Stringent V beta requirement for the development of NK1.1+ T cell receptor-alpha/beta+ cells in mouse liver.

The liver of C57BL/6 mice contains a major subset of CD4+8- and CD4-8- T cell receptor (TCR)-alpha/beta+ cells expressing the polymorphic natural killer NK1.1 surface marker. Liver NK1.1+TCR-alpha/beta+ (NK1+ T) cells require interaction with beta2-microglobulin-associated, major histocompatibility complex I-like molecules on hematopoietic cells for their development and have a TCR repertoire that is highly skewed to Vbeta8.2, Vbeta7, and Vbeta2. We show here that congenic C57BL/6.Vbeta(a) mice, which lack Vbeta8- expressing T cells owing to a genomic deletion at the Vbeta locus, maintain normal levels of liver NK1+ T cells owing to a dramatic increase in the proportion of cells expressing Vbeta7 and Vbeta2 (but not other Vbetas). Moreover, in C57BL/6 congenic TCR-V Vbeta3 and -Vbeta8.1 transgenic mice (which in theory should not express other Vbeta, owing to allelic exclusion at the TCR-beta locus), endogenous TCR-Vbeta8.2, Vbeta7, and Vbeta2 (but not other Vbetas) are frequently expressed on liver NK1+T cells but absent on lymph node T cells. Finally, when endogenous V beta expression is prevented in TCR-Vbeta3 and Vbeta8.1 transgenic mice (by introduction of a null allele at the C beta locus), the development of liver NK1+T cells is totally abrogated. Collectively, our data indicate that liver NK1+T cells have a stringent requirement for expression of TCR-Vbeta8.2, Vbeta7, or Vbeta2 for their development.

Selectively impaired development of intestinal T cell receptor gamma delta+ cells and liver CD4+ NK1+ T cell receptor alpha beta+ cells in T cell factor-1-deficient mice.

T cell factor-1 (Tcf-1) is a transcription factor that binds to a sequence motif present in several T cell-specific enhancer elements. In Tcf-1-deficient (Tcf-1-/-) mice, thymocyte development is partially blocked at the transition from the CD4-8+ immature single-positive stage to the CD4+8+ double-positive stage, resulting in a marked decrease of mature peripheral T cells in lymph node and spleen. We report here that the development of most intestinal TCR gamma delta+ cells and liver CD4+ NK1.1+TCR alpha beta+ (NK1+T) cells, which are believed to be of extrathymic origin, is selectively impaired in Tcf-1-/- mice. In contrast, thymic and thymus-derived (splenic) TCR gamma delta+ cells are present in normal numbers in Tcf-1-/- mice, as are other T cell subsets in intestine and liver. Collectively, our data suggest that Tcf-1 is differentially required for the development of some extrathymic T cell subsets, including intestinal TCR gamma delta+ cells and liver CD4+ NK1+T cells.

The use of liver biopsy evaluation in discrimination of idiopathic autoimmune hepatitis versus drug-induced liver injury.

Distinguishing drug-induced liver injury (DILI) from idiopathic autoimmune hepatitis (AIH) can be challenging. We performed a standardized histologic evaluation to explore potential hallmarks to differentiate AIH versus DILI. Biopsies from patients with clinically well-characterized DILI [n = 35, including 19 hepatocellular injury (HC) and 16 cholestatic/mixed injury (CS)] and AIH (n = 28) were evaluated for Ishak scores, prominent inflammatory cell types in portal and intra-acinar areas, the presence or absence of emperipolesis, rosette formation, and cholestasis in a blinded fashion by four experienced hepatopathologists. Histologic diagnosis was concordant with clinical diagnosis in 65% of cases; but agreement on final diagnosis among the four pathologists was complete in only 46% of cases. Interface hepatitis, focal necrosis, and portal inflammation were present in all evaluated cases, but were more severe in AIH (P < 0.05) than DILI (HC). Portal and intra-acinar plasma cells, rosette formation, and emperiopolesis were features that favored AIH (P < 0.02). A model combining portal inflammation, portal plasma cells, intra-acinar lymphocytes and eosinophils, rosette formation, and canalicular cholestasis yielded an area under the receiver operating characteristic curve (AUROC) of 0.90 in predicting DILI (HC) versus AIH. All Ishak inflammation scores were more severe in AIH than DILI (CS) (P ≤ 0.05). The four AIH-favoring features listed above were consistently more prevalent in AIH, whereas portal neutrophils and intracellular (hepatocellular) cholestasis were more prevalent in DILI (CS) (P < 0.02). The combination of portal inflammation, fibrosis, portal neutrophils and plasma cells, and intracellular (hepatocellular) cholestasis yielded an AUC of 0.91 in predicting DILI (CS) versus AIH. Conclusion: Although an overlap of histologic findings exists for AIH and DILI, sufficient differences exist so that pathologists can use the pattern of injury to suggest the correct diagnosis.

