Patients With Autoimmune Hepatitis and Nonalcoholic Fatty Liver Disease: Characteristics, Treatment, and Outcomes.

GOAL: The objective of this study was to characterize an autoimmune hepatitis (AIH)/nonalcoholic fatty liver disease (NAFLD) overlap cohort, determine if they received standard of care treatment, and delineate their outcomes in comparison with patients with AIH or NAFLD alone. BACKGROUND: AIH is a relatively rare and heterogeneously presenting liver disease of unknown etiology. NAFLD is a leading cause of liver disease worldwide. AIH treatment includes steroids, which have adverse metabolic effects that can worsen NAFLD. No treatment guidelines are available to mitigate this side on AIH/NAFLD overlap patients. Few studies to date have examined these patients' characteristics, management practices, and outcomes. MATERIALS AND METHODS: A single-center, retrospective chart review study examining biopsy-proven AIH/NAFLD, AIH, and NAFLD patients. Characteristics, treatment, and 1- and 3-year outcomes (all-cause mortality, need for liver transplantation, or decompensated cirrhosis) were evaluated. RESULTS: A total of 72 patients (36.1% AIH/NAFLD, 34.7% AIH, and 29.2% NAFLD) were included. AIH/NAFLD patients were found to be more often Hispanic/Latino, female, and with lower liver aminotransaminases, immunoglobulin G, and anti-smooth muscle antibody positivity. AIH/NAFLD patients were less likely to receive standard of care treatment. No significant differences in outcomes were seen between AIH/NAFLD and either AIH or NAFLD. CONCLUSIONS: Our study demonstrated that AIH/NAFLD patients have unique characteristics and are less likely to receive standard of care treatment compared with patients with AIH alone. Despite this, no difference in outcomes (all-cause mortality, need for liver transplantation, or decompensated cirrhosis) was seen. Given NAFLD's rising prevalence, AIH/NAFLD cases will likely increase, and may benefit from alternative treatment guidelines to prevent worsening of NAFLD.

Environmental exposures are important risk factors for advanced liver fibrosis in African American adults.

Background & Aims: The prevalence and aetiology of liver fibrosis vary over time and impact racial/ethnic groups unevenly. This study measured time trends and identified factors associated with advanced liver fibrosis in the United States. Methods: Standardised methods were used to analyse data on 47,422 participants (≥20 years old) in the National Health and Nutrition Examination Survey (1999-2018). Advanced liver fibrosis was defined as Fibrosis-4 ≥2.67 and/or Forns index ≥6.9 and elevated alanine aminotransferase. Results: The estimated number of people with advanced liver fibrosis increased from 1.3 million (95% CI 0.8-1.9) to 3.5 million (95% CI 2.8-4.2), a nearly threefold increase. Prevalence was higher in non-Hispanic Black and Mexican American persons than in non-Hispanic White persons. In multivariable logistic regression analysis, cadmium was an independent risk factor in all racial/ethnic groups. Smoking and current excessive alcohol use were risk factors in most. Importantly, compared with non-Hispanic White persons, non-Hispanic Black persons had a distinctive set of risk factors that included poverty (odds ratio [OR] 2.09; 95% CI 1.44-3.03) and susceptibility to lead exposure (OR 3.25; 95% CI 1.95-5.43) but did not include diabetes (OR 0.88; 95% CI 0.61-1.27; p =0.52). Non-Hispanic Black persons were more likely to have high exposure to lead, cadmium, polychlorinated biphenyls, and poverty than non-Hispanic White persons. Conclusions: The number of people with advanced liver fibrosis has increased, creating a need to expand the liver care workforce. The risk factors for advanced fibrosis vary by race/ethnicity. These differences provide useful information for designing screening programmes. Poverty and toxic exposures were associated with the high prevalence of advanced liver fibrosis in non-Hispanic Black persons and need to be addressed. Impact and Implications: Because liver disease often produces few warning signs, simple and inexpensive screening tests that can be performed by non-specialists are needed to allow timely diagnosis and linkage to care. This study shows that non-Hispanic Black persons have a distinctive set of risk factors that need to be taken into account when designing liver disease screening programs. Exposure to exogenous toxins may be especially important risk factors for advanced liver fibrosis in non-Hispanic Black persons.

