TCF1highPD-1+Ly108+CD8+ T Cells Are Associated with Graft Preservation in Sensitized Mice Treated with Non-Fc Receptor-Binding CD3 Antibodies.

The non-Fc-binding anti-CD3 Ab [anti-CD3F(ab')2] can induce graft acceptance depending on the therapeutic window in a rodent heart transplant model. The delayed protocol allows for early graft infiltration of lymphocytes, which may behave in an inhibitory manner. We investigated the most effective protocol for anti-CD3F(ab')2 in sensitized conditions to confirm the evidence for clinical application. C57BL/6 mice were sensitized with BALB/c tail skin grafts and transplanted with BALB/c heart grafts at 8-12 wk after sensitization. Fifty micrograms of anti-CD3F(ab')2 was administered daily for 5 consecutive days on days 1-5 (day 1 protocol) or days 3-7 (delayed protocol). In nonsensitized mice, the delayed protocol significantly prolonged graft survival after transplantation from BALB/c to naive B6 (median survival time [MST], >100 d). In contrast, the delayed protocol was unable to prevent graft rejection in sensitized mice (MST, 5 d). A significantly increased percentage of granzyme B+ CD8+ T cells was observed in the graft on day 3 posttransplantation in sensitized conditions. Further, the day 1 protocol significantly prolonged graft survival (MST, 18 d), even in sensitized conditions. Day 1 treatment significantly increased the percentage of Foxp3+CD25+CD4+ T cells and phenotypically changed CD8+ T cells in the graft (i.e., caused a significant increase in the proportion of Ly108+TCF1highPD-1+CD8+ T cells). In conclusion, different timings of delayed anti-CD3F(ab')2 treatment promoted allograft preservation in association with phenotypic changes in CD4+ and CD8+ T cells in the graft under sensitized conditions.

Clinical significance of mechanistic target of rapamycin expression in vessels that encapsulate tumor cluster-positive hepatocellular carcinoma patients who have undergone living donor liver transplantation.

Background: There is limited published information regarding the expression of mechanistic target of rapamycin (mTOR) in vessels that encapsulate tumor cluster (VETC)-positive hepatocellular carcinoma (HCC). The mTOR inhibitor, everolimus, has been approved as an immunosuppressant for use in HCC patients after living donor liver transplantation (LDLT). Methods: Using a database of 214 patients who underwent LDLT for HCC, we examined the mTOR protein and angiopoietin-2 (Ang-2) in VETC-positive HCC by immunohistochemical staining. The presence of VETC and mTOR expression were evaluated in both primary and recurrent HCC lesions. Results: Forty-three of the 214 patients (20.1%) were VETC-positive, and 29 of these 43 patients (67.4%) expressed mTOR. Relative Ang-2 expression was significantly higher in the mTOR-positive than in the mTOR-negative group (p = 0.037). Thirty-four of the 214 patients experienced HCC recurrence after LDLT; 20 of these were operable. The primary lesions of six of these 20 patients were VETC-positive; five of these six patients also had VETC-positive recurrent lesions (p < 0.001). The expression of mTOR was significantly higher in the VETC-positive lesions (p = 0.0018). Conclusions: We showed that mTOR expression was higher in the VETC-positive primary and recurrent lesions than in the VETC-negative ones.

Long-term risk of a fatty liver in liver donors.

