Liver Retransplantation Using Living Donor Grafts: A Feasible Approach for Chronic Allograft Failure.

BACKGROUND: The indication of living donor liver retransplantation (re-LDLT) for retransplant candidates with chronic allograft failure (CAF) is increasing because of the high mortality rate of patients on the waiting list. However, evidence supporting re-LDLT for CAF remains scarce because of technical difficulties. We aimed to examine the feasibility based on our significant case experience. METHODS: A total of 95 retransplant cases (adult: 53, pediatric: 42) between 2000 and 2020 were retrospectively reviewed. Graft survival after re-LDLT and deceased donor liver retransplantation (re-DDLT) was compared among recipients with CAF and acute allograft failure (AAF). RESULTS: Re-LDLTs for CAF were performed in 58 (61.1%) cases, re-DDLTs for CAF in 16 (16.8%) cases, re-LDLTs for AAF in 13 (13.7%) cases, and re-DDLTs for AAF in 8 (8.4%) cases. Re-DDLTs have become increasingly prevalent over time. Retransplantation for AAF results in lower graft survival than that for CAF in both adult and pediatric cases. All adult recipients who underwent re-LDLT for AAF died within 1 y after retransplantation. The 5-y graft survival between re-LDLT and re-DDLT for CAF was not significantly different (73.8% versus 75.0%, P = 0.84). Operation time and blood loss were not significantly different. CONCLUSIONS: The survival rate of re-LDLT for recipients with CAF is permissible. Re-LDLT may be another treatment option for recipients with CAF.

High expression of autotaxin is associated with poor recurrence-free survival in cholangiocarcinoma.

BACKGROUND AND AIM: Autotaxin (ATX) is an extracellular lysophospholipase D that catalyzes the hydrolysis of lysophosphatidylcholine into lysophosphatidic acid (LPA). Recent accumulating evidence indicates the biological roles of ATX in malignant tumors. However, the expression and clinical implications of ATX in human cholangiocarcinoma (CCA) remain elusive. METHODS: In this study, the expression of ATX in 97 human CCA tissues was evaluated by immunohistochemistry. Serum ATX levels were determined in CCA patients (n = 26) and healthy subjects (n = 8). Autotaxin expression in cell types within the tumor microenvironment was characterized by immunofluorescence staining. RESULTS: High ATX expression in CCA tissue was significantly associated with a higher frequency of lymph node metastasis (p = 0.050). High ATX expression was correlated with shorter overall survival (p = 0.032) and recurrence-free survival (RFS) (p = 0.001) than low ATX expression. In multivariate Cox analysis, high ATX expression (p = 0.019) was an independent factor for shorter RFS. Compared with low ATX expression, high ATX expression was significantly associated with higher Ki-67-positive cell counts (p < 0.001). Serum ATX levels were significantly higher in male CCA patients than in healthy male subjects (p = 0.030). In the tumor microenvironment of CCA, ATX protein was predominantly expressed in tumor cells, cancer-associated fibroblasts, plasma cells, and biliary epithelial cells. CONCLUSIONS: Our study highlights the clinical evidence and independent prognostic value of ATX in human CCA.

Ferroptosis-related gene glutathione peroxidase 4 promotes reprogramming of glucose metabolism via Akt-mTOR axis in intrahepatic cholangiocarcinoma.

The role of the ferroptosis-related gene glutathione peroxidase 4 (GPX4) in oncology has been extensively investigated. However, the clinical implications of GPX4 in patients with intrahepatic cholangiocarcinoma (ICC) remain unknown. This study aimed to evaluate the prognostic impact of GPX4 and its underlying molecular mechanisms in patients with ICC. Fifty-seven patients who underwent surgical resection for ICC between 2010 and 2017 were retrospectively analyzed. Based on the immunohistochemistry, patients were divided into GPX4 high (n = 15) and low (n = 42) groups, and clinical outcomes were assessed. Furthermore, the roles of GPX4 in cell proliferation, migration and gene expression were analyzed in ICC cell lines in vitro and in vivo. The results from clinical study showed that GPX4 high group showed significant associations with high SUVmax on 18F-fluorodeoxyglucose-positron emission tomography (≥8.0, P = 0.017), multiple tumors (P = 0.004), and showed glucose transporter 1 (GLUT1) high expression with a trend toward significance (P = 0.053). Overall and recurrence-free survival in the GPX4 high expression group were significantly worse than those in the GPX4 low expression group (P = 0.038 and P < 0.001, respectively). In the experimental study, inhibition of GPX4 attenuated cell proliferation and migration in ICC cell lines. Inhibition of GPX4 also decreased the expression of glucose metabolism-related genes, such as GLUT1 or HIF1α. Mechanistically, these molecular changes are regulated in Akt-mechanistic targets of rapamycin axis. In conclusion, this study suggested the pivotal value of GPX4 serving as a prognostic marker for patients with ICC. Furthermore, GPX4 can mediate glucose metabolism of ICC.

