Increase In Transplantation Rates Research Articles

A machine-learning approach to human ex vivo lung perfusion predicts transplantation outcomes and promotes organ utilization

Ex vivo lung perfusion (EVLP) is a data-intensive platform used for the assessment of isolated lungs outside the body for transplantation; however, the integration of artificial intelligence to rapidly interpret the large constellation of clinical data generated during ex vivo assessment remains an unmet need. We developed a machine-learning model, termed InsighTx, to predict post-transplant outcomes using n = 725 EVLP cases. InsighTx model AUROC (area under the receiver operating characteristic curve) was 79 ± 3%, 75 ± 4%, and 85 ± 3% in training and independent test datasets, respectively. Excellent performance was observed in predicting unsuitable lungs for transplantation (AUROC: 90 ± 4%) and transplants with good outcomes (AUROC: 80 ± 4%). In a retrospective and blinded implementation study by EVLP specialists at our institution, InsighTx increased the likelihood of transplanting suitable donor lungs [odds ratio=13; 95% CI:4-45] and decreased the likelihood of transplanting unsuitable donor lungs [odds ratio=0.4; 95%CI:0.16–0.98]. Herein, we provide strong rationale for the adoption of machine-learning algorithms to optimize EVLP assessments and show that InsighTx could potentially lead to a safe increase in transplantation rates.

The kidney allocation system and pediatric transplantation at 5 years.

A new Kidney Allocation System (KAS) was implemented in the United States in 2014 with the goal of improving equity and utility. In this study, we compare outcomes for kidney-alone candidates less than 18 years of age, at the time of listing, in the 5 years prior to and following policy implementation using Organ Procurement and Transplantation Network data. While the pediatric deceased donor transplant rate increased under KAS, this increase was due solely to improved access for children aged 11-17 years; there was an 18.9% decrease in the deceased donor transplant rate among children 0-5 years old, from 117.94 to 95.8 transplants per 100 person-years (p=.001). The cumulative incidence of deceased donor transplantation by 1 year after listing decreased from 39.3% in the pre-KAS era to 35.5% in the post-KAS era (p=.004), a decline that was driven entirely by longer wait times for children 0-5 years old (p=.017). Candidates with a calculated panel reactive antibody of 98%-100% experienced a significant increase in transplant rate, but there was no change in transplant rate for Black or Hispanic candidates. Overall, KAS increased transplantation access for teenaged and highly sensitized candidates but resulted in decreased access for the youngest children with no improvement in racial/ethnic equality.

The Impact of Utilizing DCD Donor Hearts on Heart Transplant Activity and Waitlist Time

<h3>Purpose</h3> Machine perfusion of donated organs after declaration of circulatory death (DCD) allows for the use of hearts previously discarded as not usable for transplantation. This opportunity potentially expands the donor pool and decreases waitlist time. This study aims to examine the impact of utilizing DCD hearts on heart transplant waitlist time <h3>Methods</h3> We retrospectively analyzed 161 patients who were listed for heart transplant from September 2019 through September 2021 at our center. These patients were separated into 2 periods centered on September 12, 2020 when transplantation of DCD donor hearts began <h3>Results</h3> Baseline patient characteristics were similar between both periods. In Period 1, 76 patients were waitlisted with 70 transplants occurring during this period, whereas in Period 2, 85 patients were waitlisted with 88 transplants occurring in this period. Thirty DCD donor heart transplants were performed in Period 2 (34% of period 2 transplants).Year over year transplant activity increased by 25.7%. Transplant rate increased from 2.06 person-year in Period 1 to 3.1 person-year in Period 2.There was no significant difference between the two periods with respect to waitlist mortality rate, length of post-transplant hospital stay, and short-term post-transplant survival. Median waiting time from listing to transplant was 17 days in Period 1 and 27 days in Period 2.There was no difference in blood types and United Network for Organ Sharing (UNOS) listing status between Period 1 and Period 2. <h3>Conclusion</h3> Our single-center analysis demonstrates that utilization of DCD donor hearts has resulted in an increase in transplant rate. Further extended follow-up is needed to determine long-term safety and efficacy of this strategy.

