Single-cell, single-nucleus, and spatial transcriptomics characterization of the immunological landscape in the healthy and PSC human liver.

BACKGROUND & AIMS: Primary sclerosing cholangitis (PSC) is an immune-mediated cholestatic liver disease for which there is an unmet need to understand the cellular composition of the affected liver and how it underlies disease pathogenesis. We aimed to generate a comprehensive atlas of the PSC liver using multi-omic modalities and protein-based functional validation. METHODS: We employed single-cell and single-nucleus RNA sequencing (47,156 cells and 23,000 nuclei) and spatial transcriptomics (one sample by 10x Visium and five samples with Nanostring GeoMx DSP) to profile the cellular ecosystem in 10 PSC livers. Transcriptomic profiles were compared to 24 neurologically deceased donor livers (107,542 cells) and spatial transcriptomics controls, as well as 18,240 cells and 20,202 nuclei from three PBC livers. Flow cytometry was performed to validate PSC-specific differences in immune cell phenotype and function. RESULTS: PSC explants with parenchymal cirrhosis and prominent periductal fibrosis contained a population of cholangiocyte-like hepatocytes that were surrounded by diverse immune cell populations. PSC-associated biliary, mesenchymal, and endothelial populations expressed chemokine and cytokine transcripts involved in immune cell recruitment. Additionally, expanded CD4+ T cells and recruited myeloid populations in the PSC liver expressed the corresponding receptors to these chemokines and cytokines, suggesting potential recruitment. Tissue-resident macrophages, by contrast, were reduced in number and exhibited a dysfunctional and downregulated inflammatory response to lipopolysaccharide and interferon-γ stimulation. CONCLUSIONS: We present a comprehensive atlas of the PSC liver and demonstrate an exhaustion-like phenotype of myeloid cells and markers of chronic cytokine expression in late-stage PSC lesions. This atlas expands our understanding of the cellular complexity of PSC and has potential to guide the development of novel treatments. IMPACT AND IMPLICATIONS: Primary sclerosing cholangitis (PSC) is a rare liver disease characterized by chronic inflammation and irreparable damage to the bile ducts, which eventually results in liver failure. Due to a limited understanding of the underlying pathogenesis of disease, treatment options are limited. To address this, we sequenced healthy and diseased livers to compare the activity, interactions, and localization of immune and non-immune cells. This revealed that hepatocytes lining PSC scar regions co-express cholangiocyte markers, whereas immune cells infiltrate the scar lesions. Of these cells, macrophages, which typically contribute to tissue repair, were enriched in immunoregulatory genes and demonstrated a lack of responsiveness to stimulation. These cells may be involved in maintaining hepatic inflammation and could be a target for novel therapies.

Pursuing living donor liver transplantation improves outcomes of patients with autoimmune liver diseases: An intention-to-treat analysis.

Living donor liver transplantation (LDLT) offers the opportunity to decrease waitlist time and mortality for patients with autoimmune liver disease (AILD), autoimmune hepatitis, primary biliary cholangitis, and primary sclerosing cholangitis. We compared the survival of patients with a potential living donor (pLDLT) on the waitlist versus no potential living donor (pDDLT) on an intention-to-treat basis. Our retrospective cohort study investigated adults with AILD listed for a liver transplant in our program between 2000 and 2021. The pLDLT group comprised recipients with a potential living donor. Otherwise, they were included in the pDDLT group. Intention-to-treat survival was assessed from the time of listing. Of the 533 patients included, 244 (43.8%) had a potential living donor. Waitlist dropout was higher for the pDDLT groups among all AILDs (pDDLT 85 [29.4%] vs. pLDLT 9 [3.7%], p < 0.001). The 1-, 3-, and 5-year intention-to-treat survival rates were higher for pLDLT versus pDDLT among all AILDs (95.7% vs. 78.1%, 89.0% vs. 70.1%, and 87.1% vs. 65.5%, p < 0.001). After adjusting for covariates, pLDLT was associated with a 38% reduction in the risk of death among the AILD cohort (HR: 0.62, 95% CI: 0.42-0.93 [ p <0.05]), and 60% among the primary sclerosing cholangitis cohort (HR: 0.40, 95% CI: 0.22-0.74 [ p <0.05]). There were no differences in the 1-, 3-, and 5-year post-transplant survival between LDLT and DDLT (AILD: 95.6% vs. 92.1%, 89.9% vs. 89.4%, and 89.1% vs. 87.1%, p =0.41). This was consistent after adjusting for covariates (HR: 0.97, 95% CI: 0.56-1.68 [ p >0.9]). Our study suggests that having a potential living donor could decrease the risk of death in patients with primary sclerosing cholangitis on the waitlist. Importantly, the post-transplant outcomes in this population are similar between the LDLT and DDLT groups.

