A Single-Center Retrospective Study to Identify Causes of Sex Differences in the Living Kidney Donor Evaluation Process.

BACKGROUND: Multiple studies have shown that females are living donors for kidney transplantation at higher rates than males. However, the underlying reasons for this observation are not well-understood. We examined the living donor evaluation process to determine the point at which sex imbalance arises. Based on a previous study, we hypothesized that both sexes are equally likely to become approved as living donors, but females are more likely to follow through with donation. METHODS: Single institution retrospective chart review of self-referrals for living donor evaluation between 1/2009 - 12/2022. Self-referrals identified using the Organ Transplant Tracking Record database and cross referenced with billing data. Exclusion at each stage of evaluation was recorded and compared between sexes using log binomial regression; unadjusted and adjusted (for donor age, race, ethnicity, relationship to recipient, and recipient sex) risk ratios (RRs) with 95% confidence interval (CI) were determined. RESULTS: 1,861 self-referrals were reviewed, including 1,214 (65.2%) females and 647 (34.8%) males, resulting in 146 approvals and 125 donations (76/125, 60.8% females, 49/125 39.2% males). Adjusted RRs indicated no significant differences between sexes in completing medical and/or psychosocial workup, having medical and/or psychosocial contraindications, being approved for donation, and proceeding with donation. The top medical contraindications for both sexes were obesity, hypertension, and nephrolithiasis. CONCLUSION: Female overrepresentation among living donors is likely due to the 1.9 times higher rate of self-referral for evaluation. After this point, both sexes were equally likely to complete workup, be approved, and follow through with donation. Increased efforts to engage males at the initial self-referral stage has the potential to expand access to living donor kidney transplantation.

Machine Perfusion Technology Drives a Major Growth Surge in Liver Transplantation.

INTRODUCTION: Machine perfusion (MP) opens the possibility to overcome the existing disbalance between supply and demand in liver transplantation. However, it has not been widely adopted across the country. We explored trends of MP adoption in the United States and their effect on center volume (CV). METHODS: We used the Standard Transplant Analysis and Research datafile from January 2010 to July 2023 to assess CV changes following MP implementation. We classified centers into MP nonusers, low MP users, and high MP (HMP) users. We used interrupted time series analysis to measure changing patterns of HMP CV before and after January 2016, marking the occurrence of the first MP case. High-volume institutions in 2015 were additionally compared to their equivalents in 2022 stratified by their MP status using Wilcoxon rank sum test. RESULTS: In our controlled interrupted time series, HMP centers had a sustained yet moderate positive trend in volume (P < 0.001). Comparing only high-volume institutions, we found no difference in the number of transplants performed in 2015 to their equivalents in 2022. In the stratified analysis, only HMP centers had a significant increase in the total number of transplants in 2022 (P = 0.032). CONCLUSIONS: MP has demonstrated to greatly improve outcomes for recipients of liver transplantation. Here, we demonstrate that centers that incorporate MP could potentially benefit from a growth in their practice as well. Further studies are needed to better characterize the features that drive transplant centers to grow across time.

Liver machine perfusion technology: Expanding the donor pool to improve access to liver transplantation.

The imbalance between organ supply and demand continues to limit the broader benefits of organ transplantation. Machine perfusion (MP) may increase the supply of donor livers by expanding the use of extended-criteria donors. Using the United Network for Organ Sharing/Organ Procurement and Transplantation Network and the Standard Transplant Analysis and Research dataset, we reviewed the effect of MP implementation on the behavior of transplant centers. We identified 15 high-utilizing MP centers that were matched to suitable controls based on volume and geographical proximity. We conducted a differences-in-differences analysis using linear regression to estimate the impact of MP adoption on the transplant centers' donor utilization. We found a significant increase in cold ischemia time and organs with donor warm ischemia time over 30 minutes (P < .05). After removing one outlier center, the analysis showed that these centers through MP accepted overall more donation after circulatory death donors, donation after circulatory death donors over 50 years old, donors with macrovesicular steatosis greater than 30% on liver biopsy, and donor warm ischemia time over 30 minutes (P < .05). MP has allowed centers to expand their use of extended-criteria donors beyond traditional cutoffs and to increase patient access to liver transplantation.

Representation of Women Authorship in the Top 5 Transplantation Journals in the United States.