Aim: Approximately 30 years have passed since the first experience of living donor liver transplantation. The time to evaluate the long-term safety of living donors has been fulfilled. Meanwhile, nonalcoholic fatty liver disease is increasingly common and a critical problem. The aim of this study was to evaluate the safety of living donor, focusing on fatty liver postdonation hepatectomy. Methods: Living donors (n = 212, 1997-2019) were evaluated by computed tomography (CT) at >1-year postdonation. A liver to spleen (L/S) ratio of <1.1 was defined as fatty liver. Results: Among 212 living liver donors, 30 (14.2%) detected fatty liver at 5.3 ± 4.2 years postdonation. The cumulative incidence rates of fatty liver were 3.1%, 12.1%, 22.1%, and 27.7% at 2, 5, 10, and 15 years postdonation, respectively. Of 30 subjects who developed fatty liver, 18 (60%) displayed a severe steatosis (L/S ratio <0.9). Five (16.7%) had a prior history of excessive alcohol abuse. More than 30% developed metabolic syndrome including obesity, hyperlipidemia, and diabetes. Although six (20%) had a Fib-4 index of >1.3, which included a case with a Fib-4 index of >2.67, no significant increased Fib-4 index was observed in the subjects with fatty liver as compared to those without fatty liver (p = 0.66). The independent predictive risk factors for developing fatty liver were male sex, pediatric recipient, and higher body mass index (>25) at donation. Conclusion: Living donors with risk factors for developing fatty liver should be carefully followed-up for the prevention and management of metabolic syndrome.

Post-transplant donor-specific anti-HLA antibodies with a higher mean fluorescence intensity are associated with graft fibrosis in pediatric living donor liver transplantation.

The roles of post-transplant anti-HLA donor specific antibody (DSA) in pediatric liver transplantation (LT), including therapeutic strategies, remain controversial. This study aimed to identify the risks of post-transplant DSA for graft fibrosis progression in pediatric living donor LT (LDLT). We retrospectively evaluated 88 LDLT pediatric cases between December 1995 and November 2019. DSAs were assessed with single antigen bead test. Graft fibrosis was histopathologically scored with METAVIR and the centrilobular sinusoidal fibrosis system. Post-transplant DSAs were detected in 37 (52.9%) cases at 10.8 (1.3-26.9) years post-LDLT. The histopathological examination of 32 pediatric cases with post-transplant DSA revealed that 7 (21.9%) with a high DSA-MFI (≥9,378) showed graft fibrosis progression (≥F2). No graft fibrosis was observed in the subjects with a low DSA-MFI. The risk factors for developing graft fibrosis in pediatric cases with post-transplant DSA were an older graft age (>46.5 years old), lower platelet count (<10.7 × 104/ml) and higher Fib4 index (>0.7807, recipient age; >1.8952, donor age). Limited efficacy of additional immunosuppressants was observed in DSA positive pediatric cases. In conclusion, pediatric cases with a high DSA-MFI and risk factors should undergo a histological examination. The appropriate treatment for post-transplant DSA in pediatric LT needs to be determined.

Impact of sustained viral response for hepatitis C virus on the outcomes of liver transplantation in hemophilic patients with human immunodeficiency virus/hepatitis C virus co-infection: A nationwide survey in Japan.

AIM: Human immunodeficiency virus (HIV)/hepatitis C virus (HCV) co-infection from blood products for hemophilia has been a social problem in Japan, and liver transplantation (LT) for these patients has been a challenging procedure. However, with the advent of the direct-acting antiviral agent for HCV and change in the policy for prioritization of deceased donor LT, the results of LT for patients co-infected with HCV/HIV may have improved. METHODS: This study was conducted to provide updated results of our nationwide survey of LT for patients co-infected with HCV/HIV, from January 1997 to December 2019. We collected data on 17 patients with HIV/HCV co-infection who underwent either deceased donor LT (n = 5) or living donor LT (n = 12). RESULTS: All the patients were men with hemophilia, and the median age was 41 (range, 23-61) years. The median CD4 count before LT was 258 (range, 63-751). Most patients had poor liver function before surgery with Child-Pugh grade C and a Model for End-stage Liver Disease score of 20 (range, 11-48). The right lobe was used for most grafts for living donor liver transplantation (n = 10). Overall survival was significantly better with a sustained viral response (SVR) than without an SVR, and a univariate analysis indicated that SVR after direct-acting antiviral or interferon/ribavirin showed the highest hazard ratio for patient survival after LT. A multivariate analysis was not possible because of the limited number of cases. CONCLUSION: SVR for HCV showed the highest impact on the outcome of LT for patients with hemophilia co-infected with HIV/HCV. SVR for HCV should be achieved before or after LT for patients with hemophilia co-infected with HIV/HCV for a better outcome.