Trajectories of patients relisted for liver transplantation.

INTRODUCTION AND OBJECTIVES: Recurrent cirrhosis complicates 10-30% of Liver transplants (LT) and can lead to consideration for re-transplantation. We evaluated the trajectories of relisted versus primary listed patients on the waitlist using a competing risk framework. MATERIALS AND METHODS: We retrospectively examined 1,912 patients listed for LT at our centre between from 2012 to 2020. Cox proportional hazard models were used to assess overall survival (OS) by listing type and competing risk analysis Fine-Gray models were used to assess cumulative incidence of transplant by listing type. RESULTS: 1,731 patients were included (104 relisted). 44.2% of relisted patients received exception points vs. 19.8% of primary listed patients (p<0.001). Patients relisted without exceptions, representing those with graft cirrhosis, had the worst OS (HR: 4.17, 95%CI 2.63 - 6.67, p=<0.0001) and lowest instantaneous rate of transplant (HR: 0.56, 95%CI 0.38 - 0.83, p=0.006) than primary listed with exception points. On multivariate analysis listing type, height, bilirubin and INR were associated with cumulative incidence of transplant, while listing type, bilirubin, INR, sodium, creatinine were associated with OS. Within relisted patients, there was a trend towards higher mortality (HR: 1.79, 95%CI 0.91 - 3.52, p=0.08) and low transplant incidence (HR: 0.51, 95%CI 0.22 - 1.15, p=0.07) for graft cirrhosis vs other relisting indications. CONCLUSIONS: Patients relisted for LT are carefully curated and comprise a minority of the waitlist population. Despite their younger age, they have worse liver/kidney function, poor waitlist survival, and decreased transplant incidence suggesting the need for early relisting, while considering standardized exception points.

Medical Assistance in Dying (MAiD) as a Source of Liver Grafts: Honouring the Ultimate Gift.

OBJECTIVE: To report the clinical outcomes of liver transplants from donors after medical assistance in dying (MAiD) versus donors after cardiac death (DCD) and deceased brain death (DBD). SUMMARY BACKGROUND DATA: In North America, the number of patients needing liver transplants exceeds the number of available donors. In 2016, MAiD was legalized in Canada. METHODS: All patients undergoing deceased donor liver transplantation at Toronto General Hospital between 2016 and 2021 were included in the study. Recipient perioperative and postoperative variables and donor physiological variables were compared among 3 groups. RESULTS: Eight hundred seven patients underwent deceased donor liver transplantation during the study period, including DBD (n=719; 89%), DCD (n=77; 9.5%), and MAiD (n=11; 1.4%). The overall incidence of biliary complications was 6.9% (n=56), the most common being strictures (n=55;6.8%), highest among the MAiD recipients [5.8% (DBD) vs. 14.2% (DCD) vs. 18.2% (MAiD); P =0.008]. There was no significant difference in 1 year (98.4% vs. 96.4% vs. 100%) and 3-year (89.3% vs. 88.7% vs. 100%) ( P =0.56) patient survival among the 3 groups. The 1- and 3- year graft survival rates were comparable (96.2% vs. 95.2% vs. 100% and 92.5% vs. 91% vs. 100%; P =0.37). CONCLUSION: With expected physiological hemodynamic challenges among MAiD and DCD compared with DBD donors, a higher rate of biliary complications was observed in MAiD donors, with no significant difference noted in short-and long-term graft outcomes among the 3 groups. While ethical challenges persist, good initial results suggest that MAiD donors can be safely used in liver transplantation, with results comparable with other established forms of donation.

Analysis of various ATP-binding cassette transporters revealed quantification of ABCB4 as a potential diagnostic tool in primary sclerosing cholangitis (PSC).