Completion of adjuvant S-1 chemotherapy after surgical resection for biliary tract cancer: A single center experience.

BACKGROUNDS: A recent randomized control trial (JCOG1202; ASCOT trial) demonstrated the efficacy of adjuvant S-1 chemotherapy (ASC) for biliary tract cancer (BTC) after surgical resection; however, the significance of the completion of ASC in the real-world setting remains unknown. METHODS: Data of consecutive patients who underwent surgical resection for biliary tract cancer (BTC) from 2011 to 2021 were retrospectively reviewed. Of these, patients who underwent ASC were enrolled in this study. Patients were divided into two groups according to whether ASC was completed: the completion group and the non-completion group. Clinicopathological features and survival outcomes were assessed. RESULTS: Of the 223 patients with BTC who underwent surgical resection, 75 patients who underwent ASC were included for analysis. Among them, 48 (64.0 %) completed the intended ASC course, while 27 cases (36.0 %) discontinued the treatment. The most common reason for the discontinuation was adverse event (n = 16, 59.3 %), followed by disease recurrence (n = 9, 33.3 %). Patients in the completion group showed significantly better overall survival (OS) (p < 0.001) and recurrence-free survival (RFS) (p < 0.001) compared to the non-completion group. Further, after excluding the patients in the non-completion group who discontinued ASC due to disease recurrence, the significance of ASC completion was retained for both OS and RFS. CONCLUSION: The completion of ASC was associated with improved prognosis in patients with BTC after surgical resection. The achievement of ASC should be the goal after surgical resection, while further study may be warranted regarding the resistance of ASC.

Current status of preoperative risk assessment for posthepatectomy liver failure in patients with hepatocellular carcinoma.

Liver resection is an effective therapeutic option for patients with hepatocellular carcinoma. However, posthepatectomy liver failure (PHLF) remains a major cause of hepatectomy-related mortality, and the accurate prediction of PHLF based on preoperative assessment of liver functional reserve is a critical issue. The definition of PHLF proposed by the International Study Group for Liver Surgery has gained acceptance as a standard grading criterion. Liver function can be estimated using a variety of parameters, including routine blood biochemical examinations, clinical scoring systems, dynamic liver function tests, liver stiffness and fibrosis markers, and imaging studies. The Child-Pugh score and model for end-stage liver disease scores are conventionally used for estimating liver decompensation, although the alternatively developed albumin-bilirubin score shows superior performance for predicting hepatic dysfunction. Indocyanine green clearance, a dynamic liver function test mostly used in Japan and other Asian countries, serves as a quantitative estimation of liver function reserve and helps determine indications for surgical procedures according to the estimated risk of PHLF. In an attempt to improve predictive accuracy, specific evaluation of liver fibrosis and portal hypertension has gained popularity, including liver stiffness measurements using ultrasonography or magnetic resonance elastography, as well as noninvasive fibrosis markers. Imaging modalities, including Tc-99m-labeled galactosyl serum albumin scintigraphy and gadolinium-enhanced magnetic resonance imaging, are used for preoperative evaluation in combination with liver volume. This review aims to provide an overview of the usefulness of current options for the preoperative assessment of liver function in predicting PHLF.

Long-term outcomes and salvageability in patients undergoing liver resection for intermediate- and advanced-stage hepatocellular carcinoma.

