Clinical Impact and Risk Factors of Seizure After Liver Transplantation: A Nested Case-Control Study.

Seizures are a frequent neurological consequence following liver transplantation (LT), however, research on their clinical impact and risk factors is lacking. Using a nested case-control design, patients diagnosed with seizures (seizure group) within 1-year post-transplantation were matched to controls who had not experienced seizures until the corresponding time points at a 1:5 ratio to perform survival and risk factor analyses. Seizures developed in 61 of 1,243 patients (4.9%) at median of 11 days after LT. Five-year graft survival was significantly lower in the seizure group than in the controls (50.6% vs. 78.2%, respectively, p < 0.001) and seizure was a significant risk factor for graft loss after adjusting for variables (HR 2.04, 95% CI 1.24-3.33). In multivariable logistic regression, body mass index <23 kg/m2, donor age ≥45 years, intraoperative continuous renal replacement therapy and delta sodium level ≥4 mmol/L emerged as independent risk factors for post-LT seizure. Delta sodium level ≥4 mmol/L was associated with seizures, regardless of the severity of preoperative hyponatremia. Identifying and controlling those risk factors are required to prevent post-LT seizures which could result in worse graft outcome.

Self-Management Using eHealth Technologies for Liver Transplant Recipients: Scoping Review.

BACKGROUND: Liver transplantation has become increasingly common as a last-resort treatment for end-stage liver diseases and liver cancer, with continually improving success rates and long-term survival rates. Nevertheless, liver transplant recipients face lifelong challenges in self-management, including immunosuppressant therapy, lifestyle adjustments, and navigating complex health care systems. eHealth technologies hold the potential to aid and optimize self-management outcomes, but their adoption has been slow in this population due to the complexity of post-liver transplant management. OBJECTIVE: This study aims to examine the use of eHealth technologies in supporting self-management for liver transplant recipients and identify their benefits and challenges to suggest areas for further research. METHODS: Following the Arksey and O'Malley methodology for scoping reviews, we conducted a systematic search of 5 electronic databases: PubMed, CINAHL, Embase, PsycINFO, and Web of Science. We included studies that (1) examined or implemented eHealth-based self-management, (2) included liver transplant recipients aged ≥18 years, and (3) were published in a peer-reviewed journal. We excluded studies that (1) were case reports, conference abstracts, editorials, or letters; (2) did not focus on the posttransplantation phase; (3) did not focus on self-management; and (4) did not incorporate the concept of eHealth or used technology solely for data collection. The quality of the selected eHealth interventions was evaluated using (1) the Template for Intervention Description and Replication guidelines and checklist and (2) the 5 core self-management skills identified by Lorig and Holman. RESULTS: Of 1461 articles, 15 (1.03%) studies were included in the final analysis. Our findings indicate that eHealth-based self-management strategies for adult liver transplant recipients primarily address lifestyle management, medication adherence, and remote monitoring, highlighting a notable gap in alcohol relapse interventions. The studies used diverse technologies, including mobile apps, videoconferencing, and telehealth platforms, but showed limited integration of decision-making or resource use skills essential for comprehensive self-management. The reviewed studies highlighted the potential of eHealth in enhancing individualized health care, but only a few included collaborative features such as 2-way communication or tailored goal setting. While adherence and feasibility were generally high in many interventions, their effectiveness varied due to diverse methodologies and outcome measures. CONCLUSIONS: This scoping review maps the current literature on eHealth-based self-management support for liver transplant recipients, assessing its potential and challenges. Future studies should focus on developing predictive models and personalized eHealth interventions rooted in patient-generated data, incorporating digital human-to-human interactions to effectively address the complex needs of liver transplant recipients. This review emphasizes the need for future eHealth self-management research to address the digital divide, especially with the aging liver transplant recipient population, and ensure more inclusive studies across diverse ethnicities and regions.

Outcomes and Risk Factors for Liver Transplantation Using graft-to-Recipient Weight Ratio Less than 0.8 Graft from Living Donors: Multicentric Cohort Study.

