Biomedical subjects

S G Hubscher

Publications and source records attributed to S G Hubscher.

At least 19 recordsLinked to original sources

PubMed2006

The polycomb group proteins, BMI-1 and EZH2, are tumour-associated antigens.

We used SEREX technology to identify novel tumour-associated antigens in patients with primary hepatocellular carcinoma and found serological responses to the polycomb group (PcG) protein BMI-1, which is overexpressed in a range of different tumour types. Further studies identified T-cell responses to both BMI-1 and another PcG protein, EZH2, in cancer patients and at relatively lower levels in some normal donors. We next identified several CD8+ T-cell epitopes derived from BMI-1 and EZH2 and demonstrated that EZH2-derived peptides elicited more significant interferon-gamma (IFN-gamma) release than BMI-1-derived peptides. That CD8(+) T cells were responsible for the observed responses was confirmed for EZH2 by both IFN-gamma capture assays and tetramer staining using an HLA-A0201-restricted, EZH2-derived YMSCSFLFNL (aa 666-674) epitope. The ability of YMSCSFLFNL (aa 666-674) to stimulate the in vitro expansion of specific T cells from peripheral blood lymphocytes was greatly enhanced when the CD25(+) T-cell population was depleted. EZH2-specific cytotoxic T lymphocyte clones specific for two HLA-A0201 epitopes were generated and found to recognise endogenously processed EZH2 in both HLA-matched fibroblasts and tumour cell lines. Given the widespread overexpression of PcG proteins in cancer and their critical role in oncogenesis, these data suggest that they may be useful targets for cancer immunotherapy.

Amino Acid Sequence↗

PubMed2004

Revealing the cause of cryptogenic cirrhosis by posttransplant liver biopsy.

INTRODUCTION: Because of the tendency for preexisting diseases to recur following liver transplantation, studying the course of patients who were transplanted for their cryptogenic cirrhosis may reveal features of the original cause. We examined the clinicopathological posttransplant progression of patients transplanted due to cryptogenic cirrhosis with emphasis on the detection of posttransplant steatosis and steatohepatitis. METHODS: The data on all patients transplanted for cryptogenic cirrhosis and their routine 1-year posttransplant liver biopsies were compared to a control group of a randomized sample of patients transplanted for other indications matched for length of follow-up. The posttransplant histological diagnosis was based on the latest available biopsy. RESULTS: Among 1710 patients, 39 present with cryptogenic etiology survived at least 1 year after transplantation. The control group consisted of 78 patients. The mean ages of the two groups were 50.7 and 49.3 years and the mean follow-up periods 6.2 and 5.7 years, both of which were similar. There was a significantly greater prevalence of posttransplant steatosis and steatohepatitis among the cryptogenic group (37.5 vs 16.7%, P = .048). The difference in patients with at least moderate steatosis was more pronounced (18.8 vs 3.3%, P = .035). Half of these cases progressed to fibrosis and cirrhosis after 48 months. CONCLUSIONS: This study found a greater incidence of allograft steatosis and steatohepatitis among patients transplanted for cryptogenic cirrhosis compared with a control group. A significant proportion of these patients developed a picture resembling nonalcoholic steatohepatitis, which progressed to fibrosis and cirrhosis.

Adult↗

PubMed2003

Antidepressant induced cholestasis: hepatocellular redistribution of multidrug resistant protein (MRP2).

BACKGROUND: We report two cases of antidepressant induced cholestasis. CASE REPORTS: We describe the first reported case of acute cholestasis due to citalopram (selective serotonin reuptake inhibitor) occurring in a patient who also experienced obstetric cholestasis in association with each of three pregnancies; in a second patient cholestasis developed due to dothiepin (tricyclic antidepressant), and six years later due to paroxetine. In both cases liver biopsies showed features of a "pure" cholestasis with total resolution within 1-6 months after withdrawal of the causative drug. Immunostaining for the canalicular transporter, multidrug resistant protein 2 (MRP2), responsible for biliary secretion of several organic anions including bilirubin glucuronides, showed sustained expression in both biopsies as well as relocalisation with appearance of strong staining of the basolateral membrane of the hepatocyte. This finding has also not been reported previously. CONCLUSIONS: We postulate that intracellular redistribution of MRP2 may reflect an adaptive compensatory mechanism which helps in the elimination of the drug or its cholestatic metabolites from the hepatocyte back to the sinusoidal space and subsequent excretion in urine. Changes seen in these two patients differ from findings previously reported in rats where downregulation of mrp2 occurs in response to experimentally induced cholestasis. We speculate that the rat is more advanced than humans in its ability to downregulate canalicular transporter expression as protection against progressive intrahepatic cholestasis.

