The 50 most-cited articles in Transplantation, 2020

The 2020 Kidney Disease: Improving Global Outcomes (KDIGO) Clinical Practice Guideline on the Evaluation and Management of Candidates for Kidney Transplantation is intended to assist health care professionals worldwide who evaluate and manage potential candidates for deceased or living donor kidney transplantation. This guideline addresses general candidacy issues such as access to transplantation, patient demographic and health status factors, and immunological and psychosocial assessment. The roles of various risk factors and comorbid conditions governing an individual's suitability for transplantation such as adherence, tobacco use, diabetes, obesity, perioperative issues, causes of kidney failure, infections, malignancy, pulmonary disease, cardiac and peripheral arterial disease, neurologic disease, gastrointestinal and liver disease, hematologic disease, and bone and mineral disorder are also addressed. This guideline provides recommendations for evaluation of individual aspects of a candidate's profile such that each risk factor and comorbidity are considered separately. The…

The coronavirus pandemic has significantly impacted solid organ transplantation (SOT). Early in the outbreak period, transplant societies recommended suspending living kidney transplant programs in communities with widespread transmission to avoid exposing recipients to increased risk of immunosuppression, while recommendations were made to reserve deceased-donor kidney transplantation for likely life-saving indications. SOT recipients may be at high risk from COVID-19 disease due to chronic immunosuppressive treatment and other medical comorbidities. Mortality rates reported between 13 to over 30% in SOT recipients. In addition to high rates of complications and mortality attributable to COVID-19 infections, the pandemic has also led to additional complexities in transplantation including new questions regarding screening of donors and recipients, decision making to accept a patient for kidney transplant or wait after pandemic. The clinical implications of COVID-19 infection may also differ depending on the type of the transplanted organ and recipient comorbidities which further…

Liver transplantation (LT) offers excellent long-term outcome for certain patients with hepatocellular carcinoma (HCC), with a push to not simply rely on tumor size and number. Selection criteria should also consider tumor biology (including alpha-fetoprotein), probability of waitlist and post-LT survival (ie, transplant benefit), organ availability, and waitlist composition. These criteria may be expanded for live donor LT (LDLT) compared to deceased donor LT though this should not adversely affect the double equipoise in LDLT, namely ensuring both acceptable recipient outcomes and donor safety. HCC patients with compensated liver disease and minimal tumor burden have low urgency for LT, especially after local-regional therapy with complete response, and do not appear to derive the same benefit from LT as other waitlist candidates. These guidelines were developed to assist in selecting appropriate HCC patients for both deceased donor LT and LDLT.

The 2020 Kidney Disease: Improving Global Outcomes (KDIGO) Clinical Practice Guideline on the Evaluation and Management of Candidates for Kidney Transplantation is intended to assist health care professionals worldwide who evaluate and manage potential candidates for deceased or living donor kidney transplantation. This guideline addresses general candidacy issues such as access to transplantation, patient demographic and health status factors, immunological and psychosocial assessment. The roles of various risk factors and comorbid conditions governing an individual's suitability for transplantation such as adherence, tobacco use, diabetes, obesity, perioperative issues, causes of kidney failure, infections, malignancy, pulmonary disease, cardiac and peripheral arterial disease, neurologic disease, gastrointestinal and liver disease, hematologic disease, and bone and mineral disorder are also addressed. This guideline provides recommendations for evaluation of individual aspects of a candidate's profile such that each risk factor and comorbidity are considered separately. The goal…

BACKGROUND: The novel coronavirus severe acute respiratory syndrome coronavirus 2 [coronavirus disease 2019 (COVID-19)] poses unique challenges for immunosuppressed patients. Solid organ transplant (SOT) recipients comprise a large proportion of this group, yet there is limited knowledge about the presentation, clinical course, and immunosuppression management of this novel infection among heart, lung, liver, pancreas, and kidney transplant recipients. METHODS: We present 21 SOT recipients diagnosed with COVID-19 between January 1, 2020 and April 22, 2020 at a US high-volume transplant center. Diagnostic workup, clinical course, immunosuppression/antiviral management, and immediate outcomes are described. RESULTS: Twenty-one (15.9%) of 132 symptomatic patients tested were positive. Mean age at diagnosis was 54.8 ± 10.9 y. Median time from transplant was 5.58 y (interquartile range 2.25, 7.33). Median follow-up was 18 d (interquartile range 13, 30). Fourteen patients required inpatient management, with 7 (50%) placed in the intensive care unit (ICU). All transplant types were…

BACKGROUND: Late antibody-mediated rejection (AMR) is a major cause of transplant failure. Potential therapeutic targets are plasma cells and natural killer (NK) cells, both expressing high levels of CD38. METHODS: Here, we report the use of CD38 monoclonal antibody daratumumab (9-mo course) in a kidney allograft recipient diagnosed with smoldering myeloma and anti-HLA class II donor-specific antibody-positive chronic active AMR 13 years after transplantation. Patient monitoring included serial HLA single-antigen testing, peripheral blood immune cell phenotyping, as well as follow-up allograft and bone marrow biopsies at 3 and 9 months, including analyses of rejection-related gene expression patterns. RESULTS: Daratumumab led to persistent CD138+ cell depletion in the bone marrow and blood and substantially decreased NK cells counts in blood and graft tissue. At the same time, donor-specific antibody in serum disappeared, and in vitro alloantibody production by CD138+ cells enriched from bone marrow aspirates was abrogated. A 3-month follow-up biopsy revealed a complete resolution…