AIMS: ATP-binding cassette transporters are important proteins in regulating bile constituent transport between hepatocytes and the bile canalicular system. Dysfunctional transporters lead to accumulation of toxic bile components within hepatocytes or the biliary system, known as cholestasis, resulting in liver damage. It has been previously reported that two particular ATP-binding cassette transporters, ABCB4 and ABCB11, have altered expression in patients with primary sclerosing cholangitis (PSC). Interested in further analysis of expression patterns of ATP-binding cassette transporters in PSC patients, we investigated liver samples from 201 patients, including 43 patients with PSC and 51 patients with primary biliary cholangitis patients (PBC). In addition to ABCB4 and ABCB11, we also included other ATP-binding cassette transporters, to determine if upregulation of ABCB4 and ABCB11 is specifically found in the liver of patients with PSC. METHODS AND RESULTS: Retrospectively, formalin-fixed and paraffin-embedded liver biopsies, resections, and explants were selected to investigate the expression of ABCB1, ABCB4, ABCB11, ABCG5/8, and FXR1 using nanoString nCounter and immunohistochemistry for validation of differently expressed transporters seen in PSC liver samples in comparison to non-PSC liver specimens. Strikingly, ABCB4 was the only ATP-binding cassette transporter showing increased gene and protein expression in hepatocytes of PSC livers when compared to non-PSC liver specimens. Furthermore, ABCB4 protein expression also correlated with disease stage in PSC. CONCLUSION: Our study concluded that altered ABCB4 expression is specifically seen in liver specimens of PSC patients. Therefore, quantitative ABCB4 analysis may be an additional useful tool for the histopathological diagnosis of PSC to distinguish this entity from other cholangiopathies.

Should advanced donor age be a deterrent in the utilization of grafts from donation after cardiac death in deceased donor liver transplantation? The Toronto experience.

BACKGROUND: Advanced donor age paired with donation after cardiac death (DCD) increases the risk of transplantation, precluding widespread use of grafts from such donors worldwide. Our aim was to analyze outcomes of liver transplantation using grafts from older DCD donors and donation after brain death (DBD) donors. METHODS: Patients who underwent liver transplantation using grafts from deceased donors between January 2016 and December 2021 were included in the study. Short-and long-term outcomes were analyzed for 4 groups of patients: those who received DCD and DBD grafts from younger (< 50 yr) and older (≥ 50 yr) donors. RESULTS: Of the 807 patients included in the analysis, 44.7% (n = 361) of grafts were received from older donors, with grafts for older DCD donors comprising 4.7% of the total cohort (n = 38). Patients who received grafts from older donors had a lower incidence of biliary strictures than those who received grafts from younger donors (7.9% v. 20.0% for DCD donation, p = 0.14, and 4.9% v. 6.8% for DBD donation, p = 0.34), with a significantly lower incidence of ischemic-type biliary strictures in patients who received grafts from older versus younger DCD donors (2.6% v. 18.0%, p = 0.04). There was no difference in 1- and 3-year graft survival rates among patients who received grafts from older and younger DCD donors (92.1% v. 90.8% and 80.2% v. 80.9%, respectively) and those who received grafts from older and younger DBD donors (90.1% v. 93.2% and 85.3% v. 84.4%, respectively) (p = 0.85). Pretransplantation admission to the intensive care unit (hazard ratio [HR] 9.041, p < 0.001) and nonalcoholic steatohepatitis (HR 2.197, p = 0.02) were found to significantly affect survival of grafts from older donors. CONCLUSION: Donor age alone should not be the criterion to determine the acceptability of grafts in liver transplantation. With careful selection criteria, older DCD donors could make a valuable contribution to expanding the liver donor pool, with grafts that produce comparable results to those obtained with standard-criteria grafts.

Unraveling the Complexity of Liver Disease One Cell at a Time.

The human liver is a complex organ made up of multiple specialized cell types that carry out key physiological functions. An incomplete understanding of liver biology limits our ability to develop therapeutics to prevent chronic liver diseases, liver cancers, and death as a result of organ failure. Recently, single-cell modalities have expanded our understanding of the cellular phenotypic heterogeneity and intercellular cross-talk in liver health and disease. This review summarizes these findings and looks forward to highlighting new avenues for the application of single-cell genomics to unravel unknown pathogenic pathways and disease mechanisms for the development of new therapeutics targeting liver pathology. As these technologies mature, their integration into clinical data analysis will aid in patient stratification and in developing treatment plans for patients suffering from liver disease.

Results of Early Transplantation for Alcohol-Related Cirrhosis: Integrated Addiction Treatment With Low Rate of Relapse.