Acute Disease↗

PubMed2001

Differential expression of chemokines and chemokine receptors shapes the inflammatory response in rejecting human liver transplants.

BACKGROUND: Graft rejection after liver transplantation is associated with a lymphocytic infiltrate, the nature of which will be determined by, among various factors, the local activity of chemokines that attract particular subsets of effector cells to the graft. METHODS: The expression of chemokines and receptors in human liver allografts was studied by immunohistochemistry of tissue and flow cytometry of blood and liver-derived lymphocytes. Receptor function was assessed with in vitro chemotaxis. RESULTS: We report increased expression of chemokine receptors CXCR3, CXCR4, and CCR5 on circulating and graft-infiltrating lymphocytes after liver transplantation. Liver-derived T cells responded to the ligands for these receptors in vitro, which suggests that the receptors are functionally active. The chemokine ligands for these receptors were detected in rejecting allografts. CXCR3 ligands interferon-inducible protein 10 and monokine-induced by gamma interferon were detected on sinusoidal endothelium and interferon-inducible T-cell alpha chemoattractant was detected on portal and hepatic vascular endothelium, whereas the CXCR4 ligand, stromal-derived factor (SDF), was restricted to biliary epithelium. CCR5 ligands have previously been shown on portal endothelium. An in vitro model of T-cell alloactivation demonstrated a similar pattern of expression of functional CXCR3, CXCR4, and CCR5 on T cells. Increased expression of chemokine receptors, especially CCR3 and CCR5, was associated with redistribution of activated Kupffer cells in rejecting grafts. CONCLUSIONS: The patterns of chemokine expression in liver allografts during rejection suggest that the recruitment and positioning of lymphocytes is mediated by specific chemokines. Although ligands for the receptors CXCR3 and CCR5 are important for recruitment, the restriction of SDF to bile ducts suggests that CXCR4 may be involved in the retention of alloactivated lymphocytes at sites of graft damage.

Chemokine CXCL10↗

PubMed2001

Are parenchymal changes in early post-transplant biopsies related to preservation-reperfusion injury or rejection?

BACKGROUND: The progression of parenchymal changes in liver allograft biopsies due to preservation-reperfusion injury (PRI) and their differentiation from rejection related changes is poorly understood. The aim of this study was to determine which changes in a 1-week posttransplant biopsy could be attributed to PRI and which to acute rejection. METHODS: One week protocol liver transplant biopsies from patients with mild PRI (day 1 AST<400 IU/L) were compared with those from patients with severe PRI (day 1 AST>2000 IU/L). Parenchymal changes (cholestasis, ballooning, steatosis, necrosis) and rejection-related inflammatory features (portal tract inflammation, bile duct inflammation, portal vein endothelial inflammation, hepatic vein endothelial inflammation, and centrilobular inflammation) were blindly assessed semiquantitatively. RESULTS: Fat, cholestasis, and hepatocyte ballooning were significantly worse in the severe PRI group, and these features showed no correlation with histological features related to acute rejection. Centrilobular hepatocyte necrosis correlated with hepatic venular endothelial inflammation and centrilobular inflammation but not with rejection related features in portal tracts or with PRI. These findings suggest that centrilobular necrosis is a manifestation of a rejection-related parenchymal injury and may involve different pathogenetic mechanisms to rejection-related features in portal tracts. CONCLUSIONS: This study indicates that in early posttransplant biopsies, fat, cholestasis, and ballooning can largely be attributed to PRI. By contrast, centrilobular hepatocyte loss should be suspected as a rejection related phenomenon, even if typical portal tract changes are not prominent, and augmentation of immunosuppression should be considered.

Adolescent↗

PubMed2001

Visualization of the transport of primary and secondary bile acids across liver tissue in rats: in vivo study with fluorescent bile acids.