Differential expression of hepatic cancer stemness and hypoxia markers in residual cancer after locoregional therapies for hepatocellular carcinoma.

Transarterial chemoembolization (TACE) and transarterial radioembolization (TARE) treatment to hepatocellular carcinoma (HCC) are effective tools to control tumor growth, prolong survival, palliate symptoms, and improve quality of life for patients with intermediate-stage HCC. Nevertheless, there is high variability of local HCC responses to locoregional therapies; therefore, better and personalized prediction of tumor response to TACE is necessary for management of patients with HCC, especially when these modalities of treatment are used to bridge patients for liver transplant. Here, we investigated differential expression of hepatic cancer stem cell and hypoxia in residual HCC after TACE treatment in comparison with TARE. A publicly available gene data set was screened for differentially expressed genes (DEGs) in TACE_Response compared with TACE_Non-response HCC. Analysis of the GSE104580 data set displayed a total of 406 DEGs, including 196 down-regulated and 210 up-regulated DEGs. Of the 196 down-regulated DEGs, three hepatic cancer stem cell (CSC) markers and 11 hypoxia-related genes were identified. Immunohistochemical staining of hepatic CSC and hypoxia markers on explant liver tissues exhibited more intense positive staining of hepatic CSC markers (CD24, EpCAM) and hypoxia marker carbonic anhydrase 9 (CA9) in residual tumor nodule from patients with HCC treated with TACE compared with nontreated patients. Furthermore, Pearson's correlation analysis revealed the significant correlation between hepatic CSC markers and hypoxia marker, CA9. Conclusion: Hepatic CSC and hypoxia markers predict nonresponse to TACE and are differentially expressed in residual tumor after TACE compared with TARE. In the long term, TACE-induced hypoxia may select an aggressive HCC phenotype.

Alcohol Consumption Accumulation of Monocyte Derived Macrophages in Female Mice Liver Is Interferon Alpha Receptor Dependent.

Monocytes develop in the bone marrow from the hematopoietic stem cells and represent heterogeneous phagocyte cells in the circulation. In homeostatic and inflammatory conditions, after recruitment into tissues, monocytes differentiate into macrophages and dendritic cells. Alcohol use causes about 3.3 million worldwide deaths per year, which is about 5.9% of all deaths. In the United States and Europe, alcohol use disorders represent the fifth leading cause of death. Females are more susceptible to alcoholic liver injury in both humans and mice. Strikingly, we still do not know how much of this difference in tissue injury is due to the differential effect of alcohol and its toxic metabolites on a) parenchymal or resident cells and/or b) immune response to alcohol. Therefore, we used a model of chronic alcohol exposure in mice to investigate the dynamics of monocytes, an innate immune cell type showed to be critical in alcoholic liver injury, by using immunophenotypic characterization. Our data reveal a sex-dimorphism of alcohol response of hepatic monocytes in female mice that is interferon receptor alpha dependent. This dimorphism could shed light on potential cellular mechanism(s) to explain the susceptibility of females to alcoholic immunopathogenesis and suggests an additional targetable pathway for alcoholic liver injury in females.

Predictors of Outcomes of COVID-19 in Patients With Chronic Liver Disease: US Multi-center Study.

