Memory-like Liver Natural Killer Cells are Responsible for Islet Destruction in Secondary Islet Transplantation.

We previously demonstrated the pivotal role of natural killer (NK) cells in islet graft loss during the early phase after intraportal syngeneic islet transplantation (IT). Liver-resident DX5- NK cells were reported to possess memory-like properties, distinguishing them from conventional DX5+ NK cells. Here, we investigated the impact of primary IT-induced liver DX5- NK cells on the engraftment of secondary-transplanted islets in mice. The culture of liver NK cells isolated from naive mice with TNF-α, IFN-γ, and IL-lß, mimicking instant blood-mediated inflammatory reaction, led to significantly increased DX5- NK cell percentage among total liver NK cells. Consistently, the prolonged expansion of DX5- CD69+ TRAIL+ CXCR3+ NK cells was observed after intraportal IT of 300 syngeneic islets (marginal mass). In most diabetic mice, 400 syngeneic islets of primary IT were sufficient to achieve normoglycaemia, whereas the same mass after secondary IT failed to induce normoglycaemia in mice that received 200 syngeneic islets during primary IT. These findings indicated that liver-resident DX5- NK cells significantly expanded even after syngeneic IT, and that these memory-like NK cells may target both originally engrafted and secondary-transplanted islets. Furthermore, anti-TNF-α treatment suppressed the expansion of liver-resident DX5- NK cells, resulting in successful islet engraftment after sequential ITs.

Acute Graft Rejection and Formation of De Novo Donor-Specific Antibodies Triggered by Low Cyclosporine Levels and Interferon Therapy for Recurrent Hepatitis C Infection After Liver Transplantation: A Case Report.

BACKGROUND: We report a case of acute rejection of a liver graft, together with the occurrence of de novo donor-specific antibodies (DSAs), in a 53-year-old Japanese man who had undergone deceased-donor liver transplantation. METHODS: The graft rejection was triggered by low cyclosporine levels and pegylated interferon treatment for the recurrence of hepatitis C virus (HCV) infection 18 months after transplantation. Although the graft was ABO-compatible, pre-formed DSA B51 was detected; therefore, total plasma exchange was performed and intravenous rituximab (500 mg/body) was administered before transplantation. RESULTS: DSA was absent 6 months after transplantation. HCV recurrence was treated with pegylated interferon-α-2a. Renal function deteriorated with this anti-HCV therapy, with serum cyclosporine levels decreasing to 50 ng/mL. A rapid virologic response was achieved, but liver function deteriorated after 3 months of anti-HCV therapy, with histologic evidence of acute cellular rejection and formation of de novo DSAs. Anti-thymocyte globulin was administered for 5 days, which led to immediate improvement in liver function. However, renal function declined, warranting hemodialysis. The patient recovered 2 months after acute rejection, although de novo DSAs persisted. CONCLUSIONS: Careful immunologic monitoring may be required for patients receiving interferon therapy for HCV infection to maintain sufficient blood levels of immunosuppressive agents and to prevent acute liver graft rejection.

Role of Natural Killer Cells in the Innate Immune System After Intraportal Islet Transplantation in Mice.

BACKGROUND: Both liver natural killer (NK) and NK T cells of the innate immune system play a crucial role in islet graft loss after intraportal islet transplantation, although a relationship between NK and NK T cells in islet loss has not been proven. In this study, we investigated the role of NK cells in the innate immune system in islet graft loss after intraportal islet transplantation. METHODS: To investigate the involvement of liver NK cells in islet destruction, we assessed the differences in graft survival after intraportal islet transplantation between CD1d-/- diabetic mice and NK cell-depleted CD1d-/- diabetic mice. RESULTS: The transplantation of 400 islets into the liver was sufficient to reverse hyperglycemia in wild-type diabetic mice (100%, 4/4). However, normoglycemia could not be achieved when 200 islets were transplanted (0%, 0/4). In contrast, intraportal transplantation of 200 islets in NK cell-depleted CD1d-/- diabetic mice ameliorated hyperglycemia in 71% of cases (5/7), whereas transplantation of the same number of islets in CD1d-/- diabetic mice did not (0%, 0/4). Histologic findings also confirmed that intact islets were observed in NK cell-depleted CD1d-/- diabetic mice, but were difficult to observe in CD1d-/- diabetic mice. CONCLUSIONS: The involvement of liver NK cells in the innate immune system related to islet graft loss after intraportal islet transplantation is revealed by improved graft survival and function in NK cell-depleted CD1d-/- diabetic mice. Our data reveal that regulation of NK cell activity is particularly important when insufficient islet numbers are used for transplantation.