BACKGROUND/AIMS: Lysyl fluorescein conjugated bile acid analogues (LFCBAA) closely parallel their natural counterparts. To assess LFCBAA as a tool for the visualization of bile acid transport within liver tissue. METHODS: Wistar rats were administered physiological concentrations of the primary bile acid analogue cholyllysyl fluoroscein (CLF) and of the secondary bile acid analogue lithocholyllysyl fluorescein (LLF) and serial liver biopsies were taken at fixed intervals. Both compounds were also injected retrogradely into the biliary tree. Frozen sections were examined by fluorescence microscopy. RESULTS: Both CLF and LLF were rapidly taken up from sinusoidal blood but differed significantly in their hepatic handling. CLF was rapidly transported into bile, whereas LLF transport was slower and produced significantly more bile duct fluorescence. LLF clearance showed a lobular gradient with last remaining bile acid being confined largely to zone 3. Both compounds were avidly taken up by cholangiocytes after injection intravenously or retrogradely into the biliary tree. CONCLUSIONS: Visualization of LFCBAA by fluorescence microscopy may yield further information regarding hepatobiliary bile acid localization during studies of physiological and pathological mechanisms involved in transport of bile acids. The presence of both compounds within cholangiocytes strongly suggests that they may undergo a degree of chole-hepatic recirculation.

Animals↗

PubMed2001

Notch receptor expression in adult human liver: a possible role in bile duct formation and hepatic neovascularization.

Notch signaling is an evolutionarily conserved mechanism, used to regulate cell fate decisions. Four Notch receptors have been identified in man (Notch-1 to -4). In this study, semiquantitative reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry were used to examine the expression pattern of Notch receptor genes in whole adult human liver and isolated liver cell preparations. All 4 receptors were expressed in the adult liver, with no significant differences in the levels of Notch-1, -2, and -4 messenger RNA (mRNA) between normal and diseased liver. However, Notch-3 expression appeared to be increased in diseased tissue. The distribution of Notch-1 and -4 in normal tissue was similar, with Notch-1 also detectable at low levels in the sinusoidal endothelium. Notch-2 expression was more widely distributed, and detectable in hepatocytes, medium-sized bile ducts, and the sinusoidal endothelium. Notch-3 expression was seen on hepatocytes, with weaker expression detectable in portal veins, hepatic arteries, and the sinusoids. In normal liver tissue Notch-1, -2, and -3 were found to be coexpressed on bile duct epithelium; however, with the exception of Notch-3 in primary sclerosing cholangitis (PSC) livers, expression was absent on proliferating ductules in all disease states examined. Interestingly, the expression of Notch-2 and -3 was associated with numerous small vessels within the portal tract septa of diseased tissue. The absence of Notch receptor expression on proliferating bile ductules and its presence on neovessels suggests that Notch signaling may be important for normal bile duct formation and the aberrant neovascularization seen in diseased liver tissue.

Adult↗

PubMed2001

CD40 activation-induced, Fas-dependent apoptosis and NF-kappaB/AP-1 signaling in human intrahepatic biliary epithelial cells.

Fas-mediated mechanisms of apoptosis are thought to be involved in the bile duct loss that characterizes diseases such as primary biliary cirrhosis (PBC). We have previously shown that activation of CD40 on hepatocytes can amplify Fas-mediated apoptosis; in the present study, we investigated interactions between CD40 and Fas in biliary epithelial cells (BEC). We report that the bile ducts in PBC liver tissue frequently express increased levels of Fas, Fas ligand (FasL), and CD40 associated with apoptotic BEC. The portal mononuclear infiltrate contains CD40L+ve T cells and macrophages, thereby demonstrating a potential mechanism for CD40 engagement in vivo. Primary cultures of human BEC also expressed Fas, FasL, and CD40 but not CD40L protein or mRNA. Activation of CD40 on BEC using recombinant CD40L increased transcriptional expression of FasL and induced apoptosis, which was inhibited by neutralizing antibodies to either Fas or FasL. Thus, CD40-induced apoptosis of BEC is mediated through Fas/FasL. We then investigated the intracellular signals and transcription factors activated in BEC and found that NF-kappaB and AP-1 were both activated after CD40 ligation. Increased functional NF-kappaB was seen early after CD40 ligation, but returned to baseline levels after 4 h. In contrast, the rapid up-regulation of AP-1 was sustained over 24 h. This study provides further functional evidence of the ability of CD40 to induce Fas/FasL-dependent apoptosis of liver epithelial cells supporting the importance of cross-talk between tumor necrosis factor (TNF) receptor family members as an amplification step in apoptosis induction. Sustained activation of AP-1 in the absence of NF-kappaB signaling may be a critical factor in determining the outcome of CD40 engagement.