OBJECTIVE: To compare graft survival after LDLT in patients receiving GRWR<0.8 versus GRWR≥0.8 grafts and identify risk factors for graft loss using GRWR<0.8 grafts. SUMMARY BACKGROUND DATA: Favorable outcomes after living donor liver transplantation (LDLT) using graft-to-recipient weight ratio (GRWR)<0.8 grafts were recently reported; however, these results have not been validated using multicenter data. METHODS: This multicentric cohort study included 3450 LDLT patients. Graft survival was compared between 1:3 propensity score-matched groups and evaluated using various Cox models in the entire population. Risk factors for graft loss with GRWR<0.8 versus GRWR≥0.8 grafts were explored within various subgroups using interaction analyses, and outcomes were stratified according to the number of risk factors. RESULTS: In total, 368 patients (10.7%) received GRWR<0.8 grafts (GRWR<0.8 group), whereas 3082 (89.3%) received GRWR≥0.8 grafts (GRWR≥0.8 group). The 5-y graft survival rate was significantly lower with GRWR<0.8 grafts than with GRWR≥0.8 grafts (85.2% vs. 90.1%, P=0.013). Adjusted hazard ratio (HR) for graft loss using GRWR<0.8 grafts in the entire population was 1.66 (95% confidence interval [CI] 1.17-2.35, P=0.004). Risk factors exhibiting significant interactions with GRWR<0.8 for graft survival were age ≥60 y, MELD score ≥15, and male donor. When ≥2 risk factors were present, GRWR<0.8 grafts showed higher risk of graft loss compared to GRWR≥0.8 graft in LDLT (HR 2.98, 95% CI 1.79-4.88, P<0.001). CONCLUSIONS: GRWR<0.8 graft showed inferior graft survival than controls (85.2% vs. 90.1%), especially when ≥2 risk factors for graft loss (among age ≥60 y, MELD score ≥15, or male donor) were present.

Outcomes of sexagenarian living liver donors in Korea: A multicenter study.

The safety of elderly living liver donors and recipient outcomes are always of concern. In the present study, the effects of age in 2 donor groups, a 60+years old group and a 50-59 years old group (referred to as the 60s and 50s donor groups, respectively), on living donor liver transplantation were compared regarding donor safety and recipient outcomes. We retrospectively identified 209 patients 50 years and above of age at 9 centers from 2005 to 2017 in Korea. The 60s donor group represented 10% (n=21) of donor patients. One case in each group was a left liver graft, respectively, and the others were right liver grafts. Postoperative complications were more common in the 60s donor group, but the proportion of Clavien-Dindo grade III in the 60s donor group did not differ from that in the 50s donor group. In-hospital mortality did not occur among donors, and donor mortality was not reported during the observation period. Postoperative total bilirubin and hospitalization in recipients of the 60s donor group were higher and longer than in recipients of the 50s donor group, respectively. Although the cumulative overall survival of the recipients in the 60s donor group was significantly lower than that of the 50s donor group, a difference was not observed in graft survival. Multivariate analysis showed that increased living liver donors age, the coexistence of HCC, and increased intraoperative blood loss during the recipient operation were important predisposing factors for patient death. Present study suggests that highly selected elderly living donors (≥60 y) can safely donate with similar recipient graft survival rates though the recipient overall patient survival is inferior compared to the 50s donor group.

Entecavir versus tenofovir on the recurrence of hepatitis B-related HCC after liver transplantation: A multicenter observational study.

Considerable controversy exists regarding the superiority of tenofovir disoproxil fumarate (TDF) over entecavir (ETV) for reducing the risk of HCC. This study aimed to compare outcomes of ETV versus TDF after liver transplantation (LT) in patients with HBV-related HCC. We performed a multicenter observational study using data from the Korean Organ Transplantation Registry. A total of 845 patients who underwent LT for HBV-related HCC were divided into 2 groups according to oral nucleos(t)ide analogue used for HBV prophylaxis post-LT: ETV group (n = 393) and TDF group (n = 452). HCC recurrence and overall death were compared in naïve and propensity score (PS)-weighted populations, and the likelihood of these outcomes according to the use of ETV or TDF were analyzed with various Cox models. At 1, 3, and 5 years, the ETV and TDF groups had similar HCC recurrence-free survival (90.7%, 85.6%, and 84.1% vs. 90.9%, 84.6%, and 84.2%, respectively, p = 0.98) and overall survival (98.4%, 94.7%, and 93.5% vs. 99.3%, 95.8%, and 94.9%, respectively, p = 0.48). The propensity score-weighted population showed similar results. In Cox models involving covariates adjustment, propensity score-weighting, competing risk regression, and time-dependent covariates adjustment, both groups showed a similar risk of HCC recurrence and overall death. In subgroup analyses stratified according to HCC burden (Milan criteria, Up-to-7 criteria, French alpha-fetoprotein risk score), pretransplantation locoregional therapy, and salvage LT, neither ETV nor TDF was superior. In conclusion, ETV and TDF showed mutual noninferiority for HCC outcomes when used for HBV prophylaxis after LT.

Inhibition of Dickkopf-1 enhances the anti-tumor efficacy of sorafenib via inhibition of the PI3K/Akt and Wnt/ß-catenin pathways in hepatocellular carcinoma.