BACKGROUND & AIMS: In 2018, our team initiated a prospective pilot program to challenge the paradigm of the "6-month rule" of abstinence for patients with alcohol-related liver disease (ALD) requiring transplant. Our pilot involved an in-depth examination of patients' alcohol use, social support, and psychiatric comorbidity, as well as the provision of pre- and post-transplantation addiction treatment. METHODS: Patients with ALD were assessed for inclusion in the pilot by a multidisciplinary team. Relapse prevention therapy was provided directly to all patients deemed to meet the program's inclusion criteria. Random biomarker testing for alcohol was used pre and post transplantation. RESULTS: We received 703 referrals from May 1, 2018 to October 31, 2020. After fulfilling the program's criteria, 101 patients (14%) were listed for transplantation and 44 (6.2%) received transplants. There were no significant differences in survival rates between those receiving transplants through the pilot program compared with a control group with more than 6 months of abstinence (P = .07). Three patients returned to alcohol use during an average post-transplantation follow-up period of 339 days. In a multivariate analysis, younger age and lower Model for End-Stage Liver Disease scores at listing were associated with an increased likelihood of a return to alcohol use (P < .05); length of abstinence was not a predictor. CONCLUSIONS: Our prospective program provided direct monitoring and relapse prevention treatment for patients with ALD and with less than 6 months of abstinence and resulted in a reduction of post-transplantation return to drinking. This pilot study provides a framework for the future of more equitable transplant care.

Superior Long-Term Outcomes of Adult Living Donor Liver Transplantation: A Cumulative Single-Center Cohort Study With 20 Years of Follow-Up.

Living donor liver transplantation (LDLT) is an attractive alternative to deceased donor liver transplantation (DDLT). Although both modalities have similar short-term outcomes, long-term outcomes are not well studied. We compared the 20-year outcomes of 668 adults who received LDLT with1596 DDLTs at the largest liver transplantation (LT) program in Canada. Recipients of LDLT were significantly younger and more often male than DDLT recipients (P < 0.001). Autoimmune diseases were more frequent in LDLT, whereas viral hepatitis and alcohol-related liver disease were more frequent in DDLT. LDLT recipients had lower Model for End-Stage Liver Disease scores (P = 0.008), spent less time on the waiting list (P < 0.001), and were less often inpatients at the time of LT (P < 0.001). In a nonadjusted analysis, 1-year, 10-year, and 20-year patient survival rates were significantly higher in LDLT (93%, 74%, and 56%, respectively) versus DDLT (91%, 67%, and 46%, respectively; log-rank P = 0.02) as were graft survival rates LDLT (91%, 67%, and 50%, respectively) versus (90%, 65%, and 44.3%, respectively, for DDLT; log-rank P = 0.31). After multivariable adjustment, LDLT and DDLT were associated with a similar hazard of patient and graft survival. Our data of 20 years of follow-up of LDLT from a single, large Western center demonstrates excellent long-term outcomes for recipients of LDLT.

Assessment of open surgical and endovascular management of true hepatic artery aneurysms over 20 years highlights increased rupture risk in females.

BACKGROUND: True hepatic artery aneurysms (HAAs) are rare but have been associated with a significant risk of rupture and associated mortality. The 2020 release of HAA-specific clinical practice guidelines represented an important step toward management standardization. However, it remains essential to build on the body of evidence to further refine these recommendations. METHODS: The HAA management and outcomes from a single academic center during a 20-year period were retrospectively reviewed. We identified 72 patients from the institutional radiology database (November 24, 1999 to 2019). Pseudoaneurysms were excluded, and 48 patients were found to have had true HAAs. Forty-three HAA patients had sufficient medical records for inclusion in the analysis. RESULTS: Of the 43 patients with HAA included, 65% were male. The mean age was 63 years (range, 22-89 years). Of the HAAs, 72% presented asymptomatically, 16% had ruptured, and 12% were symptomatic at presentation. Most HAAs were of atherosclerotic origin (74%). In addition, 16% of the patients had other visceral aneurysms and 12% had nonvisceral aneurysms on presentation. The mean HAA size overall was 3.3 cm (range, 0.8-10.8 cm), with most being solitary (72%) and involving the common hepatic artery (65%). Rupture was more common in females (40%) and those with vasculitis (67%), with females representing 86% of all patients with rupture. The mean size at intervention was 4.8 cm (21 patients [49%]). Ten patients (23%) had undergone open surgical repair (seven elective and three emergent because of rupture). Eleven patients (26%) had undergone endovascular intervention (64% elective and 36% emergent). Nonoperative management was selected for 22 patients (51%). These patients had a mean HAA diameter of 2.1 cm, and 59% had a life-limiting illness. Of the 18 patients who had been initially monitored for a mean of 3.9 ± 4.1 years, 3 had undergone elective repair and 2 had minimal growth. None of these patients had a subsequently documented rupture. CONCLUSIONS: True HAAs are a rare but important clinical phenomenon, with 16% of patients presenting with rupture in this study. Endovascular intervention is a promising alternative to open surgical repair, with no 30-day mortality, and is suitable for ruptured HAAs. Importantly, for the first time, our findings have demonstrated an increased risk of rupture for females, highlighting the need for additional data and ultimately, sex-specific guidelines.

