Evaluating the Correlation Between Anteroposterior Diameter, Body Surface Area, and Height for Liver Transplant Donors and Recipients.

Background: Small stature and female sex correlate to decreased deceased donor liver transplant (DDLT) access and higher waitlist mortality. However, efforts are being made to improve access and equity of allocation under the new continuous distribution (CD) system. Liver anteroposterior diameter (APD) is a method used by many centers to determine size compatibility for DDLT but is not recorded systematically, so it cannot be used for allocation algorithms. We therefore seek to correlate body surface area (BSA) and height to APD in donors and recipients and compare waitlist outcomes by these factors to support their use in the CD system. Methods: APD was measured from single-center DDLT recipients and donors with cross-sectional imaging. Linear, Pearson, and PhiK correlation coefficient were used to correlate BSA and height to APD. Competing risk analysis of waitlist outcomes was performed using United Network for Organ Sharing data. Results: For 143 pairs, donor BSA correlated better with APD than height (PhiK = 0.63 versus 0.20). For recipient all comers, neither BSA nor height were good correlates of APD, except in recipients without ascites, where BSA correlated well (PhiK = 0.63) but height did not. However, among female recipients, BSA, but not height, strongly correlated to APD regardless of ascites status (PhiK = 0.80 without, PhiK = 0.70 with). Among male recipients, BSA correlated to APD only in those without ascites (PhiK = 0.74). In multivariable models, both BSA and height were predictive of waitlist outcomes, with higher values being associated with increased access, decreased delisting for death/clinical deterioration, and decreased living donor transplant (model concordance 0.748 and 0.747, respectively). Conclusions: Taken together, BSA is a good surrogate for APD and can therefore be used in allocation decision making in the upcoming CD era to offset size and gender-based disparities among certain candidate populations.

A practical guide to real-world implementation of pre-emptive therapy for Cytomegalovirus disease prevention in high-risk seronegative liver transplant recipients with seropositive donors.

The Comparison of Antiviral Preventative Strategies In Liver Transplant (CAPSIL) study showed pre-emptive therapy (PET) to be superior to antiviral prophylaxis for Cytomegalovirus (CMV) disease prevention in high-risk CMV seronegative liver transplant recipients (LTRs) with seropositive donors (D+R-). Despite the statistical superiority of PET over prophylaxis in research settings, PET is perceived as a logistically more complex strategy that requires careful coordination of weekly CMV PCR testing, prompt initiation of CMV antivirals upon viremia detection, and timely cessation of antivirals following viremia resolution. Transplant centers may be hesitant to use PET for CMV disease prevention in D+R- LTRs out of concern that PET coordination is not feasible in clinical practice. We recently described our experience using PET in CMV D+R- LTRs in a real-world setting, and found it to be as effective for CMV disease prevention as PET performed as part of a clinical trial. Here, we describe a systematic approach for PET implementation in real-world settings and provide practical tools to address anticipated challenges. This framework can support transplant programs in overcoming logistical barriers to PET and incorporating an evidence-based and cost-effective CMV prevention strategy into routine care for high-risk CMV D+R- LTRs.

Anti-GSTT1 antibodies and Null genotype correlate with histological changes of antibody mediated rejection in kidney transplantation.