BACKGROUND & AIMS: Chronic liver disease (CLD) represents a major global health burden. We undertook this study to identify the factors associated with adverse outcomes in patients with CLD who acquire the novel coronavirus-2019 (COVID-19). METHODS: We conducted a multi-center, observational cohort study across 21 institutions in the United States (US) of adult patients with CLD and laboratory-confirmed diagnosis of COVID-19 between March 1, 2020 and May 30, 2020. We performed survival analysis to identify independent predictors of all-cause mortality and COVID-19 related mortality, and multivariate logistic regression to determine the risk of severe COVID-19 in patients with CLD. RESULTS: Of the 978 patients in our cohort, 867 patients (mean age 56.9 ± 14.5 years, 55% male) met inclusion criteria. The overall all-cause mortality was 14.0% (n = 121), and 61.7% (n = 535) had severe COVID-19. Patients presenting with diarrhea or nausea/vomiting were more likely to have severe COVID-19. The liver-specific factors associated with independent risk of higher overall mortality were alcohol-related liver disease (ALD) (hazard ratio [HR] 2.42, 95% confidence interval [CI] 1.29-4.55), decompensated cirrhosis (HR 2.91 [1.70-5.00]) and hepatocellular carcinoma (HCC) (HR 3.31 [1.53-7.16]). Other factors were increasing age, diabetes, hypertension, chronic obstructive pulmonary disease and current smoker. Hispanic ethnicity (odds ratio [OR] 2.33 [1.47-3.70]) and decompensated cirrhosis (OR 2.50 [1.20-5.21]) were independently associated with risk for severe COVID-19. CONCLUSIONS: The risk factors which predict higher overall mortality among patients with CLD and COVID-19 are ALD, decompensated cirrhosis and HCC. Hispanic ethnicity and decompensated cirrhosis are associated with severe COVID-19. Our results will enable risk stratification and personalization of the management of patients with CLD and COVID-19. Clinicaltrials.gov number NCT04439084.

Outcomes following SARS-CoV-2 infection in liver transplant recipients: an international registry study.

BACKGROUND: Despite concerns that patients with liver transplants might be at increased risk of adverse outcomes from COVID-19 because of coexisting comorbidities and use of immunosuppressants, the effect of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection on this patient group remains unclear. We aimed to assess the clinical outcomes in these patients. METHODS: In this multicentre cohort study, we collected data on patients with laboratory-confirmed SARS-CoV-2 infection, who were older than 18 years, who had previously received a liver transplant, and for whom data had been submitted by clinicians to one of two international registries (COVID-Hep and SECURE-Cirrhosis) at the end of the patient's disease course. Patients without a known hospitalisation status or mortality outcome were excluded. For comparison, data from a contemporaneous cohort of consecutive patients with SARS-CoV-2 infection who had not received a liver transplant were collected from the electronic patient records of the Oxford University Hospitals National Health Service Foundation Trust. We compared the cohorts with regard to several outcomes (including death, hospitalisation, intensive care unit [ICU] admission, requirement for intensive care, and need for invasive ventilation). A propensity score-matched analysis was done to test for an association between liver transplant and death. FINDINGS: Between March 25 and June 26, 2020, data were collected for 151 adult liver transplant recipients from 18 countries (median age 60 years [IQR 47-66], 102 [68%] men, 49 [32%] women) and 627 patients who had not undergone liver transplantation (median age 73 years [44-84], 329 [52%] men, 298 [48%] women). The groups did not differ with regard to the proportion of patients hospitalised (124 [82%] patients in the liver transplant cohort vs 474 [76%] in the comparison cohort, p=0·106), or who required intensive care (47 [31%] vs 185 [30%], p=0·837). However, ICU admission (43 [28%] vs 52 [8%], p<0·0001) and invasive ventilation (30 [20%] vs 32 [5%], p<0·0001) were more frequent in the liver transplant cohort. 28 (19%) patients in the liver transplant cohort died, compared with 167 (27%) in the comparison cohort (p=0·046). In the propensity score-matched analysis (adjusting for age, sex, creatinine concentration, obesity, hypertension, diabetes, and ethnicity), liver transplantation did not significantly increase the risk of death in patients with SARS-CoV-2 infection (absolute risk difference 1·4% [95% CI -7·7 to 10·4]). Multivariable logistic regression analysis showed that age (odds ratio 1·06 [95% CI 1·01 to 1·11] per 1 year increase), serum creatinine concentration (1·57 [1·05 to 2·36] per 1 mg/dL increase), and non-liver cancer (18·30 [1·96 to 170·75]) were associated with death among liver transplant recipients. INTERPRETATION: Liver transplantation was not independently associated with death, whereas increased age and presence of comorbidities were. Factors other than transplantation should be preferentially considered in relation to physical distancing and provision of medical care for patients with liver transplants during the COVID-19 pandemic. FUNDING: European Association for the Study of the Liver, US National Institutes of Health, UK National Institute for Health Research.

