Long-term persistence of seroprotection against measles following measles-mumps-rubella vaccination administered before and after pediatric liver transplantation.

Liver transplantation (LT) recipients are susceptible to infections, including measles. Concerns about the safety and efficacy of live-attenuated vaccines, such as the measles-mumps-rubella (MMR) vaccine, have led to hesitancy among providers in administering them to immunocompromised patients. This 9-year interventional study assessed seroprotection against measles following MMR vaccination in pediatric LT recipients. Of 119 participants enrolled, 60 (50%) were seroprotected against measles after transplantation. Among the 59 nonseroprotected participants, 56 fulfilled safety criteria and received MMR vaccination with a seroprotection rate of 90% (95% confidence interval [CI], 73%-98%) after a first dose, 95% (95% CI, 85%-99%) after primary vaccination with 1 to 3 doses, comparable to nonimmunocompromized populations. However, measles antibodies declined over time, suggesting the need for regular monitoring, and booster doses. Half of the vaccinees (26/53, 49%) subsequently lost seroprotection. Among them, 23 received additional doses of MMR, with a high seroconversion rate. At their last follow-up (median, 6.1 years; interquartile range, 3.0-8.1 after inclusion), 63% (95% CI, 49%-75%) of all vaccinees were seroprotected against measles. In conclusion, MMR vaccination in pediatric LT recipients offers seroprotection against measles, but long-term immunity should be monitored closely.

Ambient air pollution is associated with graft failure/death in pediatric liver transplant recipients.

Children exposed to disproportionately higher levels of air pollution experience worse health outcomes. In this population-based, observational registry study, we examine the association between air pollution and graft failure/death in children following liver transplantation (LT) in the US. We modeled the associations between air pollution (PM2.5) levels localized to the patient's ZIP code at the time of transplant and graft failure or death using Cox proportional-hazards models in pediatric LT recipients aged <19 years in the US from 2005-2015. In univariable analysis, high neighborhood PM2.5 was associated with a 56% increased hazard of graft failure/death (HR: 1.56; 95% CI: 1.32, 1.83; P < .001). In multivariable analysis, high neighborhood PM2.5 was associated with a 54% increased risk of graft failure/death (HR: 1.54; 95% CI: 1.29, 1.83; P < .001) after adjusting for race as a proxy for racism, insurance status, rurality, and neighborhood socioeconomic deprivation. Children living in high air pollution neighborhoods have an increased risk of graft failure and death posttransplant, even after controlling for sociodemographic variables. Our findings add further evidence that air pollution contributes to adverse health outcomes for children posttransplant and lay the groundwork for future studies to evaluate underlying mechanisms linking PM2.5 to adverse LT outcomes.

Normalization of lipid oxidation defects arising from hypoxia early posthepatectomy prevents liver failure in mouse.

Surgical liver failure (SLF) develops when a marginal amount of hepatic mass is left after surgery, such as following excessive resection. SLF is the commonest cause of death due to liver surgery; however, its etiology remains obscure. Using mouse models of standard hepatectomy (sHx) (68%, resulting in full regeneration) or extended hepatectomy (eHx) (86%/91%, causing SLF), we explored the causes of early SLF related to portal hyperafflux. Assessing the levels of HIF2A with or without oxygenating agent inositol trispyrophosphate (ITPP) indicated hypoxia early after eHx. Subsequently, lipid oxidation (PPARA/PGC1α) was downregulated and associated with persisting steatosis. Mild oxidation with low-dose ITPP reduced the levels of HIF2A, restored downstream PPARA/PGC1α expression along with lipid oxidation activities (LOAs), and normalized steatosis and other metabolic or regenerative SLF deficiencies. Promotion of LOA with L-carnitine likewise normalized the SLF phenotype, and both ITPP and L-carnitine markedly raised survival in lethal SLF. In patients who underwent hepatectomy, pronounced increases in serum carnitine levels (reflecting LOA) were associated with better recovery. Lipid oxidation thus provides a link between the hyperafflux of O2-poor portal blood, the metabolic/regenerative deficits, and the increased mortality typifying SLF. Stimulation of lipid oxidation-the prime regenerative energy source-particularly through L-carnitine may offer a safe and feasible way to reduce SLF risks in the clinic.

Lymphopenia at the time of transplant is associated with short-term mortality after deceased donor liver transplantation.