[Successful treatment of a fulminant-type Wilson's disease with deceased donor liver transplantation after recovery from critical illness].

A 15-year-old female patient was diagnosed with a fulminant-type Wilson's disease. She had severe illness with a Model for End-Stage Liver Disease score of 25 and new Wilson Index score of 11. She underwent plasma exchanges, hemodiafiltration, and administration of fresh frozen plasma on consecutive days. Finally, she had recovered from severe illness and was discharged from the hospital. After 18 months of waiting time, she underwent deceased liver transplantation and returned to normal daily life. In Japan, the critical shortage of donated organs requires a long waiting time. Previous studies demonstrated that artificial liver support systems, including plasma exchange and hemodiafiltration, could be useful for a fulminant-type Wilson's disease. For such a disease, multidisciplinary bridging treatments are crucial for a successful liver transplantation.

Living Donor Liver Transplantation for Hepatic Venoocclusive Disease/Sinusoidal Obstruction Syndrome Originating from Hematopoietic Stem Cell Transplantation.

Background: Venoocclusive disease (VOD), also known as sinusoidal obstruction syndrome (SOS), is a life-threatening hematopoietic stem cell transplantation (HSCT) complication. Cases of mild and moderate VOD/SOS are self-limiting; however, the mortality for severe VOD/SOS has reached 80%. Recently, defibrotide became available and has been used for VOD/SOS; however, the outcome for patients with severe VOD/SOS is not satisfactory, and liver transplantation is attempted in these severe cases. Method: We describe a case of living donor liver transplantation (LDLT) for acute liver failure secondary to VOD/SOS that originates from HSCT. Result: Liver regeneration after LDLT was impaired, and several infections were developed before liver regeneration completion. Our patient suffered sepsis and finally died of multiorgan failure. Conclusion: Severe VOD/SOS originating from HSCT is associated with a very poor prognosis. The liver transplantation outcome for VOD/SOS has not been satisfied, but it may provide long-term survival if successful. We considered liver transplantation as a therapeutic option, especially in cases where sufficient graft volume is secured, considering impaired liver regeneration under bone marrow suppression after HSCT.

Efficient multiple treatments including molecular targeting agents in a case of recurrent hepatocellular carcinoma, post-living donor liver transplantation.

Despite the promising efficacies of recently developed molecular targeting therapies for hepatocellular carcinoma, their role in liver transplantation is unknown. Here we report that multidisciplinary treatment, including novel molecular targeting therapy with lenvatinib, achieved long-term survival of a patient with post-liver transplantation recurrence of hepatocellular carcinoma. A 62 year-old man with hepatocellular carcinoma beyond the Milan criteria, arising from hepatitis B virus-associated cirrhotic liver, underwent living donor liver transplantation. However, alpha-fetoprotein level increased a month post-transplantation, and pleural dissemination and lung metastasis of hepatocellular carcinoma in the right lung were detected. The patient was initially treated with sorafenib and rapamycin, right pleurectomy and upper and middle lobectomies were attempted as the second treatment. However, remnant tumors started to grow. Subsequently, the newly molecular targeting agents; regorafenib and lenvatinib, approved for recurrent hepatocellular carcinoma in Japan, were administered. Lenvatinib efficiently reduced tumor volumes and the alpha-fetoprotein level, which contributed to maintaining better quality of life for 26 months as an outpatient. Unfortunately, sepsis caused by cholangitis and liver abscess required the discontinuation of lenvatinib, and the patient died 73 months after the recurrence of hepatocellular carcinoma. Multidisciplinary treatment including lenvatinib is potentially acceptable for recurrent hepatocellular carcinoma after liver transplantation.