BACKGROUND: Sorafenib improves the overall survival in patients with advanced hepatocellular carcinoma (HCC). Dickkopf-1 (DKK1) is commonly overexpressed in HCC. In this study, we investigated whether the inhibition of DKK1 enhances the anti-tumor efficacy of sorafenib in HCC. METHODS: HCC cells were treated with sorafenib and WAY-262611, which is an inhibitor of DKK1. Transgenic mouse models were also developed using hydrodynamic tail vein injection. Mice were orally administered with sorafenib (32 mg/kg), WAY-262611 (16 mg/kg), or sorafenib + WAY-262611 for 10 days. Mechanisms of sorafenib and WAY-262611 were explored via western blotting, immunostaining, and RNA sequencing. RESULTS: DKK1 was significantly overexpressed in patients with HCC than in the healthy controls and patients with liver diseases except HCC (all P < 0.05). Compared with sorafenib alone, sorafenib + WAY-262611 significantly inhibited the cell viability, invasion, migration, and colony formation by promoting apoptosis and altering the cell cycles in HCC cells (all P < 0.05). Moreover, sorafenib + WAY-262611 decreased the p110α, phospho-Akt (all P < 0.05), active ß-catenin (all P < 0.05) and phospho-GSK-3ß (Ser9) expression levels, while increasing the phospho-GSK-3ß (Tyr216) expression levels compared with those in the sorafenib alone in vitro and in vivo. In addition, sorafenib + WAY-262611 inhibited tumor progression by regulating cell proliferation and apoptosis, significantly better than sorafenib alone in mouse models. CONCLUSIONS: Our results indicate that DKK1 inhibition significantly enhances the anti-tumor efficacy of sorafenib by inhibiting the PI3K/Akt and Wnt/ß-catenin pathways via regulation of GSK3ß activity, suggesting a novel therapeutic strategy for HCC. Video Abstract.

Effect of statins on the recurrence of hepatocellular carcinoma after liver transplantation: An illusion revealed by exposure density sampling.

BACKGROUND: Statins have been reported to reduce overall death and hepatocellular carcinoma (HCC) recurrence in liver transplantation (LT) recipients. However, previous retrospective studies have significant flaws in immortal time bias. METHODS: Using data from 658 patients who received LT for HCC, we matched 140 statin users with statin nonusers in a 1:2 ratio at the time of the first statin administration after LT using the exposure density sampling (EDS). The propensity score, calculated using baseline variables (including explant pathology), was used for EDS to equilibrate both groups. HCC recurrence and overall death were compared after adjusting for information at the time of sampling. RESULTS: Among statin users, the median time to statin start was 219 (IQR 98-570) days, and intensity of statins was mainly moderate (87.1%). Statin users and nonusers sampled using EDS showed well-balanced baseline characteristics, including detailed tumour pathology, and similar HCC recurrence with cumulative incidences of 11.3% and 11.8% at 5 years, respectively (p = .861). In multivariate Cox models (HR 1.04, p = .918) and subgroup analyses, statins did not affect HCC recurrence. Conversely, statin users showed a significantly lower risk of overall death than nonusers (HR 0.28, p < .001). There was no difference in the type and intensity of statin usage between statin users who experienced HCC recurrence and those who did not. CONCLUSION: Upon controlling immortal time bias by EDS, statins did not affect HCC recurrence but reduced mortality after LT. Statin usage is encouraged for survival benefits but not for preventing HCC recurrence in LT recipients.

Optimal imaging criteria and modality to determine Milan criteria for the prediction of post-transplant HCC recurrence after locoregional treatment.

OBJECTIVES: We aimed to investigate the optimal radiologic method to determine Milan criteria (MC) for the prediction of recurrence in patients who underwent locoregional treatment (LRT) for hepatocellular carcinoma (HCC) and subsequent liver transplantation (LT). METHODS: This retrospective study included 121 HCC patients who underwent LRT and had both liver dynamic CT and MRI. They were classified with MC using four cross combinations of two imaging modalities (CT and MRI) and two diagnostic criteria (modified Response Evaluation Criteria in Solid Tumors [mRECIST] and Liver Imaging Reporting and Data System treatment response algorithm [LI-RADS TRA]). Competing risk regression was performed to analyze the time to recurrence after LT. The predictive abilities of the four methods for recurrence were evaluated using the time-dependent area under the curve (AUC). RESULTS: Competing risk regression analyses found that beyond MC determined by MRI with mRECIST was independently associated with recurrence (hazard ratio, 6.926; p = 0.001). With mRECIST, MRI showed significantly higher AUCs than CT at 3 years and 5 years after LT (0.597 vs. 0.756, p = 0.012 at 3 years; and 0.588 vs. 0.733, p = 0.024 at 5 years). Using the pathologic reference standard, MRI with LI-RADS TRA showed higher sensitivity (61.5%) than CT with LI-RADS TRA (30.8%, p < 0.001) or MRI with mRECIST (38.5%, p < 0.001). CONCLUSIONS: MRI with mRECIST was the optimal radiologic method to determine MC for the prediction of post-LT recurrence in HCC patients with prior LRT. KEY POINTS: • MRI with modified RECIST (mRECIST) is the optimal preoperative method to determine Milan criteria for the prediction of post-transplant HCC recurrence in patients with prior locoregional treatment. • With mRECIST, MRI was better than CT for the prediction of post-transplant recurrence.

