The histological features of chronic hepatitis C and autoimmune chronic hepatitis: a comparative analysis

Effect of ozone gas on viral kinetics and liver histopathology in hepatitis C patients

OBJECTIVES

We examine how well ozone/oxygen gas therapy treats chronic hepatitis C patients with varying degrees of liver fibrosis. Also to study the effect of giving multiple anti-oxidants with the ozone/oxygen gas mixture, to see if this addition would have any additive or synergistic effect.

METHODS

Two hundred and twenty three patients with chronic hepatitis C. Liver biopsies were carried out at after 12 weeks of administering an ozone/oxygen gas mixture.

RESULTS

The mean stage of fibrosis decreased from 1.98 to 1.41 and the mean grade of inflammation decreased from 10.08 to 7.94, both with a p value less than 0.001. After 12 weeks of treatment, mean PCR values increased. No single significant complication was recorded in a total of >9,000 settings of ozone therapy.

CONCLUSIONS

Ozone oxygen gas mixture is safe and effective in treatment of hepatic fibrosis due to chronic viral hepatitis C.

A hepatic network of dendritic cells mediates CD4 T cell help outside lymphoid organs

While CD4+ T cells are a prerequisite for CD8+ T cell-mediated protection against intracellular hepatotropic pathogens, the mechanisms facilitating the transfer of CD4-help to intrahepatic CD8+ T cells are unknown. Here, we developed an experimental system to investigate cognate CD4+ and CD8+ T cell responses to a model-antigen expressed de novo in hepatocytes and reveal that after initial priming, effector CD4+ and CD8+ T cells migrate into portal tracts and peri-central vein regions of the liver where they cluster with type-1 conventional dendritic cells. These dendritic cells are locally licensed by CD4+ T cells and expand the number of CD8+ T cells in situ, resulting in larger effector and memory CD8+ T cell pools. These findings reveal that CD4+ T cells promote intrahepatic immunity by amplifying the CD8+ T cell response via peripheral licensing of hepatic type-1 conventional dendritic cells and identify intrahepatic perivascular compartments specialized in facilitating effector T cell-dendritic cell interactions.

Autoimmune Hepatitis: From Evolution to Current Status-A Pathologist's Perspective

Autoimmune hepatitis (AIH) is a chronic, relapsing and remitting, immune-mediated liver disease that progresses to cirrhosis if left untreated. A significant number of patients may present with acute hepatitis or acute liver failure, which are often misdiagnosed as toxic liver injury. AIH shows a preponderance in young women but may be seen in children and the elderly. Diagnosis requires the integration of clinical, biochemical, and serologic parameters, along with supportive liver histology and exclusion of other causes of liver disease. Liver biopsy is a prerequisite for diagnosis of AIH, to assess severity and stage of disease, exclude other entities, and recognize any concurrent morbidities. No single biomarker or histologic feature is pathognomonic for AIH. The diagnostic and histologic criteria have undergone several modifications since the original scoring system was proposed by the International Autoimmune Hepatitis Group (IAIHG) in 1993. Recently, the IAIHG has proposed consensus recommendations for histologic criteria, relevant for both acute and chronic AIH. This review article will describe the evolving diagnostic criteria for AIH, with their limitations and utility, and with an emphasis on the role of liver histology in the diagnosis and management of AIH.

Histological improvement in chronic hepatitis C-autoimmune hepatitis overlap syndrome by glecaprevir and pibrentasvir

A 60-year-old man with type-2 diabetes and chronic hepatitis C (HCV) was diagnosed with single hepatocellular carcinoma (HCC) of 67 mm in the hepatic posterior right lobe. Lenvatinib 8 mg was initiated but discontinued because of grade 3 liver injury. The patient continued to have prolonged liver injury and persistently high immunoglobulin G levels. Antinuclear antibody titer increased from 1:40 to 1:320. Histopathological examination of a liver biopsy specimen revealed interface hepatitis with lymphocyte and plasma cell infiltration, rosette formation, and emperipolesis, suggesting the possibility of autoimmune hepatitis (AIH). First, treatment with prednisolone was initiated; however, the response was poor. After starting glecaprevir/pibrentasvir (GLE/PIB) as direct-acting antivirals (DAA), HCV RNA rapidly disappeared, and serological liver function improved. After confirmation of sustained virological response 24, HCC recurrence was observed, and partial hepatectomy was performed. Background liver findings showed that liver parenchymal inflammation improved compared with that before DAA treatment. This is the first case of HCV-AIH overlap syndrome treated with DAA using GLE/PIB. Liver function improved within a short treatment period of 8 weeks, as confirmed using serology and histology.

The many faces and pathologic diagnostic challenges of autoimmune hepatitis

Autoimmune hepatitis (AIH) is an immune-mediated chronic inflammatory liver disease, characterized by hypergammaglobulinemia, the presence of specific autoantibodies, and typical abnormalities in liver histology. Prompt diagnosis and initiation of immunosuppressive treatment are necessary for both chronic and acute onset AIH to prevent progression to end-stage liver disease or fatal liver failure. However, the diagnosis of AIH is challenging mainly because of its heterogeneous clinical, serological and pathological features. Although portal lymphoplasmacytosis and interface hepatitis are the most typical histological features of AIH, many other histological features can be observed in AIH, including emperipolesis, hepatocyte rosettes, and Kupffer cell hyaline globules. Recent studies have questioned emperipolesis and hepatocyte rosette formation as typical features of AIH, and atypical clinical and histological presentations have also been recognized. This led an international working group to propose the modified AIH diagnostic criteria. However, it is well recognized that there are no pathognomonic characteristics that can be used to diagnose AIH and careful clinicopathological correlation is required to arrive at the correct diagnosis. The aim of this review is to summarize the histological features of AIH, its varied histopathologic spectrum, recent updates and major differential diagnoses in routine clinical practice.

The liver contains distinct interconnected networks of CX3CR1 + macrophages, XCR1 + type 1 and CD301a + type 2 conventional dendritic cells embedded within portal tracts

Portal tracts are key intrahepatic structures where leukocytes accumulate during immune responses. They contain the blood inflow, which includes portal blood from the gut, and lymphatic and biliary outflow of the liver, and as such represent a key interface for potential pathogen entry to the liver. Myeloid cells residing in the interstitium of the portal tract might play an important role in the surveillance or prevention of pathogen dissemination; however, the exact composition and localization of this population has not been explored fully. Our in‐depth characterization of portal tract myeloid cells revealed that in addition to T lymphocytes, portal tracts contain a heterogeneous population of MHCII^high myeloid cells with potential antigen presenting cell (APC) function. These include a previously unreported subset of CSF1R‐dependent CX3CR1⁺ macrophages that phenotypically and morphologically resemble liver capsular macrophages, as well as the two main dendritic cell subsets (cDC1 and cDC2). These cells are not randomly distributed, but each subset forms interconnected networks intertwined with specific components of the portal tract. The CX3CR1⁺ cells were preferentially detected along the outer border of the portal tracts, and also in the portal interstitium adjacent to the portal vein, bile duct, lymphatic vessels and hepatic artery. cDC1s abounded along the lymphatic vessels, while cDC2s mostly surrounded the biliary tree. The specific distributions of these discrete subsets predict that they may serve distinct functions in this compartment. Overall, our findings suggest that portal tracts and their embedded cellular networks of myeloid cells form a distinctive lymphoid compartment in the liver that has the potential to orchestrate immune responses in this organ.