Liver Transplantation for Hepatocellular Carcinoma: How Should We Improve the Thresholds?

Hepatocellular carcinoma (HCC) is the third highest cause of cancer-related mortality, and liver transplantation is the ideal treatment for this disease. The Milan criteria provided the opportunity for HCC patients to undergo LT with favorable outcomes and have been the international gold standard and benchmark. With the accumulation of data, however, the Milan criteria are not regarded as too restrictive. After the implementation of the Milan criteria, many extended criteria have been proposed, which increases the limitations regarding the morphological tumor burden, and incorporates the tumor's biological behavior using surrogate markers. The paradigm for the patient selection for LT appears to be shifting from morphologic criteria to a combination of biologic, histologic, and morphologic criteria, and to the establishment of a model for predicting post-transplant recurrence and outcomes. This review article aims to characterize the various patient selection criteria for LT, with reference to several surrogate markers for the biological behavior of HCC (e.g., AFP, PIVKA-II, NLR, 18F-FDG PET/CT, liquid biopsy), and the response to locoregional therapy. Furthermore, the allocation rules in each country and the present evidence on the role of down-staging large tumors are addressed.

The impact of preformed donor-specific antibodies in living donor liver transplantation according to graft volume.

INTRODUCTION: The roles of preformed anti-HLA donor-specific antibodies (DSAs) in liver transplantation remain controversial. We evaluated the impact of preformed DSAs in living donor liver transplantation. METHODS: Adults who underwent living donor liver transplantation (n = 175) in our institute were included in this study. Lymphocyte cytotoxicity test (LCT), flow cytometric crossmatch (FCXM), and single-antigen bead assays were performed. RESULTS: Among adult living donor liver transplantation recipients, 27 (16.5%) and 14 (8.5%) had pretransplant FCXM-positive findings and LCT-positive findings, respectively. FCXM-positive patients displayed a significantly worse 5-year graft survival rate (77.3%; vs. DSA-negative, 91.6%). Six of 14 LCT-positive patients exhibited graft loss shortly after transplantation (5-year survival rate: 57.1%). All LCT-positive patients with graft loss underwent left lobe living donor liver transplantation. Significantly lower ratio of graft volume relative to standard liver volume (32.9 ± 5.7%) and smaller graft size (365.3 ± 57.9 g) were observed in patients with graft loss (p < .03, vs. surviving grafts). Significantly higher DSA-mean fluorescence intensity (MFI) values were present in patients with graft loss (p = .0012, vs. surviving grafts). CONCLUSIONS: Patients with preformed DSAs exhibited worse graft outcomes in living donor liver transplantation. Higher DSA-MFI values and smaller graft size were associated with worse outcomes in LCT-positive patients. High-risk patients with preformed DSAs should be considered for appropriate graft selection and application of a desensitization protocol.

Functional roles of graft-infiltrating lymphocytes during early-phase post-transplantation in mouse cardiac transplantation models.

Immunological behavior of graft-infiltrating lymphocytes (GILs) determines the graft fate (i.e., rejection or acceptance). Nevertheless, the functional alloreactivity and the phenotype of GILs at various times during the early post-transplantation phase have not been fully elucidated. We examined the immunological activities of early-phase GILs using a murine model of cardiac transplantation. GILs from 120-h allografts, but not 72-h allografts, showed robust activation and produced proinflammatory cytokines. In particular, a significant increase in CD69+ T-bet+ Nur77+ T cells was detected in 120-h allografts. Furthermore, isolated GILs were used to reconstitute BALB/c Rag2-/- γc-/- (BRG) mice. BRG mice reconstituted with 120-h GILs displayed donor-specific immune reactivity and rejected donor strain cardiac allografts; conversely, 72-h GILs exhibited weak anti-donor reactivity and did not reject allografts. These findings were confirmed by re-transplantation of cardiac allografts into BRG mice at 72-h post-transplantation. Re-transplanted allografts continued to function for >100 days, despite the presence of CD3+ GILs. In conclusion, the immunological behavior of GILs considerably differs over time during the early post-transplantation phase. A better understanding of the functional role of early-phase GILs may clarify the fate determination process in the graft-site microenvironment.