Incidence, mortality, and risk factors associated with carbapenem-resistant Acinetobacter baumannii bacteremia within 30 days after liver transplantation.

Carbapenem-resistant Acinetobacter baumannii bacteremia (CRAB-B) is a fatal infectious complication of liver transplantation (LT). This study investigated the incidence, effects, and risk factors associated with CRAB-B during the early post-LT period. Among 1051 eligible LT recipients, 29 patients experienced CRAB-B within 30 days of LT with a cumulative incidence of 2.7%. In the patients with CRAB-B (n = 29) and matched controls (n = 145) by nested-case control design, the cumulative incidence of death on days 5, 10, and 30 from the index date was 58.6%, 65.5%, and 65.5%, and 2.1%, 2.8%, and 4.2%, respectively (p < .001). Pre-transplant MELD (OR 1.11, 95% confidence interval [CI] 1.04-1.19, p = .002), severe encephalopathy (OR 4.62, 95% CI 1.24-18.61, p = .025), donor body mass index (OR .57, 95% CI .41-.75, p < .001), and reoperation (OR 6.40, 95% CI 1.19-36.82, p = .032) were independent risk factors for 30-day CRAB-B. CRAB-B showed extremely high mortality within 30 days after LT, especially within 5 days after its occurrence. Therefore, assessment of risk factors and early detection of CRAB, followed by proper treatment, are necessary to control CRAB-B after LT.

Volumetric Absorptive Microsampling for the Therapeutic Drug Monitoring of Everolimus in Patients Who Have Undergone Liver Transplant.

BACKGROUND: Therapeutic drug monitoring (TDM) of everolimus is required to prevent organ rejection in patients who have undergone transplant. Volumetric absorptive microsampling (VAMS) is a minimally invasive method for accurately collecting a small amount of blood from a patient's fingers. This study aimed to assess the applicability of VAMS for TDM of everolimus. METHODS: VAMS and venous blood samples were collected from 45 liver transplant recipients who had been receiving stable everolimus doses for at least 7 days. Whole blood everolimus concentrations were measured using ultrahigh performance liquid chromatography with tandem mass spectrometry. Deming regression and Bland-Altman analysis were performed to compare everolimus concentrations measured using VAMS (C VAMS ) and venous blood samples (C IV ). The regression coefficient (r 2 ) between C VAMS and C IV was calculated using a linear regression. The effects of the hematocrit and blood sampling time on the difference between C VAMS and C IV were investigated. RESULTS: Thirty-two participants were included in the final analysis. The Deming regression line was C IV = 1.04 × C VAMS + 0.55 [95% confidence interval (CI) of slope, 0.91-1.18; 95% CI of intercept, -0.05 to 1.16]. C VAMS and C IV were strongly correlated (r 2 = 0.92), with no proportional or constant bias. The mean difference between C VAMS and C IV was -0.79 ng/mL, with the 95% limit of agreement ranging from -2.55 to 0.97 ng/mL in a Bland-Altman plot. No effect of the hematocrit or blood sampling time was observed. CONCLUSIONS: VAMS and venous blood sampling showed good agreement for the measurement of whole blood everolimus concentrations. Less invasive VAMS can substitute for more invasive venous blood sampling in the TDM of everolimus in liver transplant patients.

Predicted Impact of the Model for End-Stage Liver Disease 3.0 in a Region Suffering Severe Organ Shortage.

BACKGROUND: The model for end-stage liver disease 3.0 (MELD3.0) is expected to address the flaws of the current allocation system for deceased donor liver transplantation (DDLT). We aimed to validate MELD3.0 in the Korean population where living donor liver transplantation is predominant due to organ shortages. METHODS: Korean large-volume single-centric waitlist data were merged with the Korean Network for Organ Sharing (KONOS) data. The 90-day mortality was compared between MELD and MELD3.0 using the C-index in 2,353 eligible patients registered for liver transplantation. Patient numbers and outcomes were compared based on changes in KONOS-MELD categorization using MELD3.0. Possible gains in MELD points and reduced waitlist mortality were analyzed. RESULTS: MELD3.0 performed better than MELD (C-index 0.893 for MELD3.0 vs. 0.889 for MELD). When stratified according to the KONOS-MELD categories, 15.9% of the total patients and 35.2% of the deceased patients were up-categorized using MELD3.0 versus MELD categories. The mean gain of MELD points was higher in women (2.6 ± 2.1) than men (2.1 ± 1.9, P < 0.001), and higher in patients with severe ascites (3.3 ± 1.8) than in controls (1.9 ± 1.8, P < 0.001); however, this trend was not significant when the MELD score was higher than 30. When the possible increase in DDLT chance was calculated via up-categorizing using MELD3.0, reducible waitlist mortality was 2.7%. CONCLUSION: MELD3.0 could predict better waitlist mortality than MELD; however, the merit for women and patients with severe ascites is uncertain, and reduced waitlist mortality from implementing MELD3.0 is limited in regions suffering from organ shortage, as in Korea.