Metabolic dysfunction and cancer in HCV: Shared pathways and mutual interactions

HCV hijacks many host metabolic processes in an effort to aid viral replication. The resulting hepatic metabolic dysfunction underpins many of the hepatic and extrahepatic manifestations of chronic hepatitis C (CHC). However, the natural history of CHC is also substantially influenced by the host metabolic status: obesity, insulin resistance and hepatic steatosis are major determinants of CHC progression toward hepatocellular carcinoma (HCC). Direct-acting antivirals (DAAs) have transformed the treatment and natural history of CHC. While DAA therapy effectively eradicates the virus, the long-lasting overlapping metabolic disease can persist, especially in the presence of obesity, increasing the risk of liver disease progression. This review covers the mechanisms by which HCV tunes hepatic and systemic metabolism, highlighting how systemic metabolic disturbance, lipotoxicity and chronic inflammation favour disease progression and a precancerous niche. We also highlight the therapeutic implications of sustained metabolic dysfunction following sustained virologic response as well as considerations for patients who develop HCC on the background of metabolic dysfunction.

B cells in autoimmune hepatitis: bystanders or central players?

B cells are central for the adaptive immune system to mount successful immune responses not only as antibody producers but also as regulators of cellular immunity. These multifaceted features are also reflected in autoimmunity where autoreactive B cells can fuel disease by production of cytotoxic autoantibodies, presentation of autoantigens to autoreactive T cells, and secretion of cytokines and chemokines that either promote detrimental immune activation or impair regulatory T and B cells. The role of B cells and autoantibodies in autoimmune hepatitis (AIH) have been controversially discussed, with typical autoantibodies and hypergammaglobulinemia indicating a key role, while strong HLA class II association suggests T cells as key players. In this review, we summarize current knowledge on B cells in AIH and how different B cell subpopulations may drive AIH progression beyond autoantibodies. We also discuss recent findings of B cell-directed therapies in AIH.

Quantitative MDCT and MRI assessment of hepatic steatosis in genotype 4 chronic hepatitis C patients with fibrosis

Background

Hepatic steatosis has been shown to worsen the course of liver disease in chronic hepatitis C (CHC) patients, and it may reduce the efficacy of antiviral therapy and accelerate disease progression. In this cross-sectional study, we aimed to evaluate the role of multidetector computed tomography and magnetic resonance imaging (MRI) in the quantitative assessment and grading of hepatic steatosis to evaluate the association between hepatic steatosis and fibrosis in Egyptian genotype 4-CHC (G4-CHC) patients.

Results

Histopathological hepatic steatosis was found in 70.3% of 155 patients. No correlation was found between the CT ratio and pathological hepatic steatosis. Proton density fat fraction, T1-fat fraction, and fat percentage correlated with histological steatosis grading (r = 0.953, p < 0.001; r = 0.380, p = 0.027 and r = 0.384, p = 0.025, respectively). An agreement between steatosis grading by histology and 1H-MRS was found in 74.2% of patients. Compared to other MRI modalities, proton density fat fraction had the highest area under the receiver operating characteristic curve (AUC), with 0.910, 0.931, and 0.975 for mild, moderate, and severe steatosis, respectively. The cutoff with the best ability to predict steatosis was > 4.95 for a proton density fat fraction (AUC = 0.958) with 95.8% sensitivity, 90% specificity, 78.5% positive predictive value, and 96.1% negative predictive value.

Conclusion

1H-MRS had good diagnostic performance in predicting hepatic steatosis in G4-CHC patients, and hence, it may offer a useful noninvasive quantitative modality for grading steatosis with clinical applicability, especially in those where a liver biopsy cannot be done.

The Oncogenic Role of Hepatitis C Virus

Persistent infection with hepatitis C virus (HCV) is a major risk factor for hepatocellular carcinoma (HCC). Accumulating evidence suggests that not only inflammation and subsequent fibrosis but also HCV itself are associated with hepatocarcinogenesis. To date, studies using transgenic mouse and cell-culture models, in which HCV proteins are expressed, indicate the direct pathogenicity of HCV, including oncogenic activity. In particular, the core protein of HCV induces excessive oxidative stress by impairing the mitochondrial electron transfer system by disrupting the function of the molecular chaperone, prohibitin. HCV also modulates intracellular signaling pathways, including mitogen-activated protein kinase, promoting the proliferation of hepatocytes. In addition, HCV induces disorders in lipid and glucose metabolism, thereby accelerating the progression of liver fibrosis and the development of HCC. Due to the development of direct-acting antivirals, which was made possible by basic research, HCV can be eradicated from almost all infected patients. However, such patients can develop HCC long after eradication of HCV, suggesting the genetic and/or epigenetic changes induced by HCV may be persistent. These results enhance our understanding of the role of HCV in hepatocarcinogenesis and will facilitate the development of therapeutic and preventive strategies for HCV-induced HCC.

Hepatitis C virus enhances Rubicon expression, leading to autophagy inhibition and intracellular innate immune activation

Autophagy, a degradation system, works to maintain cellular homeostasis. However, as the impact of Hepatitis C virus (HCV) infection on hepatocyte autophagy and its effect on HCV replication remain unclear, we examined them. HCV infection suppressed late-stage autophagy and increased Rubicon. siRNA-mediated knockdown of Rubicon promoted autophagy in HCV-infected cells. In Huh-7 cells harbouring the HCV replicon, Rubicon knockdown downregulated the expression of type 1 interferon (IFN)-related genes and upregulated HCV replication. Rubicon overexpression or administration of bafilomycin A1 or chloroquine, an inhibitor of late-stage autophagy, suppressed autophagy and activated the type 1 IFN pathway. On the other hand, Atg7 knockout suppressed early-stage autophagy and did not activate the type 1 IFN pathway. In livers of humanized liver chimeric mice, HCV infection increased Rubicon and enhanced type 1 IFN signalling. Elimination of HCV in the mice reduced the increase in Rubicon due to HCV infection. The expression levels of Rubicon and IFN-stimulated genes in chronic hepatitis C patients were higher than those in non-B, non-C hepatitis patients. HCV infection increased Rubicon and suppressed hepatocyte autophagy, leading to activation of the intracellular immune response. Rubicon induction is involved in HCV replication via activation of the intracellular immune response.

Resolution of HCV-Autoimmune Hepatitis Overlap Syndrome With Antiviral TreatmentA Paired Liver Biopsy Study

OBJECTIVES

To evaluate histologic changes occurring in patients having chronic hepatitis C and autoimmune hepatitis overlap (HCV-AIH), and who achieved virologic cure using direct-acting antiviral agents (DAA).

METHODS

Characteristics of HCV-AIH patients who underwent paired liver biopsies before and after receiving DAA treatment from 2011 to 2018 were evaluated.

RESULTS

Five HCV-AIH patients (three male; mean age, 60.4 years) underwent paired liver biopsies (average interval, 2.3 years) before and after achieving cure with DAA treatment. All patients showed virologic response, while four showed decreased inflammation, and three cases showed features of fibrosis regression. Immunohistochemical staining demonstrated significant decrease in plasma cell count in three patients (20.6 vs 11.9 plasma cells/high power field; P = .02, t test).

