Trends in Survival for Adult Organ Transplantation.

Objective: Intent-to-treat analysis follows patients from listing to death, regardless of their transplant status, and aims to provide a more holistic scope of the progress made in adult solid-organ transplantation. Background: Many studies have shown progress in waitlist and post-transplant survival for adult kidney, liver, heart, and lung transplants, but there is a need to provide a more comprehensive perspective of transplant outcomes for patients and their families. Methods: Univariable and multivariable Cox regression analyses were used to analyze factors contributing to intent-to-treat survival in 813,862 adults listed for kidney, liver, heart, and lung transplants. The Kaplan-Meier method was used to examine changes in waitlist, post-transplant, and intent-to-treat survival. Transplantation rates were compared using χ2 tests. Results: Intent-to-treat survival has steadily increased for liver, heart, and lung transplants. The percentage of patients transplanted within 1 year significantly increased for heart (57.4% from 52.9%) and lung (73.5% from 33.2%). However, the percentage of patients transplanted within 1 year significantly decreased from 35.8% to 21.2% for kidney transplant. Notably, intent-to-treat survival has decreased for kidneys despite increases in waitlist and post-transplant survival, likely because of the decreased transplant rate. Conclusion: Intent-to-treat survival steadily improved for liver, heart, and lung transplant over the 30-year study period. Continued advancements in allocation policy, immunosuppression, and improved care of patients on the waitlist may contribute to further progress in outcomes of all organs, but the increasing discrepancy in supply and demand of donor kidneys is alarming and has impeded the progress of kidney intent-to-treat survival.

Cyanobacteria and Algal-Based Biological Life Support System (BLSS) and Planetary Surface Atmospheric Revitalizing Bioreactor Brief Concept Review.

Exploring austere environments required a reimagining of resource acquisition and utilization. Cyanobacterial in situ resources utilization (ISRU) and biological life support system (BLSS) bioreactors have been proposed to allow crewed space missions to extend beyond the temporal boundaries that current vehicle mass capacities allow. Many cyanobacteria and other microscopic organisms evolved during a period of Earth's history that was marked by very harsh conditions, requiring robust biochemical systems to ensure survival. Some species work wonderfully in a bioweathering capacity (siderophilic), and others are widely used for their nutritional power (non-siderophilic). Playing to each of their strengths and having them grow and feed off of each other is the basis for the proposed idea for a series of three bioreactors, starting from regolith processing and proceeding to nutritional products, gaseous liberation, and biofuel production. In this paper, we discuss what that three reactor system will look like, with the main emphasis on the nutritional stage.

Long-term outcomes and trends in liver transplantation for hereditary hemochromatosis in the United States.

There have been conflicting data regarding liver transplantation (LT) outcomes for hereditary hemochromatosis (HH), with no recent data on LT outcomes in patients with HH in the past decade. Using the United Network for Organ Sharing registry, we evaluated waitlist and post-LT survival in all adult patients listed for HH without concomitant liver disease from 2003 to 2019. Post-LT survival for HH was compared with a propensity-matched (recipient and donor factors) cohort of recipients with chronic liver disease (CLD). From 2003 to 2019, 862 patients with HH were listed for LT, of which 55.6% ( n = 479) patients underwent LT. The 1- and 5-year post-LT survival rates in patients with HH were 88.7% (95% confidence interval [CI], 85.4%-91.4%) and 77.5% (95% CI, 72.8%-81.4%), respectively, and were comparable with those in the propensity-matched CLD cohort ( p value = 0.96). Post-LT survival for HH was lower than for Wilson's disease, another hereditary metabolic liver disease with similar LT volume ( n = 365). Predictors for long-term (5-year) post-LT mortality included presence of portal vein thrombosis (hazard ratio [HR], 1.96; 95% CI, 1.07-3.58), obesity measurements greater than Class II (HR, 1.98; 95% CI, 1.16-3.39), and Karnofsky performance status (HR, 0.98; 95% CI, 0.97-0.99) at the time of LT. The leading cause of post-LT death ( n = 145) was malignancy (25.5%), whereas cardiac disease was the cause in less than 10% of recipients. In conclusion, short- and long-term survival rates for HH are excellent and comparable with those of other LT recipients. Improving extrahepatic metabolic factors and functional status in patients with HH prior to LT may improve outcomes.

Reduction in Racial and Ethnic Disparity in Survival Following Liver Transplant for Hepatocellular Carcinoma in the Direct-acting Antiviral Era.