BACKGROUNDS: The prognosis of intermediate- and advanced-stage hepatocellular carcinoma after liver resection should be comprehensively analyzed due to the high incidence of tumor recurrence and the availability of salvage therapy. This study evaluated the long-term outcome and salvageability in these patients after liver resection. METHODS: Data from consecutive patients with intermediate- and advanced-stage hepatocellular carcinoma who underwent initial liver resection from 2000 to 2016 were retrospectively reviewed. Analyses were performed in the setting of the initial liver resection and the recurrence(s). Active salvage therapy for recurrence was defined as the implementation of each therapy with curative intent-repeat surgery, ablative therapy, and liver transplantation. RESULTS: Among the 1,013 liver resections for hepatocellular carcinoma, a total of 270 patients were eligible for this study (intermediate hepatocellular carcinoma, n = 134; advanced hepatocellular carcinoma, n = 136). The 5-year overall survival rates for intermediate and advanced-stage hepatocellular carcinoma were 49.7% and 36.8%, respectively; meanwhile, the actual recurrence rates excluding patients who died without recurrence were 94.7% and 90.7%, respectively. Active salvage therapy was performed in 43 (39.8%) patients with intermediate-stage hepatocellular carcinoma and 25 (23.4%) patients with advanced-stage hepatocellular carcinoma. Overall survival after initial liver resection, first active salvage therapy, and second/more active salvage therapy were comparable in both stages. CONCLUSIONS: This study suggests that although liver resection alone may not yield remission in most patients with intermediate and advanced-stage hepatocellular carcinoma, active salvage therapy can potentially prolong survival. Further study to identify approaches to decrease recurrence rates and increase salvageability for these patients would be warranted.

Impact of liver volumetric regeneration on survival outcomes in patients with hepatocellular carcinoma after major hepatectomy.

PURPOSE: Prognostic value of liver volumetric regeneration (LVR) in patients with hepatocellular carcinoma (HCC) who undergo major hepatectomy remains unknown. The aim of this study was to investigate the impact of LVR on long-term outcomes in these patients. METHODS: Data of 399 consecutive patients with HCC who underwent major hepatectomy between 2000 to 2018 were retrieved from a prospectively maintained institutional database. The LVR-index was defined as the relative increase in liver volume from 7 days to 3 months (RLV3m/RLV7d, where RLV3m and RLV7d is the remnant liver volume around 3 months and postoperative 7 days after surgery). The optimal cut-off value was determined using the median value of LVR-index. RESULTS: A total of 131 patients were eligible in this study. The optimal cut off value of LVR-index was 1.194. The 1-, 3-, 5- and 10-year overall survival (OS) rate of patients in the high LVR-index group were significantly better compared to those in the low LVR-index group (95.5%, 84.8%, 75.4% and 49.1% vs. 95.4%, 70.2%, 56.4%, and 19.9%, p = 0.002). Meanwhile, there was no significant difference with regards to time to recurrence between the two groups (p = 0.607). Significance of LVR-index for OS was retained after adjusting for known prognostic factors (p = 0.002). CONCLUSION: In patients with HCC undergoing major hepatectomy, LVR-index may serve as a prognostic indicator for OS.

Utility of serum autotaxin levels for predicting post hepatectomy liver failure in hepatocellular carcinoma.

BACKGROUND/PURPOSE: This study aimed to evaluate the usefulness of serum autotaxin, a novel liver fibrosis marker, for predicting post hepatectomy liver failure (PHLF) in patients undergoing hepatectomy for hepatocellular carcinoma (HCC). METHODS: Autotaxin was measured in sera from 269 patients undergoing hepatectomy for HCC. Correlations between autotaxin level, liver fibrosis stage (METAVIR F0-F4), and PHLF, as assessed by the International Study Group of Liver Surgery criteria, were analyzed. RESULTS: Median autotaxin concentrations correlated significantly with fibrosis stage (F0, 0.93; F1, 0.96; F2, 1.18; F3, 1.40; and F4, 1.47 mg/l; P < .0001). Autotaxin levels were significantly higher in female patients and hepatitis C virus antibody-positive patients compared with male or antibody-negative patients (P < .0001). PHLF grade ≥ B occurred in 25 patients (9.3%). A PHLF prediction model was constructed from four variables (autotaxin, resection rate, sex, and hepatitis C virus antibody positivity) and gave an area under the receiver operating characteristic curve of 0.8 (95% confidence interval [CI]: 0.69-0.87), which was superior to models based on ALPlat and resection rate (0.75, 95% CI: 0.64-0.83) or indocyanine green retention test and resection rate (0.72, 95% CI: 0.61-0.81). CONCLUSION: Serum autotaxin has utility for predicting liver fibrosis and PHLF in patients with HCC.