Hypoxia sensing by hepatic stellate cells leads to VEGF-dependent angiogenesis and may contribute to accelerated liver regeneration.

Portal vein ligation (PVL) induces liver growth prior to resection. Associating liver partition and portal vein ligation (PVL plus transection=ALPPS) or the addition of the prolyl-hydroxylase inhibitor dimethyloxalylglycine (DMOG) to PVL both accelerate growth via stabilization of HIF-α subunits. This study aims at clarifying the crosstalk of hepatocytes (HC), hepatic stellate cells (HSC) and liver sinusoidal endothelial cells (LSEC) in accelerated liver growth. In vivo, liver volume, HC proliferation, vascular density and HSC activation were assessed in PVL, ALPPS, PVL+DMOG and DMOG alone. Proliferation of HC, HSC and LSEC was determined under DMOG in vitro. Conditioned media experiments of DMOG-exposed cells were performed. ALPPS and PVL+DMOG accelerated liver growth and HC proliferation in comparison to PVL. DMOG alone did not induce HC proliferation, but led to increased vascular density, which was also observed in ALPPS and PVL+DMOG. Activated HSC were detected in ALPPS, PVL+DMOG and DMOG, again not in PVL. In vitro, DMOG had no proliferative effect on HC, but conditioned supernatant of DMOG-treated HSC induced VEGF-dependent proliferation of LSEC. Transcriptome analysis confirmed activation of proangiogenic factors in hypoxic HSC. Hypoxia signaling in HSC induces VEGF-dependent angiogenesis. HSC play a crucial role in the cellular crosstalk of rapid liver regeneration.

A Novel Drug, CC-122, Inhibits Tumor Growth in Hepatocellular Carcinoma through Downregulation of an Oncogenic TCF-4 Isoform.

Immunomodulatory drugs such as lenalidomide (LEN) have shown significant anti-tumor activity against hematologic malignancies and they may have similar actions on solid tumors as well. We studied the effect of a new analog of the immunomodulatory drugs (CC-122) on the growth of hepatocellular carcinoma (HCC) and explored mechanisms of anti-tumor activity by analyzing expression of a novel oncogenic T-cell factor (TCF)-4 J and its downstream gene activation. LEN and CC-122 significantly reduced the expression levels of TCF-4 J and its target genes (SPP1, AXIN2, MMP7, ASPH, CD24, ANXA1, and CAMK2N1); however, CC-122 was more potent. In a xenograft tumor model with a HAK-1A-TCF-4 J derived stable cells, tumor growth was significantly inhibited by CC-122, but not by LEN or vehicle control. The mice with HCC xenograft tumors treated with CC-122 exhibited decreased TCF-4 J expression compared to LEN and control. Furthermore, expression of TCF-4 J-responsive target genes (SPP1, AXIN2, MMP7, ASPH, JAG1, CD24, ANXA1, and CAMK2N1) was reduced by CC-122 and not by LEN or control. These results suggest that CC-122 inhibits HCC tumor growth through downregulation of the oncogenic TCF-4 J isoform.

Osteopontin deletion drives hematopoietic stem cell mobilization to the liver and increases hepatic iron contributing to alcoholic liver disease.