Absolute lymphocyte count (ALC) is considered a surrogate marker for nutritional status and immunocompetence. We investigated the association between ALC and post-liver transplant outcomes in patients who received a deceased donor liver transplant (DDLT). Patients were categorized by ALC at liver transplant: low (<500/µL), mid (500-1000/µL), and high ALC (>1000/µL). Our main analysis used retrospective data (2013-2018) for DDLT recipients from Henry Ford Hospital (United States); the results were further validated using data from the Toronto General Hospital (Canada). Among 449 DDLT recipients, the low ALC group demonstrated higher 180-day mortality than mid and high ALC groups (83.1% vs 95.8% and 97.4%, respectively; low vs mid: P = .001; low vs high: P < .001). A larger proportion of patients with low ALC died of sepsis compared with the combined mid/high groups (9.1% vs 0.8%; P < .001). In multivariable analysis, pretransplant ALC was associated with 180-day mortality (hazard ratio, 0.20; P = .004). Patients with low ALC had higher rates of bacteremia (22.7% vs 8.1%; P < .001) and cytomegaloviremia (15.2% vs 6.8%; P = .03) than patients with mid/high ALC. Low ALC pretransplant through postoperative day 30 was associated with 180-day mortality among patients who received rabbit antithymocyte globulin induction (P = .001). Pretransplant lymphopenia is associated with short-term mortality and a higher incidence of posttransplant infections in DDLT patients.

Heart-liver-kidney transplantation for AL amyloidosis using normothermic recovery and storage from a donor following circulatory death: Short-term outcome in a first-in-world experience.

AL amyloidosis is a rare condition characterized by the overproduction of an unstable free light chain, protein misfolding and aggregation, and extracellular deposition that can progress to multiorgan involvement and failure. To our knowledge, this is the first worldwide report to describe triple organ transplantation for AL amyloidosis and triple organ transplantation using thoracoabdominal normothermic regional perfusion recovery with a donation from a circulatory death (DCD) donor. The recipient was a 40-year-old man with multiorgan AL amyloidosis with a terminal prognosis without multiorgan transplantation. An appropriate DCD donor was selected for sequential heart, liver, and kidney transplants via our center's thoracoabdominal normothermic regional perfusion pathway. The liver was additionally placed on an ex vivo normothermic machine perfusion, and the kidney was maintained on hypothermic machine perfusion while awaiting implantation. The heart transplant was completed first (cold ischemic time [CIT]: 131 minutes), followed by the liver transplant (CIT: 87 minutes, normothermic machine perfusion: 301 minutes). Kidney transplantation was performed the following day (CIT: 1833 minutes). He is 8 months posttransplant without evidence of heart, liver, or kidney graft dysfunction or rejection. This case highlights the feasibility of normothermic recovery and storage modalities for DCD donors, which can expand transplant opportunities for allografts previously not considered for multiorgan transplantations.

Acute liver failure and unique challenges of pediatric liver transplantation amidst a worldwide cluster of adenovirus-associated hepatitis.

Investigation into a recent cluster of acute hepatitis in children from the southeastern United States identified human adenovirus (HAdV) DNAemia in all 9 cases. Molecular genotyping in 5 of 9 (56%) children identified HAdV type 41 in all cases (100%). Importantly, 2 children from this cluster progressed rapidly to pediatric acute liver failure (PALF) and required liver transplantation. HAdV type 41, a known cause of self-limited gastroenteritis, has not previously been associated with severe cholestatic hepatitis and liver failure in healthy children. Adenovirus polymerase chain reaction assay and sequencing of amplicons performed on DNA extracted from formalin-fixed, paraffin-embedded liver tissue also identified adenovirus species F (HAdV type 40 or 41) in these 2 children with PALF. Transplant considerations and successful liver transplantation in such situations remain scarce. In this report, we describe the clinical course, laboratory results, liver pathology, and treatment of 2 children with PALF associated with HAdV type 41, one of whom developed secondary hemophagocytic lymphohistiocytosis. Their successful posttransplant outcomes demonstrate the importance of early multidisciplinary medical management and the feasibility of liver transplantation in some children with PALF and HAdV DNAemia.

Living donor liver paired exchange between pediatric and adult recipients due to donor graft size mismatch.

Living donor liver transplantation is an effective means to decrease organ shortage. However, many potential living donors are currently being denied due to ABO incompatibility or inadequate donor liver volume. Liver paired exchange (LPE) provides a practical solution to overcome these obstacles, and yet the first case of LPE in the United States was only recently reported in 2020. Here, we report world's first case of LPE involving pediatric and adult recipients to avoid surgical complexity of the pediatric recipient and to increase the graft-to-recipient weight ratio of the adult recipient between 2 ABO compatible pairs. As living donor liver transplantation becomes more widely adopted, the need for pair exchange to improve surgical safety and postoperative outcomes between 2 ABO compatible pairs is likely to increase.

miR-449a ameliorates acute rejection after liver transplantation via targeting procollagen-lysine1,2-oxoglutarate5-dioxygenase 1 in macrophages.