Impaired antibacterial response of liver sinusoidal Vγ9+Vδ2+ T cells in patients with chronic liver disease.

OBJECTIVE: The liver acts as a frontline barrier against diverse gut-derived pathogens, and the sinusoid is the primary site of liver immune surveillance. However, little is known about liver sinusoidal immune cells in the context of chronic liver disease (CLD). Here, we investigated the antibacterial capacity of liver sinusoidal γδ T cells in patients with various CLDs. DESIGN: We analysed the frequency, phenotype and functions of human liver sinusoidal γδ T cells from healthy donors and recipients with CLD, including HBV-related CLD (liver cirrhosis (LC) and/or hepatocellular carcinoma (HCC)), alcoholic LC and LC or HCC of other aetiologies, by flow cytometry and RNA-sequencing using liver perfusates obtained during living donor liver transplantation. We also measured the plasma levels of D-lactate and bacterial endotoxin to evaluate bacterial translocation. RESULTS: The frequency of liver sinusoidal Vγ9+Vδ2+ T cells was reduced in patients with CLD. Immunophenotypic and transcriptomic analyses revealed that liver sinusoidal Vγ9+Vδ2+ T cells from patients with CLD were persistently activated and pro-apoptotic. In addition, liver sinusoidal Vγ9+Vδ2+ T cells from patients with CLD showed significantly decreased interferon (IFN)-γ production following stimulation with bacterial metabolites and Escherichia coli. The antibacterial IFN-γ response of liver sinusoidal Vγ9+Vδ2+ T cells significantly correlated with liver function, and inversely correlated with the plasma level of D-lactate in patients with CLD. Repetitive in vitro stimulation with E. coli induced activation, apoptosis and functional impairment of liver sinusoidal Vγ9+Vδ2+ T cells. CONCLUSION: Liver sinusoidal Vγ9+Vδ2+ T cells are functionally impaired in patients with CLD. Bacterial translocation and decreasing liver functions are associated with functional impairment of liver sinusoidal Vγ9+Vδ2+ T cells.

Identification of a distinct NK-like hepatic T-cell population activated by NKG2C in a TCR-independent manner.

BACKGROUND & AIMS: The liver provides a unique niche of lymphocytes enriched with a large proportion of innate-like T cells. However, the heterogeneity and functional characteristics of the hepatic T-cell population remain to be fully elucidated. METHODS: We obtained liver sinusoidal mononuclear cells from the liver perfusate of healthy donors and recipients with HBV-associated chronic liver disease (CLD) during liver transplantation. We performed a CITE-seq analysis of liver sinusoidal CD45+ cells in combination with T cell receptor (TCR)-seq and flow cytometry to examine the phenotypes and functions of liver sinusoidal CD8+ T cells. RESULTS: We identified a distinct CD56hiCD161-CD8+ T-cell population characterized by natural killer (NK)-related gene expression and a uniquely restricted TCR repertoire. The frequency of these cells among the liver sinusoidal CD8+ T-cell population was significantly increased in patients with HBV-associated CLD. Although CD56hiCD161-CD8+ T cells exhibit weak responsiveness to TCR stimulation, CD56hiCD161-CD8+ T cells highly expressed various NK receptors, including CD94, killer immunoglobulin-like receptors, and NKG2C, and exerted NKG2C-mediated NK-like effector functions even in the absence of TCR stimulation. In addition, CD56hiCD161-CD8+ T cells highly respond to innate cytokines, such as IL-12/18 and IL-15, in the absence of TCR stimulation. We validated the results from liver sinusoidal CD8+ T cells using intrahepatic CD8+ T cells obtained from liver tissues. CONCLUSIONS: In summary, the current study found a distinct CD56hiCD161-CD8+ T-cell population characterized by NK-like activation via TCR-independent NKG2C ligation. Further studies are required to elucidate the roles of liver sinusoidal CD56hiCD161-CD8+ T cells in immune responses to microbial pathogens or liver immunopathology. LAY SUMMARY: The role of different immune cell populations in the liver is becoming an area of increasing interest. Herein, we identified a distinct T-cell population that had features similar to those of natural killer (NK) cells - a type of innate immune cell. This distinct population was expanded in the livers of patients with chronic liver disease and could thus have pathogenic relevance.