Nonsuperiority of technetium-99m-galactosyl human serum albumin scintigraphy over conventional volumetry for assessing the future liver remnant in patients undergoing hepatectomy after portal vein embolization.

BACKGROUND: Technetium-99m-galactosyl human serum albumin scintigraphy is preferred for assessing the liver functional reserve in patients undergoing hepatectomy, but its superiority over computed tomography volumetry after portal vein embolization and subsequent hepatectomy remains elusive. We aimed to compare technetium-99m-galactosyl human serum albumin scintigraphy with conventional computed tomography volumetry for predicting posthepatectomy liver failure in patients after portal vein embolization. METHODS: This retrospective study analyzed 152 consecutive patients who underwent hepatobiliary cancer resection after portal vein embolization between 2006 and 2021. Posthepatectomy liver failure was graded according to the International Study Group of Liver Surgery criteria. The predictive abilities for posthepatectomy liver failure were compared between the future remnant uptake (%) by technetium-99m-galactosyl human serum albumin scintigraphy and the future remnant volume (%) by computed tomography volumetry. RESULTS: Future remnant uptake (%) was significantly greater than future remnant volume (%) after portal vein embolization (47.9% vs 40.8%; P < .001), while the values were comparable before portal vein embolization (32.7% vs 31.2%; P = .116). Receiver operating characteristic curve analysis revealed that post-portal vein embolization future remnant volume (%) had a significantly higher area under the curve than post-portal vein embolization future remnant uptake (%) (0.709 vs 0.630; P = .046) for predicting posthepatectomy liver failure. Multivariable analysis revealed that post-portal vein embolization future remnant volume (%) independently predicted posthepatectomy liver failure, but future remnant uptake (%) did not. Although the incidence of posthepatectomy liver failure grade ≥B was 17.8% when indocyanine green-clearance of the future liver remnant based on both future remnant volume (%) and future remnant uptake (%) was ≥0.05, it was higher in other combinations: 55.6% for indocyanine green clearance of the remnant volume ≥0.05/indocyanine green clearance of the remnant uptake ≤0.05; 50.0% for indocyanine green clearance of the remnant volume ≤0.05/indocyanine green clearance of the remnant uptake ≥0.05; and 50% for indocyanine green clearance of the remnant volume ≤0.05/indocyanine green clearance of the remnant uptake ≤0.05. CONCLUSIONS: Technetium-99m-galactosyl human serum albumin scintigraphy is not superior to computed tomography volumetry for assessing the future liver remnant in patients undergoing major hepatectomy after portal vein embolization.

A Conceptual Classification of Resectability for Hepatocellular Carcinoma.

BACKGROUNDS: In the era of multidisciplinary treatment strategy, resectability for hepatocellular carcinoma (HCC) should be defined. This study aimed to propose and validate a resectability classification of HCC. METHODS: We proposed following the three groups; resectable-(R), borderline resectable-(BR), and unresectable (UR)-HCCs. Resectable two groups were sub-divided according to the value of indocyanine green clearance of remnant liver (ICG-Krem) and presence of macrovascular invasion (MVI); BR-HCC was defined as resectable HCCs with MVI and/or ICG-Krem≥0.03-<0.05, and R-HCC was the remaining. Consecutive patients with HCC who underwent liver resection (LR) and non-surgical treatment(s) (i.e., UR-HCC) between 2011 and 2017 were retrospectively analyzed to validate the proposed classification. RESULTS: A total of 361 patients were enrolled in the study. Of these, R-, BR- and UR-HCC were found in 251, 46, and 64 patients, respectively. In patients with resected HCC, ICG-Krem≥0.05 was associated with decreased risk of clinically relevant posthepatectomy liver failure (p=0.013) and the presence of MVI was associated with worse overall survival (OS) (p<0.001). The 3-5-years OS rates according to the proposed classification were 80.3, and 68.3% versus 51.4, and 35.6%, in the R and BR groups, respectively (both p<0.001). Multivariate analysis showed BR-HCC was independently associated with poorer OS (p<0.001) after adjusting for known tumor prognostic factors. Meanwhile, BR-HCC was associated with benefit in terms of OS compared with UR-HCC (p<0.001). CONCLUSION: Our proposal of resectability for HCC allows for stratifying survival outcomes of HCC and may help to determine treatment strategy.