MELD and Child-Pugh Scores Are Related to Immune Status of Intrahepatic Natural Killer Cells in Liver Transplant Candidates.

BACKGROUND: The role and phenotypic alterations of intrahepatic natural killer (NK) cells in liver disease were investigated. Although intrahepatic NK cells reportedly functionally deteriorate in the fibrotic liver, it remains unclear how the clinical severity of liver disease affects intrahepatic NK cells in patients with advanced liver failure. METHODS: We analyzed the phenotypic properties of intrahepatic NK cells by using mononuclear cells extracted from ex vivo liver perfusate effluents from patients who underwent liver transplantation. The relationship between the clinical severity of liver disease and the phenotype of intrahepatic NK cells in these patients was also evaluated. To estimate the immunological responsiveness of intrahepatic NK cells, phenotypic enhancement after interleukin-2 stimulation was analyzed. RESULTS: Intrahepatic NK cells from patients with advanced liver failure exhibited down-regulated monomodal expression of NKp46, a major activating molecule. Notably, the expression level of NKp46 decreased depending on the severity of liver disease, Model for End-Stage Liver Disease score, and Child-Pugh score rather than the etiology. After in vitro recombinant interleukin-2 stimulation, the enhancement of expression of cytotoxic molecules, NKp44, and tumor necrosis factor-related apoptosis-inducing ligand was significantly impaired in intrahepatic NK cells from patients with liver failure, concurrently with decreased expression of CD122 and interleukin-2 receptor beta. CONCLUSIONS: Our results suggest that terminal deterioration of liver environments by chronic liver disease impairs the potential of local NK cells, depending on the severity of the deterioration. These influences of advanced liver failure on intrahepatic NK cells may be attributed to multicentric carcinogenesis in patients with liver failure.

Principal component analysis uncovers cytomegalovirus-associated NK cell activation in Ph+ leukemia patients treated with dasatinib.

Dasatinib treatment markedly increases the number of large granular lymphocytes (LGLs) in a proportion of Ph+ leukemia patients, which associates with a better prognosis. The lymphocytosis is predominantly observed in cytomegalovirus (CMV)-seropositive patients, yet detectable CMV reactivation exists only in a small fraction of patients. Thus, etiology of the lymphocytosis still remains unclear. Here, we identified NK cells as the dominant LGLs expanding in dasatinib-treated patients, and applied principal component analysis (PCA) to an extensive panel of NK cell markers to explore underlying factors in NK cell activation. PCA displayed phenotypic divergence of NK cells that reflects CMV-associated differentiation and genetic differences, and the divergence was markedly augmented in CMV-seropositive dasatinib-treated patients. Notably, the CMV-associated highly differentiated status of NK cells was already observed at leukemia diagnosis, and was further enhanced after starting dasatinib in virtually all CMV-seropositive patients. Thus, the extensive characterization of NK cells by PCA strongly suggests that CMV is an essential factor in the NK cell activation, which progresses stepwise during leukemia and subsequent dasatinib treatment most likely by subclinical CMV reactivation. This study provides a rationale for the exploitation of CMV-associated NK cell activation for treatment of leukemias.

Fc-Gamma Receptor Polymorphisms Predispose Patients to Infectious Complications After Liver Transplantation.