Outcomes of Robotic Living Donor Right Hepatectomy From 52 Consecutive Cases: Comparison With Open and Laparoscopy-assisted Donor Hepatectomy.

OBJECTIVE: To investigate the feasibility and safety of RLDRH. SUMMARY OF BACKGROUND DATA: Data for minimally invasive living-donor right hepatectomy, especially RLDRH, from a relatively large donor cohort that have not been reported yet. METHODS: From March 2016 to March 2019, 52 liver donors underwent RLDRH. The clinical and perioperative outcomes of RLDRH were compared with those of CODRH (n = 62) and LADRH (n = 118). Donor satisfaction with cosmetic results was compared between RLDRH and LADRH using a body image questionnaire. RESULTS: Although RLDRH was associated with longer operative time (minutes) (RLDRH, 493.6; CODRH, 404.4; LADRH, 355.9; P < 0.001), mean estimated blood loss (mL) was significantly lower (RLDRH, 109.8; CODRH, 287.1; LADRH, 265.5; P = 0.001). Postoperative complication rates were similar among the 3 groups (RLDRH, 23.1%; CODRH, 35.5%; LADRH, 28.0%; P = 0.420). Regarding donor satisfaction, body image and cosmetic appearance scores were significantly higher in RLDRH than in LADRH. After propensity score matching, RLDRH showed less estimated blood loss compared to those of CODRH (RLDRH, 114.7 mL; CODRH, 318.4 mL; P < 0.001), but complication rates were similar among the three groups (P = 0.748). CONCLUSIONS: RLDRH resulted in less blood loss compared with that of CODRH and similar postoperative complication rates to CODRH and LADRH. RLDRH provided better body image and cosmetic results compared with those of LADRH. RLDRH is feasible and safe when performed by surgeons experienced with both robotic and open hepatectomy.

Subclassification of Microscopic Vascular Invasion in Hepatocellular Carcinoma.

OBJECTIVE: To investigate whether subclassification of microscopic vascular invasion (MiVI) affects the long-term outcome after curative surgical resection or liver transplantation (LT) in patients with hepatocellular carcinoma (HCC). SUMMARY OF BACKGROUND DATA: The most important factor for TNM staging in HCC is MiVI, which includes all vascular invasions detected on microscopic examination. However, there is a broad spectrum of current definitions for MiVI. METHODS: In total, 412 consecutive patients with HCC who underwent curative surgical resection without any preoperative treatment or gross vascular invasion were histologically evaluated for MiVI. Patients with MiVI were subclassified into 2 groups: microvessel invasion (MI; n = 164) only and microscopic portal vein invasion (MPVI; n = 36). Clinicopathologic features were compared between 2 groups (MI vs MPVI), whereas disease-free survival (DFS) and overall survival (OS) after resection were analyzed among 3 groups (no vascular invasion [NVI] vs MI vs MPVI). These subclassifications were validated in a cohort of 197 patients with HCC who underwent LT. RESULTS: The MPVI group showed more aggressive tumor characteristics, such as higher tumor marker levels (alpha-fetoprotein, P = 0.006; protein induced by vitamin K absence-II, P = 0.001) and poorer differentiation (P = 0.011), than the MI group. In multivariate analysis, both MI and MPVI were independent prognostic factors for DFS (P = 0.001 and <0.001, respectively) and OS (P = 0.005 and <0.001, respectively). In the validation cohort, 5-year DFS was 89%, 67.9%, and 0% in the NVI, MI, and MPVI groups, respectively (P < 0.001), whereas 5-year OS was 79.1%, 55.0%, and 15.4%, respectively (P < 0.001). CONCLUSIONS: Based on subclassification of MiVI in HCC, MPVI was associated with more aggressive clinicopathologic characteristics and poorer survival than MI only. Therefore, the original MiVI classification should be divided into MI and MPVI.

Optimal drainage of anastomosis stricture after living donor liver transplantation.