BACKGROUND: In the United States, only 13% of transplant surgeons are women. We evaluated gender distribution and trends of American authorship over the past 10 y in high-impact solid organ transplantation journals to gain insight into the current status of women authorship in transplantation. METHODS: Original articles from 2012 to 2021 from the 5 highest-impact solid organ transplantation journals were extracted from Scopus. First and last author's gender was predicted using Genderize.io. Data of first and last authors, article type and topic, location, citation, and funding metrics were analyzed. Chi-square, logistic regression, and trend tests were performed where appropriate. Statistical significance was set at <0.05. RESULTS: Women's first and last authorship increased over time among all journals. There was an increase in women first authors in the American Journal of Transplantation and in senior women authors in Liver Transplantation and Transplantation . Significant differences in gender authorship in lung, intestine, pancreas, general, and islet cell transplantation were found. Women's last authorship was associated with 1.69 higher odds of having a woman first author when adjusting for year and journal. There was an increase in the rate of women's first and last author collaborations over the years. Women last authors had 1.5 higher odds of being funded by the National Institutes of Health over the years. CONCLUSIONS: Despite an increase in women transplant surgeons and physicians, the gap in women authorship in transplantation persists. Women's last authorship was associated with higher odds of having a woman first author, pointing to the importance of mentorship for women joining the transplant academia.

The power of partnership: Exploring collaboration dynamics in U.S. transplant research.

INTRODUCTION: Collaboration is one of the hallmarks of academic research. This study analyzes collaboration patterns in U.S. transplant research, examining publication trends, productive institutions, co-authorship networks, and citation patterns in high-impact transplant journals. METHODS: 4,265 articles published between 2012 and 2021 were analyzed using scientometric tools, logistic regression, VantagePoint software, and Gephi software for network visualization. RESULTS: 16,003 authors from 1,011 institutions and 59 countries were identified, with Harvard, Johns Hopkins, and University of Pennsylvania contributing the most papers. Odds of international collaboration significantly increased over time (OR 1.03; p â€‹= â€‹0.040), while odds of citation in single-institution collaborations decreased (OR 0.99; p â€‹= â€‹0.016). Five major scientific communities and central institutions (Harvard University and University of Pittsburgh) connecting them were identified, revealing interconnected research clusters. CONCLUSIONS: Collaboration enhances knowledge exchange and research productivity, with an increasing trend of institutional and international collaboration in U.S. transplant research. Understanding this community is essential for promoting research impact and forming strategic partnerships.

Tixagevimab-Cilgavimab Decreases the Rate of SARS-CoV-2 Infection Among Solid Organ Transplant Recipients.

BACKGROUND: SARS-CoV-2 infection in solid organ transplant (SOT) recipients is associated with high morbidity and mortality. Tixagevimab/cilgavimab monoclonal antibodies were previously authorized for pre-exposure prophylaxis for immunocompromised individuals. We aimed to determine if tixagevimab/cilgavimab could prevent breakthrough SARS-CoV-2 infection in SOT recipients. MATERIAL AND METHODS: We conducted a prospective single-center study of SOT recipients who received tixagevimab/cilgavimab compared with those who did not. Demographics, type of transplant, immunosuppression regimen, COVID-19 vaccination status, and tixagevimab/cilgavimab administration data were collected. Participants were interviewed for 6 months or until they tested positive for SARS-CoV-2, whichever came first. Kaplan-Meier SARS-CoV-2-free survival curves were created based on the tixagevimab/cilgavimab administration date and SARS-CoV-2 infection. The log-rank test was used for comparison. Univariate and multivariate Cox regression models were constructed. RESULTS: The study cohort included 323 patients. Two hundred forty-eight received tixagevimab/cilgavimab, and 75 did not (control). COVID-19 vaccination rate was higher among tixagevimab/cilgavimab recipients than nontixagevimab/cilgavimab recipients (99.6% vs 92.0%; P < .001). Twenty-six patients in the tixagevimab/cilgavimab group (10.5%) and 23 in the control group (30.7%) tested positive for SARS-CoV-2 infection (P < .001). In a multivariate analysis, receipt of tixagevimab/cilgavimab and duration from transplant were both associated with reduced risk of SARS-CoV-2 infection (hazard ratio 0.431; 95% CI 0.224-0.828 and hazard ratio 0.917; 95% CI 0.861-0.978, respectively). CONCLUSION: During the study period, SOT recipients who received tixagevimab/cilgavimab had a significantly lower rate of SARS-CoV-2 infection. There were no differences in symptom frequency, illness severity, hospitalization rate, or treatment of SARS-CoV-2 infection.