Apoptosis↗

PubMed2000

Increased incidence of chronic rejection in adult patients transplanted for autoimmune hepatitis: assessment of risk factors.

BACKGROUND/AIM: It remains uncertain whether autoimmune hepatitis (AIH), as an original indication for orthotopic liver transplantation (OLTX), predisposes to the development of chronic rejection (CR) after surgery and published reports on heterogeneous groups of patients provided conflicting data. In this work we analyzed the incidence and risk factors for CR in a large cohort of adult patients transplanted for AIH in our unit. RESULTS: A total of 1190 adult patients received OLTX in our center between 1982 and 1998. A total of 77 patients (6.5%) were transplanted for AIH and 12 (15.6%) patients from this group developed clinical and histological features of CR within a median time of 3.5 months after OLTX. Patients with AIH who developed CR were younger than other AIH patients at OLTX (32 vs. 44.2 ys; P=0.015) and more often had histological features of moderate or severe acute rejection (83 vs. 34%; P=0.002) on early post-OLTX biopsies. The incidence of CR in AIH patients was significantly higher than in subjects transplanted for other indications such as primary biliary cirrhosis (8.2%; P<0.05), primary sclerosing cholangitis (5.2%; P<0.05) or alcoholic cirrhosis (2.0%; P<0.001). Also, we observed a tendency to decreased incidence of CR with time in all transplanted subjects. CONCLUSIONS: Apart from younger age at OLTX and higher incidence of severe acute rejection, patients with AIH who developed CR did not differ from other subjects transplanted for this indication. Unlike other studies, not stratified by diagnosis, recipient CMV negative status, young donor age, and HLA DR matching were not identified as risk factors for CR in AIH.

Adult↗

PubMed2000

Characterization and isolation of ductular cells coexpressing neural cell adhesion molecule and Bcl-2 from primary cholangiopathies and ductal plate malformations.

It has recently been shown that reactive bile ductules display neuroendocrine features, including immunoreactivity for the neural cell adhesion molecule (NCAM). In this study we have compared the immunohistochemical expression of NCAM with that of HEA-125 (biliary specific) and LKM-1 (hepatocyte specific) and other markers relevant to morphogenesis (Bcl-2, EMA) and cell proliferation (Ki-67) in cryostat sections from different chronic liver diseases and from fetal livers at different gestational ages. In parallel, viable NCAM-positive ductular cells were purified from collagenase digests of cirrhotic livers by immunomagnetic separation and characterized by immunocytochemistry and transmission electron microscopy. We demonstrated that reactive ductules with atypical morphology coexpressed NCAM and Bcl-2 and were found mainly in congenital diseases associated with ductal plate malformation and in primary cholangiopathies. On the contrary, reactive ductules with typical morphology were negative for NCAM/Bcl-2 and positive for EMA. Reactive ductules coexpressing NCAM/Bcl-2 were negative for the proliferation marker Ki-67 and appeared to be directly connected with periportal hepatocytes. In fetal livers NCAM/Bcl-2 was transiently expressed during the early developmental stages of ductal plate (10-16 weeks) and started to disappear as the ductal plate began duplicating. NCAM-positive ductal plate cells were Ki-67 negative, becoming positive in duplicated segments. Thus the histogenesis of ductular reactive cells seems to recapitulate the early stages of biliary ontogenesis. In primary cholangiopathies and ductal plate malformations, these cells do not appear to maturate further, and thus abundant ductular structures coexist with vanishing mature ducts. These NCAM-positive ductular cells were immunopurified from patients with chronic cholestatic liver diseases and showed ultrastructural features consistent with a less differentiated phenotype than mature cholangiocytes. These isolated cells represent a useful model for in vitro studies.

Antigens, Surface↗

PubMed2000

Wilson's disease with superimposed autoimmune features: report of two cases and review.