A case report of percutaneous direct injection of N-butyl-2-cyanoacrylate (NBCA) to treat a pancreatic duodenal stump leak after a simultaneous pancreas and kidney transplantation.

BACKGROUND: Simultaneous pancreas and kidney transplantation (SPK) is a treatment option for patients with end-stage renal disease due to type 1 diabetes mellitus. We report a patient with a refractory fistula due to leakage from the duodenal stump of the pancreas graft after an SPK with bladder drainage who was successfully treated with a percutaneous direct injection of N-butyl-2-cyanoacrylate (NBCA). CASE PRESENTATION: A 60-year-old female with a 33-year history of type 1 diabetes mellitus and a 10-year history of renal replacement therapy underwent an SPK in 2015. At the time of transplantation, an abdominal aortic aneurysm with a high risk of rupture was treated by a Y-graft replacement prior to the SPK. Bladder drainage of the pancreas graft was chosen to avoid a vessel graft infection. The patient's postoperative course was uneventful. The patient was discharged on postoperative day 93 with good-functioning pancreas and kidney grafts. One and a half years after the operation, the patient was found to have acute graft pancreatitis and a leak from the duodenal stump of the pancreas graft due to a paralytic neurogenic bladder. The insertion of an indwelling catheter into the bladder and the endoscopic-guided insertion of a catheter into the graft pancreatic duct through the duodenum/bladder anastomosis did not result in the closure of the fistula. Therefore, NBCA was injected at the site of the leak point using CT-guided technique. The fistula was completely closed immediately after the injection, with no recurrences of leaks. CONCLUSIONS: A percutaneous direct injection of NBCA is one of the treatment options to treat intractable fistulas.

The Efficacy of the Hepatocyte Spheroids for Hepatocyte Transplantation.

The safety and short-term efficacy of hepatocyte transplantation (HCTx) have been widely proven. However, issues such as reduced viability and/or function of hepatocytes, insufficient engraftment, and lack of a long-term effect have to be overcome for widespread application of HCTx. In this study, we evaluated hepatocyte spheroids (HSs), formed by self-aggregation of hepatocytes, as an alternative to hepatocytes in single-cell suspension. Hepatocytes were isolated from C57BL/6 J mice liver using a three-step collagenase perfusion technique and HSs were formed by the hanging drop method. After the spheroids formation, the HSs showed significantly higher mRNA expression of albumin, ornithine transcarbamylase, glucose-6-phosphate, alpha-1-antitrypsin, low density lipoprotein receptor, coagulation factors, and apolipoprotein E (ApoE) than 2 dimensional (2D)-cultured hepatocytes (p < 0.05). Albumin production by HSs was significantly higher than that by 2D-cultured hepatocytes (9.5 ± 2.5 vs 3.5 ± 1.8 µg/dL, p < 0.05). The HSs, but not single hepatocytes, maintained viability and albumin mRNA expression in suspension (92.0 ± 2.8% and 1.03 ± 0.09 at 6 h). HSs (3.6 × 106 cells) or isolated hepatocytes (fSH, 3.6 × 106 cells) were transplanted into the liver of ApoE knockout (KO-/-) mice via the portal vein. Following transplantation, serum ApoE concentration (ng/mL) of HS-transplanted mice (1w: 63.1 ± 56.7, 4w: 17.0 ± 10.9) was higher than that of fSH-transplanted mice (1 w: 33.4 ± 13.0, 4w: 13.7 ± 9.6). In both groups, the mRNA levels of pro-inflammatory cytokines (IL-6, IL-1ß, TNF-α, MCP-1, and MIP-1ß) were upregulated in the liver following transplantation; however, no significant differences were observed. Pathologically, transplanted HSs were observed as flat cell clusters in contact with the portal vein wall on day 7. Additionally, ApoE positive cells were observed in the liver parenchyma distant from the portal vein on day 28. Our results indicate that HS is a promising alternative to single hepatocytes and can be applied for HCTx.