Two Years after the Removal of Donation Service Area from Lung Allocation in the US

<h3>Purpose</h3> The Organ Procurement and Transplantation Network (OPTN) US lung allocation policy was altered in 2017 by changing the first geographic unit of lung allocation from the donation service area (DSA) to a 250 nautical mile (NM) radius around the donor hospital. <h3>Methods</h3> OPTN data on lung candidates and recipients age gt; 11 was analyzed pre (11/26/2015- 11/24/2017) and post allocation policy change (11/25/2017- 11/24/2019). Cohorts were compared to study the differences. <h3>Results</h3> An increase was seen in the match lung allocation score (LAS) at transplant from pre to post era (mean pre=47.25 vs. post=49.79, p < 0.001) and a similar increase in the volume of transplants for candidates with an LAS over 50 (pre=1,260; post=1,702). The waiting list mortality and transplant rate did not change when examined by LAS and diagnosis group except for LAS group 60-70 which saw a significant increase in transplant rate (pre= 429 (95% CI: 357, 512) vs. post=642 (95%CI: 558, 734)). The distance between the donor hospital and transplant center increased (median pre=109NM vs. post=166NM, p < 0.001) and subsequent increase in ischemic time (mean pre=5.3 hrs. vs. post=5.7 hrs., p < 0.001). Despite the increase in distance and ischemic time the discard rate for non-DCD and non-perfused lungs remained stable (pre=3.6 vs. post=4.0, p=0.15). Unadjusted 6-month patient post-transplant survival is unchanged (93.5% pre vs. 93.2% post). <h3>Conclusion</h3> Under the current system, lungs are being placed to sicker candidates with similar short-term post-transplant outcomes compared to the older allocation system. The next step for the lung allocation system in the US is a move to the Continuous Distribution framework to avoid hard boundaries in geography and other clinical classifications. The OPTN Lung Transplantation Committee is using these results and additional analyses to make evidence-based decisions for allocating lungs under the new framework.

The state of haematopoietic cells transplantation in Latin America

Haematopoietic cells transplantation began in Latin America in the early 1980s. Since then there has been a steady increase in transplantation rates (transplants per 10 million population) despite technical complexity and considerable expense. 13 (46%) of 28 countries in Latin America have established transplantation programmes (figure). In 2011, experts from these countries formed a Latin America Bone Marrow Transplant Group (LABMT), which has subsequently done annual surveys of transplantation activity in the region.

Comparing outcomes for infiltrative and restrictive cardiomyopathies under the new heart transplant allocation system

The new heart transplantation (HT) allocation policy was introduced on 10/18/2018. Using the UNOS registry, we examined early outcomes following HT for restrictive cardiomyopathy, hypertrophic cardiomyopathy, cardiac sarcoidosis, or cardiac amyloidosis compared to the old system. Those listed who had an event (transplant, death, or waitlist removal) prior to 10/17/2018 were in Era 1, and those listed on or after 10/18/2018 were in Era 2. The primary endpoint was death on the waitlist or delisting due to clinical deterioration. A total of 1232 HT candidates were included, 855 (69.4%) in Era 1 and 377 (30.6%) in Era 2. In Era 2, there was a significant increase in the use of temporary mechanical circulatory support and a reduction in the primary endpoint, (20.9 events per 100 PY (Era 1) vs. 18.6 events per 100 PY (Era 2), OR 1.98, p=.005). Median waitlist time decreased (91 vs. 58days, p<.001), and transplantation rate increased (119.0 to 204.7 transplants/100 PY for Era 1 vs Era 2). Under the new policy, there has been a decrease in waitlist time and waitlist mortality/delisting due to clinical deterioration, and an increase in transplantation rates for patients with infiltrative, hypertrophic, and restrictive cardiomyopathies without any effect on post-transplant 6-month survival.

The Impact of Utilizing Hepatitis C Virus Nucleic Acid Test-Positive Donor Heart on Heart Transplant Waitlist Time

Purpose Highly effective direct-acting antiviral therapy for hepatitis C virus (HCV) allows the use of organs from viremic, nucleic acid test-positive (NAT+) donors in non-HCV-infected recipients. This opportunity potentially expands donor pool and decreases waitlist time. This study aims to examine the impact of utilizing HCV NAT+ donor heart on heart transplant (HTx) waitlist time. Methods We retrospectively analyzed 126 patients who were listed for HTx from April 2016 through April 2018 at our center. These patients were separated into 2 periods centered on April 27, 2017 when transplantation of HCV NAT+ donor hearts into non-HCV-infected recipients began. Results Baseline patient characteristics were similar between both periods. In Period 1, 74 patients were on HTx waitlist with 52 of them ultimately transplanted, whereas in Period 2, 52 patients were listed and 36 of them transplanted. Fifteen patients were transplanted with HCV NAT+ donor hearts since April 27, 2017. Transplant rate increased from 0.83 person-year in Period 1 to 2.31 person-year in Period 2 (p Conclusion Our single-center analysis demonstrates that utilization of HCV NAT+ donor heart has resulted in an increase in transplant rate and a reduction in HTx waitlist time. Further extended follow-up is needed to determine long-term safety and efficacy of this strategy.