We describe two females, 15 and 23 years old, respectively, who presented with classical features of Wilson's disease (WD) and several features of autoimmune hepatitis (AIH). The first patient was initially diagnosed as AIH and treated with prednisolone which caused clinical improvement, with an increase of serum albumin from 22 to 30 g/L, and a decrease of aspartate aminotransferase from 103 to 47 U/L. Subsequent diagnosis of WD and introduction of penicillamine gave excellent improvement and complete normalization of liver function tests. The second patient, at first also diagnosed as having AIH, was treated with steroids and azathioprine with initial improvement, but subsequent deterioration. The diagnosis of WD was made 2 years after initial diagnosis of AIH, as the patient reached end-stage liver disease and required a transplant. Therefore, d-penicillamine treatment was not attempted. We conclude that, in patients with AIH, a thorough screening for WD is necessary, particularly when the response to steroid therapy is poor. Conversely, in patients suffering from WD with superimposed features of AIH, a combination of steroids and penicillamine may be of benefit.

Adolescent↗

PubMed1999

Chemokine and chemokine receptor interactions provide a mechanism for selective T cell recruitment to specific liver compartments within hepatitis C-infected liver.

The role played by chemokines in regulating the selective recruitment of lymphocytes to different tissue compartments in disease is poorly characterized. In hepatitis C infection, inflammation confined to portal areas is associated with a less aggressive course, whereas T cell infiltration of the liver parenchyma is associated with progressive liver injury and cirrhosis. We propose a mechanism to explain how lymphocytes are recruited to hepatic lobules during bursts of necroinflammatory activity in chronic hepatitis C infection. We report here that lymphocytes infiltrating hepatitis C-infected liver express high levels of the chemokine receptors CCR5 and CXCR3. However, whereas the CCR5 ligands macrophage inflammatory protein-1alpha and -1beta were largely confined to vessels within portal tracts, the CXCR3 ligands IFN-inducible protein-10 and monokine-induced by IFN-gamma were selectively up-regulated on sinusoidal endothelium. In vitro, human hepatic sinusoidal endothelial cells secreted IFN-inducible protein-10 and monokine-induced by IFN-gamma in response to stimulation with IFN-gamma in combination with either IL-1 or TNF-alpha. This suggests that intrahepatic Th1 cytokines drive the increased expression of IFN-inducible protein-10 and monokine-induced by IFN-gamma and thereby promote the continuing recruitment of CXCR3-expressing T cells into the hepatic lobule in chronic hepatitis C infection.

Cell Movement↗

PubMed1999

Recurrence of autoimmune hepatitis after liver transplantation.

BACKGROUND: The literature data on the recurrence of autoimmune hepatitis (AIH) after orthotopic liver transplantation (OLTX) is scanty. METHODS: We analyzed the frequency of recurrent AIH in 47 patients who had been transplanted for AIH and survived at least 1 year after surgery. The following criteria were applied to diagnose recurrence: (1) positive autoantibodies in the titer> or =1:40; (2) hypertransaminasemia; (3) histological features of chronic hepatitis; (4) need of reintroduction or significant increase of steroids; and (5) lack of serum markers of viral hepatitis. RESULTS: A total of 13 patients (1 male/12 females) developed recurrent AIH after an interval of 6-63 months after OLTX (mean 29 months). Mean AST level at recurrence was 542+/-129 U/L. Three patients from this group needed regrafting. Mismatch of DR3+ recipient and DR3- donor was not more common in the recurrent disease group (37%) compared to the nonrecurrence group (31%) (P=NS). CONCLUSIONS: Recurrence of AIH after OLTX was diagnosed in a high proportion of patients and some of them required regrafting. DR3+ patients are not particularly prone to develop recurrence.

Analysis of Variance↗

PubMed1999

CD40 activation induces apoptosis in cultured human hepatocytes via induction of cell surface fas ligand expression and amplifies fas-mediated hepatocyte death during allograft rejection.