BACKGROUND: Highly HLA sensitized patients have limited access to life-saving kidney transplantation because of a paucity of immunologically suitable donors. Imlifidase is a cysteine protease that cleaves IgG leading to a rapid decrease in antibody level and inhibition of IgG-mediated injury. This study investigates the efficacy and safety of imlifidase in converting a positive crossmatch test to negative, allowing highly sensitized patients to be transplanted with a living or deceased donor kidney. METHODS: This open-label, single-arm, phase 2 trial conducted at 5 transplant centers, evaluated the ability of imlifidase to create a negative crossmatch test within 24 h. Secondary endpoints included postimlifidase donor-specific antibody levels compared with predose levels, renal function, and pharmacokinetic/pharmacodynamic profiles. Safety endpoints included adverse events and immunogenicity profile. RESULTS: Of the transplanted patients, 89.5% demonstrated conversion of baseline positive crossmatch to negative within 24 h after imlifidase treatment. Donor-specific antibodies most…

BACKGROUND: Normothermic machine perfusion (NMP) bears the potential for significant prolongation of liver preservation before transplantation. Although safety and feasibility have been recently published, no data are available describing the significant challenges of establishing NMP programs outside clinical studies. We herein present our experience and propose a multidisciplinary approach for liver NMP in the clinical routine. METHODS: In February 2018, liver NMP was introduced for routine use in marginal organs, logistic challenges, and complex recipients at our institution. In a multidisciplinary effort among transplant coordinators, perfusionists, transplant surgeons, anesthesia, nurses, blood bank as well as laboratory staff, a clinical routine was established and 34 NMP cases were performed without critical incidents or organ loss. RESULTS: Nine livers were discarded due to poor organ quality and function observed during NMP. Twenty-five livers were successfully transplanted after preservation of up to 38 h. The extended criteria donors rate was 100% and 92% in discarded and…

BACKGROUND: Liver transplantation (LT) from controlled donation after circulatory death (cDCD) was initiated in France in 2015 under a protocol based on the use of normothermic regional perfusion (NRP) before organ procurement. The aim was to compare outcomes following cDCD LT with NRP and donation after brain death (DBD) LT. METHODS: This is a multicenter retrospective study comparing cDCD LT with NRP and DBD LT. A case-matched study (1:2) was performed using the variables such as recipient and donor age, indication of LT. RESULTS: A total of 50 patients from the cDCD group were matched to 100 patients from the DBD group. From postoperative days 1-4, serum transaminase release was significantly lower in the cDCD group compared to the DBD group (P < 0.05). Early allograft dysfunction (cDCD: 18% versus DBD: 32%; P = 0.11), acute kidney injury (26% versus 33%; P = 0.49), 90-d graft loss (2% versus 5%; P = 0.66), and arterial (4% versus 12%; P = 0.19) and biliary (16% versus 17%; P = 0.94) complications were similar between the 2 groups. The 2-y graft survival was 88% for cDCD group…

BACKGROUND: A concern about the susceptibility of immunocompromised patients to the worldwide pandemic of coronavirus disease 2019 (COVID-19) has been raised. We aimed at describing COVID-19 infections in the French cohort of lung transplant (LT) patients. METHODS: Multicenter nationwide cohort study of all LT recipients with COVID-19 diagnosed from March 1 to May 19, 2020. Recipient main characteristics and their management were retrieved. Hospitalization characteristics, occurrence of complications and survival were analyzed. RESULTS: Thirty-five LT patients with a COVID-19 infection were included. Median age was 50.4 (40.6-62.9) years, 16 (45.7%) were female, and 80% were double-LT recipients. Infection was community-acquired in 25 (71.4%). Thirty-one (88.6%) required hospitalization, including 13 (41.9%) in the intensive care unit. The main symptoms of COVID-19 were fever, cough, and diarrhea, present in 71.4%, 54.3%, and 31.4% of cases, respectively. Extension of pneumonia on chest CT was moderate to severe in 51.4% of cases. Among the 13 critically ill patients, 7 (53.9%)…

BACKGROUND: There is a scarcity of data on the consequences of coronavirus disease-19 (COVID-19) infections in kidney transplant recipients (KTRs) from emerging countries. METHODS: Here, we present a cohort study of 13 transplant centers in India including 250 KTR (226 living and 24 deceased donors) with polymerase chain reaction-confirmed COVID-19 positivity from March 23, 2020, until September 15, 2020. We detailed demographics, immunosuppression regimen, clinical profile, treatment, and outcomes. RESULTS: Median age of transplant recipients was 43 years, and recipients presented at a median of 3.5 years after transplant. Most common comorbidities (94%) included arterial hypertension (84%) and diabetes (32%); presenting symptoms at the time of COVID-19 included fever (88%), cough (72%), and sputum production (52%). Clinical severity ranged from asymptomatic (6%), mild (60%), and moderate (20%) to severe (14%). Strategies to modify immunosuppressants included discontinuation of antimetabolites without changes in calcineurin inhibitors and steroids (60%). Risk factors for mortality…

BACKGROUND: SARS-CoV-2 infection is heterogeneous in clinical presentation and disease evolution. To investigate whether immune response to the virus can be influenced by genetic factors, we compared HLA and AB0 frequencies in organ transplant recipients and waitlisted patients according to presence or absence of SARS-CoV-2 infection. METHODS: A retrospective analysis was performed on an Italian cohort composed by transplanted and waitlisted patients in a January 2002 to March 2020 time frame. Data from this cohort were merged with the Italian registry of COVID+ subjects, evaluating infection status of transplanted and waitlisted patients. A total of 56 304 cases were studied with the aim of comparing HLA and AB0 frequencies according to the presence (n = 265, COVID+) or absence (n = 56 039, COVID-) of SARS-CoV-2 infection. RESULTS: The cumulative incidence rate of COVID-19 was 0.112% in the Italian population and 0.462% in waitlisted/transplanted patients (OR = 4.2; 95% CI, 3.7-4.7; P < 0.0001). HLA-DRB1*08 was more frequent in COVID+ (9.7% and 5.2%: OR = 1.9, 95% CI, 1.2-3.1; P =…