We investigated the impact of polymorphisms in host innate immunoregulatory genes on the development of infectious complications after liver transplantation (LT). The single-nucleotide polymorphisms (SNPs) of C1QA [276A/G], FCGR2A [131H/R], and FCGR3A [158F/V], genes encoding the Fc gamma receptor (FcγR), were analyzed in 89 living donor LT recipients in relation to the occurrences of postoperative infectious complications within 30 days after LT. Consistent with a lower affinity of the isoform encoded by FCGR3A [158F] to both IgG1 and IgG3, a significantly higher incidence of bloodstream infections (BSI) was observed in the FCGR3A [158F/V or F/F] than in the FCGR3A [158V/V] individuals. The combination of FCGR2A and FCGR3A SNPs further stratified the incidence of BSI, regardless of C1QA SNP. The predominant causative pathogen of BSI in the FCGR3A [158F/F or F/V] patients was gram-positive cocci (73.3%), of which one third was methicillin-resistant Staphylococcus aureus. No differences were observed in the incidence of fungal infections or in cytomegalovirus infections with respect to the three gene polymorphisms. Our findings indicate that FcγR SNPs are predisposing factors for BSI and can predict mortality after LT. This study provides a foundation for further prospective studies on a larger scale.

Two patients treated with simeprevir plus pegylated-interferon and ribavirin triple therapy for recurrent hepatitis C after living donor liver transplantation: case report.

We previously reported our data on telaprevir (TVR) used in combination with pegylated-interferon and ribavirin (PEG-IFN/RBV) for the treatment of recurrent hepatitis C virus (HCV) genotype 1 infection after liver transplantation (LT). TVR substantially increases the blood levels of immunosuppressive agents such as cyclosporine and tacrolimus for drug-drug interactions. On the other hand, the effect of simeprevir (SMV) on the blood levels of these immunosuppressive agents is unclear. We report 2 patients who achieved viral responses with little effect on the blood levels of cyclosporine and tacrolimus using SMV plus PEG-IFN/RBV treatment. The first was a 71-year-old woman with HCV-related liver cirrhosis and hepatocellular carcinoma who failed to respond to PEG-IFN/RBV after living donor LT. She was treated with 40 mg/d of cyclosporine, and received SMV plus PEG-IFN/RBV treatment. The second was a 65-year-old man with HCV-related liver cirrhosis who failed to respond to PEG-IFN/RBV after living donor LT. He was treated with 3 mg/d of tacrolimus, and received SMV plus PEG-IFN/RBV treatment. Serum HCV RNA became undetectable using TaqMan polymerase chain reaction (PCR) test after 4 weeks of treatment in both patients, and no remarkable fluctuation in blood concentration was observed either in cyclosporine or tacrolimus during the 12 weeks of SMV treatment. Completion of 12-week SMV triple therapy was followed by PEG-IFNα2b plus RBV, and both patients achieved sustained virological response 12 weeks after the end of treatment. SMV plus PEG-IFNRBV treatment showed a remarkable viral response with little effect on blood levels of immunosuppressive agents for recurrent HCV genotype 1 infection after LT.

Clinical efficacy of simultaneous splenectomy in liver transplant recipients with hepatitis C virus.

BACKGROUND: Interferon (IFN) therapy is a well-established antiviral treatment for hepatitis C virus (HCV) - infected patients. However, susceptibility to thrombocytopenia is a major obstacle in its initiation or continuation, particularly in patients with HCV who underwent liver transplantation (LT). We previously showed that the coexistence of splenomegaly and thrombocytopenia could result in persistent thrombocytopenia after LT. Here we retrospectively evaluated the validity of this criterion for simultaneous splenectomy in recipients with HCV. PATIENTS AND METHODS: Subjects included 36 recipients with HCV who received LT between January 2006 and February 2012 at Hiroshima University. We analyzed the spleen volume, body surface area, platelet (PLT) count, and rate of completion or continuation with IFN therapy in these recipients. RESULT: Of these recipients, 30 did not require simultaneous splenectomy according to the criterion, and 24 actually did not receive simultaneous splenectomy. In this group, 21 (87.5%) started IFN therapy. Fifteen (71.4%) of these recipients completed or continued IFN therapy, whereas 13 (61.9%) achieved either a sustained virological response (SVR) or an end-of-treatment response. The PLT count increased to >100,000/mm(3) 1 month after LT in 16 (66.7%) recipients from this group. CONCLUSION: Our criterion detected the PLT count outcome after LT in recipients with HCV and achieved a better SVR result after IFN therapy.