Triazolopyrimidine derivative NK026680 and donor-specific transfusion induces CD4+CD25+Foxp3+ T cells and ameliorates allograft rejection in an antigen-specific manner.

We have previously demonstrated the unique properties of a new triazolopyrimidine derivative, NK026680, which exerts immunosuppressive effects in rat heart transplant model and confers tolerogeneic properties on ex vivo-conditioned dendritic cells in mice. We herein demonstrate that NK026680 promotes the expansion of regulatory T cells (Tregs) with potent immunoregulatory effects when used in combination with donor-specific transfusion (DST). BALB/c (H-2d) heart graft were transplanted into C57BL/6 (H-2b) mice following intravenous injection of donor splenocytes (DST) and oral administration of NK026680. The NK026680 plus DST treatment markedly prolonged the survival time of the donor-graft, but not that of the 3rd party-graft (C3H; H-2k). Treg cells in the recipient spleen on day 0 expanded when stimulated with donor-antigens in vivo and in vitro. After heart transplantation, Treg cells accumulated into the graft and increased in the spleen. NK026680 plus DST also decreased activated CD8+ T cells in the spleen and inhibited infiltration of CD8+ T cells into the graft. Depletion of CD25+ cells inhibited the graft prolonging effect of the NK026680 plus DST treatment. NK026680 administration together with DST induces potent immunoregulatory effects in an antigen-specific manner, likely due to the in vivo generation of donor-specific Tregs.

De novo hepatocellular carcinoma in living donor liver grafts: A Japanese multicenter experience.

AIM: Direct-acting antivirals for hepatitis C virus have reduced the decompensation risk. Immunosuppressants for transplantation raise the risk of occurrence of de novo malignancies. We assessed the probabilities of and risk factors for de novo hepatocellular carcinoma (HCC) development post-living donor liver transplantation (LDLT). METHODS: We retrospectively evaluated the data of developed HCC in a graft including metastatic HCC post-LDLT from 2779 adult cases collected from nine major liver transplantation centers in Japan. RESULTS: Of 2779 LDLT adult recipients, 34 (1.2%) developed HCCs in their grafts. Of 34, five HCCs appeared to be de novo because of a longer period to tumor detection (9.7 [6.4-15.4] years) and no HCC within the native liver of the two recipients. The donor origin of three of five de novo HCCs was confirmed using microsatellite analysis in resected tissue. Primary disease of all five was hepatitis C virus-related cirrhosis, of which two were treated with direct-acting antivirals. Four of five developed HCC de novo in the hepatitis B core antibody-positive grafts. De novo HCCs had favorable prognosis; four of five were cured with complete remission. However, recurrent HCC (n = 29) in the graft had a poorer outcome, especially in patients with neutrophil to lymphocyte ratio scores above 4 (median survival time, 262 [19-463] days). CONCLUSION: Analysis of the database from major liver transplantation institutes in Japan revealed that de novo HCCs determined by microsatellite analysis were rarely detected, but the majority were successfully treated. LDLT recipients with higher risks of de novo HCC, including those with hepatitis B core antibody-positive grafts, should be carefully followed by surveillance of the liver graft.

Post-transplant indolent T cell lymphoproliferative disorder in living donor liver transplantation: a case report.