Living donor liver paired exchange: A North American first.

Paired organ exchange can be used to circumvent living donor-recipient ABO incompatibilities. Herein, we present the first case of successful liver paired exchange in North America. This 2-way swap required 4 simultaneous operations: 2 living donor hepatectomies and 2 living donor liver transplants. A nondirected anonymous living donor gift initiated this domino exchange, alleviating an ABO incompatibility in the other donor-recipient pair. With careful attention to ethical and logistical issues, paired liver exchange is a feasible option to expand the donor pool for incompatible living liver donor-recipient pairs.

Renal Dysfunction After Liver Transplantation: Effect of Donor Type.

Recipients of donation after circulatory death (DCD) grafts are reportedly at higher risk of developing renal dysfunction after liver transplantation (LT). We compared the development of acute kidney injury (AKI) and chronic kidney disease (CKD) after LT in recipients of DCD versus donation after brain death (DBD) or living donor liver transplantation (LDLT) livers. Adult recipients of DBD, LDLT, and DCD between 2012 and 2016 at Toronto General Hospital were included. AKI was defined as a post-LT increase of serum creatinine (sCr) ≥26.5 µmol/L within 48 hours or a ≥50% increase from baseline, and CKD was defined as an estimated glomerular filtration rate <60 mL/minute for >3 months. A total of 681 patients (DCD, n = 57; DBD, n = 446; and LDLT, n = 178) with similar baseline comorbidities were included. Perioperative AKI (within the first 7 postoperative days) was observed more frequently in the DCD group (61%; DBD, 40%; and LDLT, 44%; P = 0.01) and was associated with significantly higher peak AST levels (P < 0.001). Additionally, patients in the DCD group had a significantly higher peak sCr (P < 0.001) and a trend toward higher rates of AKI stage 3 (DCD, 33%; DBD, 21%; LDLT, 21%; P = 0.11). The proportions of recovery from AKI (DCD, 77%; DBD, 72%; LDLT, 78%; P = 0.45) and patients developing CKD (DCD, 33%; DBD, 32%; LDLT, 32%; P = 0.99) were similar. Nevertheless, patients who received DCD or DBD LT and required perioperative renal replacement therapy showed significantly lower patient survival in multivariate analysis (hazard ratio, 7.90; 95% confidence interval, 4.51-13.83; P < 0.001). In conclusion, recipients of DCD liver grafts experience higher rates of short-term post-LT renal dysfunction compared with DBD or LDLT. Additional risk factors for the development of severe kidney injury, such as high Model for End-Stage Liver Disease score, massive transfusions, or donor age ≥60 years should be avoided.

Effect of vessel preservation on splenic volume and function in patients with spleen preserving distal pancreatectomies.

BACKGROUND: Spleen preservation during distal pancreatectomy (SpDP) can be accomplished by a variety of surgical approaches, but the impact on spleen function is unknown. This study aimed to compare spleen volume, function and complications between patients who underwent vessel sparing (VSDP) vs. vessel ligating (Warshaw, WDP) SpDP. METHODS: All patients who underwent SpDP at the Toronto General Hospital from 2006 to 2015 were included. Primary outcomes were pre- and post-operative spleen volumes and contrast enhancement on CT, hematologic parameters, and spleen-related complications. RESULTS: 82 patients underwent SpDP with median follow up of 20.4 months. Splenic volumes were able to be calculated on 44 patients (VSDP n = 8, WDP n = 36). There was no difference between WDP and VSDP in operative duration, blood loss, hospital length of stay, or Clavien-Dindo ≥3 complication rate. Spleen volumes did not differ from baseline in either group. On postoperative imaging more WDP patients had areas of splenic hypoperfusion (p = 0.032). These differences resolved by 3 months after surgery, there were no instances of long term infectious or bleeding complications related to poor splenic function or gastric varices. CONCLUSION: Both WDP and VSDP achieve splenic preservation. Neither technique resulted in clinically apparent spleen related complications. There is no difference in splenic volume and function in the short/long term.

Donor outcomes in anonymous live liver donation.