BACKGROUND: The presence of anti-Glutathione S-transferase T1 (GSTT1) antibodies (abs) has been hypothesized as a pathogenic contributor in antibody-mediated rejection (AMR). METHODS: We aimed to evaluate the relationship between genetic variants of GSTT1, anti-GSTT1 abs and AMR in a cohort of 87 kidney transplant (KTx) patients using Immucor's non-HLA Luminex assay. Patients were classified according to biopsy-proven AMR and HLA-DSA status: AMR with positive anti-HLA-DSAs (AMR/DSA+, n = 29), AMR but no detectable anti-HLA-DSAs (AMR/DSA-, n = 28) and control patients with stable allograft function and no evidence of rejection (n = 30). RESULTS: At an MFI cut-off of 3000, the overall prevalence of anti-GSTT1 abs was 18.3%. The proportion of patients with anti-GSTT1 abs was higher in the AMR/DSA- group (25%), compared to the control (13.3%) and AMR/DSA+ group (3.4%) (p = 0.06). Among patients with anti-GSTT1 abs, the MFI was higher in AMR/DSA- and GSTT1-Null patients. Of 81 patients who underwent GSTT1 genotyping, 19.8% were homozygotes for the null allele (GSTT1-Null). GSTT1-Null status in the transplant recipients was associated with the development of anti-GSTT1 abs (OR, 4.49; 95%CI, 1.2-16.7). In addition, GSTT1-Null genotype (OR 26.01; 95%CI, 1.63-404) and anti-GSTT1 ab positivity (OR 14.8; 95%CI, 1.1-190) were associated with AMR. Within AMR/DSA- patients, the presence of anti-GSTT1 abs didn't confer a higher risk of failure within the study observation period. CONCLUSION: The presence of anti-GSTT1 abs and GSTT1-Null genotype is associated with AMR, but do not appear to lead to accelerated graft injury in this cohort of early allograft injury changes, with a limited period of follow-up.

Association of Body Surface Area With Access to Deceased Donor Liver Transplant and Novel Allocation Policies.

Importance: Small waitlist candidates are significantly less likely than larger candidates to receive a liver transplant. Objective: To investigate the magnitude of the size disparity and test potential policy solutions. Design, Setting, and Participants: A decision analytical model was generated to match liver transplant donors to waitlist candidates based on predefined body surface area (BSA) ratio limits (donor BSA divided by recipient BSA). Participants included adult deceased liver transplant donors and waitlist candidates in the Organ Procurement and Transplantation Network database from June 18, 2013, to March 20, 2020. Data were analyzed from January 2021 to September 2021. Exposures: Candidates were categorized into 6 groups according to BSA from smallest (group 1) to largest (group 6). Waitlist outcomes were examined. A match run was created for each donor under the current acuity circle liver allocation policy, and the proportion of candidates eligible for a liver based on BSA ratio was calculated. Novel allocation models were then tested. Main Outcomes and Measures: Time on the waitlist, assigned Model for End-Stage Liver Disease (MELD) score, and proportion of patients undergoing a transplant were compared by BSA group. Modeling under the current allocation policies was used to determine baseline access to transplant by group. Simulation of novel allocation policies was performed to examine change in access. Results: There were 41 341 donors (24 842 [60.1%] male and 16 499 [39.9%] female) and 84 201 waitlist candidates (53 724 [63.8%] male and 30 477 [36.2%] female) in the study. The median age of the donors was 42 years (IQR, 28-55) and waitlist candidates, 57 years (IQR, 50-63). Females were overrepresented in the 2 smallest BSA groups (7100 [84.0%] and 7922 [61.1%] in groups 1 and 2, respectively). For each increase in group number, waitlist time decreased (234 days [IQR, 48-700] for group 1 vs 179 days [IQR, 26-503] for group 6; P < .001) and the proportion of the group undergoing transplant likewise improved (3890 [46%] in group 1 vs 4932 [57%] in group 6; P < .001). The smallest 2 groups of candidates were disadvantaged under the current acuity circle allocation model, with 37% and 7.4% fewer livers allocated relative to their proportional representation on the waitlist. Allocation of the smallest 10% of donors (by BSA) to the smallest 15% of candidates overcame this disparity, as did performing split liver transplants. Conclusions and Relevance: In this study, liver waitlist candidates with the smallest BSAs had a disadvantage due to size. Prioritizing allocation of smaller liver donors to smaller candidates may help overcome this disparity.

Real-world effectiveness of preemptive therapy (PET) for cytomegalovirus (CMV) disease prevention in CMV high-risk donor seropositive/recipient seronegative (D+R-) liver transplant recipients (LTxR).