Potential benefit of mixed lymphocyte reaction assay-based immune monitoring after living donor liver transplantation for recipients with autoimmune hepatitis.

BACKGROUND: Recipients with autoimmune hepatitis (AIH) have a higher incidence of both rejection and recurrence after liver transplantation (LT) when compared with cholestatic liver diseases such as primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC). This is due to the lack of an immune monitoring system, making it difficult to control immunosuppressant agents. In this study, we examine the benefit of the carboxyfluorescein diacetate succinimidyl ester-mixed lymphocyte reaction (CFSE-MLR) monitoring system for evaluating the immune status in recipients with AIH and PBC/PCS after LT. METHOD: Recipients who underwent LT (9 AIH and 11 PBC/PSC) from 2002 to 2013 at Hiroshima University were enrolled in this study. The correlation between the result of CFSE-MLR and the outcome, bacteremia, rejection, and/or recurrence was examined. RESULT: The cumulative survival rates for 5 years after LT revealed preferable outcomes for both groups (AIH 85.7%, PBC/PCS 80%). None of the recipients in the AIH group developed bacteremia during 90 days after LT, whereas three recipients from the PBC/PCS group (27%) developed bacteremia. The recurrence rate (AIH 33%, PBC/PSC 27%) was the same as the reported data; however, there was a lower incidence of acute rejection rate in our institution (AIH 11%, PBC/PSC 27%). In the CFSE-MLR assay, the stimulation index of CD4(+) T cells in the anti-self reaction was increased in recurrent cases, whereas no elevation of anti-donor reaction was observed in either CD4(+) or CD8(+) T cells. CONCLUSION: Optimization of the immunosuppressant agents based on the CSFE-MLR assay after LT achieved a preferable outcome in recipients with both AIH and PBC/PCS. Therefore, CFSE-MLR assay might be a useful tool for predicting the recurrence of autoimmune liver diseases by monitoring anti-self reactivity of CD4(+) T cells.

Bile CXC motif chemokine 10 levels correlate with anti-donor cytotoxic T cell responses after liver transplantation.

BACKGROUND: CXC motif chemokine 10 (CXCL10), known as interferon-γ-induced protein 10, is an inflammatory cytokine secreted by various cells in response to interferon-γ. CXCR3, the receptor of CXCL10, is predominantly expressed on activated T, B, natural killer, and dendritic cells, as well as macrophages. CXCR3 promotes chemotaxis upon binding CXCL10. Serum CXCL10 levels have recently attracted attention as a post-transplantation biomarker for graft rejection. However, the correlation between the degree of T cell response to allostimulation and CXCL10 levels remains unclear. In this study, we investigated the serum and bile CXCL10 levels of patients who underwent living donor liver transplantation (LDLT) and compared them with the T cell responses to allostimulation. PATIENTS AND METHODS: Between February 2009 and August 2012, 41 patients underwent LDLT at Hiroshima University Hospital. Serum and bile CXCL10 levels were measured weekly for 4 weeks after surgery, while the T cell responses to allostimulation were evaluated using a mixed lymphocyte reaction with an intracellular carboxyfluorescein diacetate succinimidyl ester-labeling technique that we regularly use to monitor the immune response to anti-donor and anti-third-party stimulation after liver transplantation. The stimulation index (SI) and CD25 expression of the CD4+ and CD8+ T cell subsets in response to allostimulation were then analyzed using flow cytometry. RESULTS: Serum CXCL10 levels were significantly correlated with the SI values for CD8+ T cells in response to both types of allostimulation. Bile CXCL10 levels were significantly correlated with CD25 expression of CD8+ T cell subsets, especially in response to anti-donor stimulation. Patients with higher bile CXCL10 levels suffered from severe acute cellular rejection that was refractory to steroid pulse. CONCLUSION: Measurements of bile CXCL10 levels could predict anti-donor cytotoxic T cell responses in liver transplant recipients.

Risk factors for development of new-onset diabetes mellitus and progressive impairment of glucose metabolism after living-donor liver transplantation.