Drug-induced autoimmune liver disease: A diagnostic dilemma of an increasingly reported disease.

The aetiology of autoimmune hepatitis (AIH) is uncertain but the disease can be triggered in susceptible patients by external factors such as viruses or drugs. AIH usually develops in individuals with a genetic background mainly consisting of some risk alleles of the major histocompatibility complex (HLA). Many drugs have been linked to AIH phenotypes, which sometimes persist after drug discontinuation, suggesting that they awaken latent autoimmunity. At least three clinical scenarios have been proposed that refers to drug- induced autoimmune liver disease (DIAILD): AIH with drug-induced liver injury (DILI); drug induced-AIH (DI-AIH); and immune mediated DILI (IM-DILI). In addition, there are instances showing mixed features of DI-AIH and IM-DILI, as well as DILI cases with positive autoantibodies. Histologically distinguishing DILI from AIH remains a challenge. Even more challenging is the differentiation of AIH from DI-AIH mainly relying in histological features; however, a detailed standardised histologic evaluation of large cohorts of AIH and DI-AIH patients would probably render more subtle features that could be of help in the differential diagnosis between both entities. Growing information on the relationship of drugs and AIH is being available, being drugs like statins and biologic agents more frequently involved in cases of DIAILD. In addition, there is some evidence on the fact that patients diagnosed with DIAILD may have had a previous episode of hepatotoxicity. Further collaborative studies in DIAILD will strengthen the knowledge and understanding of this intriguing and complex disorder which might represent different phenotypes across the spectrum of disease.

Minimization of calcineurin inhibitors to improve long-term outcomes in kidney transplantation.

Long-term outcomes after kidney transplantation remain suboptimal, despite the great achievements observed in recent years with the use of modern immunosuppressive drugs. Currently, the calcineurin inhibitors (CNI) cyclosporine and tacrolimus remain the cornerstones of immunosuppressive regimens in many centers worldwide, regardless of their well described side-effects, including nephrotoxicity. In this article, we review recent CNI-minimization strategies in kidney transplantation, while emphasizing on the importance of long-term follow-up and patient monitoring. Finally, accumulating data indicate that low-dose CNI-based regimens would provide an interesting balance between efficacy and toxicity.

Coxiella burnetii as a possible cause of autoimmune liver disease: a case report.

INTRODUCTION: Q fever is a zoonotic infection that may cause severe hepatitis. Q-fever hepatitis has not yet been associated with autoimmune hepatitis and/or primary biliary cirrhosis. CASE PRESENTATION: We describe a 39-year-old man of Sri Lankan origin with chronic Q-fever hepatitis who developed autoantibodies compatible with autoimmune hepatitis/primary biliary cirrhosis overlap syndrome. Ursodeoxycholic acid in addition to antibiotic therapy markedly improved hepatic enzyme levels suggesting that autoimmunity, potentially triggered by the underlying infection, was involved in the pathogenesis of liver damage. CONCLUSION: We suggest that Coxiella burnetii might trigger autoimmune liver disease. Patients with Q-fever hepatitis who respond poorly to antibiotics should be investigated for serological evidence of autoimmune hepatitis, primary biliary cirrhosis or overlap syndrome, as these patients could benefit from adjunctive therapy with ursodeoxycholic acid. Conversely, C. burnetii serology might be necessary in patients with autoimmune liver disease in order to exclude underlying Coxiella infection.

Infrequent promoter methylation of the MGMT gene in liver metastases from uveal melanoma.

Uveal melanoma is associated with a high mortality rate once metastases occur, with over >90% of metastatic patients dying within less than 1 year from metastases to the liver. The intraarterial hepatic (iah) administration of the alkylating agent fotemustine holds some promise with response rates of 36% and median survival of 15 months. Here, we investigated whether the DNA-repair-protein MGMT may be involved in the variability of response to fotemustine and temozolomide in uveal melanoma. Epigenetic inactivation of MGMT has been demonstrated to be a predictive marker for benefit from alkylating agent therapy in glioblastoma. We found a methylated MGMT promoter in 6% of liver metastases from 34 uveal melanoma patients. The mean MGMT activity measured in liver metastases with negligible liver tissue content was significantly lower than in liver tissue (146 versus 523 fmol/mg protein, p = 0.002). Expression of the MGMT protein was detectable in 50% of 88 metastases by immunohistochemistry on a tissue microarray. Expression was heterogeneous, and in accordance with MGMT activity data, usually lower than in the surrounding liver. Differential MGMT activity/expression between metastasis and liver tissue and more efficient depletion of MGMT with higher doses of alkylating agent therapy using iah delivery may provide the pharmacologic window for the higher response rate. However, these results do not support MGMT methylation status or protein expression as predictive markers for treatment outcome to iah chemotherapy with alkylating agents.