BACKGROUND: Despite superiority of preemptive therapy (PET) compared to universal prophylaxis for prevention of cytomegalovirus (CMV) disease in the CAPSIL randomized trial among CMV D+R- liver transplant recipients (LTxRs), real-world effectiveness may be lower because of logistical concerns about feasibility of PET. METHODS: We retrospectively assessed PET as standard clinical care at a single transplant center among 50 consecutive adult CMV D+R- LTxRs undergoing a first liver transplant between 4/4/2019 and 5/18/2021 and compared outcomes and adherence to those randomized to PET in the CAPSIL study (N = 100). The primary outcome was CMV disease and secondary outcomes were biopsy-confirmed acute allograft rejection, retransplant, invasive fungal infections, and death, all assessed by 1-year post-transplant. Exploratory outcomes included virologic parameters and measures of adherence to protocol-specified CMV qPCR monitoring. RESULTS: Baseline characteristics were similar between groups. The cumulative incidence of CMV disease at 1-year post-transplant was 4/50 (8%) versus 9/100 (9%) in the real-world and CAPSIL cohorts, respectively, p = 1.0. The rate of breakthrough CMV disease during the 100-day PET period was low (2/50 [4%]) and similar to the PET cohort from the CAPSIL study (3/100 [3%]).  All secondary and exploratory outcomes were not significantly different between the real-world and CAPSIL PET cohorts. CONCLUSIONS: In this first reported study of real-world PET, the feasibility and effectiveness for CMV disease prevention and for other clinical outcomes in CMV D+R- LTxRs were similar to those reported with PET in a clinical trial. Additional studies to confirm feasibility and generalizability in other settings are warranted.

Deceased donor kidneys are discarded at higher rates when labeled as high kidney donor profile index.

The kidney donor risk index (KDRI) and percentile conversion, kidney donor profile index (KDPI), provide a continuous measure of donor quality. Kidneys with a KDPI >85% (KDPI85 ) are referred to as "high KDPI." The KDPI85 cutoff changes every year, impacting which kidneys are labeled as KDPIHIGH . We examine kidney utilization around the KDPI85 cutoff and explore the "high KDPI" labeling effect. KDRI to KDPI Mapping Tables from 2012 to 2020 were used to determine the yearly KDRI85 value. Organ Procurement and Transplantation Network data was used to calculate discard rates and model organ use. KDRI85 varied between 1.768 and 1.888. In a multivariable analysis, kidney utilization was lower for KDPI 86% compared with KDPI 85% kidneys (p = .046). Kidneys with a KDRI between 1.785-1.849 were classified as KDPIHIGH in the years 2015-2017 and KDPILOW in the years 2018-2020. The discard rate was 44.9% when labeled as KDPIHIGH and 39.1% when labeled as KDPILOW (p < .01). For kidneys with the same KDRI, the high KDPI label is associated with increased discard. We should reconsider the appropriateness of the "high KDPI" label.

Building a Utility-based Liver Allocation Model in Preparation for Continuous Distribution.

BACKGROUND: The current model for end-stage liver disease-based liver allocation system in the United States prioritizes sickest patients first at the expense of long-term graft survival. In a continuous distribution model, a measure of posttransplant survival will also be included. We aimed to use mathematical optimization to match donors and recipients based on quality to examine the potential impact of an allocation system designed to maximize long-term graft survival. METHODS: Cox proportional hazard models using organ procurement and transplantation network data from 2008 to 2012 were used to place donors and waitlist candidates into 5 groups of increasing risk for graft loss (1-lowest to 5-highest). A mixed integer programming optimization model was then used to generate allocation rules that maximized graft survival at 5 and 8 y. RESULTS: Allocation based on mathematical optimization improved 5-y survival by 7.5% (78.2% versus 70.7% in historic cohort) avoiding 2271 graft losses, and 8-y survival by 9% (71.8% versus 62.8%) avoiding 2725 graft losses. Long-term graft survival for recipients within a quality group is highly dependent on donor quality. All candidates in groups 1 and 2 and 43% of group 3 were transplanted, whereas none of the candidates in groups 4 and 5 were transplanted. CONCLUSIONS: Long-term graft survival can be improved using a model that allocates livers based on both donor and recipient quality, and the interaction between donor and recipient quality is an important predictor of graft survival. Considerations for incorporation into a continuous distribution model are discussed.

Machine Perfusion Decreases Delayed Graft Function in Donor Grafts With High Kidney Donor Profile Index.