We propose that a novel mechanism of hepatocyte apoptosis, involving a cooperative interaction between CD40 and Fas, is involved in the hepatocyte loss of chronic liver allograft rejection. We detected increased hepatocyte expression of Fas, Fas ligand (FasL), and CD40 associated with dropout of centrilobular (acinar zone 3) hepatocytes in chronic allograft rejection. Expression of CD40 ligand (CD40L) was also increased but was largely restricted to CD68(+) macrophages. A functional role for CD40 and Fas in hepatocyte apoptosis was demonstrated in vitro using primary human hepatocytes and the HepG2 cell line in both of which apoptosis was induced, not only by cross-linking Fas directly but also via CD40 activation. Our data suggest that CD40 activation induces apoptosis via Fas because (a) ligation of CD40 upregulated hepatocyte FasL expression, and (b) apoptosis induced via activation of CD40 was prevented by a neutralizing monoclonal antibody to FasL. Thus, CD40 engagement triggers apoptosis of human hepatocytes and might amplify Fas-dependent hepatocyte apoptosis in chronic rejection and other inflammatory liver diseases in which Fas-mediated apoptosis is involved.

Antibodies, Monoclonal↗

PubMed1999

Expression and function of CXC and CC chemokines in human malignant liver tumors: a role for human monokine induced by gamma-interferon in lymphocyte recruitment to hepatocellular carcinoma.

Chemotactic cytokines (chemokines) play an important role in the recruitment of lymphocytes to tissue by regulating cellular adhesion and transendothelial migration. This study examined the expression and function of CXC (human monokine induced by gamma-interferon [HuMig], interleukin-8 [IL-8], and interferon-inducible protein-10 [IP-10]) and CC (macrophage inflammatory protein-1alpha [MIP-1alpha], MIP-1beta, regulated upon activation normal T lymphocyte expressed and secreted (RANTES), and macrophage chemoattractant protein-1 [MCP-1]) chemokines and their respective receptors on lymphocytes infiltrating human liver tumors. Chemokine and chemokine receptor expression was assessed by immunohistochemistry, flow cytometry, in situ hybridization and ribonuclease (RNAse) protection assays and function by in vitro chemotaxis of tumor-derived lymphocytes to purified chemokines and to HepG2 tumor cell culture supernatants. Tumor-derived lymphocytes showed strong chemotactic responses to both CC and CXC chemokines in vitro and expressed high levels of CXCR3 (HuMig and IP-10 receptor) and CCR5 (RANTES, MIP-1alpha, and MIP-1beta receptor). Expansion of tumor-derived lymphocytes in recombinant IL-2 increased expression of CXCR3. The corresponding chemokines were detected on vascular endothelium (HuMig, IL-8, MIP-1alpha, and MIP-1beta) and sinusoidal endothelium (HuMig, MIP-1alpha, MIP-1beta) in hepatocellular carcinoma. In vitro, HepG2 cells secreted functional chemotactic factors for tumor-derived lymphocytes that could be inhibited using anti-CCR5 or anti-CXCR3 monoclonal antibodies (MoAbs). Thus, lymphocytes infiltrating human liver tumors express receptors for and respond to both CXC and CC chemokines. The relevant chemokine ligands are expressed in hepatocellular carcinoma (HCC), particularly HuMig, which was strongly expressed by tumor endothelium, suggesting that they play a role in lymphocyte recruitment to these tumors in vivo. The ability of HepG2 cells to secrete lymphocyte chemotactic factors in vitro suggests that the tumor contributes to lymphocyte recruitment in vivo.

Aged↗

PubMed1999

Fas/Fas ligand interaction in human colorectal hepatic metastases: A mechanism of hepatocyte destruction to facilitate local tumor invasion.