Barriers to kidney transplants in Indonesia: a literature review

People living with chronic kidney disease will require renal dialysis or a kidney transplant to maintain life. Although Indonesia has a developing healthcare industry, Indonesia's kidney transplant rates are lower than comparable nations. To explore the healthcare literature to identify barriers to kidney transplants in particular in relation to Indonesia. Healthcare databases were searched (CINAHL, Medline, EBSCOhostEJS, Blackwell Synergy, Web of Science, PubMed, Google Scholar and Proquest 5000) using the search terms: transplant, kidney disease, renal, dialysis, haemodialysis, Indonesia and nursing. The search was limited to English and Indonesian language data sources from 1997 to 2007. Reference lists of salient academic articles were hand searched. The results of our search identified six articles that met our criteria. Costs are the major barrier to kidney transplant in Indonesia, followed by cultural beliefs, perception of the law, lack of information and lack of infrastructure. In addition, kidney disease prevention strategies are required. There are many complex socio-economic, geographical, legal, cultural and religious factors that contribute to low kidney transplant rates in Indonesia. Although an increase in transplantation rates will require strategies from various agencies, healthcare professionals, including nurses, can play a role in overcoming some barriers. Community education programmes, improving their own education levels and by increasing empowerment in nursing we may contribute to improved kidney transplant rates in Indonesia.

Model for end-stage liver disease (MELD) for liver allocation: A 5-year score card

Model for end-stage liver disease (MELD) for liver allocation: A 5-year score card

Analysis of Model for End-Stage Liver Disease (MELD) Score in a Liver Transplantation Waiting List

Background The Model for End-Stage Liver Disease (MELD) was introduced in 1999 to quantify the 3-month prognosis of cirrhotic patients after a transjugular intrahepatic portosystemic shunt (TIPS). Because of the imbalance between organ donors and patients on the waiting list, the MELD was adopted by the United States in 2002 to allocate liver grafts for transplantation. Preliminary results have indicated a reduction in waiting list deaths and an increase in transplantation rates for candidates. Seeking to find a new model to predict death on the waiting list and after liver transplantation, retrospective studies have examined MELD scores in waiting list patients. The aim of this study was to analyze the MELD scores of patients on the liver waiting list for comparisons between transplanted patients. Patients and Methods A retrospective study was performed analyzing 131 registrations of 127 orthotopic liver transplant (OLT) patients (4 underwent retransplantation) grafted between November 2000 and January 2006, excluding 24 patients: 2 had urgent retransplantations due to hepatic artery thrombosis and 22 had incomplete data. These patients were divided into 3 groups: group I (transplanted patients)—53 patients underwent 55 OLT; group II—29 patients who died on the waiting list; group III—patients on the waiting list including 23 patients still waiting as of the date of the study. Results The main indication for OLT was hepatitis C virus cirrhosis (50.50%), followed by alcoholic liver cirrhosis (23.30%), cryptogenic cirrhosis (12.60%), autoimmune hepatitis (5.80%), hepatitis B virus cirrhosis (4.85%), and primary biliary cirrhosis (2.91%). Group I: MELD score 15.62 (range, 6–39) on admission to the list, and 18.87 (range, 7–39) at transplantation. The mean waiting time for OLT was 478.39 days (range, 2–1270 days). The 38 patients who survived underwent 39 OLT (1 retransplantation). The MELD score at entrance to the list was 14.62 (range, 7–30) and at transplantation, 17.70 (range, 7–39). The mean time between admission to the list and transplantation was 505.37 days (range, 6–1270 days). The 15 patients who died had received 16 OLT (1 retransplantation). Their MELD scores were 17.80 (range, 6–39) and 21.81 (range, 9–39) at admission to the list and at transplantation, respectively, with a mean time on the waiting list of 417.93 days (range, 2–872 days). Group II: 29 patients died before OLT, at a mean age of 52.60 years (range, 22–67 years). Their MELD score was 19.24 (range, 7–45), and the interval between admission to the waiting list and death was 249.55 days (range, 3–1247 days). Group III: 23 patients still active on the OLT waiting list at the time of study displayed a mean MELD score of 13.65 (range, 6–28) and 354.30 days (range, 2–905 days) waiting until the moment. In conclusion, MELD score at the time of admission to the waiting list was higher among those patients who died either awaiting a liver graft (19.24) or after OLT (17.80) compared with those who survived after OLT (14.60) or are still awaiting OLT (13.65).