The COVID-19 pandemic has hit the entire world in an almost unprecedented way. The crisis has spread rapidly, disease burden and casualties continue to rise, and the impact of the crisis is spreading through developing countries. Social distancing, travel restrictions, and intensified testing have improved the rate of the rise in new cases in some regions; however, it remains unclear when normality will return. Mechanisms of the disease remain largely unclear; treatment, if available, is mostly supportive. As during times of war, the challenges of the coronavirus crisis change our views in almost any aspect. Transplant patients and those with end-stage organ failure are in a particular vulnerable position. Elective surgeries including live donor transplant procedures have paused in many countries. Deceased donor transplants, where the procedure is established, continue in some countries, albeit with modified donor and recipient criteria, in an attempt to reduce the risk of COVID transmission or an infection after transplantation. Those who are immunocompromised are probably at…

Liver transplantation for cholangiocarcinoma has been an absolute contraindication worldwide due to poor results. However, in recent years and thanks to improvements of patient management and treatments of this cancer, this indication has been revisited. This consensus paper, approved by the International Liver Transplant Society, aims to provide a collection of expert opinions, consensus, and best practices surrounding liver transplantation for cholangiocarcinoma.

BACKGROUND: Median survival in patients with hepatocellular carcinoma (HCC) and portal vein tumor thrombosis (PVTT) is 2-6 months; conventionally liver transplantation is contraindicated. METHODS: We studied outcomes following living donor liver transplantation (LDLT) post-PVTT downstaging (DS) with stereotactic body radiotherapy (SBRT), and tumor ablation (with transarterial chemo- or radio-embolization). RESULTS: Of 2348 consecutive LDLTs, 451 were for HCC, including 25 with PVTT (mainly Vp1-3) after successful DS and 20 with Vp1/2 PVTT without previous treatment. DS was attempted in 43, was successful in 27 (63%), and 25 underwent LDLT. Median alpha fetoprotein (AFP) at diagnosis and pre-LDLT were 78.1 ng/mL (3-58 200) and 55 ng/mL (2-7320), respectively. Mean DS to LDLT time was 10.2 weeks (5-16). Excluding 2 postoperative deaths, 1- and 5-year overall survival (OS) and recurrence-free survival (RFS) were 82%, 57%, and 77%, 51%, respectively, comparable to survival in 382 HCC patients without PVTT undergoing upfront LDLT (5-y OS 65%, P = 0.06; RFS 66%, P = 0.33, respectively).…

BACKGROUND: Critically ill cirrhotic patients are increasingly transplanted, but there is no consensus about futile liver transplantation (LT). Therefore, the decision to delay or deny LT is often extensively debated. These debates arise from different opinions of futility among transplant team members. This study aims to achieve a multinational and multidisciplinary consensus on the definition of futility in LT and to develop well-articulated criteria for not proceeding with LT due to futility. METHODS: Thirty-five international experts from anesthesiology/intensive care, hepatology, and transplant surgery were surveyed using the Delphi method. More than 70% of similar answers to a question were necessary to define agreement. RESULTS: The panel recommended patient and graft survival at 1 year after LT to define futility. Severe frailty and persistent fever or <72 hours of appropriate antimicrobial therapy in case of ongoing sepsis were considered reasons to delay LT. A simple assessment of the number of organs failing was considered the most appropriate way to decide whether LT…

Tacrolimus was discovered in 1984 and entered clinical use shortly thereafter, contributing to successful solid organ transplantation across the globe. In this review, we cover development of tacrolimus, its evolving clinical utility, and issues affecting its current usage. Since earliest use of this class of immunosuppressant, concerns for calcineurin-inhibitor toxicity have led to efforts to minimize or eliminate these agents in clinical regimens but with limited success. Current understanding of the role of tacrolimus focuses more on its efficacy in preventing graft rejection and graft loss. As we enter the fourth decade of tacrolimus use, newer studies utilizing novel combinations (as with the mammalian target of rapamycin inhibitor, everolimus, and T-cell costimulation blockade with belatacept) offer potential for enhanced benefits.

Because of the high demand of organs, the usage of marginal grafts has increased. These marginal organs have a higher risk of developing ischemia-reperfusion injury, which can lead to posttransplant complications. Ex situ machine perfusion (MP), compared with the traditional static cold storage, may better protect these organs from ischemia-reperfusion injury. In addition, MP can also act as a platform for dynamic administration of pharmacological agents or gene therapy to further improve transplant outcomes. Numerous therapeutic agents have been studied under both hypothermic (1-8°C) and normothermic settings. Here, we review all the therapeutics used during MP in different organ systems (lung, liver, kidney, heart). The major categories of therapeutic agents include vasodilators, mesenchymal stem cells, antiinflammatory agents, antiinfection agents, siRNA, and defatting agents. Numerous animal and clinical studies have examined MP therapeutic agents, some of which have even led to the successful reconditioning of discarded grafts. More clinical studies, especially randomized…

BACKGROUND: The regional impact of coronavirus disease 2019 on solid organ transplantation in the United States has not been fully evaluated. METHODS: A retrospective analysis of month-to-month trends on waitlist additions, waitlist deaths, and transplant surgeries between all United Network for Organ Sharing (UNOS) regions was performed. A linear regression model trained on historical data was used to estimate anticipated transplantation volume. RESULTS: All UNOS regions reported a decrease in total waitlist additions and transplant surgeries. The largest decreases in total transplants were identified in regions 1, 2, 6, and 9, with regions 2, 7, 8, and 9 noting the largest decrease in waitlist additions. Six of the 11 regions noted increases in waitlist deaths, with UNOS regions 9, 1, and 2, all located within the Northeast, noting the highest percent increase in waitlist deaths at 170%, 89%, and 54%, respectively. The largest reductions in solid organ transplantation and waitlist deaths were seen in kidney and lung transplantation. Current transplantation volume is significantly…