Characterization and role of collagen gene expressing hepatic cells following partial hepatectomy in mice.

BACKGROUND AND AIMS: The mechanism underlying liver regeneration following partial hepatectomy (PH) is not fully elucidated. We aimed to characterize collagen gene expressing hepatic cells following PH and examine their contribution to liver regeneration. APPROACH AND RESULTS: Col-GFP mice, which express GFP under the control of the collagen gene promoter, were used to detect collagen gene expressing cells following PH. The GFP-expressing cells were analyzed via single-cell RNA sequencing (scRNA-seq). Additionally, Col-ER Cre/RFP and Col-ER Cre/DTA mice were utilized to examine the cell fates and functional roles of collagen gene expressing cells in liver regeneration, respectively. The number of collagen gene expressing cells was found to be increased on day 3 and subsequently decreased on day 7 following PH. ScRNA-seq analysis of sorted collagen gene expressing cells showed that the regenerating liver was characterized by three distinct hepatic stellate cell (HSC) clusters, including one representing classic myofibroblasts. The other HSC clusters included an intermediately activated HSC cluster and a proliferating HSC cluster. Of these, the latter cluster was absent in the CCl 4 -induced liver fibrosis model. Cell fate tracing analysis using Col-ER Cre/RFP mice demonstrated that the collagen gene expressing cells escaped death during regeneration and remained in an inactivated state in the liver. Further, depletion of these cells using Col-ER Cre/DTA mice resulted in impaired liver regeneration. CONCLUSIONS: Heterogeneous HSC clusters, one of which was a unique proliferating cluster, were found to appear in the liver following PH. Collagen gene expressing cells, including HSCs, were found to promote liver regeneration.

Narrow-Band Emitting Phosphor Na2Cs2Sr(B9O15)2:Eu2+ Discovered from Local Structure Similarity with Sulfate Phosphor.

Narrow-band emitting phosphors are required to improve the performance of phosphor-converted light-emitting diodes. Here, we found a new narrow-band emitting phosphor Na2Cs2Sr(B9O15)2:Eu2+ using the local structure similarity with a known narrow-band emitting phosphor. In a 2D scatter plot of the structural similarity between the local structures, the Sr site in Na2Cs2Sr(B9O15)2 was located near the Ba site of the known narrow-band emitting sulfate phosphor BaSO4:Eu2+ with a distorted local structure. We synthesized Na2Cs2Sr(B9O15)2:Eu2+ and characterized the luminescence properties by microspectroscopy. Na2Cs2Sr(B9O15)2:Eu2+ showed a violet luminescence peaked at 417 nm, and the full-width at half-maximum was as narrow as 26 nm (1497 cm-1).

The Role of Mesothelin in Activation of Portal Fibroblasts in Cholestatic Liver Injury.