CONCLUSIONS

Histologic improvements in inflammation and fibrosis are noted in most HCV-AIH patients after DAA treatment, suggesting that the autoimmune component of the HCV-AIH overlap syndrome is merely a secondary phenomenon of viral infection.

Spleen stiffness to liver stiffness ratio significantly differs between ALD and HCV and predicts disease-specific complications

Background & Aims

Both liver stiffness (LS) and spleen stiffness (SS) are widely used to non-invasively assess liver fibrosis and portal hypertension, respectively. We aimed to identify the impact of disease etiology, namely the localization of inflammation (portal vs. lobular), on the SS/LS ratio.

Methods

In this multicenter study, LS and SS were prospectively assessed in 411 patients with alcohol-related liver disease (ALD) or hepatitis C virus (HCV) using FibroScan® (Echosens, Paris); changes in these parameters were also studied in response to treatment (alcohol withdrawal, HCV therapy). LS and spleen length (SL) were further analyzed in a retrospective cohort of 449 patients with long-term data on decompensation/death.

Results

Both, SS and SL were significantly higher in HCV compared to ALD (42.0 vs. 32.6 kPa, p≪0.0001, 15.6 vs. 11.9 cm, p≪0.0001) despite a lower mean LS in HCV. Consequently, the SS to LS ratio and the SL to LS ratio were significantly higher in HCV (3.8 vs. 1.72 and 1.46 vs. 0.86, p≪0.0001) through all fibrosis stages. Notably, SL linearly increased with SS and the relation between SS and SL was identical in HCV and ALD. In contrast, livers were much larger in ALD at comparable LS. After treatment, LS significantly decreased in both diseases without significant changes to the SS/LS ratio. In the prognostic cohort, patients with ALD had higher LS values (30.5 vs. 21.3 kPa) and predominantly presented with jaundice (65.2%); liver failure was the major cause of death (p≪0.01). In contrast, in HCV, spleens were larger (17.6 vs. 12.1 cm) while variceal bleeding was the major cause of decompensation (73.2%) and death (p≪0.001).

Conclusion

Both SS/LS and SL/LS ratios are significantly higher in patients with portal HCV compared to lobular ALD. Thus, combined LS and SS or SL measurements provide additional information about disease etiology and disease-specific complications.

Lay summary

Herein, we show that patients with hepatitis C virus infection (HCV) have higher spleen stiffness and portal pressure than patients with alcohol-related liver disease (ALD), within the same fibrosis stage and matched to liver stiffness. Thus, the spleen stiffness to liver stiffness ratio is significantly higher in patients with HCV compared to ALD. Additionally, patients with HCV more commonly progress to portal hypertension-related complications (e.g. variceal bleeding), while patients with ALD more commonly progress to liver failure (e.g. jaundice). The spleen stiffness to liver stiffness ratio is a useful tool to confirm disease etiology and predict disease-specific complications.

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SS/LS ratio is significantly higher in patients with portal HCV compared to lobular ALD.

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Patients with HCV have higher SS and portal pressure than patients with ALD and the same LS.

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Patients with HCV die earlier from portal hypertension-related complications.

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Patients with ALD die earlier from liver failure.

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Combined LS and SS measurements provide extra information about disease etiology and disease-specific complications.

Cellular and Molecular Mechanisms of Autoimmune Hepatitis

Autoimmune hepatitis is an uncommon idiopathic syndrome of immune-mediated destruction of hepatocytes, typically associated with autoantibodies. The disease etiology is incompletely understood but includes a clear association with human leukocyte antigen (HLA) variants and other non-HLA gene variants, female sex, and the environment. Pathologically, there is a CD4+ T cell-rich lymphocytic inflammatory infiltrate with variable hepatocyte necrosis and subsequent hepatic fibrosis. Attempts to understand pathogenesis are informed by several monogenetic syndromes that may include autoimmune liver injury, by several drug and environmental agents that have been identified as triggers in a minority of cases, by human studies that point toward a central role for CD4+ effector and regulatory T cells, and by animal models of the disease. Nonspecific immunosuppression is the current standard therapy. Further understanding of the disease's cellular and molecular mechanisms may assist in the design of better-targeted therapies, aid the limitation of adverse effects from therapy, and inform individualized risk assessment and prognostication.

Chronic Hepatitis C and Direct Acting Antivirals

The hepatitis C virus (HCV) is the most common blood-borne infection in the United States and is the most common cause of end-stage liver disease requiring liver transplant. Over the last 10 years, direct acting antiviral therapies have revolutionized HCV treatment, increasing the cure rates from less than 50% to more than 90% in those who reach access to care. This article is an overview for pathologists and clinicians covering the histologic findings of HCV as well as direct acting antiviral therapy.

Eradication of hepatitis C virus is associated with the attenuation of steatosis as evaluated using a controlled attenuation parameter

Chronic hepatitis C virus (HCV) infection was shown to cause hepatic steatosis or suppression of serum lipid levels. However, little is known about the changes in hepatic steatosis following HCV eradication. We aimed to evaluate this issue using the controlled attenuation parameter (CAP), which was recently shown to provide a standardized non-invasive measure of hepatic steatosis. We enrolled 70 patients with chronic HCV infections and steatosis (CAP of over 248 dB/m) who had achieved a sustained viral response at 12 weeks after discontinuation of antiviral treatment using direct-acting antivirals (DAA). We then evaluated the state of hepatic steatosis before and after HCV eradication. We also investigated the changes in serum parameters such as cholesterol and glucose levels. The median value of CAP level decreased significantly after HCV eradication from 273 dB/m to 265 dB/m (P = 0.034). Also, LDL and HDL cholesterol levels increased significantly after HCV eradication (P = 0.002 and P = 0.027, respectively). In conclusion, a decrease in hepatic steatosis after HCV eradication with DAA was revealed in chronic hepatitis C patients with significant steatosis. Cancellation of the viral effect is a possible underlying cause of hepatic steatosis improvement and increase in HDL and LDL cholesterol levels.

RNA helicase DDX3 maintains lipid homeostasis through upregulation of the microsomal triglyceride transfer protein by interacting with HNF4 and SHP

Multifunctional RNA helicase DDX3 participates in HCV infection, one of the major causes of hepatic steatosis. Here, we investigated the role of DDX3 in hepatic lipid metabolism. We found that HCV infection severely reduced DDX3 expression. Analysis of intracellular triglyceride and secreted ApoB indicated that lipid accumulations were increased while ApoB secretion were decreased in DDX3 knockdown HuH7 and HepG2 cell lines. Down-regulation of DDX3 significantly decreased protein and transcript expression of microsomal triglyceride transfer protein (MTP), a key regulator of liver lipid homeostasis. Moreover, DDX3 interacted with hepatocyte nuclear factor 4 (HNF4) and small heterodimer partner (SHP), and synergistically up-regulated HNF4-mediated transactivation of MTP promoter via its ATPase activity. Further investigation revealed that DDX3 interacted with CBP/p300 and increased the promoter binding affinity of HNF4 by enhancing HNF4 acetylation. Additionally, DDX3 partially relieved the SHP-mediated suppression on MTP promoter by competing with SHP for HNF4 binding which disrupted the inactive HNF4/SHP heterodimer while promoted the formation of the active HNF4 homodimer. Collectively, these results imply that DDX3 regulates MTP gene expression and lipid homeostasis through interplay with HNF4 and SHP, which may also reveal a novel mechanism of HCV-induced steatosis.