The aim of this study was to investigate the role of osteopontin (OPN) in hematopoietic stem cell (HPSC) mobilization to the liver and its contribution to alcoholic liver disease (ALD). We analyzed young (14-16 weeks) and old (>1.5 years) wild-type (WT) littermates and global Opn knockout (Opn-/- ) mice for HPSC mobilization to the liver. In addition, WT and Opn-/- mice were chronically fed the Lieber-DeCarli diet for 7 weeks. Bone marrow (BM), blood, spleen, and liver were analyzed by flow cytometry for HPSC progenitors and polymorphonuclear neutrophils (PMNs). Chemokines, growth factors, and cytokines were measured in serum and liver. Prussian blue staining for iron deposits and naphthol AS-D chloroacetate esterase staining for PMNs were performed on liver sections. Hematopoietic progenitors were lower in liver and BM of young compared to old Opn-/- mice. Granulocyte colony-stimulating factor and macrophage colony-stimulating factor were increased in Opn-/- mice, suggesting potential migration of HPSCs from the BM to the liver. Furthermore, ethanol-fed Opn-/- mice showed significant hepatic PMN infiltration and hemosiderin compared to WT mice. As a result, ethanol feeding caused greater liver injury in Opn-/- compared to WT mice. Conclusion: Opn deletion promotes HPSC mobilization, PMN infiltration, and iron deposits in the liver and thereby enhances the severity of ALD. The age-associated contribution of OPN to HPSC mobilization to the liver, the prevalence of PMNs, and accumulation of hepatic iron, which potentiates oxidant stress, reveal novel signaling mechanisms that could be targeted for therapeutic benefit in patients with ALD. (Hepatology Communications 2018;2:84-98).

Increased hepatic progenitor cell response and ductular reaction in patients with severe recurrent HCV post-liver transplantation.

OBJECTIVES: Post-liver transplant (LT) hepatitis C virus (HCV) patients may develop allograft cirrhosis and rarely fibrosing cholestatic hepatitis (FCH), while others have a stable course. Hepatic progenitor cells (HPC) may be implicated in liver injury and fibrogenesis through ductular reaction (DR). We studied HPC response and DR in three distinct post-LT patterns of HCV: stable recurrence, allograft cirrhosis, and FCH. METHODS: We identified 52 patients with untreated recurrent HCV and longitudinal liver biopsies (20 stable/23 cirrhosis/9 FCH) and eight healthy controls. Archived liver biopsy specimens for three time points (LT; initial recurrence; and clinical outcome) were stained for cytokeratin-7. Manual HPC counts and DR quantification using image analysis were performed. RESULTS: HCV counts and DR at LT did not differ across groups. At initial recurrence, HPC expansion occurred only in patients who developed cirrhosis, while prominent DR was present in those who developed FCH vs. stable and controls (p < 0.05). At outcome biopsies, HPC response and DR were increased in cirrhosis and FCH vs. stable and controls (p < 0.05). HPC response and DR did not differ in stable vs. CONCLUSIONS: These findings suggest that an altered HPC response assessed by cytokeratin-7 stain after LT may predict severity of HCV recurrence.

The dynamic and clinical significance of autoantibodies and immunoglobulins in liver transplant recipients.

Little is known about autoantibody pattern in liver transplantation (LT). The aim of the study was to examine autoantibodies (AAB) and immunoglobulins in patients with end-stage liver disease before and after LT. Patients with LT who underwent post-LT biopsies between 10/2008 and 8/2011 were enrolled. AAB were assessed at the time of LT and liver biopsy. Demographics, serum immunoglobulins, AAB, and liver histology (explant, post-LT biopsies) were analyzed. Two hundred and twenty patients (M/F 143/77; age at LT 54 (19-73)) were included; AAB and immunoglobulins were evaluated in 76 patients. Length of follow-up from LT was 285 (30-1462) days. Sixty-one percent of patients had hepatitis C (HCV); 83% developed recurrent HCV. A significant decrease in IgG, IgA, IgM (p < 0.001 each), anticardiolipin antibodies IgG and IgM (p = 0.02), and beta-2 microglobulin (p = 0.004) was observed post-LT. HCV patients had higher IgG (p = 0.005), rheumatoid factor (p = 0.044) before LT; elevated IgM was associated with increased inflammation in the explant (p = 0.007). Lower IgG levels and antismooth muscle antibodies were present before LT in a higher percentage in patients who would develop recurrent HCV (p = 0.004, p = 0.077, respectively). In conclusion, AAB change significantly after LT and have a different pattern in HCV. Some immunological markers are associated with HCV recurrence and advanced inflammation on explant.