Although liver transplantation (LT) is the best treatment for patients with localized hepatocellular carcinoma (HCC), recurrence occurs in 6%-18% of patients. Several factors, particularly morphological criteria combined with dynamic parameters, known before LT modify this risk and combined in prediction models may be used to stratify patients at need of variable surveillance strategies. Additional variables though likely explain differences in recurrence rates in patients with the same pre-LT HCC status. One of these variables is possibly immunosuppression (IS). Once recurrence takes place, management is highly heterogenous. Within the International Liver Transplantation Society Consensus Conference on Liver Transplant Oncology, working group 4 aim was to analyze the data regarding posttransplant management of recipients undergoing LT for HCC. Three areas of research were considered: (1) cancer prediction models and surveillance strategies; (2) tailored IS for cancer recipients; and (3) new adjuvant therapies for HCC recurrence. Following formulation of several questions, a…

BACKGROUND: Currently, no surveillance guidelines for hepatocellular carcinoma (HCC) recurrence after liver transplantation (LT) exist. In this retrospective, multicenter study, we have investigated the role of surveillance imaging on postrecurrence outcomes. METHODS: Patients with recurrent HCC after LT from 2002 to 2016 were reviewed from 3 transplant centers (University of California San Francisco, Mayo Clinic Florida, and University of Toronto). For this study, we proposed the term cumulative exposure to surveillance (CETS) as a way to define the cumulative sum of all the protected intervals that each surveillance test provides. In our analysis, CETS has been treated as a continuous variable in months. RESULTS: Two hundred twenty-three patients from 3 centers had recurrent HCC post-LT. The median follow-up was 31.3 months, and median time to recurrence was 13.3 months. Increasing CETS was associated with improved postrecurrence survival (hazard ratio, 0.94; P < 0.01) as was treatment of recurrence with resection or ablation (hazard ratio, 0.31; P < 0.001). An receiver operating…

BACKGROUND: Solid organ transplant (SOT) recipients are considered to be "vulnerable" to COVID-19 infection due to immunosuppression. To date, there are no studies that compared the disease severity of COVID-19 in SOT recipients with nontransplant patients. METHODS: In this case-control study, we compared the outcomes of COVID-19 between SOT recipients and their matched nontransplant controls. The cases were all adult SOT recipients (N = 41) from our academic health center who were diagnosed with COVID-19 between March 10, 2020 and May 15, 2020 using positive reverse transcriptase polymerase chain reaction for SARS-CoV2. The controls (N = 121) were matched on age (±5 y), race, and admission status (hospital or outpatient). The primary outcome was death and secondary outcomes were severe disease, intubation and renal replacement therapy (RRT). RESULTS: Median age of SOT recipients (9 heart, 3 lung, 16 kidney, 8 liver, and 5 dual organ) was 60 y, 80% were male and 67% were Black. Severe disease adjusted risk of death was similar in both the groups (hazard ratio = 0.84 [0.32-2.20]).…

BACKGROUND: Although graft loss is a primary endpoint in many studies in kidney transplantation and a broad spectrum of risk factors has been identified, the eventual causes of graft failure in individual cases remain ill studied. METHODS: We performed a single-center cohort study in 1000 renal allograft recipients, transplanted between March 2004 and February 2013. RESULTS: In total, 365 graft losses (36.5%) were identified, of which 211 (57.8%) were due to recipient death with a functioning graft and 154 (42.2%) to graft failure defined as return to dialysis or retransplantation. The main causes of recipient death were malignancy, infections, and cardiovascular disease. The main causes of graft failure were distinct for early failures, where structural issues and primary nonfunction prevailed, compared to later failures with a shift towards chronic injury. In contrast to the main focus of current research efforts, pure alloimmune causes accounted for only 17.5% of graft failures and only 7.4% of overall graft losses, although 72.7% of cases with chronic injury as presumed reason…

BACKGROUND: Coronavirus infectious disease 2019 (COVID-19) pandemic has posed at risk the kidney transplant (KT) population. We describe clinical pictures, risk factors for death, and chances to recovery in a large cohort of KT recipients with COVID-19. METHODS: Inclusion in a Spanish prospectively filled registry was allowed for KT cases with confirmed COVID-19. Outcomes were assessed as in-hospital mortality or recovery. RESULTS: The study population comprised of 414 patients. Fever, respiratory symptoms, and dyspnea were the most frequent COVID-19-related symptoms, and 81.4% of them had pneumonia. More than one-third of patients showed digestive symptoms at diagnosis, combinations of nausea, vomiting, and diarrhea. Most patients were hospitalized, 12.1% in intensive care units, and 17.6% needed ventilator support. Treatment for COVID-19 included frequently hydroxychloroquine, azithromycin, high-dose steroids, lopinavir/ritonavir, and tocilizumab. After a mean follow-up of 44 days, the fatality rate was 26.3%. Pneumonia without gastrointestinal symptoms was associated with a 36.3%…

Interleukin-6 (IL-6) is a cytokine with critical innate and adaptive immunity functions. Its diverse immunological and physiological actions include direction of immune cell differentiation, initial response to invading pathogens and ischemic injury, sustained plasma cell growth, and immunoglobulin production. IL-6 transcriptional dysregulation is commonly seen in patients with autoimmune or inflammatory disorders. Emerging information suggests that IL-6 transcription is upregulated in patients with kidney and heart transplant rejection and may account for perpetuation of inflammatory responses in the allograft, leading to allograft rejection and vasculopathy. IL-6-directed therapeutics include monoclonal antibodies directed at IL-6, the IL-6 receptor (IL-6R), and Janus kinase inhibitors. IL-6-mediated signaling to cell targets is unique, involving classic signaling (IL-6->IL-6R) cell membrane receptors, transsignaling (IL-6->soluble IL-6R->gp130) which activates any cell, and the recently discovered IL-6/IL-6R transpresentation in which antigen-presenting cells synthesize and…