Hepatitis C Virus, Insulin Resistance, and Steatosis

Hepatitis C virus (HCV) is one of the main causes of liver disease worldwide. Liver steatosis is a common finding in many hepatic and extrahepatic disorders, the most common being metabolic syndrome (MS). Over time, it has been shown that the frequent coexistence of these two conditions is not coincidental, since many epidemiological, clinical, and experimental studies have indicated HCV to be strongly associated with liver steatosis and numerous metabolic derangements. Here, we present an overview of publications that provide clinical evidence of the metabolic effects of HCV and summarize the available data on the pathogenetic mechanisms of this association. It has been shown that HCV infection can induce insulin resistance (IR) in the liver and peripheral tissues through multiple mechanisms. Substantial research has suggested that HCV interferes with insulin signaling both directly and indirectly, inducing the production of several proinflammatory cytokines. HCV replication, assembly, and release from hepatocytes require close interactions with lipid droplets and host lipoproteins. This modulation of lipid metabolism in host cells can induce hepatic steatosis, which is more pronounced in patients with HCV genotype 3. The risk of steatosis depends on several viral factors (including genotype, viral load, and gene mutations) and host features (visceral obesity, type 2 diabetes mellitus, genetic predisposition, medication use, and alcohol consumption). HCV-related IR and steatosis have been shown to have a remarkable clinical impact on the prognosis of HCV infection and quality of life, due to their association with resistance to antiviral therapy, progression of hepatic fibrosis, and development of hepatocellular carcinoma. Finally, HCV-induced IR, oxidative stress, and changes in lipid and iron metabolism lead to glucose intolerance, arterial hypertension, hyperuricemia, and atherosclerosis, resulting in increased cardiovascular mortality.

MicroRNA-185-5p mediates regulation of SREBP2 expression by hepatitis C virus core protein

AIM: To investigate the molecular mechanism for regulation of cholesterol metabolism by hepatitis C virus (HCV) core protein in HepG2 cells.

METHODS: HCV genotype 1b core protein was cloned and expressed in HepG2 cells. The cholesterol content was determined after transfection. The expression of sterol regulatory element binding protein 2 (SREBP2) and the rate-limiting enzyme in cholesterol synthesis (HMGCR) was measured by quantitative real-time PCR and immunoblotting after transfection. The effects of core protein on the SREBP2 promoter and 3’-untranslated region were analyzed by luciferase assay. We used different target predictive algorithms, microRNA (miRNA) mimics/inhibitors, and site-directed mutation to identify a putative target of a particular miRNA.

RESULTS: HCV core protein expression in HepG2 cells increased the total intracellular cholesterol level (4.05 ± 0.17 vs 6.47 ± 0.68, P = 0.001), and this increase corresponded to an increase in SREBP2 and HMGCR mRNA levels (P = 0.009 and 0.037, respectively) and protein expression. The molecular mechanism study revealed that the HCV core protein increased the expression of SREBP2 by enhancing its promoter activity (P = 0.004). In addition, miR-185-5p expression was tightly regulated by the HCV core protein (P = 0.041). Moreover, overexpression of miR-185-5p repressed the SREBP2 mRNA level (P = 0.022) and protein expression. In contrast, inhibition of miR-185-5p caused upregulation of SREBP2 protein expression. miR-185-5p was involved in the regulation of SREBP2 expression by HCV core protein.

CONCLUSION: HCV core protein disturbs the cholesterol homeostasis in HepG2 cells via the SREBP2 pathway; miR-185-5p is involved in the regulation of SREBP2 by the core protein.

Primary sclerosing cholangitis: detailed histologic assessment and integration using bioinformatics highlights arterial fibrointimal hyperplasia as a novel feature

OBJECTIVES

Liver biopsy diagnosis of primary sclerosing cholangitis (PSC) is difficult. We performed a detailed histologic analysis of PSC cases using novel bioinformatics analysis to identify histologic features that may be useful in its diagnosis.

METHODS

PSC liver explants were examined and compared with primary biliary cirrhosis and hepatitis C explants to act as controls. Demographic, macroscopic, and histologic variables were analyzed using both conventional statistics and an integrative bioinformatics approach, significance analysis of microarrays (SAM), and hierarchical clustering analysis (HCA).

RESULTS

The PSC group was younger and had distinctive PSC features, including bile duct scars, onion-skin fibrosis, and arterial fibrointimal hyperplasia. SAM allowed the integration of variables by comparing PSC and control groups, whereas HCA was able to correctly categorize each group.

CONCLUSIONS

This study demonstrates characteristic PSC histology as well as arterial hyperplasia to be distinctive features that may aid in PSC diagnosis and be confirmed by bioinformatics.

Assessment of the histopathological key features in autoimmune hepatitis

AIMS

In this study, we aimed to evaluate the use of typical histological features of both the revised original (1999) and simplified (2008) criteria in the diagnosis of autoimmune hepatitis (AIH) in clinical practice.

METHODS AND RESULTS

We performed a detailed histopathological evaluation of the pretreatment biopsies of 63 AIH patients, and used biopsies of 62 untreated chronic viral hepatitis patients [hepatitis B (n = 21) or hepatitis C (n = 41)] as a reference cohort. Biopsies were systematically reviewed for inflammation, fibrosis and the presence of interface hepatitis, plasma cells, rosettes and emperipolesis with a well-defined assessment method. AIH biopsies showed more interface hepatitis (87% versus 63%, P = 0.002), more plasma cell-rich infiltrates (48% versus 27%, P = 0.02), more rosettes (49% versus 23%, P = 0.004) and more emperipolesis (78% versus 50%, P = 0.001) than chronic viral hepatitis biopsies. Emperipolesis (P = 0.01) and rosettes (P < 0.01) were superior to plasma cells and interface hepatitis as independent predictors for AIH. Moderate to severe lymphocytic cholangitis was found in 28% of AIH patients.

CONCLUSIONS

Emperipolesis and rosette formation are superior histological predictors of AIH than the classic hallmark features of interface hepatitis and plasma cells. In addition, moderate to severe lymphocytic cholangitis does not preclude the diagnosis of AIH.

Hepatitis C virus-associated cancer

Hepatitis C virus (HCV) is one of the major etiologic agents of liver cancer. HCV is an RNA virus that, unlike hepatitis B virus, is unable to integrate into the host genome. Through complex interactions between viral and host proteins that induce host responses and promote inflammation, fibrosis, and ultimately cirrhosis, HCV infection can result in the development of hepatocellular carcinoma (HCC). The HCV oncogenic process involves genetic and epigenetic alterations and oncogenic effects mediated by viral proteins in the activation of cellular oncogenes, inactivation of tumor-suppressor genes, and dysregulation of multiple signal-transduction pathways. Advances in genetics and gene expression profiling have enhanced our current understanding of the pathways involved in HCV-associated liver cancer development. In this review, we summarize the current understanding of mechanisms of hepatocarcinogenesis induced by HCV infection.