BACKGROUND & AIMS: Black patients with hepatocellular cancer (HCC), often attributed to hepatitis C virus (HCV) infection, have suboptimal survival following liver transplant (LT). We evaluated the impact of direct-acting antiviral (DAA) availability on racial and ethnic disparities in wait list burden post-LT survival for candidates with HCC. METHODS: Using the United Network for Organ Sharing registry, we identified patients with HCC who were listed and/or underwent LT from 2009 to 2020. Based on date of LT, patients were categorized into 2 era-based cohorts: the pre-DAA era (LT between 2009 and 2011) and DAA era (LT between 2015 and 2017, with follow-up through 2020). Kaplan-Meier and Cox proportional hazards analyses were used to compare post-LT survival, stratified by era and race and ethnicity. RESULTS: Annual wait list additions for HCV-related HCC decreased significantly in White and Hispanic patients during the DAA era, with no change (P = .14) in Black patients. Black patients had lower 3-year survival than White patients in the pre-DAA era (70.6% vs 80.1%, respectively; P < .001) but comparable survival in the DAA era (82.1% vs 85.5%, respectively; P = .16). 0n multivariable analysis, Black patients in the pre-DAA era had a 53% higher risk (adjusted hazard ratio [HR], 1.53; 95% confidence interval [CI], 1.28-1.84), for mortality than White patients, but mortality was comparable in the DAA era (adjusted HR, 1.23; 95% CI, 0.99-1.52). In a stratified analysis in Black patients, HCV-related HCC carried more than a 2-fold higher risk of mortality in the pre-DAA era (adjusted HR, 2.86; 95% CI, 1.50-5.43), which was reduced in the DAA era (adjusted HR, 1.34; 95% CI, 0.78-2.30). CONCLUSIONS: With the availability of DAA therapy, racial disparities in post-LT survival have improved.

Improved Survival After Liver Transplantation for Patients With Human Immunodeficiency Virus (HIV) and HIV/Hepatitis C Virus Coinfection in the Integrase Strand Transfer Inhibitor and Direct-Acting Antiviral Eras.

BACKGROUND: People with human immunodeficiency virus (HIV) with and without hepatitis C virus (HCV) coinfection had poor outcomes after liver transplant (LT). Integrase strand transfer inhibitors (INSTIs) and direct-acting antivirals (DAAs) have changed the treatment landscape for HIV and HCV, respectively, but their impact on LT outcomes remains unclear. METHODS: This retrospective analysis of adults with HIV monoinfection (n = 246) and HIV/HCV coinfection (n = 286) who received LT compared mortality in patients with HIV who received LT before versus after approval of INSTIs and in patients with HIV/HCV coinfection who received LT before versus after approval of DAAs. In secondary analysis, we compared the outcomes in the different eras with those of propensity score-matched control cohorts of LT recipients without HIV or HCV infection. RESULTS: LT recipients with HIV monoinfection did not experience a significant improvement in survival between the pre-INSTI and INSTI recipients with HIV (adjusted hazard ratio [aHR], 0.70 [95% confidence interval {CI}, .36-1.34]). However, recipients with HIV/HCV coinfection in the DAA era had a 47% reduction (aHR, 0.53 [95% CI, .31-9.2] in 1-year mortality compared with coinfected recipients in the pre-DAA era. Compared to recipients without HIV or HCV, HIV-monoinfected recipients had higher mortality during the pre-INSTI era, but survival was comparable between groups during the INSTI era. HIV/HCV-coinfected recipients also experienced comparable survival during the DAA era compared to recipients without HCV or HIV. CONCLUSIONS: Post-LT survival for people with HIV monoinfection and HIV/HCV coinfection has improved with the introduction of INSTI and DAA therapy, suggesting that LT has become safer in these populations.

Early Impact of MMaT-3 Policy on Liver Transplant Waitlist Outcomes for Hepatocellular Carcinoma.