BACKGROUND: Intraoperative fluid management may affect the outcome after kidney transplantation. However, the amount and type of fluid administered, and monitoring techniques vary greatly between institutions and there are limited prospective randomized trials and meta-analyses to guide fluid management in kidney transplant recipients. METHODS: Members of the American Society of Anesthesiologists (ASA) committee on transplantation reviewed the current literature on the amount and type of fluids (albumin, starches, 0.9% saline, and balanced crystalloid solutions) administered and the different monitors used to assess fluid status, resulting in this consensus statement with recommendations based on the best available evidence. RESULTS: Review of the current literature suggests that starch solutions are associated with increased risk of renal injury in randomized trials and should be avoided in kidney donors and recipients. There is no evidence supporting the routine use of albumin solutions in kidney transplants. Balanced crystalloid solutions such as Lactated Ringer are associated…

BACKGROUND: Uterus transplantation is a treatment for absolute uterine infertility and can be performed with living and deceased donors. Given the safety and increased utilization of robotic assistance with other gynecologic and transplant donor operations, we adopted a robot-assisted approach to donor hysterectomy. This study compared early outcomes and morbidity of the robot-assisted approach to donor hysterectomy with the traditionally performed open approach and addressed whether the robot-assisted approach is safe and offers advantages for the donor. METHODS: Our institution has performed 18 living donor hysterectomies for uterus transplantation. This retrospective review compared the last 5 cases utilizing a robot-assisted technique and vaginal extraction of the uterus graft with the first 13 cases performed with an open laparotomy technique. Demographic, intraoperative, and postoperative data were examined. RESULTS: There were no differences between the robot-assisted and the open living donor group with respect to age, body mass index, or gynecological history. Although the…

BACKGROUND: The epidemiological and clinical characteristics of solid organ transplant (SOT) patients during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) epidemic remains unclear. We conducted a matched retrospective cohort study to compare clinical outcomes among SOT recipients with the general population and to assess immunosuppression management. METHODS: Adult SOT recipients with laboratory polymerase chain reaction-confirmed SARS-CoV-2 infection admitted to a tertiary-care hospital in Barcelona, Spain, from March 11 to April 25, 2020, were matched to controls (1:4) on the basis of sex, age, and age-adjusted Charlson's Index. Patients were followed for up to 28 days from admission or until censored. Primary endpoint was mortality at 28 days. Secondary endpoints included admission to the intensive care unit and secondary complications. Drug-drug interactions (DDI) between immunosuppressants and coronavirus disease 2019 (COVID-19) management medication were collected. RESULTS: Forty-six transplant recipients and 166 control patients were included. Mean (SD) age…

Cell-free DNA (cfDNA) exists in plasma and can be measured by several techniques. It is now possible to differentiate donor-derived cfDNA (ddcfDNA) from recipient cfDNA in the plasma or urine of solid organ transplant recipients in the absence of donor and recipient genotyping. The assessment of ddcfDNA is being increasingly studied as a noninvasive means of identifying acute rejection (AR) in solid organ transplants, including subclinical AR. We herein review the literature on the correlation of ddcfDNA with AR in kidney transplantation. There have been at least 15 observational studies that have assessed ddcfDNA in urine or plasma using various methodologies with various thresholds for abnormality. Overall, elevated ddcfDNA indicates allograft injury as may occur with AR, infection, or acute tubular injury but may also be found in clinically stable patients with normal histology. Sensitivity is greater for antibody-mediated AR than for cell-mediated AR, and normal levels do not preclude significant cell-mediated rejection. Measurement of ddcfDNA is not a replacement for biopsy…

BACKGROUND: Intrahepatic cholangiocarcinoma (iCCA) is a contraindication to liver transplantation in most centers worldwide. Therefore, only a few such cases have been performed in each individual center, and the need for a systematic review and meta-analysis to cumulatively pool these results is apparent. METHODS: A systematic literature review was conducted using the MEDLINE and Cochrane Library databases according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement (end-of-search date: May 29, 2020). Meta-analyses of proportions were conducted to pool the overall survival (OS), recurrence-free survival (RFS), and overall recurrence rates using the random-effects model. Meta-regression was used to examine cirrhosis and incidental diagnosis as confounders on OS and RFS. RESULTS: Eighteen studies comprising 355 patients and a registry study of 385 patients were included. The pooled 1-, 3-, and 5-y OS rates were 75% (95% CI, 64%-84%), 56% (95% CI, 46%-67%), and 42% (95% CI, 29%-55%), respectively. The pooled 1-, 3-, and 5-y RFS rates were 70% (95% CI,…

Critical patients of coronavirus disease (COVID-19) have worse outcomes and higher mortality. Recent reports have shown pathologic findings of COVID-19, whereas these tissues were taken from postmortem evaluation.1 Information on histologic findings of COVID outside of the autopsy setting is limited. As far as we know, this is the first case about pathologic findings of critical COVID-19 underwent lung transplantation, which was predescribed on February 27, 2020.2 The 66-y-old patient presented with high fever and cough when he reached Shenzhen city from the Wuhan epidemic on January 4, 2020. On admission, the viral infection was verified by nasal swab and bronchial alveolar lavage fluids through qRT-PCR (GeneoDX Co., Ltd., Shanghai). The brightness of the lungs was increased and multiple shadows were observed by chest computed tomography. This patient had no preexisting interstitial lung disease. He had progressive deterioration from mild to critical condition during the 45-d duration, which was accompanied by increased plasma levels of IL-6 (range, 9.6–5000.0 pg/mL), CD4+T (range,…