Fibrosis is a common consequence of abnormal wound healing, which is characterized by infiltration of myofibroblasts and formation of fibrous scar. In liver fibrosis, activated Hepatic Stellate Cells (aHSCs) and activated Portal Fibroblasts (aPFs) are the major contributors to the origin of hepatic myofibroblasts. aPFs are significantly involved in the pathogenesis of cholestatic fibrosis, suggesting that aPFs may be a primary target for anti-fibrotic therapy in cholestatic injury. aPFs are distinguishable from aHSCs by specific markers including mesothelin (Msln), Mucin 16 (Muc16), and Thymus cell antigen 1 (Thy1, CD90) as well as fibulin 2, elastin, Gremlin 1, ecto-ATPase nucleoside triphosphate diphosphohydrolase 2. Msln plays a critical role in activation of PFs, via formation of Msln-Muc16-Thy1 complex that regulates TGFß1/TGFßRI-mediated fibrogenic signaling. The opposing pro- and anti-fibrogenic effects of Msln and Thy1 are key components of the TGFß1-induced activation pathway in aPFs. In addition, aPFs and activated lung and kidney fibroblasts share similarities across different organs with expression of common markers and activation cascade including Msln-Thy1 interaction. Here, we summarize the potential function of Msln in activation of PFs and development of cholestatic fibrosis, offering a novel perspective for anti-fibrotic therapy targeting Msln.

Impact of Preoperative CEA Uptrend on Survival Outcomes in Patients with Colorectal Liver Metastasis After Hepatectomy.

BACKGROUND: Preoperative carcinoembryonic antigen (CEA) has been reported as a prognostic factor in patients with colorectal liver metastasis (CRLM) after hepatectomy. However, the impact of a preoperative "CEA uptrend" on prognosis after hepatectomy in these patients remains unknown. This study assessed the impact of CEA uptrend on prognosis in patients undergoing hepatectomy for CRLM. METHODS: Consecutive patients with CRLM who underwent hepatectomy between 2009 and 2018 were retrospectively analyzed. Patients with CRLM for whom CEA was measured both around 1 month before (CEA-1m) and within 3 days (CEA-3d) before hepatectomy were enrolled. A CEA-3d higher than both the upper limit of normal (5 ng/ml) and CEA-1m was defined as a CEA uptrend. RESULTS: Study participants comprised 212 patients with CRLM. Of these, 88 patients (41.5%) showed a CEA uptrend. CEA uptrend indicated better discriminatory ability (corrected Akaike information criteria, 733.72) and homogeneity (likelihood ratio chi-square value, 18.80) than CEA-3d or CEA-1m. Patients with CEA uptrend showed poorer overall survival than those without CEA uptrend (p < 0.001). After adjusting for known prognostic factors, the prognostic significance of CEA uptrend retained (hazard ratio 2.63, 95% confidence interval 1.63-4.26, p < 0.001). In subgroup analyses, the prognostic significance of CEA uptrend was retained irrespective of the status of RAS mutation or response to preoperative chemotherapy. CONCLUSIONS: CEA uptrend offers better prediction of survival outcomes than conventional CEA measurements in patients undergoing hepatectomy for CRLM.

Acute coronary syndrome after liver transplantation in a young primary biliary cholangitis recipient with dyslipidemia: a case report.

BACKGROUND: Primary biliary cholangitis (PBC) is a chronic, progressive liver disease associated with dyslipidemia. There is a consensus that PBC does not accelerate coronary artery disease despite high cholesterol levels, so the screening test for the coronary artery is not routinely performed before liver transplantation (LT). To date, no report has described the potential risk of PBC-related dyslipidemia for developing acute coronary syndrome (ACS) after LT. CASE PRESENTATION: A 40-year-old Asian female with a known history of PBC underwent ABO-incompatible living-donor LT, with her husband as the donor. Although she had high cholesterol and triglyceride levels that were refractory to medications, she passed all routine preoperative examinations, including cardiopulmonary function tests and infection screenings. One week after LT, she developed ACS with 90% stenosis of both the left anterior descending artery and left circumflex artery. Emergent stent implantation was successfully performed followed by dual antiplatelet therapy. The long history of PBC and associated severe dyslipidemia for 10 years would have accelerated the atherosclerosis, causing latent stenosis in the coronary artery. Inapparent stenosis might have become apparent due to unstable hemodynamics during the acute phase after LT. CONCLUSIONS: PBC-related dyslipidemia potentially brings a risk for developing ACS after LT. This experience suggests that the preoperative evaluation of the coronary artery should be considered for high-risk patients, especially those who have drug-resistant dyslipidemia.

Bile Duct Regeneration with an Artificial Bile Duct Made of Gelatin Hydrogel Nonwoven Fabrics.