Acute rejection (AR) is an important factor that leads to poor prognosis after liver transplantation (LT). Macrophage M1-polarization is an important mechanism in AR development. MicroRNAs play vital roles in disease regulation; however, their effects on macrophages and AR remain unclear. In this study, rat models of AR were established following LT, and macrophages and peripheral blood mononuclear cells were isolated from rats and humans, respectively. We found miR-449a expression to be significantly reduced in macrophages and peripheral blood mononuclear cells. Overexpression of miR-449a not only inhibited the M1-polarization of macrophages in vitro but also improved the AR of transplant in vivo. The mechanism involved inhibiting the noncanonical nuclear factor-kappaB (NF-κB) pathway. We identified procollagen-lysine1,2-oxoglutarate5-dioxygenase 1 (PLOD1) as a target gene of miR-449a, which could reverse miR-449a's inhibition of macrophage M1-polarization, amelioration of AR, and inhibition of the NF-κB pathway. Overall, miR-449a inhibited the NF-κB pathway in macrophages through PLOD1 and also inhibited the M1-polarization of macrophages, thus attenuating AR after LT. In conclusion, miR-449a and PLOD1 may be new targets for the prevention and mitigation of AR.

Preliminary safety and efficacy of laser stricturotomy for treatment of refractory biliary anastomotic strictures following liver transplantation.

Biliary anastomotic stricture (BAS) is a frequent complication of liver transplantation and is associated with reduced graft survival and patient morbidity. Existing treatments for BAS involve dilation of the stricture though placement of 1 or more catheters for 6 to 24 months yielding limited effectiveness in transplant patients. In this case series, we present preliminary safety and efficacy of a novel percutaneous laser stricturotomy treatment in a cohort of 5 posttransplant patients with BAS refractory to long-term large bore catheterization. In all patients, holmium or thulium laser was used to excise the stricture and promote biliary re-epithelization. There were no periprocedural complications. Technical success was 100% and at mean follow-up time of 22 months, there have been no recurrences. In conclusion, percutaneous laser stricturotomy demonstrates preliminary safety and efficacy in treatment of refractory BAS following liver transplantation.

Single-center analysis of organ offers and workload for liver and kidney allocation.

The volume of abdominal organ offers received by the Baylor Simmons Transplant Institute has increased over time, resulting in a higher workload for our donor call team. To quantify the increase in organ offers, determine the characteristics of these offers, and estimate the impact on our transplant center workload, we collected center-specific organ offer data from May 2019 to July 2021 using the UNOS Center Acceptance and Refusal Evaluation Report and performed a time study that collected the number of communications and time spent on communications for organ offers made during a typical week. The total offers per month increased by 140% (270/month to 648/month), while the number of transplanted organs remained stable. In addition, the percentage of offers for organs that were never transplanted increased from 54% to 75%. In a representative week-long time study, surgeons made 505, center coordinators 590, and answering service coordinators 318 distinct communications, averaging 3, 4, and 2 communications/hour. Between November 2019 and July 2021, offer-related workload increased by an estimated 97%. These results demonstrate a sizeable inefficiency in abdominal organ allocation associated with a nonrecoverable cost to our transplant center.

Awarding additional MELD points to the shortest waitlist candidates improves sex disparity in access to liver transplant in the United States.

Since the introduction of the MELD-based allocation system, women are now 30% less likely than men to undergo liver transplant (LT) and have 20% higher waitlist mortality. These disparities are in large part due to height differences in men and women though no national policies have been implemented to reduce sex disparities. Patients were identified using the Scientific Registry of Transplant Recipients (SRTR) from 2014 to 2019. Patients were categorized into five groups by first dividing into thirds by height then dividing the shortest third into three groups to capture more granular differences in the most disadvantaged patients (<166 cm). We then used LSAM to model waitlist outcomes in five versions of awarding additional MELD points to shorter candidates compared to current policy. We identified two proposed policy changes LSAM scenarios that resulted in improvement in LT and death percentage for the shortest candidates with the least negative impact on taller candidates. In conclusion, awarding an additional 1-2 MELD points to the shortest 8% of LT candidates would improve waitlist outcomes for women. This strategy should be considered in national policy allocation to address sex-based disparities in LT.

Long-term outcomes of resection versus transplantation for neuroendocrine liver metastases meeting the Milan criteria.