Despite improvements in postliver transplant outcomes through refinements in perioperative management and surgical techniques, several changing trends in liver transplantation have presented challenges. Mortality on the waitlist remains high. In the United States, Europe, and the United Kingdom, there is an increasing need for liver transplantation, primarily as a result of increased incidence of nonalcoholic steatohepatitis-related cirrhosis and cancer indications. Meanwhile, donor suitability has decreased, as donors are often older and have more comorbidities. Despite a mismatch between organ need and availability, many organs are discarded. Notwithstanding this, many solutions have been developed to overcome these challenges. Innovative techniques in allograft preservation, viability assessment, and reconditioning have allowed the use of suboptimal organs with adequate results. Refinements in surgical procedures, including live donor liver transplantations, have increased the organ pool and are decreasing the time and mortality on the waitlist. Despite many challenges, a similar…

BACKGROUND: Neighborhood socioeconomic deprivation is associated with adverse health outcomes. We sought to determine if neighborhood socioeconomic deprivation was associated with adherence to immunosuppressive medications after liver transplantation. METHODS: We conducted a secondary analysis of a multicenter, prospective cohort of children enrolled in the medication adherence in children who had a liver transplant study (enrollment 2010-2013). Participants (N = 271) received a liver transplant ≥1 year before enrollment and were subsequently treated with tacrolimus. The primary exposure, connected to geocoded participant home addresses, was a neighborhood socioeconomic deprivation index (range 0-1, higher indicates more deprivation). The primary outcome was the medication level variability index (MLVI), a surrogate measure of adherence to immunosuppression in pediatric liver transplant recipients. Higher MLVI indicates worse adherence behavior; values ≥2.5 are predictive of late allograft rejection. RESULTS: There was a 5% increase in MLVI for each 0.1 increase in deprivation index…

Uncontrolled donation after circulatory death (uDCD) refers to donation from persons who die following an unexpected and unsuccessfully resuscitated cardiac arrest. Despite the large potential for uDCD, programs of this kind only exist in a reduced number of countries with a limited activity. Barriers to uDCD are of a logistical and ethical-legal nature, as well as arising from the lack of confidence in the results of transplants from uDCD donors. The procedure needs to be designed to reduce and limit the impact of the prolonged warm ischemia inherent to the uDCD process, and to deal with the ethical issues that this practice poses: termination of advanced cardiopulmonary resuscitation, extension of advanced cardiopulmonary resuscitation beyond futility for organ preservation, moment to approach families to discuss donation opportunities, criteria for the determination of death, or the use of normothermic regional perfusion for the in situ preservation of organs. Although the incidence of primary nonfunction and delayed graft function is higher with organs obtained from uDCD donors,…

Liver transplantation (LT) has revolutionized outcomes for cirrhotic patients. Current liver allocation policies dictate patients with highest short-term mortality receive the highest priority, thus, several patients become increasingly ill on the waitlist. Given cirrhosis is a progressive disease, it can be complicated by the occurrence of acute-on-chronic liver failure (ACLF), a syndrome defined by an acute deterioration of liver function associated with extrahepatic organ failures requiring intensive care support and a high short-term mortality. Successfully bridging to transplant includes accurate prognostication and prioritization of ACLF patients awaiting LT, optimizing intensive care support pre-LT, and tailoring immunosuppressive and anti-infective therapies post-LT. Furthermore, predicting futility (too sick to undergo LT) in ACLF is challenging. In this review, we summarize the role of LT in ACLF specifically highlighting (a) current prognostic scores in ACLF, (b) critical care management of the ACLF patient awaiting LT, (c) donor issues to consider in transplant in ACLF,…

BACKGROUND: Spain has been amongst the countries most affected by the COVID-19 pandemic, which has posed significant challenges to the donation and transplantation program. Despite a dramatic decrease of donation and transplantation activities during the critical early weeks of the outbreak, the program has recovered and is learning to cope with COVID-19. METHODS: We describe the 4 pillars upon which the Spanish donation and transplantation program has been rebuilt. RESULTS: (1) Standards have been developed and progressively updated for the evaluation and selection of potential donors and recipients with regards to SARS-CoV-2 infection. (2) Spain has been actively generating evidence to assess the validity of our standards and to understand the natural history of the infection in transplant recipients. No case of donor-derived COVID-19 has been reported to date. COVID-19 has been more frequent and has had a more aggressive course in recipients of solid organ transplants than in the general population, but this seems largely explained by the demographics and comorbidity of…

The use of artificial intelligence and machine learning (ML) has revolutionized our daily lives and will soon be instrumental in healthcare delivery. The rise of ML is due to multiple factors: increasing access to massive datasets, exponential increases in processing power, and key algorithmic developments that allow ML models to tackle increasingly challenging questions. Progressively more transplantation research is exploring the potential utility of ML models throughout the patient journey, although this has not yet widely transitioned into the clinical domain. In this review, we explore common approaches used in ML in solid organ clinical transplantation and consider opportunities for ML to help clinicians and patients. We discuss ways in which ML can aid leverage of large complex datasets, generate cutting-edge prediction models, perform clinical image analysis, discover novel markers in molecular data, and fuse datasets to generate novel insights in modern transplantation practice. We focus on key areas in transplantation in which ML is driving progress, explore the future…

BACKGROUND: Cystatin C (CysC) is an early biomarker of renal dysfunction scarcely studied in patients awaiting liver transplantation (LT). Sarcopenia is frequent in cirrhosis and impacts prognosis. We aimed to assess the capability of these factors to predict survival and acute-on-chronic liver failure (ACLF) in patients awaiting LT, as well as early post-LT outcomes. METHODS: Single-center study that included all cirrhotic patients listed for LT between 2014 and 2017. Competing risk regression analysis was used to evaluate the capability of liver-, kidney-, and global status-related variables at waitlist (WL) inclusion to predict WL mortality and ACLF. Variables associated with post-LT outcomes were evaluated with logistic regression analysis. RESULTS: One-hundred-and-eighty patients were included. Fifty-six (31%) patients developed ACLF, 54 (30%) underwent LT and 35 (19%) died. In the adjusted competing risk regression analysis, CysC ≥ 1.5 mg/L, sarcopenia and MELD-Na were independent predictors of ACLF in the WL, while CysC ≥ 1.5 mg/L, sarcopenia and albumin were independent…