BACKGROUND: New-onset diabetes mellitus (NODM) has a negative impact on graft and patient survivals. Hepatitis C virus (HCV) infection, high body mass index, increased donor and recipient ages, and calcineurin inhibitor (CNI) type have been identified as risk factors for the development of NODM. We aimed to elucidate the risk factors for the development of NODM and those for progressive glucose intolerance in adult living-donor liver transplant (LDLT) recipients. METHODS: We collected data from 188 primary liver transplant recipients (age > 16 years) who underwent LDLT from June 1991 to December 2011 at Hiroshima University Hospital. Risk factors for NODM and progressive impairment of glucose metabolism in pre-transplantation diabetes mellitus (DM) recipients were examined. RESULTS: Pre-transplantation DM was diagnosed in 32 recipients (19.3%). The overall incidence of NODM was 6.0% (8/134 recipients). Multivariate analysis revealed that old recipient age (≥55 years) is a unique predictive risk factor for developing NODM. The incident of pre-transplantation DM was significantly higher in recipients with HCV infection than in those without HCV. A high pre-transplantation triglyceride level was an independent risk factor for progressive impairment of glucose tolerance among 32 LDLT recipients with pre-transplantation DM. All of the NODM patients were being treated with tacrolimus at the time of diagnosis. Switching the CNI from tacrolimus to cyclosporine allowed one-half of the patients (4/8) to withdraw from insulin-dependent therapy. NODM and post-transplantation glucose intolerance had no negative impact on patient and graft outcomes. CONCLUSIONS: Older age of the recipient (≥55 years) was a significant risk factor for NODM. Hypertriglyceridemia in the recipients with DM is an independent risk factor for post-transplantation progressive impairment of glucose metabolism. NODM had no negative impact on outcomes in the LDLT recipients.

Multiple hepatic vein reconstruction using an all-in-one sleeve patch graft technique in living donor liver transplantation: a case report.

Maintaining hepatic inflow and appropriate venous drainage is important for maximizing the capacity of the retrieved graft in liver transplantation. Here, we report a successful case of multiple hepatic vein (HV) reconstruction using an all-in-one sleeve patch graft of the autologous great saphenous vein to ensure adequate blood flow through the HV. A patient with hepatocellular carcinoma caused by hepatitis C virus-induced cirrhosis underwent living donor liver transplantation using a right lobe graft. A preoperative dynamic computed tomography scan and intraoperative findings revealed that the graft had three middle HV tributaries, a superficial vein, segment VIII HV (V8), and segment V HV (V5). The openings of the superficial vein and V8 were located very close to that of the right hepatic vein (RHV) in the cutting surface. Each HV had significant diameter and drainage territory requiring reconstruction. An autologous great saphenous vein was used to create a sleeve patch to incorporate the close-packed HV openings. The autologous sleeve patch graft was sutured to the openings of the RHV and the superficial vein and the hole created on the sleeve patch graft was anastomosed to the openings of V8 directly on the back table to create an all-in-one sleeve patch. For the V5 reconstruction, the recipient's intrahepatic portal vein graft was used to create an interpositional conduit from the recipient's V5 to the inferior vena cava. The postoperative course was uneventful and postoperative studies revealed good graft function with excellent blood flow in the HV.

Renal vein extension using an autologous renal vein in a living donor with double inferior vena cava: a case report.

BACKGROUND: When the kidney from a living donor with a double inferior vena cava (IVC) is harvested for renal transplantation, the short length of the renal vein may eventually create a technical problem for graft implantation. Herein, we have reported a rare case of renal vein extension using an autologous renal vein in a living donor with a double IVC. CASE REPORT: A 70-year-old man with end-stage renal disease owing to autosomal-dominant polycystic kidney disease underwent a living donor kidney graft from his wife who had a double IVC. Because of the enlarged kidneys, the patient underwent a bilateral native nephrectomy with concomitant renal transplantation to create space in the pelvis. At nephrectomy, the recipient's renal vein was used to extend the donor renal vein. On the back table, the vein graft was sutured to the donor renal vein, permitting a 3.0-cm extension. RESULTS: The transplantation was performed safely without any complications; the recipient's renal function and blood flow were excellent after the operation. CONCLUSION: This case illustrated that an autologous renal vein graft is a preferable option to extend of short donor renal vein for recipients who require a simultaneous native nephrectomy.