BACKGROUND: Endoscopic biliary stenting (EBS) with a fully covered, self-expandable metallic stent (FC-SEMS) and plastic stent (PS) is safe and efficient for biliary anastomotic strictures (ASs) after a deceased donor liver transplantation. Limited studies have investigated the use of FC-SEMSs for biliary strictures post-living donor liver transplantation (LDLT). We compared the resolution rate of biliary ASs post-LDLT and the 12-month recurrence rates post-stent removal between EBS with an FC-SEMS, PS, and percutaneous transhepatic biliary drainage (PTBD). METHODS: Patients with biliary ASs after an LDLT (mean age: 57.3 years, 76.1% men) hospitalized between 2014 and 2017 were enrolled. Endoscopic retrograde cholangiopancreatography (ERCP) was repeated every 3-4 months. Patients were followed-up for at least 1-year post-stent removal. RESULTS: Of the 75 patients enrolled, 16, 20, and 39 underwent EBS with an FC-SEMS, PS, and PTBD, respectively. Median follow-up period was 39.2 months. Fewer ERCP procedures were needed in the FC-SEMS group than in the PS group (median, 2 vs. 3; P = 0.20). Median stent indwelling periods were 4.7, 9.3, and 5.4 months in the FC-SEMS, PS, and PTBD groups, respectively (P = 0.006). The functional resolution rate was lower in the PS group (16/20) than in the FC-SEMS (16/16) or PTBD (39/39) group (P = 0.005). The radiologic resolution rate was higher in the FC-SEMS group (16/16) than in the PS group (14/20) (P = 0.07). The 12-month recurrence rates showed no significant differences (FC-SEMS, 4/16; PS, 3/16; PTBD, 6/39; P = 0.66). The rates of complications during treatment differed significantly between the groups (P = 0.04). Stent migration occurred in 1 (6.3%) and 5 (25.0%) patients in the FC-SEMS and PS groups, respectively (P = 0.59). CONCLUSIONS: EBS with an FC-SEMS is comparable with EBS with a PS or PTBD in terms of biliary stricture resolution and 12-month recurrence rates. The use of FC-SEMSs is potentially effective and safe for biliary AS resolution after LDLT.

Early reduction of regulatory T cells is associated with acute rejection in liver transplantation under tacrolimus-based immunosuppression with basiliximab induction.

Regulatory T (Treg) cells are important in preventing acute rejection (AR) in solid organ transplantation, but the clinical relevance of the different kinetics early after liver transplantation (LT) in acute rejectors and non-rejectors is unclear. We analyzed peripheral blood samples of 128 LT recipients receiving basiliximab induction plus tacrolimus immunosuppression. Samples were obtained at pretransplant, D7, and D30 after LT. Frequency and phenotype of Tregs were analyzed by flow cytometry. The predictive value of Treg frequency at D7 was assessed for suspected acute rejection (SAR) and was validated for biopsy-proven AR (BPAR). We found that the frequencies of total and activated Tregs at D7 were significantly lower in recipients with SAR and BPAR. Treg was more reduced in BPARs by in vitro tacrolimus treatment in the presence of basiliximab. Moreover, an early reduction of Treg frequency in rejectors was associated with a greater increase in Treg apoptosis and further attenuated IL-2 signaling. D7 Treg frequency was an independent risk factor for SAR, which was also validated for BPAR. In conclusion, first-week peripheral blood Treg frequency correlates with AR after LT under tacrolimus-based immunosuppression, which needs to be proven in larger, geographically and clinically diverse populations.

Human liver CD8+ MAIT cells exert TCR/MR1-independent innate-like cytotoxicity in response to IL-15.

BACKGROUND & AIMS: Mucosal-associated invariant T (MAIT) cells, the most abundant innate-like T cells in the human liver, can be activated by cytokines during viral infection without TCR stimulation. Here, we examined the mechanisms underlying TCR/MR1-independent innate-like cytotoxicity of cytokine-activated liver MAIT cells. We also examined the phenotype and function of MAIT cells from patients with acute viral hepatitis. METHODS: We obtained liver sinusoidal mononuclear cells from donor liver perfusate during liver transplantation and examined the effect of various cytokines on liver MAIT cells using flow cytometry and in vitro cytotoxicity assays. We also obtained peripheral blood and liver-infiltrating T cells from patients with acute hepatitis A (AHA) and examined the phenotype and function of MAIT cells using flow cytometry. RESULTS: IL-15-stimulated MAIT cells exerted granzyme B-dependent innate-like cytotoxicity in the absence of TCR/MR1 interaction. PI3K-mTOR signaling, NKG2D ligation, and CD2-mediated conjugate formation were critically required for this IL-15-induced innate-like cytotoxicity. MAIT cells from patients with AHA exhibited activated and cytotoxic phenotypes with higher NKG2D expression. The innate-like cytotoxicity of MAIT cells was significantly increased in patients with AHA and correlated with serum alanine aminotransferase levels. CONCLUSIONS: Taken together, the results demonstrate that liver MAIT cells activated by IL-15 exert NKG2D-dependent innate-like cytotoxicity in the absence of TCR/MR1 engagement. Furthermore, the innate-like cytotoxicity of MAIT cells is associated with liver injury in patients with AHA, suggesting that MAIT cells contribute to immune-mediated liver injury. LAY SUMMARY: Immune-mediated liver injury commonly occurs during viral infections of the liver. Mucosal-associated invariant T (MAIT) cells are the most abundant innate-like T cells in the human liver. Herein, we have identified a mechanism by which MAIT cells circumvent conventional T cell receptor interactions to exert cytotoxicity. We show that this innate-like cytotoxicity is increased during acute hepatitis A virus infection and correlates with the degree of hepatocyte injury.