BACKGROUND: Facial vascularized composite allotransplantation (fVCA) presents an established approach to restore form and function of patients with catastrophic facial defects. Skin is one of the target tissues of the rejection process, and due to its easy accessibility has become the gold standard in the diagnosis of rejection. Mucosal rejection frequently occurs; however, the added value of mucosal rejection assessment for patient management is unknown. METHODS: We conducted a systematic review of manuscripts listed in the MEDLINE/PubMed and GoogleScholar databases to identify articles that provide data on mucosal rejection following fVCA. For inclusion, papers had to be available as full-text and written in English. Non-VCA studies and animal studies were excluded. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. RESULTS: We included 17 articles that described changes in allotransplanted mucosa of fVCAs. These articles yielded data on 168 BANFF graded biopsies of corresponding skin and mucosa biopsies. Rejection grades were…

BACKGROUND: Donor-derived cell-free DNA (dd-cfDNA) is a potential noninvasive molecular marker of graft rejection after kidney transplant, whose diagnostic accuracy remains controversial. METHODS: We performed a systematic review and metaanalysis to evaluate the diagnostic accuracy of dd-cfDNA. Relevant literature was searched from online databases, and the data on the diagnostic accuracy of discriminating main rejection episodes (MRE) and antibody-mediated rejection (AMR) were merged, respectively. RESULTS: Nine studies were included in the metaanalysis, of which 6 were focused on the diagnostic accuracy of dd-cfDNA for MRE, whose pooled sensitivity, specificity, area under the receiver operating characteristics curve, diagnostic odds ratio, overall positive likelihood ratio, and negative likelihood ratio with 95% confidence intervals were 0.70 (0.57-0.81), 0.78 (0.70-0.84), 0.81 (0.77-0.84), 8.18 (5.11-13.09), 3.15 (2.47-4.02), and 0.39 (0.27-0.55), respectively. Five tests were focused on discriminating AMR, whose pooled indicators were 0.84 (0.75-0.90), 0.80 (0.74-0.84), 0.89…

BACKGROUND: The number of patients awaiting liver transplantation (LT) in Spain has halved from 2015 to 2019 due to the reduction of candidates with hepatitis C and the successful implementation of nonheart beating donation programs across the country. The Spanish Society for Liver Transplantation has committed to take advantage of this situation by developing consensus around potential areas to expand the current indications for LT. The consensus group was composed of 6 coordinators and 23 expert delegates, each one representing an LT institution in Spain. METHODS: A modified Delphi approach was used to identify areas to expand indications for LT and to build consensus around paramount aspects, such as inclusion criteria and waitlist prioritization within each area. The scientific evidence and strength of recommendations were assessed by the "Grading of Recommendations Assessment, Development, and Evaluation" system. RESULTS: The consensus process resulted in the identification of 7 potential areas to expand criteria in LT: recipient's age, hepatocellular carcinoma, alcoholic…

BACKGROUND: Solid organ transplant (SOT) recipients may be more vulnerable to coronavirus disease 2019 (COVID-19). Data on the clinical course of COVID-19 in immunosuppressed patients are limited, and the optimal management strategy for these patients is yet unclear. METHODS: We present 53 SOT recipients (31 kidney transplant recipients, 8 liver transplant recipients, 5 heart transplant recipients, 5 lung transplant recipients, 3 liver-kidney transplant recipients, and 1 kidney-after-heart transplant recipient), transplanted at a Swedish high-volume transplant center and each diagnosed with COVID-19 between February 21, 2020 and June 22, 2020. Demographic, clinical, and treatment data were extracted from the electronic patient files. RESULTS: Patients reported fever (61%), cough (43%), diarrhea (31%), and upper respiratory symptoms (29%). The median age was 56 years, and 57% were male. According to severity, 55% had mild, 13% had moderate, 19% had severe, and 13% had critical disease. Thirty-seven patients (70%) were hospitalized, with 8 requiring intensive care. Thirteen of the 37…

Advances in genetic engineering, particularly CRISPR/Cas9, have resulted in the development of a triple glycan-knockout (TKO) pig. There is minimal human antipig antibody binding to TKO pig cells. The TKO background has decreased antibody binding to a sufficiently low level that any additional xenoantigens expressed on the cells can now be more easily detected. One of these xenoantigens is the swine major histocompatibility complex, termed swine leukocyte antigens (SLA). SLA are the homolog to HLAs, a protein complex expressed on human tissue capable of stimulating the development of new antibodies in allotransplantation. These antibodies can result in graft failure through hyperacute, acute, or chronic rejection. Our knowledge of SLA, particularly in the last 5 years, has grown considerably. The presence, cause, and methods to detect anti-SLA antibodies will need to be carefully considered for the first clinical trial of xenotransplantation. The focus of this review is to summarize the role of SLA in xenotransplantation and consider whether it will prove to be a major barrier.…

BACKGROUND: The risk of COVID-19 infection in transplant recipients (TRs) is unknown. Patients on dialysis may be exposed to greater risk of infection due to an inability to isolate. Consideration of these competing risks is important before restarting suspended transplant programs. This study compared outcomes in kidney and kidney/pancreas TRs with those on the waiting list, following admission with COVID-19 in a high-prevalence region. METHODS: Audit data from all 6 London transplant centers were amalgamated. Demographic and laboratory data were collected and outcomes included mortality, intensive care (ITU) admission, and ventilation. Adult patients who had undergone a kidney or kidney/pancreas transplant, and those active on the transplant waiting list at the start of the pandemic were included. RESULTS: One hundred twenty-one TRs and 52 waiting list patients (WL) were admitted to hospital with COVID-19. Thirty-six TR died (30%), while 14 WL patients died (27% P = 0.71). There was no difference in rates of admission to ITU or ventilation. Twenty-four percent of TR required renal…

