Honoring the gift: The transformative potential of transplant-declined human organs.

For decades, transplantation has been a life-saving treatment for those fortunate enough to gain access. Nevertheless, many patients die waiting for an organ and countless more never make it onto the waitlist because of a shortage of donor organs. Concurrently, thousands of donated organs are declined for transplant each year because of concerns about poor outcomes post-transplant. The decline of any donated organ-even if medically justified-is tragic for both the donor family and potential recipients. In this Personal Viewpoint, we discuss the need for a new mindset in how we honor the gift of organ donation. We believe that the use of transplant-declined human organs in translational research has the potential to hasten breakthrough discoveries in a multitude of scientific and medical areas. More importantly, such breakthroughs will allow us to properly value every donated organ. We further discuss the many practical challenges that such research presents and offer some possible solutions based on experiences in our own research laboratories. Finally, we share our perspective on what we believe are the necessary next steps to ensure a future where every donated organ realizes its full potential to impact the lives of current and future patients.

Wanted: An endothelial cell targeting atlas for nanotherapeutic delivery in allograft organs.

Despite the profound shortage of organs available for transplant in the U.S., over 5,000 donated organs were declined for use in 2020. Many of these organs were declined due to donor comorbidities or preservation injuries that predispose grafts to rejection and loss. The risks of these poor outcomes can potentially be reduced by pre-transplant application of normothermic machine perfusion (NMP). To date, the clinical use of NMP has focused on extending preservation and improving organ assessment, but the opportunity for ex situ therapeutic delivery may be the most transformative aspect of this technology. In this Personal Viewpoint, we argue that the endothelial cells (ECs) that line the graft vasculature are an accessible, under-exploited, and attractive target for transplant therapeutics delivered during NMP. We further contend that molecularly targeted nanoparticles (NPs) represent a promising therapeutic vehicle particularly well-suited to NMP. However, to achieve this potential, we need to answer the following three key questions: (1) What EC sub-populations exist within an organ? (2) How can these cells be accessed? (3) And most important, how can preferential retention of NPs by the cells of interest be maximized? Here we argue for creating an EC-targeting atlas as a body of knowledge that answers these questions.

Correction to: Advanced Modeling to Predict Pneumonia in Combat Trauma Patients.

In the original article, the units indicated on the y-axes of Fig. 3 are incorrectly labelled. The correct label is pg/mL. Following is the corrected Fig. 3.

Advanced Modeling to Predict Pneumonia in Combat Trauma Patients.

BACKGROUND: Tools to assist clinicians in predicting pneumonia could lead to a significant decline in morbidity. Therefore, we sought to develop a model in combat trauma patients for identifying those at highest risk of pneumonia. METHODS: This was a retrospective study of 73 primarily blast-injured casualties with combat extremity wounds. Binary classification models for pneumonia prediction were developed with measurements of injury severity from the Abbreviated Injury Scale (AIS), transfusion blood products received before arrival at Walter Reed National Military Medical Center (WRNMMC), and serum protein levels. Predictive models were generated with leave-one-out-cross-validation using the variable selection method of backward elimination (BE) and the machine learning algorithms of random forests (RF) and logistic regression (LR). BE was attempted with two predictor sets: (1) all variables and (2) serum proteins alone. RESULTS: Incidence of pneumonia was 12% (n = 9). Different variable sets were produced by BE when considering all variables and just serum proteins alone. BE selected the variables ISS, AIS chest, and cryoprecipitate within the first 24 h following injury for the first predictor set 1 and FGF-basic, IL-2R, and IL-6 for predictor set 2. Using both variable sets, a RF was generated with AUCs of 0.95 and 0.87-both higher than LR algorithms. CONCLUSION: Advanced modeling allowed for the identification of clinical and biomarker data predictive of pneumonia in a cohort of predominantly blast-injured combat trauma patients. The generalizability of the models developed here will require an external validation dataset.

The Role of Vascular Biomarkers in Outcomes of Patients with Kidney Disease.