OBJECTIVES: Kidney transplant is the optimal treatment for patients with end-stage renal disease. The effects of using machine perfusion for donor kidneys with varying Kidney Donor Profile Index scores are unknown. We sought to assess the impact of machine perfusion on the incidence of delayed graft function in different score groups of kidney grafts classified with the Kidney Donor Profile Index. MATERIALS AND METHODS: We conducted a retrospective analysis from January 2008 through September 2017 of adult recipients (≥ 18 years old) undergoing kidney-only transplant from deceased donors. All transplant recipients were followed until December 2017. Recipients who received multiorgan transplants or kidneys from living donors were excluded from our analyses. Recipients were divided according to 5 donor categories of Kidney Donor Profile Index scores (0-20, 21-40, 41-60, 61-80, and 81-100). Logistic regression analysis was performed for each score group to determine the effects of machine perfusion on development of delayed graft function within each score group. RESULTS: Our study included 101222 recipients who met the inclusion criteria. Multivariate analysis revealed that machine perfusion was associated with significantly decreased development of delayed graft function only in donors with high-risk profiles: the 61 to 80 score group (odds ratio = 0.83; confidence interval, 0.78-0.89) and the 81 to 100 score group (odds ratio = 0.72; confidence interval, 0.67-0.78). CONCLUSIONS: Machine perfusion is beneficial in reducing delayed graft function only in donor kidneys with a higher risk profile.

Listing practices and graft utilization of hepatitis C-positive deceased donors in liver and kidney transplant.

BACKGROUND: The opioid epidemic has resulted in increasing the incidence of hepatitis C virus in the general population and more deceased organ donors with hepatitis C in the United States. We aim to describe how the changing donor landscape affects patterns of liver and kidney transplantation among donors, waitlist candidates, and transplanted recipients. METHODS: Using data supplied by the United Network for Organ Sharing, we examined donor hepatitis C virus antibody (Ab) and nucleic acid testing (NAT) status, center waitlist patterns, and liver and kidney transplants and discards between 2015 and 2017 by 6-month periods. RESULTS: We observed an increase in donors with any marker of the hepatitis C virus (n = 283 [6.2%] in period 1 to n = 384 [7.4%] in period 5, P = .008) and antibody positive nucleic acid testing negative donors (n = 81 [1.8%] in period 1 to n = 131 [2.5%] in period 5, P < .001). We observed a significant increase in aviremic recipients of liver transplants from antibody positive nucleic acid testing negative donors (n = 1 [1.7%] in period 1, to n = 27 [31.0%] in period 5, P = .005) and a significant decrease in the antibody positive nucleic acid testing positive liver discard rate (P = .01). By the end of the study, 75.8% (n = 97) of recipients of antibody positive nucleic acid testing negative kidneys were hepatitis C virus negative, an increase from 10.6% (n = 5) in period 1. CONCLUSION: The number of donors with the hepatitis C virus is increasing. We observed a concomitant increase in the transplantation of kidneys and livers from aviremic donors, and the recipient population of these organs is increasingly hepatitis C virus negative.

Living Donation Versus Donation After Circulatory Death Liver Transplantation for Low Model for End-Stage Liver Disease Recipients.

In this era of organ scarcity, living donor liver transplantation (LDLT) is an alternative to using deceased donors, and in Western countries, it is more often used for recipients with low Model for End-Stage Liver Disease (MELD) scores. We sought to compare the patient survival and graft survival between recipients of liver transplantation from living donors and donation after circulatory death (DCD) donors in patients with low MELD scores. This is a retrospective cohort analysis of adult liver transplant recipients with a laboratory MELD of ≤20 who underwent transplantation between January 1, 2003 and March 31, 2016. Recipients were categorized by donor graft type (DCD or LDLT), and recipient and donor characteristics were compared. Ten-year patient and graft survival curves were calculated using Kaplan-Meier analyses, and a mixed-effects model was performed to determine the contributions of recipient, donor, and center variables on patient and graft survival. There were 36,705 liver transplants performed: 32,255 (87.9%) from DBD donors, 2166 (5.9%) from DCD donors, and 2284 (6.2%) from living donors. In the mixed-effects model, DCD status was associated with a higher risk of graft failure (relative risk [RR], 1.27; 95% confidence interval [CI], 1.16-1.38) but not worse patient survival (RR, 1.27; 95% CI, 0.96-1.67). Lower DCD center experience was associated with a 1.21 higher risk of patient death (95% CI, 1.17-1.25) and a 1.13 higher risk of graft failure (95% CI, 1.12-1.15). LDLT center experience was also predictive of patient survival (RR, 1.03; 95% CI, 1.02-1.03) and graft failure (RR, 1.05; 95% CI, 1.05-1.06). In conclusion, for liver transplant recipients with low laboratory MELD, LDLT offers better graft survival and a tendency to better patient survival than DCD donors.