BACKGROUND: Xenogeneic organ transplantation has been proposed as a potential approach to fundamentally solve organ shortage problem. Xenogeneic immune responses across species is one of the major obstacles for clinic application of xeno-organ transplantation. The generation of glycoprotein galactosyltransferase α 1, 3 (GGTA1) knockout pigs has greatly contributed to the reduction of hyperacute xenograft rejection. However, severe xenograft rejection can still be induced by xenoimmune responses to the porcine major histocompatibility complex antigens swine leukocyte antigen class I and class II. METHODS: We simultaneously depleted GGTA1, β2-microglobulin (β2M), and major histocompatibility complex class II transactivator (CIITA) genes using clustered regularly interspaced short palindromic repeats and CRISPR-associated proteins technology in Bamma pig fibroblast cells, which were further used to generate GGTA1β2MCIITA triple knockout (GBC-3KO) pigs by nuclear transfer. RESULTS: The genotype of GBC-3KO pigs was confirmed by polymerase chain reaction and Sanger sequencing, and the…

The humanization of animals is a powerful tool for the exploration of human disease pathogenesis in biomedical research, as well as for the development of therapeutic interventions with enhanced translational potential. Humanized models enable us to overcome biologic differences that exist between humans and other species, while giving us a platform to study human processes in vivo. To become humanized, an immune-deficient recipient is engrafted with cells, tissues, or organoids. The mouse is the most well studied of these hosts, with a variety of immunodeficient strains available for various specific uses. More recently, efforts have turned to the humanization of other animal species such as the rat, which offers some technical and immunologic advantages over mice. These advances, together with ongoing developments in the incorporation of human transgenes and additional mutations in humanized mouse models, have expanded our opportunities to replicate aspects of human allotransplantation and to assist in the development of immunotherapies. In this review, the immune and tissue…

BACKGROUND: There is a growing interest in left lateral sectionectomy for donor hepatectomy. No data are available concerning the safety of the robotic (ROB) approach. METHODS: A retrospective comparative study was conducted on 75 consecutive minimally invasive donor hepatectomies. The first 25 ROB procedures performed from November 2018 to July 2019 were compared with our first (LAP1) and last 25 (LAP2) laparoscopic cases performed between May 2013 and October 2018. Short-term donors and recipients' outcomes were analyzed. RESULTS: No conversions were noticed in ROB whereas 2 conversions (8%) were recorded in LAP1 and none in LAP2. Blood loss was significantly less in ROB compared with LAP1 (P ≤ 0.001) but not in LAP2. Warm ischemia time was longer in ROB (P ≤ 0.001) with respect to the other groups. Operative time was similar in the 3 groups (P = 0.080); however, the hospital stay was shorter in ROB (P = 0.048). The trend in operative time in ROB was significantly shorter compared to LAP1 and LAP2: linear R2 0.478, P≤0.001; R2 0.012, P = 0.596; R3 0.004, P = 0.772, respectively.…

Liver transplantation (LT) for unresectable colorectal liver metastases has long been abandoned because of dismal prognoses. After the dark ages, advances in chemotherapy and diagnostic imaging have enabled strict patient selection, and the pioneering study from the Oslo group has contributed to the substantial progress in this field. For unresectable neuroendocrine liver metastases, LT for patients who met the Milan criteria was able to achieve excellent long-term outcomes. The guidelines further adopted in the United States and Europe were based on these criteria. For hepatoblastoma, patients with unresectable and borderline-resectable disease are considered good candidates for LT; however, the indications are yet to be defined. In the budding era of transplant oncology, it is critically important to recognize the current status and unsolved questions for each disease entity. These guidelines were developed to serve as a beacon of light for optimal patient selection for LT and set the stage for future basic and clinical studies.

BACKGROUND: Portopulmonary hypertension (POPH) is the presence of pulmonary arterial (PA) hypertension in patients with portal hypertension and is associated with significant morbidity and mortality. In a cohort of POPH patients, we describe the clinical outcomes of POPH patients who underwent liver transplantation (LT). METHODS: Retrospectively collected data from a prospectively assembled cohort of all consecutive POPH adults evaluated in 3 transplant centers from 1996 to 2019. RESULTS: From a cohort of 228 POPH patients, 50 patients underwent LT. Significant hemodynamic improvement after PA-targeted therapy was observed, with 58% receiving only monotherapy pretransplant. After LT, 21 (42%) patients were able to discontinue and remained off PA-targeted therapy. The 1-, 3-, and 5-y unadjusted survival rates after LT were 72%, 63%, and 60%, respectively. An elevated pulmonary vascular resistance (PVR) before LT was associated with worse survival rate (HR, 1.91; 95% CI, 1.07-3.74, P = 0.04). No survival difference was observed in those granted MELD exception or transplants performed…

BACKGROUND: Liver graft viability assessment has long been considered a limit of hypothermic oxygenated machine perfusion (HOPE). Aim of this study was assessing correlations of easily available perfusate parameters (PP) (aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, glucose, lactate, and pH) with graft features and outcome. METHODS: In the period October 2018-February 2020, perfusate samples were obtained every 30 minutes during 50 dual-HOPE (D-HOPE) procedures. Correlations of PP with graft factors, 90-day graft loss, early allograft dysfunction (EAD), L-GrAFT score, acute kidney injury, and comprehensive complication index were analyzed using Pearson coefficient, receiver-operating characteristics analysis and by univariable and multivariable regression. RESULTS: Median D-HOPE time was 122 minutes. All parameters were normalized to liver weight. Only macrovesicular steatosis (MaS) significantly impacted PP levels and slope. Grafts with ≥30% MaS exhibited significantly different PP values and slope. Graft loss and EAD rate were 2% (n = 1) and 26% (n…