To reduce the disparity in access to liver transplant (LT), United Network for Organ Sharing implemented an exception policy in May 2019, which capped hepatocellular carcinoma (HCC) exception score to the median Model for End-Stage Liver Disease (MELD) at transplant within the donor service area minus 3 points (MMaT-3) after the 6-mo wait period. We aimed to evaluate how this policy affected HCC waitlist outcomes. Methods: Using United Network for Organ Sharing data, we analyzed waitlist outcomes in HCC patients at the time they received exception points from in the pre-MMaT era (August 15, 2017, to November 15, 2018) and MMaT era (June 1, 2019, to August 30, 2020). Comparisons were made within the HCC group and HCC versus non-HCC (at time of listing) groups in the pre-MMaT and MMaT eras and regions were grouped as low, medium, and high MELD based on MMaT. Results: HCC group: LT probability within HCC patients decreased by 20% (subhazard ratio [sHR], 0.78; 95% confidence interval [CI], 0.74-0.85) between the eras and decreased by 41% in low MELD regions (sHR, 0.59; 95% CI, 0.52-0.66). Waitlist dropout was unchanged. Matched HCC versus non-HCC groups: HCC patients had 80% higher LT probability (sHR, 1.84; 95% CI, 1.71-1.99) than non-HCC patients in the pre-MMaT era; which decreased to a 14% higher LT probability in MMaT era. In low and medium regions, HCC patients had over twofold higher LT probability in the pre-MMaT era, which decreased to a ~20% higher probability (sHR, 1.14; 95% CI, 1.06-1.23) in the MMaT era. After implementation of the acuity circle policy, HCC patients had lower LT probability (sHR, 0.84; 95% CI, 0.74-0.94) than non-HCC patients. Conclusions: The geographic disparity between HCC and non-HCC patients has improved with the MMaT-3 policy. Despite lower LT probability for HCC patients, waitlist dropout was not adversely impacted.

Biologically-Based and Physiochemical Life Support and In Situ Resource Utilization for Exploration of the Solar System-Reviewing the Current State and Defining Future Development Needs.

The future of long-duration spaceflight missions will place our vehicles and crew outside of the comfort of low-Earth orbit. Luxuries of quick resupply and frequent crew changes will not be available. Future missions will have to be adapted to low resource environments and be suited to use resources at their destinations to complete the latter parts of the mission. This includes the production of food, oxygen, and return fuel for human flight. In this chapter, we performed a review of the current literature, and offer a vision for the implementation of cyanobacteria-based bio-regenerative life support systems and in situ resource utilization during long duration expeditions, using the Moon and Mars for examples. Much work has been done to understand the nutritional benefits of cyanobacteria and their ability to survive in extreme environments like what is expected on other celestial objects. Fuel production is still in its infancy, but cyanobacterial production of methane is a promising front. In this chapter, we put forth a vision of a three-stage reactor system for regolith processing, nutritional and atmospheric production, and biofuel production as well as diving into what that system will look like during flight and a discussion on containment considerations.

Impact of COVID-19 Pandemic on Liver Transplantation and Alcohol-Associated Liver Disease in the USA.

BACKGROUND AND AIMS: The surge in unhealthy alcohol use during the COVID-19 pandemic may have detrimental effects on the rising burden of alcohol-associated liver disease (ALD) on liver transplantation (LT) in the USA. We evaluated the effect of the pandemic on temporal trends for LT including ALD. APPROACH AND RESULTS: Using data from United Network for Organ Sharing, we analyzed wait-list outcomes in the USA through March 1, 2021. In a short-period analysis, patients listed or transplanted between June 1, 2019, and February 29, 2020, were defined as the "pre-COVID" era, and after April 1, 2020, were defined as the "COVID" era. Interrupted time-series analyses using monthly count data from 2016-2020 were constructed to evaluate the rate change for listing and LT before and during the COVID-19 pandemic. Rates for listings (P = 0.19) and LT (P = 0.14) were unchanged during the pandemic despite a significant reduction in the monthly listing rates for HCV (-21.69%, P < 0.001) and NASH (-13.18%; P < 0.001). There was a significant increase in ALD listing (+7.26%; P < 0.001) and LT (10.67%; P < 0.001) during the pandemic. In the COVID era, ALD (40.1%) accounted for more listings than those due to HCV (12.4%) and NASH (23.4%) combined. The greatest increase in ALD occurred in young adults (+33%) and patients with severe alcohol-associated hepatitis (+50%). Patients with ALD presented with a higher acuity of illness, with 30.8% of listings and 44.8% of LT having a Model for End-Stage Liver Disease-Sodium score ≥30. CONCLUSIONS: Since the start of COVID-19 pandemic, ALD has become the most common indication for listing and the fastest increasing cause for LT. Collective efforts are urgently needed to stem the rising tide of ALD on health care resources.