Transplant tourism complicated by life-threatening New Delhi metallo-ß-lactamase-1 infection.

Transplant tourism, which is the practice of traveling to other countries for transplant, continues to be a major problem worldwide. We describe a patient who traveled to Pakistan and underwent commercial kidney transplant. He developed life-threatening infections from New Delhi metallo-ß-lactamase-1-producing Enterobacter cloacae and Rhizopus oryzae, resulting in a necrotizing kidney allograft infection and subsequent external iliac artery rupture. He survived after a prolonged course of nonstandardized antimicrobial therapy, including a combination of aztreonam and ceftazidime-avibactam, and aggressive surgical debridement with allograft nephrectomy. The early timing of infection with these unusual organisms localized to the allograft suggests contamination and substandard care at the time of transplant. This case highlights the challenges of caring for these infections and serves as a cautionary tale for the potential complications of commercial transplant tourism.

Utilization of Standard Criteria Donor and Expanded Criteria Donor Kidneys After Kidney Allocation System Implementation.

BACKGROUND Implementation of the Kidney Allocation System (KAS) changed how kidneys are allocated and the information on which organ utilization decisions are based. We aimed to evaluate how KAS implementation changed kidney utilization and recipient outcomes. MATERIAL AND METHODS Using the United Network for Organ Sharing database, we identified recipients of kidney transplants from donors with kidney donor profile index (KDPI) of 61-90% in the 5-years pre- and 18-months post-KAS implementation and examined patient and graft survival and donor kidney discard rates based on standard criteria donor (SCD) or expanded criteria donor (ECD) status. RESULTS The proportion of ECD kidneys was unchanged pre- versus post-KAS. Post-KAS, SCD kidneys were less likely to be transplanted into young recipients while ECD kidneys were more likely to be transplanted. SCD kidneys in the post-KAS period conferred a 1.42 (95% CI: 1.18-1.73) times higher adjusted mortality and 2% lower 1-year survival (94.2% vs. 96.2%, P<0.001) but had unchanged graft failure compared to pre-KAS. For ECD kidneys, there was no difference in mortality or graft survival. The discard rate increased after KAS for both SCD and ECD kidneys (P<0.05) but was not different between SCD and ECD kidneys for any KDPI group. CONCLUSIONS After KAS implementation, patient survival for recipients of SCD kidneys was significantly worse.

Is Kidney Donor Profile Index (KDPI) Valid for Hepatitis C Aviremic Kidneys?

The Kidney Donor Risk Index (KDRI) and Kidney Donor Profile Index (KDPI) assist clinicians with the selection of deceased donor kidneys. This scoring system is based on 10 donor factors including Hepatitis C virus (HCV) status from serological or NAT testing. The donor HCV status (i.e., having either a positive hepatitis C antibody (Ab) or nucleic acid testing (NAT) result) increases the hazard ratio for graft failure by 1.27 and the KDPI by approximately 20%. Whether this increase in KDPI is a true reflection of graft quality for HCV seropositive but not viremic donors is unknown. Further investigations are needed to maximize the use of these organs.

Changing landscape of hepatitis C virus-positive donors.

With the introduction of the new highly effective antiviral therapies, there has been a dramatic increase in the use of the hepatitis C virus (HCV)-positive livers in HCV-positive recipients. In the majority of studies, HCV positivity was defined as a donor testing HCV Ab positive. In 2015, all Organ Procurement Organizations were mandated to perform and report HCV Nucleic Acid Amplification Testing (NAT) results on all deceased and living donors. Studies are not yet available on how organs are being utilized based on NAT status and whether NAT status affects recipient outcomes. Further studies are needed to maximize the use of these organs.