Evaluation of the antitumoral effect sunitinib eluting beads in VX2 liver tumour in a rabbit model.

Background: We demonstrated that DC Bead (Biocompatibles UK, Ltd) could be loaded with sunitinib and injected intra-arterially in the rabbit without unexpected toxicity. The purpose of this study is to evaluate the antitumoral effect of sunitinib eluting beads in the VX2 tumor model of liver cancer. Methods: VX2 tumors were implanted in the left liver lobe of New-Zealand white rabbits. Animals were assigned to 3 groups: Group 1 (n=6) received 1.5mg of sunitinib loaded in 0.05ml of 100-300um DC Bead, group 2 (n=5) received 0.05ml of 100-300um DC Bead, group 3 (n=5) received 0.05ml NaCl 0.9% in the left hepatic artery. One animal in each group was sacrificed at 24 hours and the others were followed for survival until day 15. Liver enzymes were measured daily. In group 1, plasmatic sunitinib concentration were measured daily by LC MS/MS tandem mass spectroscopy. At day 15 all living animals were sacrificed. After sacrifice, the livers were harvested for determination of the VEGF receptor tyrosine kinase activity by western blot and histopathological examination. Results: In group 1, no animals died during follow-up. In group 2, 2 animals died during follow-up on day x. In control group 3, 3 animals died during follow up on day x. In group 1 plasmatic sunitinib levels remained under therapeutic concentration throughout the experiment. Very high concentrations of sunitinib were measured in the liver tissue 24 and 15 days after embolization. Inhibition of the phosphorylation of the RTK was demonstrated at 24h and 15 days in groups 1. Sunitinib eluting beads seemed to penetrate in the tumor more effectively and there was more necrosis around the beads than their bland counterparts. Conclusions: Administration of sunitinib eluting beads in VX2 carrying rabbits resulted invery high drug concentrations at the site of embolization with minimal systemic passage. Despite the very high tissular sunitinib concentration we did not observe any additional toxicity with loaded beads. Sunitinib eluting beads inhibit the activation of RTK's triggered by ischemia and seem to prolong survival of the treated animals. Therefore we consider that local treatment with sunitinib may provide a promising approach for the treatment of liver cancer.

Complications de la chirurgie hépatique chez les patients cirrhotiques atteints d'un carcinome hépatocellulaire

INTRODUCTION. Une augmentation de l'incidence du carcinome hépatocellulaire (CHC) a été constatée dans les pays occidentaux ces dernières années. Il fait parti des cinq premières causes de mortalité dans le monde. Il se développe généralement sur une cirrhose, moins fréquemment sur une hépatopathie non cirrhotique et plus rarement sur un foie sain. La gravité de la cirrhose est évaluée notamment par le score de Child-­‐Pugh, puis le traitement adéquat est défini selon la classification du Barcelona Clinical Liver Cancer (BCLC). Depuis 2008, le service de chirurgie viscérale du CHUV a introduit un nouveau test quantitatif et qualitatif d'évaluation hépatique pré-­‐opératoire qui comprend une clairance au vert d'indocyanine (ICG), agent biologique qui ne change pas lors de son métabolisme hépatique. C'est un test de rétention qui nous permet de mieux évaluer les réserves hépatiques chez les patients cirrhotiques. OBJECTIF. L'objectif de ce travail est d'évaluer rétrospectivement sur la base de dossiers médicaux de malades tous les cas opérés de CHC dans le service entre 2008 et 2012, qui ont eu une évaluation pré-­‐opératoire selon le score de Child-­‐Turcotte-­‐Pugh (CTP) et de Barcelona Clinical Liver Cancer (BCLC)) en les comparant avec l'ICG test et les critères de Makuuchi. METHODE. Analyse statistique de la mortalité et de la morbidité de ces 2 groupes de patients. RESULTATS ESCOMPTES. Comparer nos résultats avec ceux publiés dans la littérature récente par les centres spécialisés pour la chirurgie hépatobiliaire. CONCLUSION. La chirurgie hépatique chez les patients cirrhotiques ne se limite plus à la chirurgie d'hypertension portale. L'amélioration des tests pré-­‐opératoires nous a permis de mieux choisir les patients accessibles à une chirurgie de résection, vu que la mortalité sur la liste d'attente de transplantation hépatique pour les patients atteints de CHC avoisine 8% par année.

