their toxic health effects and ways to mitigate these effects. Climate change, air pollution, microplastics, tobacco smoke, changes and loss of biodiversity, alterations in dietary habits, and the microbiome due to modernization, urbanization, and globalization constitute our surrounding environment and external exposome. Some of these factors disrupt the epithelial barriers of the skin and mucosal surfaces, and these disruptions have been linked in the last few decades to the increasing prevalence and severity of allergic and inflammatory diseases such as atopic dermatitis, food allergy, allergic rhinitis, chronic rhinosinusitis, eosinophilic esophagitis, and asthma. The epithelial barrier hypothesis provides a mechanistic explanation of how these factors can explain the rapid increase in allergic and autoimmune diseases. In this review, we discuss factors affecting the planet's health in the context of the 'epithelial barrier hypothesis,' including climate change, pollution, changes and loss of biodiversity, and emphasize the changes in the external exposome in the last few decades and their effects on allergic diseases. In addition, the roles of increased dietary fatty acid consumption and environmental substances (detergents, airborne pollen, ozone, microplastics, nanoparticles, and tobacco) affecting epithelial barriers are discussed. Considering the emerging data from recent studies, we suggest stringent governmental regulations, global policy adjustments, patient education, and the establishment of individualized control measures to mitigate environmental threats and decrease allergic disease.

Prevalence, Clinical Characteristics, and Outcomes Among Lung Transplant Recipients of Donors With Cocaine Use

INTRODUCTION

There is limited data regarding lung transplant (LT) outcomes among recipients of donors with a history of cocaine use. We sought to assess the burden of cocaine abuse among LT donors, describe their characteristics, and evaluate the association with post-transplant outcomes.

METHODS

From the United Network for Organ Sharing database, we included adult patients (age ≥18 years) who underwent LT between 1996 and 2014 (N = 20,106; mean age 53.7 ± 13 years; male: 57%). Study groups were divided based on the donor history of recent cocaine abuse (last 6 months). Donor and recipient characteristics were compared between the 2 groups. With 1-year survival as the primary endpoint, multivariate logistic regression analysis was conducted to assess for an independent association with the donor history of cocaine use.

RESULTS

The overall frequency of donors with any history of cocaine use was 10.9% (n = 2189), although less than half were current users (n = 1001, 4.98%). Unadjusted 1-year survival was worse among recipients of donors with current cocaine use, although it did not achieve statistical significance (84.4% vs 82.2%; odds ratio 1.17, 95% confidence interval 0.99-1.38; P = .07). After adjusting for potential confounders, the current use of cocaine was not associated with 1-year survival (adjusted OR 1.06, 95% CI 0.95-1.18; P = .29).

CONCLUSIONS

A significant proportion of lung donors have a history of cocaine abuse. Although unadjusted early outcomes appear to worsen among recipients of active cocaine users, an independent association was not seen with 1-year survival. The current analysis supports the continued use of donors with a history of cocaine abuse, assuming they meet other criteria for organ quality.

Procurement of lungs from brain-dead donors

Lung transplantation is the procedure of choice in many patients with end-stage lung disease and is being performed more frequently around the world. However, there continues to be shortage of donor organs with the ever-expanding number of recipients on the waiting list, leading to liberalization of the lung donor selection criteria with increasing acceptance of marginal donors while striving for excellent results. This has placed an increasing emphasis on the technique of donor lung procurement and preservation from marginal donors. Good judgment and procurement techniques are necessary to obtain high-quality donor lungs for transplantation and optimize long-term results. This is a review of our current technique used for the procurement of the lungs from brain-dead donors.

Intoxicated Donors and Heart Transplant Outcomes: Long-Term Safety

Supplemental Digital Content is available in the text.

Background:

The opioid crisis has led to an increase in available donor hearts, although questions remain about the long-term outcomes associated with the use of these organs. Prior studies have relied on historical information without examining the toxicology results at the time of organ offer. The objectives of this study were to examine the long-term survival of heart transplants in the recent era, stratified by results of toxicological testing at the time of organ offer as well as comparing the toxicology at the time of donation with variables based on reported history.

Methods:

The United Network for Organ Sharing database was requested as well as the donor toxicology field. Between 2007 and 2017, 23 748 adult heart transplants were performed. United Network for Organ Sharing historical variables formed a United Network for Organ Sharing Toxicology Score and the measured toxicology results formed a Measured Toxicology Score. Survival was examined by the United Network for Organ Sharing Toxicology Score and Measured Toxicology Score, as well as Cox proportional hazards models incorporating a variety of risk factors.

Results:

The number and percent of donors with drug use has significantly increased over the study period (P<0.0001). Cox proportional hazards modeling of survival including toxicological and historical data did not demonstrate differences in post-transplant mortality. Combinations of drugs identified by toxicology were not associated with differences in survival. Lower donor age and ischemic time were significantly positively associated with survival (P<0.0001).

Conclusions:

Among donors accepted for transplantation, neither history nor toxicological evidence of drug use was associated with significant differences in survival. Increasing use of such donors may help alleviate the chronic donor shortage.