BACKGROUND: Vascular biomarkers may explain the link between acute kidney injury (AKI) and poor long-term outcomes such as cardiovascular disease (CVD). Vessel injury is exceedingly common in AKI and contributes to the development of kidney fibrosis and CVD. As prominent determinants of vessel stability in the body, angiopoietins and other prominent vascular biomarkers may explain this biological link. SUMMARY: Angiopoietin-1 (Angpt-1) promotes vessel stability by decreasing inflammation, apoptosis, and vessel permeability. By contrast, angiopoietin-2 (Angpt-2) blocks the binding of Angpt-1 to its receptor and thus contributes to vessel instability and permeability. Based on our findings, higher levels of Angpt-1 relative to Angpt-2 were strongly associated with less risk of kidney disease progression, heart failure, and death in hospitalized patients with AKI. In chronic kidney disease patients, it has been shown that endothelial damage in glomerular vasculature triggers Angpt-2 secretion, leading to poor outcomes such as CVD and mortality. Furthermore, in kidney transplant recipients, Angpt-2 levels significantly decrease after transplantation suggesting that transplantation may reduce Angpt-2 levels and decrease rates of poor outcomes. Other vascular health pathways - such as vascular endothelial growth factor and placental growth factor - were associated with improved rates of survival after cardiac surgery in participants with and without AKI. KEY MESSAGES: Vascular health biomarkers provide actionable pathways for clinical intervention in reducing CVD and mortality for AKI patients. There is great need for future research that focuses on developing robust prognostic vascular biomarker panels in order to help identify high-risk AKI survivors who may benefit from targeted follow-up and therapy, with the intention to prevent kidney and cardiac complications.

Driving biology: The effect of standardized wound management on wound biomarker profiles.

BACKGROUND: The timing of coverage of an open wound is based on heavily on clinical gestalt. DoD's Surgical Critical Care Initiative created a clinical decision support tool that predicts wound closure success using clinical and biomarker data. The military uses a regimented protocol consisting of serial washouts and debridements. While decisions around wound closure in civilian centers are subject to the same clinical parameters, preclosure wound management is, generally, much more variable. We hypothesized that the variability in management would affect local biomarker expression within these patients. METHODS: We compared data from 116 wounds in 73 military patients (MP) to similar data from 88 wounds in 78 civilian patients (CP). We used Wilcoxon rank-sum tests to assess concentrations of 32 individual biomarkers taken from wound effluent. Along with differences in the debridement frequency, we focused on these local biomarkers in MP and CP at both the first washout and the washout performed just prior to attempted closure. RESULTS: On average, CP waited longer from the time of injury to closure (21.9 days, vs. 11.6 days, p < 0.0001) but had a similar number of washouts (3.86 vs. 3.44, p = 0.52). When comparing the wound effluent between the two populations, they had marked biochemical differences both when comparing the results at the first washout and at the time of closure. However, in a subset of civilian patients whose average number of days between washouts was never more than 72 hours, these differences ceased to be significant for most variables. CONCLUSION: There were significant differences in the baseline biochemical makeup of wounds in the CP and MP. These differences could be eliminated if both were treated under similar wound care paradigms. Variations in therapy affect not only outcomes but also the actual biochemical makeup of wounds. LEVEL OF EVIDENCE: Therapeutic, level IV.

Vacuum-assisted vegetation removal with percutaneous lead extraction: a systematic review of the literature.

PURPOSE: To perform a systematic review of reports in which the AngioVac™ percutaneous vacuum-assisted aspiration system was successfully used to debulk or remove vegetations prior to percutaneous lead extraction. METHODS: We included all studies and case reports that used a percutaneous aspiration technique for vegetation removal or debulking with percutaneous lead extraction for patients with lead-associated endocarditis. Ten reports and retrospective data from our centers were used, which included a total of 88 patients and 205 leads. RESULTS: The percutaneous aspiration procedure was completely or partially successful in 86 patients (97.7%). The lead extraction procedure itself was successful in 87 patients (98.9%). The aspiration procedure and lead extraction were done concomitantly in 81 patients (92.0%). Four patients (4.5%) had major complications (two due to vascular injuries, one due to coronary sinus injury, and one due to tricuspid valve injury). There were no complications from the aspiration procedure, and no cases were associated with procedure-related mortality. CONCLUSION: While patients with large vegetations have historically been referred for surgical lead extraction, data are lacking in its techniques and outcomes. Existing data suggest that percutaneous vacuum-assisted aspiration for vegetation removal or debulking in endocarditis prior to or concurrent with percutaneous lead extraction has a high success rate with a low complication rate across a broad series of patients.