Optimisation of a quantitative polymerase chain reaction-based strategy for the detection and quantification of human herpesvirus 6 DNA in patients undergoing allogeneic haematopoietic stem cell transplantation

Human herpesvirus 6 (HHV-6) may cause severe complications after haematopoietic stem cell transplantation (HSCT). Monitoring this virus and providing precise, rapid and early diagnosis of related clinical diseases, constitute essential measures to improve outcomes. A prospective survey on the incidence and clinical features of HHV-6 infections after HSCT has not yet been conducted in Brazilian patients and the impact of this infection on HSCT outcome remains unclear. A rapid test based on real-time quantitative polymerase chain reaction (qPCR) has been optimised to screen and quantify clinical samples for HHV-6. The detection step was based on reaction with TaqMan® hydrolysis probes. A set of previously described primers and probes have been tested to evaluate efficiency, sensitivity and reproducibility. The target efficiency range was 91.4% with linearity ranging from 10-106 copies/reaction and a limit of detection of five copies/reaction or 250 copies/mL of plasma. The qPCR assay developed in the present study was simple, rapid and sensitive, allowing the detection of a wide range of HHV-6 loads. In conclusion, this test may be useful as a practical tool to help elucidate the clinical relevance of HHV-6 infection and reactivation in different scenarios and to determine the need for surveillance.

CD1d-restricted NK T cells are dispensable for specific antibody responses and protective immunity against liver stage malaria infection in mice.

Immunization with a single dose of irradiated sporozoites is sufficient to induce protection against malaria in wild-type mice. Although this protection is classically attributed to conventional CD4+ and CD8+ T cells, several recent reports have suggested an important role for CD1-restricted NK T cells in immunity to malaria. In this study, we directly compared the ability of C57BL/6 wild-type and CD1-deficient mice to mount a protective immune response against Plasmodium berghei sporozoites. Our data indicate that CD1-restricted NK T cells are not required for protection in this model system. Moreover, specific IgG antibody responses to the P. berghei circumsporozoite repeat sequence were also unaffected by CD1 deficiency. Collectively, our data demonstrate that CD1-restricted NK T cells are dispensable for protective immunity to liver stage P. berghei infection.

Using immunoglobulin Y as an alternative antibody for the detection of hepatitis A virus in frozen liver sections

An increasing amount of research has been conducted on immunoglobulin Y (IgY) because the use of IgY offers several advantages with respect to diagnostic testing, including its easy accessibility, low cost and translatability to large-scale production, in addition to the fact that it can be ethically produced. In a previous work, immunoglobulin was produced and purified from egg yolks (IgY) reactive to hepatitis A virus (HAV) antigens. In the present work, this anti-HAV-specific IgY was used in an indirect immunofluorescence assay to detect viral antigens in liver biopsies that were obtained from experimentally infected cynomolgus monkeys. Fields that were positive for HAV antigen were detected in liver sections using confocal microscopy. In conclusion, egg yolks from immunised hens may be a reliable source for antibody production, which can be employed for immunological studies.

Umbilical cord blood transplantation from unrelated donors in patients with Philadelphia chromosome-positive acute lymphoblastic leukemia.

There are very few disease-specific studies focusing on outcomes of umbilical cord blood transplantation for Philadelphia chromosome-positive acute lymphoblastic leukemia. We report the outcome of 45 patients with Philadelphia chromosome-positive acute lymphoblastic leukemia who underwent myeloablative single unit cord blood transplantation from unrelated donors within the GETH/GITMO cooperative group. Conditioning regimens were based on combinations of thiotepa, busulfan, cyclophospamide or fludarabine, and antithymocyte globulin. At the time of transplantation, 35 patients (78%) were in first complete remission, four (8%) in second complete remission and six (14%) in third or subsequent response. The cumulative incidence of myeloid engraftment was 96% at a median time of 20 days and significantly better for patients receiving higher doses of CD34(+) cells. The incidence of acute grade II-IV graft-versus-host disease was 31%, while that of overall chronic graft-versus-host disease was 53%. Treatment-related mortality was 17% at day +100 and 31% at 5 years. The 5-year relapse, event-free survival and overall survival rates were 31%, 36% and 44%, respectively. Although the event-free and overall survival rates in patients without BCR/ABL transcripts detectable at time of transplant were better than those in whom BCR/ABL transcripts were detected (46% versus 24% and 60% versus 30%, respectively) these differences were not statistically significant in the univariate analysis (P=0.07). These results demonstrate that umbilical cord blood transplantation from unrelated donors can be a curative treatment for a substantial number of patients with Philadelphia chromosome-positive acute lymphoblastic leukemia.