BACKGROUND: Post-transplant lymphoproliferative disorder (PTLD) of T cell type has been rarely reported. Accurate diagnosis of this life-threatening rare form of PTLD is important for the treatment strategy. CASE PRESENTATION: A 7-year-old boy had severe diarrhea and weight loss progressively at 7 years post-living donor liver transplantation (LDLT) for biliary atresia. Endoscopy in the gastrointestinal (GI) tract revealed multiple erosions and ulcer lesions with prominent intraepithelial lymphocytosis in the duodenum and terminal ileum. Immunohistochemical examination demonstrated that these accumulated lymphocytes mainly comprised small- to medium-sized T cells expressing CD3, CD4, CD5, CD7, and CD103, but lacking CD8, CD56, and Epstein-Barr virus-encoded small RNAs. In addition, T cell receptor ß gene rearrangement was detected by polymerase chain reaction analysis. Comprehensively, the lesions were best interpreted as post-transplant indolent T cell lymphoproliferative disorder (LPD) of the intestine. Clinical remission was achieved by reducing the immunosuppressant. CONCLUSION: A rarely reported indolent type of T cell LPD in post-LDLT was diagnosed by direct inspection and histological investigation. Although the histological classification and therapeutic strategy for post-transplant indolent T cell LPD have not been established, reducing immunosuppression allowed complete remission in our case. To prevent the incidence of PTLD and de novo malignancy, developing a methodology to set a proper dose of immunosuppressant is required.

Second Case of Deceased Donor Liver Transplantation in a Patient Co-infected with HIV and HCV in Japan: Special Reference to the Management of Complicated Coagulopathy Due to a Diverse Spectrum of Preformed Anti-HLA Antibodies.

We report the second case of deceased donor liver transplantation in a patient co-infected with human immunodeficiency virus (HIV) and hepatitis C virus (HCV) in Japan. A 48-year-old patient with hemophilia A was infected with HIV and HCV through contaminated factor VIII concentrate in his childhood and developed cirrhosis and hepatocellular carcinoma. The patient was on the transplant list for a deceased donor liver. The patient had broad spectrum anti-HLA class I and II antibodies, which may be attributed to repeated whole blood transfusions in the past. Catastrophic coagulopathy during the surgery was predicted because of the underlying hemophilic status and severe thrombocytopenia requiring HLA-matched platelet products, which are difficult to obtain quickly. To maintain adequate platelet counts (> 5 × 104/µL) while awaiting liver transplantation, a thrombopoietin receptor agonist and rituximab were administered. During surgery, factor VIII concentrate was administered according to a previously planned protocol. Adequate hemostasis was obtained, and the operation was completed without uncontrollable coagulopathy. The postoperative course was uneventful, and the patient was discharged on postoperative day 41. Detailed planning is required for surgical patients with hemophilia and HIV/HCV cirrhosis, especially for those with a diverse spectrum of anti-HLA antibodies.

Novel immunological approach to asses donor reactivity of transplant recipients using a humanized mouse model.

In organ transplantation, a reproducible and robust immune-monitoring assay has not been established to determine individually tailored immunosuppressants (IS). We applied humanized mice reconstituted with human (hu-) peripheral blood mononuclear cells (PBMCs) obtained from living donor liver transplant recipients to evaluate their immune status. Engraftment of 2.5 × 106 hu-PBMCs from healthy volunteers and recipients in the NSG mice was achieved successfully. The reconstituted lymphocytes consisted mainly of hu-CD3+ lymphocytes with predominant CD45RA-CD62Llo TEM and CCR6-CXCR3+CD4+ Th1 cells in hu-PBMC-NSG mice. Interestingly, T cell allo-reactivity of hu-PBMC-NSG mice was amplified significantly compared with that of freshly isolated PBMCs (p < 0.05). Furthermore, magnified hu-T cell responses to donor antigens (Ag) were observed in 2/10 immunosuppressed recipients with multiple acute rejection (AR) experiences, suggesting that the immunological assay in hu-PBMC-NSG mice revealed hidden risks of allograft rejection by IS. Furthermore, donor Ag-specific hyporesponsiveness was maintained in recipients who had been completely weaned off IS (n = 4), despite homeostatic proliferation of hu-T cells in the hu-PBMC-NSG mice. The immunological assay in humanized mice provides a new tool to assess recipient immunity in the absence of IS and explore the underlying mechanisms to maintaining operational tolerance.