The prevalence of bright liver echo pattern in patients with chronic hepatitis C: correlation with steatosis and fibrosis

PURPOSE

To evaluate the prevalence of bright liver echo pattern (BLP) on ultrasonography and its correlation with liver steatosis (LS), and fibrosis in patients with chronic hepatitis C. The usefulness of detecting skip areas for steatosis diagnosis has also been evaluated.

METHODS

The study included 88 patients with chronic hepatitis C (55 men, 33 women, average age 45.7 ± 11.2 years). Ultrasound examination was performed in all patients before liver biopsy. The presence of BLP was assessed and graded from 1 to 3. Hypoechogenic areas (skip areas) around the gallbladder or near the portal vein were also evaluated. Hepatic fibrosis was assessed using the Ishak fibrosis score. Steatosis was graded as follows: 1, 2, 3 (<30, 30-70, >70 % of hepatocytes affected, respectively).

RESULTS

Fifty-three of the 88 patients (60 %) showed BLP (40 grade 1, 13 grades 2 or 3). Skip areas were found in 14 patients (16 %). Histological steatosis was observed in 40 patients (45 %) and in 10 of them (25 %) was grades 2 and 3 (4 and 6 patients, respectively). As regards fibrosis, 2 patients showed F0, 34 F1, 28 F2, 20 F3, 4 F4, none of them F5 and F6. BLP of grades 2 or 3 and presence of skip areas were strongly correlated with LS (P = 0.00007 and P = 0.00003, respectively). No correlation was found between BLP and fibrosis. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of BLP for LS were 75, 50, 56, 68 and 61 %, respectively. When BLP of grades 2 and 3 and LS of 30 % or more were correlated, the sensitivity, specificity, PPV, NPV and accuracy of BLP were 72, 96, 61, 96 and 90 %, respectively. As regards skip areas the sensitivity, specificity, PPV, NPV and accuracy for LS were 35, 100, 100, 64 and 70 %, respectively.

CONCLUSIONS

In a well-defined group of patients with chronic hepatitis C, the detection of BLP grades 2 and 3 has a good sensitivity and high specificity for high grades of steatosis. A high specificity but low sensitivity for liver steatosis was also found for skip areas, whereas mild fibrosis does not seem to correlate with the hyperechogenicity of the liver.

Histologic findings predictive of a diagnosis of de novo autoimmune hepatitis after liver transplantation in adults

BACKGROUND

Autoimmune hepatitis (AIH) after liver transplantation has been defined histologically as a "hepatitic" pattern of injury, characterized by lymphoplasmacytic inflammation with necroinflammatory activity (NIA), comparable with findings seen in native livers. This definition, however, is difficult to apply in practice because specific histologic criteria are not clearly delineated. This study aimed to determine which histologic features correlated best with clinical and serologic features of dAIH.

METHODS

Index liver biopsies from patients with autoimmune-like hepatitis transplanted for non-AIH in two centers (n=35 and 20) were reviewed. Histologic features were correlated with the clinical diagnosis of AIH based on a retrospective review of clinical and serologic data, including therapeutic response.

RESULTS

A clinical diagnosis of AIH was retrospectively assigned to 24 of 35 (68%) and 18 of 20 (90%) patients, respectively (P=0.10). In multivariate analysis, centrilobular NIA and centrilobular plasma cell (PC) ratio of 30% to 50% were independently discriminating for a clinical diagnosis of AIH (P=0.04 and 0.05, respectively). The best level of predictability (99.6%) was mathematically achieved when severe centrilobular NIA and centrilobular PC ratio of 30% to 50% were both present.

CONCLUSION

A histologic pattern of centrilobular injury including increased NIA and increased PC infiltration correlates with measurements of autoimmunity in liver recipients. It could be used to segregate cases for further study and introduced into the AIH scoring systems when applied in the context of liver transplantation.

Utility of controlled attenuation parameter measurement for assessing liver steatosis in Japanese patients with chronic liver diseases

AIM

Steatosis is a common histological feature of chronic liver disease, especially alcoholic and non-alcoholic fatty liver disease, as well as chronic hepatitis C. A recent study showed that evaluating the controlled attenuation parameter (CAP) with transient elastography was an efficient way of non-invasively determining the severity of hepatic steatosis. The objective of this study was to prospectively evaluate the utility of CAP for diagnosing steatosis in patients with chronic liver disease.

METHODS

One hundred and fifty-five consecutive patients with suspected chronic liver disease underwent steatosis diagnosis using CAP, blood sample analyses, computed tomography for assessing the liver/spleen ratio and liver biopsy. Steatosis was graded according to the percentage of fat-containing hepatocytes: S0, less than 5%; S1, 5-33%; S2, 34-66%; and S3: more than 66%.

RESULTS

The CAP was significantly correlated with steatosis grade, and there were significant differences between the CAP value of the S0 patients and those of the patients with other grades of steatosis. S0 and S1-3 hepatic steatosis were considered to represent mild and significant steatosis, respectively. The CAP values of the patients with mild and significant steatosis were significantly different (P < 0.0001). The area under the receiver-operator curve (AUROC) value of the CAP for diagnosing significant steatosis was 0.878 (95% confidence interval, 0.818-0.939), and the optimal CAP cut-off value for detecting significant steatosis was 232.5 db/m. In multivariate analysis, the CAP (P = 0.0002) and the liver to spleen ratio (P = 0.004) were found to be significantly associated with significant steatosis.

CONCLUSION

The CAP is a promising tool for rapidly and non-invasively diagnosing steatosis.

Autoimmune Hepatitis

Autoimmune hepatitis is a chronic necroinflammatory disease of unknown etiology that is characterized by increased aminotransferases, serum autoantibodies, increased immunoglobulin G levels, and histological interface hepatitis. The disease does not have a pathognomonic clinical, laboratory, or histological feature; diagnosis depends on a combination of clinical and pathologic criteria which also form the basis for a weighted scoring system to aid diagnosis. Liver biopsy is an essential part of the diagnostic criteria and is also crucial to the management of the disease. This review focuses on the diagnosis, microscopic features, differential diagnosis and overlap syndromes of autoimmune hepatitis.

Tumor-initiating stem-like cells and drug resistance: carcinogenesis through Toll-like receptors, environmental factors, and virus

Neoplasms contain distinct subpopulations of cells known as tumor-initiating stem-like cells (TICs) that have been identified as key drivers of tumor growth and malignant progression with drug resistance. Stem cells normally proliferate through self-renewing divisions in which the two daughter cells differ markedly in their proliferative potential, with one displaying the differentiation phenotypes and another retaining self-renewing activity. Therefore, understanding the molecular mechanisms of hepatocarcinogenesis will be required for the eventual development of improved therapeutic modalities for treating hepatocellular carcinoma (HCC). Hepatitis C virus (HCV) and hepatitis B virus is a major cause of HCC. Compelling epidemiologic evidence identifies obesity and alcohol as co-morbidity factors that can increase the risk of HCV patients for HCC, especially in alcoholics or obese patients. The mechanisms underlying liver oncogenesis, and how environmental factors contribute to this process, are not yet understood. The HCV-Toll-like receptor 4 (TLR4)-Nanog signaling network is established since alcohol/obesity-associated endotoxemia then activates TLR4 signaling, resulting in the induction of the stem cell marker Nanog expression and liver tumors. Liver TICs are highly sensitized to leptin and exposure of TICs to leptin increases the expression and activity of an intrinsic pluripotency-associated transcriptional network comprised of signal transducer and activator of transcription 3, SOX2, OCT4, and Nanog. Stimulation of the pluripotency network may have significant implications for hepatocellular oncogenesis via genesis and maintenance of TICs. It is important to understand how HCV induces liver cancer through genesis of TICs so that better prevention and treatment can be found. This article reviews the oncogenic pathways to generate TICs.