BACKGROUND & AIMS: Death rates on liver transplant waiting lists range from 5%-25%. Herein, we report a unique experience with 50 anonymous individuals who volunteered to address this gap by offering to donate part of their liver to a recipient with whom they had no biological connection or prior relationship, so called anonymous live liver donation (A-LLD). METHODS: Candidates were screened to confirm excellent physical, mental, social, and financial health. Demographics and surgical outcomes were analyzed. Qualitative interviews after donation examined motivation and experiences. Validated self-reported questionnaires assessed personality traits and psychological impact. RESULTS: A total of 50 A-LLD liver transplants were performed between 2005 and 2017. Most donors had a university education, a middle-class income, and a history of prior altruism. Half were women. Median age was 38.5 years (range 20-59). Thirty-three (70%) learned about this opportunity through public or social media. Saving a life, helping others, generativity, and reciprocity for past generosity were motivators. Social, financial, healthcare, and legal support in Canada were identified as facilitators. A-LLD identified most with the personality traits of agreeableness and conscientiousness. The median hospital stay was 6 days. One donor experienced a Dindo-Clavien Grade 3 complication that completely resolved. One-year recipient survival was 91% in 22 adults and 97% in 28 children. No A-LLD reported regretting their decision. CONCLUSIONS: This is the first and only report of the characteristics, motivations and facilitators of A-LLD in a large cohort. With rigorous protocols, outcomes are excellent. A-LLD has significant potential to reduce the gap between transplant organ demand and availability. LAY SUMMARY: We report a unique experience with 50 living donors who volunteered to donate to a recipient with whom they had no biological connection or prior relationship (anonymous living donors). This report is the first to discuss motivations, strategies and facilitators that may mitigate physical, social and ethical risk factors in this patient population. With rigorous protocols, anonymous liver donation and recipient outcomes are excellent; with appropriate clinical expertise and system facilitators in place, our experience suggests that other centers may consider the procedure for its significant potential to reduce the gap between transplant organ demand and availability.

Live donor liver transplantation for patients with hepatocellular carcinoma offers increased survival vs. deceased donation.

BACKGROUND & AIMS: There are conflicting reports on the outcomes after live donor liver transplantation in patients with hepatocellular carcinoma (HCC). We aimed to compare the survival of patients with HCC, with a potential live donor (pLDLT) at listing vs. no potential donor (pDDLT), on an intention-to-treat basis. METHODS: All patients with HCC listed for liver transplantation between 2000-2015 were included. The pLDLT group was comprised of recipients with a potential live donor identified at listing. Patients without a live donor were included in the pDDLT group. Survival was assessed by the Kaplan-Meier method. Multivariable Cox regression was applied to identify potential predictors of mortality. RESULTS: A total of 219 patients were included in the pLDLT group and 632 patients in the pDDLT group. In the pLDLT group, 57 patients (26%) were beyond the UCSF criteria whereas 119 patients (19%) in the pDDLT group were beyond (p = 0.02). Time on the waiting list was shorter for the pLDLT than the pDDLT group (4.8 [2.9-8.5] months vs. 6.2 [3.0-12.0] months, respectively, p = 0.02). The dropout rate was 32/219 (14.6%) in the pLDLT and 174/632 (27.5%) in the pDDLT group, p <0.001. The 1-, 3- and 5-year intention-to-treat survival rates were 86%, 72% and 68% in the pLDLT vs. 82%, 63% and 57% in the pDDLT group, p = 0.02. Having a potential live donor was a protective factor for death (hazard ratio [HR] 0.67; 95% CI 0.53-0.86). Waiting times of 9-12 months (HR 1.53; 95% CI 1.02-2.31) and ≥12 months (HR 1.69; 95% CI 1.23-2.32) were predictors of death. CONCLUSION: Having a potential live donor at listing was associated with a significant decrease in the risk of death in patients with HCC in this intention-to-treat analysis. This benefit is related to a lower dropout rate and a shorter waiting period. LAY SUMMARY: Liver transplantation (LT) offers the best chance of survival for patients with hepatocellular carcinoma and can be performed using grafts from deceased donors or live donors. In this work, we aimed to assess the differences in survival after live donor LT when compared to deceased donor LT. We studied 219 patients listed for live donor LT and 632 patients listed for deceased donor LT. Patients who had a potential live donor at the time of listing had a higher survival rate. Therefore, being listed for a live donor LT was a protective factor against death.

Outcomes of radiofrequency ablation as first-line therapy for hepatocellular carcinoma less than 3 cm in potentially transplantable patients.