ß-PDGF receptor expressed by hepatic stellate cells regulates fibrosis in murine liver injury, but not carcinogenesis.

BACKGROUND & AIMS: Rapid induction of ß-PDGF receptor (ß-PDGFR) is a core feature of hepatic stellate cell activation, but its cellular impact in vivo is not well characterized. We explored the contribution of ß-PDGFR-mediated pathway activation to hepatic stellate cell responses in liver injury, fibrogenesis, and carcinogenesis in vivo using genetic models with divergent ß-PDGFR activity, and assessed its prognostic implications in human cirrhosis. METHODS: The impact of either loss or constitutive activation of ß-PDGFR in stellate cells on fibrosis was assessed following carbon tetrachloride (CCl4) or bile duct ligation. Hepatocarcinogenesis in fibrotic liver was tracked after a single dose of diethylnitrosamine (DEN) followed by repeated injections of CCl4. Genome-wide expression profiling was performed from isolated stellate cells that expressed or lacked ß-PDGFR to determine deregulated pathways and evaluate their association with prognostic gene signatures in human cirrhosis. RESULTS: Depletion of ß-PDGFR in hepatic stellate cells decreased injury and fibrosis in vivo, while its auto-activation accelerated fibrosis. However, there was no difference in development of DEN-induced pre-neoplastic foci. Genomic profiling revealed ERK, AKT, and NF-κB pathways and a subset of a previously identified 186-gene prognostic signature in hepatitis C virus (HCV)-related cirrhosis as downstream of ß-PDGFR in stellate cells. In the human cohort, the ß-PDGFR signature was not associated with HCC development, but was significantly associated with a poorer outcome in HCV cirrhosis. CONCLUSIONS: ß-PDGFR is a key mediator of hepatic injury and fibrogenesis in vivo and contributes to the poor prognosis of human cirrhosis, but not by increasing HCC development.

Central role of conventional dendritic cells in regulation of bone marrow release and survival of neutrophils.

Neutrophils are the most abundant cell type in the immune system and play an important role in the innate immune response. Using a diverse range of mouse models with either defective dendritic cell (DC) development or conditional DC depletion, we provide in vivo evidence indicating that conventional DCs play an important role in the regulation of neutrophil homeostasis. Flk2, Flt3L, and Batf3 knockout mice, which have defects in DC development, have increased numbers of liver neutrophils in the steady state. Conversely, neutrophil frequency is reduced in DC-specific PTEN knockout mice, which have an expansion of CD8(+) and CD103(+) DCs. In chimeric CD11c-DTR mice, conventional DC depletion results in a systemic increase of neutrophils in peripheral organs in the absence of histological inflammation or an increase in proinflammatory cytokines. This effect is also present in splenectomized chimeric CD11c-DTR mice and is absent in chimeric mice with 50% normal bone marrow. In chimeric CD11c-DTR mice, diphtheria toxin treatment results in enhanced neutrophil trafficking from the bone marrow into circulation and increased neutrophil recruitment. Moreover, there is an increased expression of chemokines/cytokines involved in neutrophil homeostasis and reduced neutrophil apoptosis. These data underscore the role of the DC pool in regulating the neutrophil compartment in nonlymphoid organs.

Medullary thymic epithelial cell depletion leads to autoimmune hepatitis.