Nutrition therapy for liver diseases based on the status of nutritional intake

The dietary intake of patients with nonalcoholic fatty liver disease (NAFLD) is generally characterized by high levels of carbohydrate, fat, and/or cholesterol, and these dietary patterns influence hepatic lipid metabolism in the patients. Therefore, careful investigation of dietary habits could lead to better nutrition therapy in NAFLD patients. The main treatment for chronic hepatitis C (CHC) is interferon-based antiviral therapy, which often causes a decrease in appetite and energy intake; hence, nutritional support is also required during therapy to prevent undernourishment, treatment interruption, and a reduction in quality of life. Moreover, addition of some nutrients that act to suppress viral proliferation is recommended. As a substitutive treatment, low-iron diet therapy, which is relatively safe and effective for preventing hepatocellular carcinoma, is also recommended for CHC patients. Some patients with liver cirrhosis (LC) have decreased dietary energy and protein intake, while the number of LC patients with overeating and obesity is increasing, indicating that the nutritional state of LC patients has a broad spectrum. Therefore, nutrition therapy for LC patients should be planned on an assessment of their complications, nutritional state, and dietary intake. Late evening snacks, branched-chain amino acids, zinc, and probiotics are considered for effective nutritional utilization.

IL28B polymorphism is associated with fatty change in the liver of chronic hepatitis C patients

BACKGROUND

Several single nucleotide polymorphisms (SNPs) within the interleukin 28B (IL28B) locus are associated with sustained viral response in chronic hepatitis C (HCV) patients who were treated with pegylated interferon (PEG-IFN) plus ribavirin (RBV) combination therapy. Recently, an association between γ-GTP level and IL28B genotype was identified. In this study, the relationship between IL28B genotype and liver steatosis was analyzed.

METHODS

One hundred fifty-three patients who underwent liver biopsy before PEG-IFN plus RBV combination therapy were enrolled. The level of liver steatosis was measured using a BIOREVO BZ-9000 microscope, and the proportion of fatty change and clear cell change were calculated using Dynamic cell count BZ-H1C software. IL28B SNP genotype (rs8099917) was determined using the Invader Assay.

RESULTS

Vesicular change was significantly associated with body mass index (BMI), HCV RNA titer, serum aspartate aminotransferase, γ-GTP, IL28B genotype and liver fibrosis level (P < 0.05). Clear cell change was significantly associated with serum aspartate aminotransferase, γ-GTP and IL28B genotype by univariate logistic regression analysis (P < 0.05). Under multiple logistic regression, IL28B genotype (OR(adj) = 8.158; 95% CI 2.412-27.589), liver fibrosis (OR(adj) = 2.541; 95% CI 1.040-6.207) and BMI (OR(adj) = 1.147; 95% CI 1.011-1.301) were significant independent factors for vesicular change and IL28B genotype (OR(adj) = 3.000; 95% CI 1.282-7.019) for clear cell change.

CONCLUSION

In this study, a new quantitative method to objectively evaluate hepatic steatosis was described. IL28B genotypes were significantly associated with both vesicular and clear cell changes of livers in chronic hepatitis C patients.

Elevated serum CK18 levels in chronic hepatitis C patients are associated with advanced fibrosis but not steatosis

Cytokeratin-18 (CK-18) is a major intermediate filament protein in liver cells. The M30 fragment of CK-18 has been identified as a useful marker of apoptosis associated with fibrosis and steatosis in nonalcoholic steatohepatitis (NASH). We sought to assess the relationship of this marker and steatosis in a cohort of adult patients with chronic hepatitis C. The study cohort included sera from 267 treatment-naïve chronic hepatitis C (CHC) patients and 100 healthy controls with normal alanine aminotransferase (ALT). Biopsies from CHC patients were assessed for METAVIR fibrosis stage, Histology Activity Index (HAI) inflammation score and steatosis grade by expert histopathologists. The M30 fragment of CK-18 was quantified by ELISA. Wilcoxon Rank Sum, Spearman Correlation and Linear Regression tests were performed for statistical analysis. Median CK-18 levels were higher in CHC patients compared to controls (411 vs 196 U/L, P < 0.0001). Fibrosis stage was associated with increasing serum CK-18 levels (P = 0.015) and CK-18 levels were higher for F2-F4 vs F0-F1 (500 vs 344 U/L; P = 0.001). There was no association between CK-18 and increasing steatosis grade 1, 2 or 3 (460.7 vs 416.8 vs 508.3 U/L; P = 0.35) and presence or absence of steatosis (445.3 vs 365.8 U/L; P = 0.075). Fibrosis stage was independently associated with serum M30 in a multivariable linear regression model (P = 0.03). CK-18 levels were higher in CHC compared to healthy controls and associated with hepatic fibrosis. There was no difference in CK-18 M30 levels between CHC patients with and without steatosis. Although apoptosis may still contribute to hepatitis C virus (HCV)-mediated steatosis, our results suggest that serum CK-18 will not be a clinically useful test for identifying significant steatosis in CHC.

Current trends in the diagnosis and treatment of autoimmune hepatitis in Japan

While a certain international consensus has been reached regarding the diagnosis and treatment of autoimmune hepatitis (AIH), there are some unique clinical characteristics of AIH in Japan. For diagnosis of AIH using the new simplified criteria proposed by the International Autoimmune Hepatitis Group, it is necessary to re-evaluate the antibody titer determined by using HEp-2 cells, which are widely used in Japan, and the finding of emperipolesis in liver histology, although the criteria are useful for rapid identification of AIH in routine clinical practice. The use of azathioprine as first-line therapy for AIH is limited in Japan because the drug is not covered by the Japanese national health insurance. Concomitant use of ursodeoxycholic acid (UDCA) to reduce corticosteroids and use of UDCA as monotherapy are therefore considered promising. Moreover, a relatively good survival rate has been reported in patients who developed AIH-induced acute liver failure and underwent living-donor liver transplantation. Current trends in the diagnosis and treatment of AIH in Japan are described in this report with a review of recent findings.