BACKGROUND & AIMS: Radiofrequency ablation (RFA) is an effective treatment for single hepatocellular carcinoma (HCC) ≤3 cm. Disease recurrence is common, and in some patients will occur outside transplant criteria. We aimed to assess the incidence and risk factors for recurrence beyond Milan criteria in potentially transplantable patients treated with RFA as first-line therapy. METHODS: We performed a retrospective cohort study of potentially transplantable patients with new diagnoses of unifocal HCC ≤3 cm that underwent RFA as first-line therapy between 2000-2015. We defined potentially transplantable patients as those aged <70 years without any comorbidities that would preclude transplant surgery. Incidence of recurrence beyond Milan criteria was compared across 2 groups according to HCC diameter at the time of ablation: (HCC ≤2 cm vs. HCC >2 cm). Competing risks Cox regression was used to identify predictors of recurrence beyond Milan criteria. RESULTS: We included 301 patients (167 HCC ≤2 cm and 134 HCC >2 cm). Recurrence beyond Milan criteria occurred in 36 (21.6%) and 47 (35.1%) patients in the HCC ≤2 cm and the HCC >2 cm groups, respectively (p = 0.01). The 1-, 3- and 5-year actuarial survival rates after RFA were 98.2%, 86.2% and 79.0% in the HCC ≤2 cm group vs. 93.3%, 77.6% and 70.9% in the HCC >2 cm group (p = 0.01). Tumor size >2 cm (hazard ratio 1.94; 95%CI 1.25-3.02) and alpha-fetoprotein levels at the time of ablation (100-1,000 ng/ml: hazard ratio 2.05; 95%CI 1.10-3.83) were found to be predictors of post-RFA recurrence outside Milan criteria. CONCLUSION: RFA for single HCC ≤3 cm provides excellent short- to medium-term survival. However, we identified patients at higher risk of recurrence beyond Milan criteria. For these patients, liver transplantation should be considered immediately after the first HCC recurrence following RFA. LAY SUMMARY: Radiofrequency ablation and liver transplantation are treatment options for early stages of hepatocellular carcinoma (HCC). After ablation some patients will experience recurrence or metastatic spread of the initial tumor or may develop new tumors within the liver. Despite close follow-up, these recurrences can progress rapidly and exceed transplant criteria, preventing the patient from receiving a transplant. We identified that patients with HCC >2 cm and higher serum alpha-fetoprotein are at greater risk of recurrence beyond the transplant criteria. These data suggest that liver transplantation should be considered immediately after the first HCC recurrence for these patients.

Predictors of De Novo Nonalcoholic Fatty Liver Disease After Liver Transplantation and Associated Fibrosis.

Nonalcoholic fatty liver disease (NAFLD) can occur de novo in patients undergoing liver transplantation (LT) for indications other than NAFLD, and it has been increasingly recognized as a complication in the post-LT setting. This study aims to better characterize de novo NAFLD after LT by identifying risk factors for its development, describing incidence and extent of fibrosis, assessing the diagnostic utility of noninvasive serum fibrosis algorithms, and comparing survival to those without NAFLD. This was a retrospective single-center analysis of de novo NAFLD in a post-LT cohort. Those whose primary indication for LT was nonalcoholic steatohepatitis (NASH) were excluded. Risk factors were analyzed by univariate and multivariate analyses. De novo NAFLD and fibrosis were assessed on posttransplant liver biopsies, and noninvasive fibrosis scores were calculated from concomitant blood tests. After applying the exclusion criteria, 430 for-cause post-LT biopsies were evaluated; 33.3% (n = 143) had evidence of de novo steatosis and/or NASH at a median of 3.0 years after transplant. On multivariate analysis, body mass index (BMI; odds ratio [OR], 1.12; P < 0.001), diabetes mellitus (OR, 3.01; P = 0.002), hepatitis C virus (OR, 4.61; P < 0.001), weight gain (OR, 1.03; P = 0.007), and sirolimus use (OR, 3.11; P = 0.02) were predictive of de novo NAFLD after LT. Significant fibrosis (≥F2) was present in almost 40% of the cohort. Noninvasive serum fibrosis scores were not useful diagnostic tests. There was no significant difference in the short-term or longterm survival of patients who developed de novo NAFLD. In conclusion, diabetes, BMI, weight gain after LT, and sirolimus-based immunosuppression, in keeping with insulin resistance, were the only modifiable factors associated with development of de novo NAFLD. A significant proportion of patients with de novo NAFLD had fibrosis and given the limited utility of noninvasive serum fibrosis algorithms, alternative noninvasive tools are required to screen for fibrosis in this population. There was no significant difference in the short-term or longterm survival of patients who developed de novo NAFLD.