Financial benefit of a smoking cessation program prior to elective colorectal surgery.

BACKGROUND: Cigarette smoking increases the risk of postoperative complications nearly 2-fold. Preoperative smoking cessation programs may reduce complications as well as overall postoperative costs. We aim to create an economic evaluation framework to estimate the potential value of preoperative smoking cessation programs for patients undergoing elective colorectal surgery. METHODS: A decision-analytic model from the payer perspective was developed to integrate the costs and incidence of 90-day postoperative complications and readmissions for a cohort of patients undergoing elective colorectal surgery after a smoking cessation program versus usual care. Complication, readmission, and cost data were derived from a cohort of 534 current smokers and recent quitters undergoing elective colorectal resections in Washington State's Surgical Care and Outcomes Assessment Program linked to Washington State's Comprehensive Hospital Abstract Reporting System. Smoking cessation program efficacy was obtained from the literature. Sensitivity analyses were performed to account for uncertainty. RESULTS: For a cohort of patients, the base case estimates imply that the total direct medical costs for patients who underwent a preoperative smoking cessation program were on average $304 (95% CI: $40-$571) lower per patient than those under usual care during the first 90 days after surgery. The model was most sensitive to the odds of recent quitters developing complications or requiring readmission, and smoking program efficacy. CONCLUSIONS: A preoperative smoking cessation program is predicted to be cost-saving over the global postoperative period if the cost of the intervention is below $304 per patient. This framework allows the value of smoking cessation programs of variable cost and effectiveness to be determined.

Expanding access to transplantation with hepatitis C-positive donors: A new perspective on an old issue.

With the need for organs far exceeding supply, donors previously exposed to hepatitis B (HBV) and hepatitis C (HCV) viral infections should be considered for transplantation. Although many centers have protocols for transplanting organs from HBV core antibody-positive (HBcAb+) donors into select recipients, in the era of direct-acting antivirals (DAAs), a new focus should be placed on HCV-positive donors. The transmission rate from HCV antibody-positive (HCVAb+) nucleic acid testing negative (HCV NAT-) donors is expected to be very low, and we encourage use of such organs in HCV recipients provided a normal biopsy, appropriate counseling, and careful post-transplant monitoring. While transmission of HCV from HCV NAT+ donors is universal, the success of DAA in obtaining a sustained viral response in post-transplant recipients should make the use of these organs more appealing. We herein provide information to help guide the use of organs from HCV donors.

Recent trends in liver transplantation for alcoholic liver disease in the United States.

AIM: To examine temporal changes in the indications for liver transplantation (LT) and characteristics of patients transplanted for alcoholic liver disease (ALD). METHODS: We performed a retrospective cohort analysis of trends in the indication for LT using the United Network for Organ Sharing (UNOS) database between 2002 and 2015. Patients were grouped by etiology of the liver disease and characteristics were compared using χ2 and t-tests. Time series analysis was used identifying any year with a significant change in the number of transplants per year for ALD, and before and after eras were modeled using a general linear model. Subgroup analysis of recipients with ALD was performed by age group, gender, UNOS region and etiology (alcoholic cirrhosis, alcoholic hepatitis and hepatitis C - alcoholic cirrhosis dual listing). RESULTS: Of 74216 liver transplant recipients, ALD (n = 9400, 12.7%) was the third leading indication for transplant after hepatitis C and hepatocellular carcinoma. Transplants for ALD, increased from 12.8% (553) in 2002 to 16.5% (1020) in 2015. Time series analysis indicated a significant increase in the number of transplants per year for ALD in 2013 (P = 0.03). There were a stable number of transplants per year between 2002 and 2012 (linear coefficient 3, 95%CI: -4.6, 11.2) an increase of 177 per year between 2013 and 2015 (95%CI: 119, 234). This increase was significant for all age groups except those 71-83 years old, was observed for both genders, and was incompletely explained by a decrease in transplants for hepatitis C and ALD dual listing. All UNOS regions except region 9 saw an increase in the mean number of transplants per year when comparing eras, and this increase was significant in regions 2, 3, 4, 5, 6, 8, 10 and 11. CONCLUSION: There has been a dramatic increase in the number of transplants for ALD starting in 2013.