Human subtilase SKI-1/S1P is a master regulator of the HCV Lifecycle and a potential host cell target for developing indirect-acting antiviral agents

HCV infection is a major risk factor for liver cancer and liver transplantation worldwide. Overstimulation of host lipid metabolism in the liver by HCV-encoded proteins during viral infection creates a favorable environment for virus propagation and pathogenesis. In this study, we hypothesize that targeting cellular enzymes acting as master regulators of lipid homeostasis could represent a powerful approach to developing a novel class of broad-spectrum antivirals against infection associated with human Flaviviridae viruses such as hepatitis C virus (HCV), whose assembly and pathogenesis depend on interaction with lipid droplets (LDs). One such master regulator of cholesterol metabolic pathways is the host subtilisin/kexin-isozyme-1 (SKI-1) – or site-1 protease (S1P). SKI-1/S1P plays a critical role in the proteolytic activation of sterol regulatory element binding proteins (SREBPs), which control expression of the key enzymes of cholesterol and fatty-acid biosynthesis. Here we report the development of a SKI-1/S1P-specific protein-based inhibitor and its application to blocking the SREBP signaling cascade. We demonstrate that SKI-1/S1P inhibition effectively blocks HCV from establishing infection in hepatoma cells. The inhibitory mechanism is associated with a dramatic reduction in the abundance of neutral lipids, LDs, and the LD marker: adipose differentiation-related protein (ADRP)/perilipin 2. Reduction of LD formation inhibits virus assembly from infected cells. Importantly, we confirm that SKI-1/S1P is a key host factor for HCV infection by using a specific active, site-directed, small-molecule inhibitor of SKI-1/S1P: PF-429242. Our studies identify SKI-1/S1P as both a novel regulator of the HCV lifecycle and as a potential host-directed therapeutic target against HCV infection and liver steatosis. With identification of an increasing number of human viruses that use host LDs for infection, our results suggest that SKI-1/S1P inhibitors may allow development of novel broad-spectrum biopharmaceuticals that could lead to novel indirect-acting antiviral options with the current standard of care.

Chronic hepatitis C virus (HCV) infection is one of the leading causes of liver cancer and liver transplantation worldwide. No vaccine is available for preventing the spread of HCV, and the current therapeutic regimen is only moderately effective and causes serious side effects. New antiviral agents are required to treat HCV infection, but the high mutation rate of HCV hinders the effectiveness of virus-specific inhibitors. Targeting the host enzymes required for HCV to replicate offers a promising new direction for antiviral therapy. During infection, HCV promotes excessive fat accumulation in the liver, which benefits the virus as this promotes formation of lipid droplets, a cellular organelle essential for assembly of new HCV infectious viral particles. Here, we report the development of a specific inhibitor targeting SKI-1/S1P, a host enzyme required for lipid production in human cells. We show that inhibiting SKI-1/S1P activity in human liver cells effectively blocks lipid droplet formation and HCV infection. Many prevalent human viruses, such as dengue, rotavirus, and hepatitis B virus, hijack host lipid metabolic pathways similar to those targeted by HCV to complete their lifecycle. Thus, we propose that cellular SKI-1/S1P is a potential target for developing desperately needed novel broad-spectrum antiviral drugs.

Beneficial IL28B genotype associated with lower frequency of hepatic steatosis in patients with chronic hepatitis C

BACKGROUND & AIMS

IL28B polymorphisms have been associated with both treatment induced and spontaneous clearance of hepatitis C virus (HCV). We previously found that LDL cholesterol levels were higher in chronic hepatitis C (CHC) patients with the CC genotype at the rs12979860 polymorphism, located proximal to the IL28 gene. Here we analyzed the association of steatosis with IL28B genotype in treatment naïve patients with CHC.

METHODS

Two independent cohorts of 145 genotype 1 infected patients from an antifibrotic study and 180 genotype 1 patients from Duke were analyzed for the presence and severity of steatosis in relation to the rs12979860 polymorphism at the IL28B locus. TaqMan assay based genotyping classified three groups CC, CT, and TT.

RESULTS

CC genotype was associated with a lower prevalence of steatosis. In the antifibrotic study, steatosis was found in 47.6% (50/105) of IL28B non-CC vs. 22.5% (9/40; p=0.008) in CC patients. Similarly, steatosis was found in 67.4% (89/132) of non-CC patients compared to only 39.6% (19/48; p=0.001) of CC patients in the Duke cohort.

CONCLUSIONS

IL28B CC genotype is associated with less pronounced disturbances of lipid metabolism, as reflected both in serum lipoprotein levels and hepatic steatosis, in HCV infection.

Liver biopsies in chronic viral hepatitis: beyond grading and staging

CONTEXT

Knowledge of the etiology and pathogenesis of chronic viral hepatitis has grown immensely during the past 50 years. The terminology used to assess liver biopsies with chronic viral hepatitis and the role of the liver biopsy itself have also evolved during this time. Although the focus of much discussion regarding diagnostic assessment of liver biopsies in patients with viral hepatitis has been on grading of activity and staging of fibrosis, each biopsy is also an opportunity to assess many other important features.

OBJECTIVES

To discuss opportunities provided by biopsies to assess features such as the presence of virus-associated premalignant or malignancy-related changes, and the presence of other concomitant diseases, including fatty liver disease of diverse causes, and hemochromatosis, hereditary or otherwise.

DATA SOURCES

The data were obtained from published literature and professional experience.

CONCLUSIONS

The evaluation of liver biopsies with chronic viral hepatitis has evolved beyond grading and staging. Pathologists need to be aware of the other features that may have important clinical implications.

Analysis of the sustained virological response in patients with chronic hepatitis C and liver steatosis

CONTEXT

Chronic hepatitis C as well as non-alcoholic fatty liver disease are recognized as the main cause of liver disease in Western countries. It is common to see the concomitance of the diseases and the influence of steatosis in the sustained virological response of patients with hepatitis C virus.

OBJECTIVE

Assess the sustained virological response in chronic hepatitis C patients according to the presence of liver steatosis.

METHODS

One hundred sixty patients with chronic hepatitis C were retrospectively evaluated. Demographic data such as gender, age, body mass index, presence of diabetes mellitus and systemic arterial hypertension, virus genotype and use of pegylated interferon were analyzed, as was the staging of fibrosis and the presence of steatosis at histology.

RESULTS

Most patients were male (57.5%), with a mean age of 48 ± 9.7 years. The most frequent genotype observed was 3 (56.9%) and, in the histological evaluation, steatosis was observed in 65% of the patients (104/160). Sustained virological response in patients with steatosis occurred in 38.5%, and in 32.1% in patients without steatosis (P = 0.54). When we analyzed possible factors associated with the presence of steatosis, only body mass index and systemic arterial hypertension revealed a significant association. When the factors that influenced sustained virological response were evaluated in a logistic regression, genotype and use of pegylated interferon proved to be independent factors associated to the response.

CONCLUSION

In the evaluated patients the presence of liver steatosis did not influence the sustained virological response of patients with chronic hepatitis C treated with interferon and ribavirin.

Ineffective CD8(+) T-cell immunity to adeno-associated virus can result in prolonged liver injury and fibrogenesis

Chronic viral hepatitis depends on the inability of the T-cell immune response to eradicate antigen. This results in a sustained immune response accompanied by tissue injury and fibrogenesis. We have created a mouse model that reproduces these effects, based on the response of CD8(+) T cells to hepatocellular antigen delivered by an adeno-associated virus (AAV) vector. Ten thousand antigen-specific CD8(+) T cells undergo slow expansion in the liver and can precipitate a subacute inflammatory hepatitis with stellate cell activation and fibrosis. Over time, antigen-specific CD8(+) T cells show signs of exhaustion, including high expression of PD-1, and eventually both inflammation and fibrosis resolve. This model allows the investigation of both chronic liver immunopathology and its resolution.