Management and surveillance of non-functional pancreatic neuroendocrine tumours: Retrospective review.

BACKGROUND: /Objective. To determine the outcomes of a non-operative management approach for sporadic, small, non-functional pancreatic neuroendocrine tumours. METHODS: A retrospective chart review of patients with non-functional pancreatic neuroendocrine tumours initially managed non-operatively at a single institution was performed. Patients were identified through a search of radiologic reports, and individuals with ≥2 cross-sectional imaging studies performed >6 months apart from Jan. 1, 2000 to Dec. 31, 2013 were included. Data on tumour size, radiologic characteristics at diagnosis, interval radiologic growth, and surgical outcomes were recorded. RESULTS: Over the thirteen-year study period, 95 patients met inclusion criteria and were followed radiologically for a median of 36 months (18-69 months). Median initial tumour size on first imaging was 14.0 mm (IQR 10-19 mm). Median overall tumour growth rate was 0.03 mm/month (IQR: 0.00-0.14 mm/month). There was no significant relationship between initial tumour size and growth rate for tumours ≤ 2 cm or for lesions between 2 and 4 cm. Thirteen (14%) patients initially managed non-operatively underwent resection during the follow-up period. Reasons for surgery included interval tumour growth, patient anxiety or preference, or diagnostic uncertainty. Median time to surgery was 14 months (IQR 8-19 months). No patients progressed beyond resectability or developed metastatic disease during the observation period. CONCLUSION: For patients with sporadic, small, non-functional pancreatic neuroendocrine tumours, radiologic surveillance appears to be a safe initial approach to management.

The basis of liver regeneration: A systems biology approach.

INTRODUCTION: Liver regeneration is a normal response to liver injury. The aim of this study was to determine the molecular basis of liver regeneration, through an integrative analysis of high-throughput gene expression datasets. METHODS: We identified and curated datasets pertaining to liver regeneration from the Gene Expression Omnibus, where regenerating liver tissue was compared to healthy liver samples. The key dysregulated genes and pathways were identified using Ingenuity Pathway Analysis software. There were three eligible datasets in total. RESULTS: In the early phase after hepatectomy, inflammatory pathways such as Nrf2 oxidative stress-mediated response and cytokine signaling were significantly upregulated. At peak regeneration, we discovered that cell cycle genes were predominantly expressed to promote cell proliferation. Using the Betweenness centrality algorithm, we discovered that Jun is the key central gene in liver regeneration. Calcineurin inhibitors may inhibit liver regeneration, based on predictive modeling. CONCLUSION: There is a paucity of human literature in defining the molecular mechanisms of liver regeneration along a time continuum. Nonetheless, using an integrative computational analysis approach to the available high-throughput data, we determine that the oxidative stress response and cytokine signaling are key early after hepatectomy, whereas cell cycle control is important at peak regeneration. The transcription factor Jun is central to liver regeneration and a potential therapeutic target. Future studies of regeneration in humans along a time continuum are needed to better define the underlying mechanisms, and ultimately enhance care of patients with acute and chronic liver failure while awaiting transplant.

The Ubiquitin-Specific Protease 18 Promotes Hepatitis C Virus Production by Increasing Viral Infectivity.

BACKGROUND AND AIMS: Ubiquitin-specific protease 18 (USP18) is involved in immunoregulation and response to interferon- (IFN-) based treatment in patients chronically infected with hepatitis C virus (HCV). We investigated whether and how its upregulation alters HCV infection. METHODS: Overexpression of wild-type (USP18 WT) or catalytically inactive mutant (USP18 C64S) USP18 was examined for effects on HCV replication in the absence and presence of IFNα or IFNλ using both the HCV-infective model and replicon cells. The IFN signaling pathway was assessed via STAT1 phosphorylation (western blot) and downstream ISG expression (real-time PCR). Mechanistic roles were sought by quantifying microRNA-122 levels and J6/JFH1 infectivity of Huh7.5 cells. RESULTS: We found that overexpression of either USP18 WT or USP18 C64S stimulated HCV production and blunted the anti-HCV effect of IFNα and IFNλ in the infective model but not in the replicon system. Overexpressed USP18 showed no effect on Jak/STAT signaling nor on microRNA-122 expression. However, USP18 upregulation markedly increased J6/JFH1 infectivity and promoted the expression of the key HCV entry factor CD81 on Huh7.5 cells. CONCLUSIONS: USP18 stimulates HCV production and blunts the effect of both type I and III IFNs by fostering a cellular environment characterized by upregulation of CD81, promoting virus entry and infectivity.