TRAF6, an E3 ubiquitin protein ligase, plays a critical role in T cell tolerance by regulating medullary thymic epithelial cell (mTEC) development. mTECs regulate T cell tolerance by ectopically expressing self-antigens and eliminating autoreactive T cells in the thymus. Here we show that mice with mTEC depletion due to conditional deletion of Traf6 expression in murine thymic epithelial cells (Traf6ΔTEC mice) showed a surprisingly narrow spectrum of autoimmunity affecting the liver. The liver inflammation in Traf6ΔTEC mice exhibited all the histological and immunological characteristics of human autoimmune hepatitis (AIH). The role of T cells in AIH establishment was supported by intrahepatic T cell population changes and AIH development after transfer of liver T cells into immunodeficient mice. Despite a 50% reduction in natural Treg thymic output, peripheral tolerance in Traf6ΔTEC mice was normal, whereas compensatory T regulatory mechanisms were evident in the liver of these animals. These data indicate that mTECs exert a cell-autonomous role in central T cell tolerance and organ-specific autoimmunity, but play a redundant role in peripheral tolerance. These findings also demonstrate that Traf6ΔTEC mice are a relevant model with which to study the pathophysiology of AIH, as well as autoantigen-specific T cell responses and regulatory mechanisms underlying this disease.

Hepatic macrophages but not dendritic cells contribute to liver fibrosis by promoting the survival of activated hepatic stellate cells in mice.

UNLABELLED: Although it is well established that hepatic macrophages play a crucial role in the development of liver fibrosis, the underlying mechanisms remain largely elusive. Moreover, it is not known whether other mononuclear phagocytes such as dendritic cells (DCs) contribute to hepatic stellate cell (HSC) activation and liver fibrosis. We show for the first time that hepatic macrophages enhance myofibroblast survival in a nuclear factor kappa B (NF-κB)-dependent manner and thereby promote liver fibrosis. Microarray and pathway analysis revealed no induction of HSC activation pathways by hepatic macrophages but a profound activation of the NF-κB pathway in HSCs. Conversely, depletion of mononuclear phagocytes during fibrogenesis in vivo resulted in suppressed NF-κB activation in HSCs. Macrophage-induced activation of NF-κB in HSCs in vitro and in vivo was mediated by interleukin (IL)-1 and tumor necrosis factor (TNF). Notably, IL-1 and TNF did not promote HSC activation but promoted survival of activated HSCs in vitro and in vivo and thereby increased liver fibrosis, as demonstrated by neutralization in coculture experiments and genetic ablation of IL-1 and TNF receptor in vivo. Coculture and in vivo ablation experiments revealed only a minor contribution to NF-κB activation in HSCs by DCs, and no contribution of DCs to liver fibrosis development, respectively. CONCLUSION: Promotion of NF-κB-dependent myofibroblast survival by macrophages but not DCs provides a novel link between inflammation and fibrosis.

GM-CSF controls nonlymphoid tissue dendritic cell homeostasis but is dispensable for the differentiation of inflammatory dendritic cells.

GM-CSF (Csf-2) is a critical cytokine for the in vitro generation of dendritic cells (DCs) and is thought to control the development of inflammatory DCs and resident CD103(+) DCs in some tissues. Here we showed that in contrast to the current understanding, Csf-2 receptor acts in the steady state to promote the survival and homeostasis of nonlymphoid tissue-resident CD103(+) and CD11b(+) DCs. Absence of Csf-2 receptor on lung DCs abrogated the induction of CD8(+) T cell immunity after immunization with particulate antigens. In contrast, Csf-2 receptor was dispensable for the differentiation and innate function of inflammatory DCs during acute injuries. Instead, inflammatory DCs required Csf-1 receptor for their development. Thus, Csf-2 is important in vaccine-induced CD8(+) T cell immunity through the regulation of nonlymphoid tissue DC homeostasis rather than control of inflammatory DCs in vivo.