Although choledochojejunostomy is the standard technique for biliary reconstruction, there are various associated problems that need to be solved such as reflux cholangitis. Interposition with an artificial bile duct (ABD) to replace the resected bile duct maintains a physiological conduit for bile and may solve this problem. This study investigated the usefulness of an ABD made of gelatin hydrogel nonwoven fabric (GHNF). GHNF was prepared by the solution blow spinning method. The migration and activity of murine fibroblast L929 cells were examined in GHNF sheets. L929 cells migrated into GHNF sheets, where they proliferated and synthesized collagen, suggesting GHNF is a promising scaffold for bile duct regeneration. ABDs made of GHNF were implanted in place of resected bile duct segments in rats. The rats were killed at 2, 6, and 12 weeks postimplantation. The implantation site was histologically evaluated for bile duct regeneration. At postoperative 2 weeks, migrating cells were observed in the ABD pores. The implanted ABD was mostly degraded and replaced by collagen fibers at 6 weeks. Ki67-positive bile duct epithelial cells appeared within the implanted ABD. These were most abundant within the central part of the ABD after 6 weeks. The percentages of Ki67-positive cells were 31.7 ± 9.1% in the experimental group and 0.8 ± 0.6% in the sham operation group at 6 weeks (p < 0.05), indicating that mature biliary epithelial cells at the stump proliferated to regenerate the biliary epithelium. Biliary epithelial cells had almost completely covered the bile duct lumen at 12 weeks (epithelialization ratios: 10.4 ± 6.9% at 2 weeks, 93.1 ± 5.1% at 6 weeks, 99.2 ± 1.6% at 12 weeks). The regenerated epithelium was positive for the bile duct epithelium marker cytokeratin 19. Bile duct regeneration was accompanied by angiogenesis, as evidenced by the appearance of CD31-positive vascular structures. Capillaries were induced 2 weeks after implantation. The number of capillaries reached a maximum at 6 weeks and decreased to the same level as that of normal bile ducts at 12 weeks. These results showed that an ABD of GHNF contributed to successful bile duct regeneration in rats by facilitating the cell migration required for extracellular matrix synthesis, angiogenesis, and epithelialization. Impact Statement Development of an artificial bile duct (ABD) enables physiological biliary reconstruction and may solve clinical problems associated with choledochojejunostomy. In this study, we created ABDs with gelatin hydrogel nonwoven fabric and implanted them in place of resected bile duct in rats. We evaluated the process of bile duct regeneration as well as decomposition of the ABD and demonstrated successful regeneration of resected bile duct, highlighting the possibility of this novel biliary reconstruction method to replace choledochojejunostomy.

Increased Expressions of Programmed Death Ligand 1 and Galectin 9 in Transplant Recipients Who Achieved Tolerance After Immunosuppression Withdrawal.

Programmed death 1 (PD1)/its ligand PD-L1 concomitant with T cell immunoglobulin and mucin domain-containing protein 3 (TIM-3)/its ligand galectin 9 (Gal-9) and the forkhead box P3 (FOXP3) might be involved in tolerance after liver transplantation (LT). Liver biopsies from 38 tolerant, 19 nontolerant (including 16 samples that triggered reintroduction of immunosuppression [IS] and 19 samples after IS reintroduction), and 38 control LT patients were studied. The expressions of PD1, PD-L1, Gal-9, and FOXP3 were determined by immunohistochemical and immunofluorescence (IF) staining. The success period of IS withdrawal was calculated using Kaplan-Meier curve analysis. Tolerant and control patients exhibited higher PD-L1, Gal-9, and FOXP3 levels than nontolerant patients at the moment of triggering IS reintroduction. High expressions of PD-L1 and Gal-9 were associated with prolonged success of tolerance (83.3% versus 36.7% [P < 0.01] and 73.1% versus 42.9% [P = 0.03]). A strong correlation between PD-L1 and Gal-9 expression levels was detected (Spearman r = 0.73; P ≤ 0.001), and IF demonstrated colocalization of PD-L1 and Gal-9 in the cytoplasm of hepatocytes. In conclusion, the present study demonstrated that increased expressions of PD-L1 and Gal-9 were associated with sustained tolerance after IS withdrawal in pediatric liver transplantation.