Liver resection (LR) is considered the treatment of choice for resectable neuroendocrine liver metastases (NELM), while liver transplantation (LT) is currently reserved for highly selected unresectable patients. We retrospectively analyzed data from consecutive patients undergoing either curative resection or transplantation for liver-only NELM meeting Milan criteria at a single center between 1984 and 2019. Patients who fit Milan criteria were 48 in the transplantation group and 56 in the resection group. After a median follow-up of 158 months for the transplantation group and 126 for the resection group, the 10-year survival rate was 93% for transplantation and 75% for resection (p = .007). The 10-year disease-free survival rate was 52% for transplantation and 18% for resection (p < .001). Transplantation was associated with improved survival at univariate analysis. The median disease-free interval between surgery and recurrence was 78 months for transplantation vs. 24 months for resection (p < .001). The transplantation group had more multisite recurrences (12/25, 48% vs. 5/42, 12% in the resection group, p = .001), while most recurrences in the resection group were intra-hepatic (37/42, 88%, versus 2/25, 8% in the transplantation group). In conclusion, LT was associated with improved survival outcomes in NELM meeting the Milan criteria compared with LR.

Successful liver transplantation in patients with active SARS-CoV-2 infection.

The Coronavirus Disease 2019 (COVID-19) pandemic has substantially impacted solid organ transplantation, including temporary inactivation of waitlist candidates with COVID-19 infection. We report two cases of liver transplantation (LT) in individuals with asymptomatic COVID-19 infection. The first patient is a 68-year-old female with decompensated cirrhosis complicated by worsening frailty and sarcopenia. The second patient is a 22-year-old female with acute liver failure likely secondary to drug/toxin exposure. Both patients were treated with COVID-19-directed therapies and neither patient developed symptomatic disease. These cases demonstrate that LT can be safely performed in select patients with asymptomatic COVID-19 infection at the time of transplant.

Center-level and region-level variations in liver transplantation practices following acuity circles policy change.

Although early studies suggest the Acuity Circles (AC) allocation policy has increased access to deceased donor liver transplants (DDLTs) for patients with the highest MELD scores, changes in center- and region-level practices among patients with the highest MELD scores in response to AC are not well-characterized. OPTN/UNOS data were analyzed to compare center-level changes in the number of DDLTs based on allocation-MELD (aMELD) categories used for AC sharing performed in the 18-month periods before and after AC enactment on February 4, 2020. There was large center-level variation in the number and proportion of aMELD ≥ 37 DDLTs performed from pre-AC to AC period; 13 centers accounted for 196 of the 198 total net increase in aMELD ≥ 37 DDLTs performed after AC, 5 of these being from UNOS region 5. Similar center-level variation was seen for MELD 33-36 and MELD 29-32 DDLTs, with 17 centers and 14 centers, respectively, accounting for the entire net increase in DDLTs in the aMELD categories. In conclusion, AC increased access to livers for transplantation for high MELD patients nationally, but imbalances remain in transplant practice patterns at the center and regional levels. Longer-term study is necessary to assess effectiveness of AC in improving equitability of liver transplantations.

Adoptive immunotherapy overcomes genetic susceptibility to bloodstream infections due to fc-gamma receptor polymorphisms after liver transplantation.

Single nucleotide polymorphisms (SNPs) in FCGR3A can predict the susceptibility of liver transplant (LT) recipients to bloodstream infections (BSI) and clinical outcomes following living-donor LT (LDLT). Here, we retrospectively analyzed the relationship of adoptive immunotherapy with activated natural killer (NK) cells from perfusate effluents of liver allografts against BSI following LDLT. Higher BSI incidence and lower survival were observed in LT recipients with FcγRIIIa (158F/F or F/V) (n = 81) who did not receive adoptive immunotherapy (n = 55) than in those who did (n = 26) (BSI frequency, 36.4% vs. 11.5%; p = .033; log-rank p = .047). After matching patient background using propensity score, similar results were obtained (BSI ratio, 41.7% vs. 12.5%; p = .049; log-rank p = .039). The predominant BSI pathogens in patients who did and did not receive adoptive immunotherapy were gram-negative rods (n = 3, 100%) and gram-positive cocci (GPC) (n = 15, 65.2%), respectively. The proportion of NK cells administered to patients with BSI was significantly lower than that administered to patients without BSI (Number: 80.3 (29.9-239.2) × 106 cells vs. 37.1 (35.6-50.4) × 106 ; p = .033, percentage; 14.1 (13.3-17.8)% vs. 34.6 (16.5-47)%, p = .0078). Therefore, adoptive immunotherapy with NK cells was associated with the reduced post-transplant BSI related to GPCs due to FcγRIIIa SNP in LT recipients.