The Impact of Accepting Living Kidney Donors With Mild Hypertension or Proteinuria on Transplantation Rates

As waiting times for kidney transplantation increase, individuals with hypertension or proteinuria may be considered as eligible living donors. We set out to determine how frequently donors are excluded because of hypertension or proteinuria and to what extent accepting such donors would increase transplantation rates. Wait lists from 4 Canadian transplantation centers were examined for causes of living kidney donor exclusion. Donors with hypertension (clinic blood pressure >140/90 mm Hg or requiring antihypertensive medication) or proteinuria historically have been excluded at these centers. We define potentially acceptable hypertension as a clinic blood pressure less than 150/100 mm Hg or less than 140/90 mm Hg if administered a single antihypertensive medication and define acceptable proteinuria as protein of 0.15 to 0.3 g/d. Only 35% (124 of 352 patients) of wait-listed patients had a living donor evaluated (n = 180 potential donors). Primary reasons for donor exclusion were immunologic: a positive cross-match (32%; n = 59) or blood group type incompatibility (22%; n = 40). Hypertension or proteinuria were less common (17%; n = 31). Of 31 donors excluded for hypertension or proteinuria, only 13 had results in the acceptable range. Acceptance of these donors would have resulted in transplantation of 3% (12 of 352 patients) of the wait-list population. Accepting living donors with mild hypertension and proteinuria will lead to a slight increase in transplantation rates. Efforts to improve living donor awareness and overcome immunologic barriers to transplantation may have a greater impact.

Regional sharing for adult status 1 candidates: Reduction in waitlist mortality

The intent of regional sharing for status 1 candidates is to promote timely access to donor livers. Presumably this decreases waitlist mortality. Little published data exists that supports this policy. Organ Procurement and Transplantation Network data was used to calculate region 4 and national adult waitlist death and transplant rates 4 yr prior to (period A) and after (period B) implementation of the sharing agreement in July 1999. Death and transplant rates were calculated using a competing risk analysis. Regional sharing resulted in a reduction in adult status 1 waitlist death rate and an increase in transplant rate for region 4 candidates at 7 and 14 days (P > 0.05) without a change in the death rate at 90 days for the non-status 1 candidates. National data showed a significant increase in transplant rate at 7 days and reduction in waitlist death rate at 14 days after listing (P < 0.05). Status 1 waiting time was decreased from 10 to 3 days (P < 0.05). Adult patient survival was not significantly different between the periods. In conclusion, regional sharing for status 1 candidates results in an increased transplant rate and a reduction in waitlist mortality. Sharing did not impact waitlist mortality for non-status 1 candidates.

Evidence-based evolution of the MELD/PELD liver allocation policy

Evidence-based evolution of the MELD/PELD liver allocation policy

Results of the first year of the new liver allocation plan.

Liver allocation policy in the U.S. was recently changed to a continuous disease severity scale with minimal weight given to time waiting in an effort to better prioritize deceased donor liver transplant candidates. We compared rates of waiting list registrations, removals, transplants, and deaths during the year prior to implementation of the new liver allocation policy (2/27/01-2/26/02, Era 1) with the first year's experience (2/27/02-2/26/03, Era 2) under this new policy. Rates were adjusted for 1,000 patient years on the waiting list and compared using z-tests. A 1-sided test was used to compare death rates; 2-sided tests were used to compare transplant rates. Overall and subgroup analyses were performed for demographic, geographic, and medical strata. In Era 2, we observed a 12% reduction in new liver transplant waiting list registrations, with the largest reductions seen in new registrants with low MELD/PELD scores. In Era 2, there was a 3.5% reduction in waiting list death rate (P =.076) and a 10.2% increase in cadaveric transplants (P <.001). The reduction in waiting list mortality and increase in transplantation rates were evenly distributed across all demographic and medical strata, with some variation across geographic variables. Early patient and graft survival after deceased donor liver transplantation remains unchanged. In conclusion, by eliminating the categorical waiting list prioritization system that emphasized time waiting, the new system has been associated with reduced registrations and improved transplantation rates without increased mortality rates for individual groups of waiting candidates or changes in early transplant survival rates.