This study demonstrates a novel role for the Fas pathway in the promotion of local tumor growth by inducing apoptotic cell death in normal hepatocytes at the tumor margin in colorectal hepatic metastases. Our results show that >85% of lymphocytes infiltrating colorectal liver cancer express high levels of Fas-ligand (Fas-L) by flow cytometry. Using immunohistochemistry of tumor tissue we showed strong Fas expression in noninvolved hepatocytes, whereas Fas-L expression was restricted to tumor cells and infiltrating lymphocytes at the tumor margin. Apoptosis was observed in 45 +/- 13% of the Fas(high) hepatocytes at the tumor margin whereas only 7 +/- 3% tumor cells were apoptotic (n = 10). In vitro, primary human hepatocytes expressed Fas receptor and crosslinking with anti-Fas antibody induced apoptosis in 44 +/- 5% of the cells compared with 4. 6 +/- 1.0% in untreated controls (P = 0.004). Both tumor-infiltrating lymphocytes (TIL) and human metastatic colon cancer cells cells are able to induce Fas-mediated apoptosis of primary human hepatocytes in coculture cytotoxic assays. TIL induced apoptosis in 47 +/- 9% hepatocytes compared with control 4.3 +/- 1. 0% (P = 0.009) and this effect was reduced by anti-human Fas-L mAb (18.7 +/- 1.3%, P = 0.009). SW620 cells induced apoptosis in 26 +/- 2% hepatocytes compared with control 5.6 +/- 1.7% (P = 0.004) and this was reduced to 11.2 +/- 1.8% (P = 0.004) in the presence of anti-human Fas-L mAb. These data suggest that the inflammatory response at the margin of colorectal liver metastases induces Fas expression in surrounding hepatocytes, allowing them to be killed by Fas-L-bearing TIL or tumor cells and facilitating the invasion of the tumor into surrounding liver tissue.

Aged↗

PubMed1999

Autoimmune liver disease in patients with neoplastic diseases.

BACKGROUND: Development of de novo autoimmune liver disease has not been well documented in patients with malignant diseases. METHODS/RESULTS: In this paper we report on a series of six patients with neoplastic disorders who acquired liver disease with autoimmune features. Five patients had suffered from haematological neoplasms and one from colonic cancer. In two patients, liver disease was detected at the time of presentation with malignancy. In the remaining four, all of whom were successfully treated for malignancies, features of liver disease presented at intervals 24-72 months after the cancer diagnosis. Twelve liver specimens (11 biopsies and one hepatectomy specimen) were obtained at time intervals of 1-76 months after initial presentation of neoplastic disease. Biopsies from three patients showed features of hepatitis (one acute, one sub-acute, one chronic). Two patients had histological features suggestive of an overlap syndrome (one autoimmune hepatitis/primary biliary cirrhosis, one autoimmune hepatitis/primary sclerosing cholangitis). The sixth patient had features of autoimmune cholangiopathy. All but one responded well to steroid therapy with complete clinical and biochemical remission obtained 4 weeks to 8 months after steroid introduction. We discuss briefly possible aetiologies of autoimmune liver disease in these patients. CONCLUSIONS: Autoimmune liver disease may be precipitated by therapy for neoplastic disease or malignant disease itself. The unusually heterogeneous clinicopathological findings in this group as well as the response to treatment support the concept of a wide spectrum of manifestations of autoimmune liver disease. The results may also suggest that autoimmune liver disease may be possibly added to the list of paraneoplastic syndromes. Further prospective studies are required to confirm a causal association and to determine whether the mechanisms involved are disease- or treatment-related.

Adult↗

PubMed1999

Selection of hepatitis B surface "escape" mutants during passive immune prophylaxis following liver transplantation: potential impact of genetic changes on polymerase protein function.

CASE REPORT: A patient is described who developed hepatitis B virus (HBV) reinfection five months following liver transplantation. Failure of hepatitis B immunoglobulin prophylaxis was associated with the emergence of mutations. HBV gene sequencing identified nucleotide substitutions associated with amino acid changes, one within the major hydrophilic region (MHR) of the HBV surface antigen at amino acid position 144 and one outside the MHR. Because of the overlapping reading frames of surface and polymerase genes, the latter surface antigen change was associated with an amino acid change in the polymerase protein. The patient developed significant allograft hepatitis and was treated with lamivudine (3TC) 100 mg daily. Rapid decline of serum HBV DNA was observed with loss of HBV e antigen and HBV surface antigen from serum. There was normalisation of liver biochemistry, and liver immunohistochemistry showed a reduction in HBV core and disappearance of HBs antigen staining. CONCLUSION: Surface antigen encoding gene mutations associated with HBIg escape may be associated with alteration of the polymerase protein. The polymerase changes may affect sensitivity to antiviral treatment. Selection pressure on one HBV reading frame (for example, HBIg pressure on HBsAg, or nucleoside analogue pressure on polymerase protein) may alter the gene product of the overlapping frame. Such interactions are relevant to strategies employing passive immune prophylaxis and antiviral treatment.

Aged↗