Recurrent hepatitis C and acute allograft rejection: clinicopathologic features with emphasis on the differential diagnosis between these entities

Chronic hepatitis C virus infection is the leading etiology for liver transplantation in the United States. Recurrent hepatitis C occurs nearly universally in these patients and represents a serious posttransplantation complication. Despite the detailed characterization of the histologic features of both recurrent hepatitis C and acute cellular rejection (ACR) over the last decades, the pathologic distinction between these 2 conditions remains one of the greatest diagnostic challenges in liver pathology. An accurate diagnosis, nevertheless, plays an essential role in patient management, as different therapeutic strategies are used for these conditions. In this review, the clinicopathologic features of posttransplantation recurrent hepatitis C and ACR are discussed, with emphasis on distinguishing histopathologic features, morphologic variants, ancillary techniques, and diagnostic pitfalls.

Hepatitis B and C virus hepatocarcinogenesis: lessons learned and future challenges

Worldwide, hepatocellular carcinoma (HCC) is one of the most common cancers. It is thought that 80% of hepatocellular carcinomas are linked to chronic infections with the hepatitis B (HBV) or hepatitis C (HCV) viruses. Chronic HBV and HCV infections can alter hepatocyte physiology in similar ways and may utilize similar mechanisms to influence the development of HCC. There has been significant progress towards understanding the molecular biology of HBV and HCV and identifying the cellular signal transduction pathways that are altered by HBV and HCV infections. Although the precise molecular mechanisms that link HBV and HCV infections to the development of HCC are not entirely understood, there is considerable evidence that both inflammatory responses to infections with these viruses, and associated destruction and regeneration of hepatocytes, as well as activities of HBV- or HCV-encoded proteins, contribute to hepatocyte transformation. In this review, we summarize progress in defining mechanisms that may link HBV and HCV infections to the development of HCC, discuss the challenges of directly defining the processes that underlie HBV- and HCV-associated HCC, and describe areas that remain to be explored.

Relationship between plasma cells and hepatic stellate cells in autoimmune hepatitis

Autoimmune hepatitis is an inflammatory chronic disease of the liver, which frequently results in cirrhosis. The present study aimed to verify the relationship between plasma cells and stellate cells in autoimmune hepatitis. Thirty-three pre-treatment, 11 post-treatment, and 10 normal liver biopsies were reviewed. Sirius Red staining (for semi-quantitative analysis of hepatic fibrosis) and immunohistochemistry were carried out: double staining for smooth muscle α-actin and plasma cell marker (for detection and localization of activated hepatic stellate cells and plasma cells, respectively); and single staining for glial fibrillary acid protein (for detection of hepatic stellate cells). We found an increase in the stellate cell population, mainly with an activated phenotype in autoimmune hepatitis, compared to the control group (liver specimens with no histological evidence of liver disease, obtained from patients undergoing hepatic resection for benign liver mass). A positive significant correlation was observed between stellate cells and scores of fibrosis (measured by Sirius Red) and the number of plasma cells. Additionally, there was a co-localization of plasma cells and activated stellate cells. We also observed a reduction in the number of plasma cells, hepatic stellate cells, and fibrosis in patients who had successfully been treated and had a second liver biopsy post-treatment. Our findings support that the number of plasma cells can be a surrogate marker for the severity of liver disease, reflecting the number of hepatic stellate cells and the amount of fibrosis. It remains to be seen if this is a result of a direct interaction between the plasma cells and hepatic stellate cells or the response to the same stimulus that affects both cellular types.

Early predictors of corticosteroid treatment failure in icteric presentations of autoimmune hepatitis

Autoimmune hepatitis (AIH) typically responds to treatment in 90% of patients. Early prediction of treatment outcome would be advantageous in clinical practice. We evaluated whether parameters at initiation of therapy or changes in these parameters at day 3 and day 7 following corticosteroid initiation predicted treatment failure. Treatment-naive, jaundiced patients presenting to our tertiary unit between 1999-2009 were identified and mathematical models of prognosis in liver disease scores calculated at day 0, day 3, and day 7. Overall, 72 patients were identified (48 women, 24 men). Treatment failure occurred in 18% (13/72) of patients. At diagnosis, higher median bilirubin (451 μmol/L versus 262 μmol/L, P = 0.02), INR (1.62 versus 1.33, P = 0.005), model for endstage liver (MELD) score (26 versus 20, P = 0.02), MELD-sodium (Na) score (27 versus 22, P = 0.03) and United Kingdom endstage liver disease score (UKELD) score (59 versus 57, P = 0.01) significantly correlated with treatment failure. Analysis of area under the receiver operator characteristic curve (AUROC) values at day 7 identified change (Δ) bilirubin (AUROC 0.68), Δ creatinine (0.69), Δ MELD (0.79), Δ MELD-Na (0.83) and Δ UKELD (0.83) best predicted treatment failure. Specifically, a fall in UKELD of less than 2 points predicted treatment failure with a sensitivity of 85% and specificity of 68%. Of 13 treatment failures, nine required second-line immunosuppression, three required emergency transplant, and one died of sepsis. In total, four patients died in the treatment failure group compared with one in the responder group (4/13 = 31% versus 1/59 = 1.7%, P = 0.003).

CONCLUSION

Approximately 20% of icteric AIH presentations fail corticosteroid therapy. This is associated with significant mortality and the need for emergency transplantation. Treatment failure is best predicted by change in MELD-Na and UKELD at day 7. Early identification of nonresponders may allow timely escalation of immunosuppression to prevent clinical deterioration.

Pathogenesis of lipid metabolism disorder in hepatitis C: polyunsaturated fatty acids counteract lipid alterations induced by the core protein

BACKGROUND & AIMS

Disturbance in lipid metabolism is one of the features of chronic hepatitis C, being a crucial determinant of the progression of liver fibrosis. Experimental studies have revealed that the core protein of hepatitis C virus (HCV) induces steatosis.

METHODS

The activities of fatty acid metabolizing enzymes were determined by analyzing the fatty acid compositions in HepG2 cells with or without core protein expression.

RESULTS

There was a marked accumulation of triglycerides in core-expressing HepG2 cells. While the oleic/stearic acid (18:1/18:0) and palmitoleic/palmitic acid ratio (16:1/16:0) were comparable in both the core-expressing and the control cells, there was a marked accumulation of downstream product, 5,8,11-eicosatrienoic acid (20:3(n-9)) in the core-expressing HepG2 cells. The addition of eicosatetraynoic acid, which inhibits delta-6 desaturase activity which is inherently high in HepG2 cells, led to a marked accumulation of oleic and palmitoleic acids in the core-expressing cells, showing that delta-9 desaturase was activated by the core protein. Eicosapentaenoic acid (20:5(n-3)) or arachidonic acid (20:4(n-6)) administration significantly decreased delta-9 desaturase activity, the concentration of 20:3(n-9), and triglyceride accumulation. This lipid metabolism disorder was associated with NADH accumulation due to mitochondrial dysfunction, and was reversed by the addition of pyruvate through NADH utilization.

CONCLUSIONS

The fatty acid enzyme, delta-9 desaturase, was activated by HCV core protein and polyunsaturated fatty acids counteracted this impact of the core protein on lipid metabolism. These results may open up new insights into the mechanism of lipid metabolism disorder associated with HCV infection and provide clues for the development of new therapeutic devices.