Optimization of immunosuppressive therapy based on a multiparametric mixed lymphocyte reaction assay reduces infectious complications and mortality in living donor liver transplant recipients.

AIM: We investigated the clinical relevance of immune monitoring by a multiparametric mixed lymphocyte reaction (MLR) assay, wherein the number and phenotype of alloreactive precursors can be quantified by combining the results of carboxyfluorescein diacetate succinimidyl ester labeling and flow cytometry analysis. METHODS: In 51 adult patients undergoing living donor liver transplantation (OLT), immunosuppressive drugs were dosed on the basis of immune monitoring by the MLR assay (optimized protocol: group O). In 64 other patients, the agents were prescribed according to empirical regimens (empirical protocol: group E). In group O, MLR assays were performed at 2- to 4-week intervals until 3 months after OLT and thereafter at 3- to 6-month intervals. Therapeutic adjustments for immunosuppressants were determined by tapering the doses in cases of anti-donor hyporesponsiveness for both CD4+ and CD8+ T-cell subsets. RESULTS: The 1-year patient and graft survivals in groups O versus E were 90.2% versus 76.6%, respectively. The incidence of acute rejection episodes (ARE) among group O (13.7%) were lower than in cohort E (28.1%). None of the patients in group O while four patients (3%) in group E already have shown chronic rejection to date. The incidences of bacteremia and fungal infections in group O (9.8% and 7.5%, respectively) were lower than in cohort E (18.8% and 12.6%, respectively). CONCLUSION: A multiparametric MLR assay may facilitate the development of adequate immunosuppressive regimens.

Successful treatment of Trichosporon fungemia in a patient with refractory acute myeloid leukemia using voriconazole combined with liposomal amphotericin B.

Trichosporon fungemia is a rare and fatal fungal infection that occurs in patients with prolonged neutropenia associated with hematologic malignancies. A 21-year-old male developed Trichosporon fungemia during remission induction therapy for acute myeloid leukemia (AML). Although two courses of induction therapy failed to induce a remission of AML, combination therapy with voriconazole and liposomal amphotericin B (L-AmB) followed by monocyte colony-stimulating factor ameliorated the Trichosporon fungemia and enabled the patient to receive reduced-intensity bone marrow transplantation (BMT) from his human leukocyte antigen-A one-locus mismatched mother. The patient achieved a durable remission after BMT without exacerbation of Trichosporon fungemia. The combination therapy with voriconazole and L-AmB may therefore be useful in controlling Trichosporon fungemia associated with prolonged neutropenia after remission induction therapy for AML.

Allogeneic hematopoietic stem cell transplantation for acute myeloid leukemia with t(6;9)(p23;q34) dramatically improves the patient prognosis: a matched-pair analysis.

Acute myeloid leukemia (AML) with t(6;9)(p23;q34) is well known to have a poor prognosis treated with chemotherapy and autotransplantation. The presence of this karyotype is an indicator for allogeneic hematopoietic stem cell transplantation (HSCT); however, the impact of t(6;9)(p23;q34) on the HSCT outcome remains unclear. We conducted a matched-pair analysis of de novo AML patients with and without t(6;9)(p23;q34) using data obtained from the Japanese HSCT data registry. A total of 57 patients with t(6;9)(p23;q34) received transplants between 1996 and 2007, and 171 of 2056 normal karyotype patients matched for age, disease status at HSCT and graft source were selected. The overall survival, disease-free survival, cumulative incidence of relapse and the non-relapse mortality in t(6;9)(p23;q34) patients were comparable to those for normal karyotype patients. A univariate analysis showed that t(6;9)(p23;q34) had no significant impact on the overall survival. These findings suggest that allogeneic HSCT may overcome the unfavorable impact of t(6;9)(p23;q34) as an independent prognostic factor.