Functions of human liver CD69+CD103-CD8+ T cells depend on HIF-2α activity in healthy and pathologic livers.

BACKGROUND & AIMS: Human liver CD69+CD8+ T cells are ~95% CD103- and ~5% CD103+. Although CD69+CD103+CD8+ T cells show tissue residency and robustly respond to antigens, CD69+CD103-CD8+ T cells are not yet well understood. METHODS: Liver perfusate and paired peripheral blood were collected from healthy living donors and recipients with cirrhosis during liver transplantation. Liver tissues were obtained from patients with acute hepatitis A. Phenotypic and functional analyses were performed by flow cytometry. Gene expression profiles were determined by microarray and quantitative reverse transcription PCR. PT-2385 was used to inhibit hypoxia-inducible factor (HIF)-2α. RESULTS: Human liver CD69+CD103-CD8+ T cells exhibited HIF-2α upregulation with a phenotype of tissue residency and terminal differentiation. CD103- cells comprised non-hepatotropic virus-specific T cells as well as hepatotropic virus-specific T cells, but CD103+ cells exhibited only hepatotropic virus specificity. Although CD103- cells were weaker effectors on a per cell basis than CD103+ cells, following T cell receptor or interleukin-15 stimulation, they remained the major CD69+CD8+ effector population in the liver, surviving with less cell death. An HIF-2α inhibitor suppressed the effector functions and survival of CD69+CD103-CD8+ T cells. In addition, HIF-2α expression in liver CD69+CD103-CD8+ T cells was significantly increased in patients with acute hepatitis A or cirrhosis. CONCLUSIONS: Liver CD69+CD103-CD8+ T cells are tissue resident and terminally differentiated, and their effector functions depend on HIF-2α. Furthermore, activation of liver CD69+CD103-CD8+ T cells with HIF-2α upregulation is observed during liver pathology. LAY SUMMARY: The immunologic characteristics and the role of CD69+CD103-CD8+ T cells, which are a major population of human liver CD8+ T cells, remain unknown. Our study shows that these T cells have a terminally differentiated tissue-resident phenotype, and their effector functions depend on a transcription factor, HIF-2α. Furthermore, these T cells were activated and expressed higher levels of HIF-2α in liver pathologies, suggesting that they play an important role in immune responses in liver tissues and the pathogenesis of human liver disease.

Autologous Adipose Tissue-Derived Mesenchymal Stem Cells Introduced by Biliary Stents or Local Immersion in Porcine Bile Duct Anastomoses.

Biliary complications (strictures and leaks) represent major limitations in living donor liver transplantation. Mesenchymal stem cells (MSCs) are a promising modality to prevent biliary complications because of immunosuppressive and angiogenic properties. Our goal was to evaluate the safety of adipose-derived MSC delivery to biliary anastomoses in a porcine model. Secondary objectives were defining the optimal method of delivery (intraluminal versus extraluminal) and to investigate MSC engraftment, angiogenesis, and fibrosis. Pigs were divided into 3 groups. Animals underwent adipose collection, MSC isolation, and expansion. Two weeks later, animals underwent bile duct transection, reanastomosis, and stent insertion. Group 1 received plastic stents wrapped in unseeded Vicryl mesh. Group 2 received stents wrapped in MSC-seeded mesh. Group 3 received unwrapped stents with the anastomosis immersed in an MSC suspension. Animals were killed 1 month after stent insertion when cholangiograms and biliary tissue were obtained. Serum was collected for liver biochemistries. Tissue was used for hematoxylin-eosin and trichrome staining and immunohistochemistry for MSC markers (CD44 and CD34) and for a marker of neoangiogenesis (CD31). There were no intraoperative complications. One pig died on postoperative day 3 due to acute cholangitis. All others recovered without complications. Cholangiography demonstrated no biliary leaks and minimal luminal narrowing. Surviving animals exhibited no symptoms, abnormal liver biochemistries, or clinically significant biliary stricturing. Group 3 showed significantly greater CD44 and CD34 staining, indicating MSC engraftment. Fibrosis was reduced at the anastomotic site in group 3 based on trichrome stain. CD31 staining of group 3 was more pronounced, supporting enhanced neoangiogenesis. In conclusion, adipose-derived MSCs were safely applied to biliary anastomoses. MSCs were locally engrafted within the bile duct and may have beneficial effects in terms of fibrosis and angiogenesis.