Outcome of Living-Donor Liver Transplantation Using Grafts from Donors Treated for Fatty Liver.

BACKGROUND The aim of this study was to determine the efficacy of treating donors' fatty liver (FL) and to assess early graft function in recipients who received treated FL grafts in living-donor liver transplantation (LDLT). MATERIAL AND METHODS Data were collected for adult-to-adult LDLTs. Donors diagnosed with FL (FL group) received diet-exercise and pharmacological treatment. The perioperative findings and early transplanted graft function were compared with those of donors without FL (non-FL group) during the same period. RESULTS Of 30 donors, 8 were determined to have FL. The median duration of treatment for FL was 58 days. The liver-to-spleen attenuation ratios on CT scan in the FL group were significantly improved after treatment: 0.95 (0.62-1.06) to 1.2 (1.12-1.46) (P=0.003). Liver biopsy prior to donor surgery showed ≤10% fatty infiltration. Postoperative laboratory findings of the donors in the FL group were comparable to those in the non-FL group: maximum alanine transaminase (189.6±94.7 IU/L vs. 196.8±57.4) and maximum total bilirubin (2.2±1.1 mg/dL vs. 1.7±0.5 mg/dL). No major complications were observed after donor hepatectomy in either group. There were no significant differences between the 2 groups in early graft function, as evaluated by laboratory data, ascites volume, and bile production 2 weeks postoperatively. Graft and patient survival were 100% in both groups at 3 months. CONCLUSIONS Preoperative intentional treatment for FL was effective. Early graft function and donor postoperative course were comparable in the 2 groups. These results suggest that well-treated steatotic grafts can be used without jeopardizing donor safety.

Transiently Activated Human Regulatory T Cells Upregulate BCL-XL Expression and Acquire a Functional Advantage in vivo.

Regulatory T cells (Tregs) can control excessive or undesirable immune responses toward autoantigens, alloantigens, and pathogens. In transplantation, host immune responses against the allograft are suppressed through the use of immunosuppressive drugs, however this often results in life-threatening side effects including nephrotoxicity and an increased incidence of cancer and opportunistic infections. Tregs can control graft-vs.-host disease and transplant rejection in experimental models, providing impetus for the use of Tregs as a cellular therapy in clinical transplantation. One of the major barriers to the widespread use of Treg cellular therapy is the requirement to expand cells ex vivo to large numbers in order to alter the overall balance between regulatory and effector cells. Methods that enhance suppressive capacity thereby reducing the need for expansion are therefore of interest. Here, we have compared the function of freshly-isolated and ex vivo-manipulated human Tregs in a pre-clinical humanized mouse model of skin transplantation. Sorted human CD127loCD25+CD4+ Tregs were assessed in three different conditions: freshly-isolated, following transient in vitro activation with antiCD3/antiCD28 beads or after ex vivo-expansion for 2 weeks in the presence of antiCD3/antiCD28 beads and recombinant human IL2. While ex vivo-expansion of human Tregs increased their suppressive function moderately, transient in vitro-activation of freshly isolated Tregs resulted in a powerful enhancement of Treg activity sufficient to promote long-term graft survival of all transplants in vivo. In order to investigate the mechanisms responsible for these effects, we measured the expression of Treg-associated markers and susceptibility to apoptosis in activated Tregs. Transiently activated Tregs displayed enhanced survival and proliferation in vitro and in vivo. On a molecular level, Treg activation resulted in an increased expression of anti-apoptotic BCL2L1 (encoding BCL-XL) which may be at least partially responsible for the observed enhancement in function. Our results suggest that in vitro activation of human Tregs arms them with superior proliferative and survival abilities, enabling them to more effectively control alloresponses. Importantly, this transient activation results in a rapid functional enhancement of freshly-isolated Tregs, thereby providing an opportunity to eliminate the need for in vitro expansion in select circumstances. A protocol employing this technique would therefore benefit from a reduced requirement for large cell numbers for effective therapy.