Dendritic cells in alcoholic liver injury and fibrosis.

Alcohol consumption impairs the development of innate and adaptive immune responses, however the exact mechanism by which alcohol leads to immune defects remains to be established. Dendritic cells (DCs) form a heterogeneous population of hematopoietic cells that are present in all tissues including the liver. DC are initially described playing a key role in the induction of innate and adaptive immune response against specific antigens. In our presentation, we discussed few new aspects of DC development, critical assessment of DC in non-lymphoid organs and the impact of alcohol consumption on DC function. Understanding the mechanism by which DC modulate liver function after alcohol consumption may help uncover novel therapeutic strategies for the treatment of these conditions.

Hemophagocytic syndrome occurring in an adult liver transplant recipient having Still's disease.

Hemophagocytic syndrome is a potentially fatal complication that rarely occurs after liver transplantation. We present a 25-year-old man with a history of Still's disease who presented with fever, arthralgia, and elevated serum ferritin levels 6 months after undergoing liver transplantation for fulminant hepatic failure due to autoimmune hepatitis potentially triggered by infliximab therapy. Liver biopsy demonstrated features consistent with hemophagocytic syndrome. The patient was successfully treated with a course of high dose steroids and had complete resolution of his symptoms and normalization of liver chemistry test abnormalities. Patients with Still's disease may rarely complicate with fulminant hepatic failure with infliximab therapy. Hemophagocytic syndrome a rare potentially life threatening condition may occur in such patients following liver transplantation.

Hepatic fibrosis.

PURPOSE OF REVIEW: This review will summarize the most significant work that contributed to the understanding of liver fibrosis progression and resolution, which in turn has yielded new areas of therapeutic targeting. RECENT FINDINGS: Liver fibrosis is the result of an imbalance between production and dissolution of extracellular matrix. Stellate cells, portal myofibroblasts, and bone marrow derived cells converge in a complex interaction with hepatocytes and immune cells to provoke scarring in response to liver injury. Uncovering the specific effects of growth factors on these cells, defining the interaction of different cell population during liver fibrosis and characterizing the genetic determinants of fibrosis progression will enable the discovery of new therapeutic approaches. SUMMARY: The outcome of improved understanding of liver fibrosis process, especially the regulation and activation of stellate cells, is reflected in the development of new therapeutic strategies, which are validated in animal models.

Generation of immune responses against hepatitis C virus by dendritic cells containing NS5 protein-coated microparticles.

Dendritic cells (DCs) internalize and process antigens as well as activate cellular immune responses. The aim of this study was to determine the capacity of DCs that contain antigen-coated magnetic beads to induce immunity against the nonstructural hepatitis C virus (HCV) antigen 5 (NS5). Splenocytes derived from Fms-like tyrosine kinase receptor 3 (Flt3) ligand-pretreated BALB/c mice were incubated with magnetic beads coated with HCV NS5, lipopolysaccharide (LPS), and/or anti-CD40; purified; and used for immunization. Cellular immunity was measured using cytotoxic T-lymphocyte (CTL) and T-cell proliferation assays, intracellular cytokine staining, and a syngeneic tumor challenge using NS5-expressing SP2/0 myeloma cells in vivo. Splenocytes isolated from animals vaccinated with DCs containing beads coated with NS5, LPS, and anti-CD40 secreted elevated levels of interleukin-2 (IL-2) and gamma interferon in the presence of NS5. The numbers of CD4(+), IL-2-producing cells were increased >5-fold in the group immunized with DCs containing beads coated with NS5, LPS, and anti-CD40, paralleled by an enhanced splenocyte proliferative response. Immunization promoted antigen-specific CTL activity threefold compared to the level for control mice and significantly reduced the growth of NS5-expressing tumor cells in vivo. Thus, strategies that employ NS5-coated beads induce cellular immune responses in mice, which correlate well with the natural immune responses that occur in individuals who resolve HCV.