Serum chemokine CXC ligand 10 (CXCL10) predicts fibrosis progression after liver transplantation for hepatitis C infection

Serum inducible protein 10 kDa/C-X-C motif chemokine 10 levels predict regression of M2BPGi-based liver fibrosis after hepatitis C virus eradication by direct-acting antiviral agents

AIM

It is desirable to identify predictors of regression of liver fibrosis after achieving sustained virological response by anti-hepatitis C virus (anti-HCV) therapy. We retrospectively investigated the serum interferon-γ inducible protein 10 kDa (IP-10) level as a predictive indicator of regression of liver fibrosis after successful hepatitis C virus eradication by direct-acting antiviral agents (DAAs) therapy.

METHODS

The study participants were recruited from a historical cohort of 116 chronically hepatitis C virus-infected patients who had achieved sustained virological response by DAAs therapy and whose serum Mac-2 binding protein glycosylation isomer (M2BPGi) levels at baseline (before DAAs therapy) were ≥2.0 cut-off index. We defined patients with M2BPGi levels <1.76 and ≥1.76 cut-off index at 2 years after the end of treatment (EOT) as the regression (n = 71) and non-regression (n = 45) groups, respectively.

RESULTS

Multivariate analyses revealed that the albumin-bilirubin score at baseline, and albumin-bilirubin score, Fibrosis-4 index at 24 weeks after the EOT, and serum IP-10 change from baseline to 24 weeks after the EOT (IP-10 change) were significantly associated with regression of M2BPGi-based liver fibrosis. In addition, IP-10 change was significantly associated with regression of M2BPGi-based liver fibrosis by a multivariate analysis, even when the serum M2BPGi levels were aligned by propensity score matching and in patients with advanced M2BPGi-based liver fibrosis: M2BPGi levels ≥3.3 cut-off index at baseline.

CONCLUSIONS

Serum IP-10 change from baseline to 24 weeks after the EOT is a feasible predictor of regression of M2BPGi-based liver fibrosis after achieving sustained virological response with DAA therapy.

A Comprehensive Review of Liver Allograft Fibrosis and Steatosis: From Cause to Diagnosis

Despite advances in posttransplant care, long-term outcomes for liver transplant recipients remain unchanged. Approximately 25% of recipients will advance to graft cirrhosis and require retransplantation. Graft fibrosis progresses in the context of de novo or recurrent disease. Recurrent hepatitis C virus infection was previously the most important cause of graft failure but is now curable in the majority of patients. However, with an increasing prevalence of obesity and diabetes and nonalcoholic fatty liver disease as the most rapidly increasing indication for liver transplantation, metabolic dysfunction-associated liver injury is anticipated to become an important cause of graft fibrosis alongside alloimmune hepatitis and alcoholic liver disease. To better understand the landscape of the graft fibrosis literature, we summarize the associated epidemiology, cause, potential mechanisms, diagnosis, and complications. We additionally highlight the need for better noninvasive methods to ameliorate the management of graft fibrosis. Some examples include leveraging the microbiome, genetic, and machine learning methods to address these limitations. Overall, graft fibrosis is routinely seen by transplant clinicians, but it requires a better understanding of its underlying biology and contributors that can help inform diagnostic and therapeutic practices.

Integrating inflammatory biomarker analysis and artificial-intelligence-enabled image-based profiling to identify drug targets for intestinal fibrosis

Intestinal fibrosis, often caused by inflammatory bowel disease, can lead to intestinal stenosis and obstruction, but there are no approved treatments. Drug discovery has been hindered by the lack of screenable cellular phenotypes. To address this, we used a scalable image-based morphology assay called Cell Painting, augmented with machine learning algorithms, to identify small molecules that could reverse the activated fibrotic phenotype of intestinal myofibroblasts. We then conducted a high-throughput small molecule chemogenomics screen of approximately 5,000 compounds with known targets or mechanisms, which have achieved clinical stage or approval by the FDA. By integrating morphological analyses and AI using pathologically relevant cells and disease-relevant stimuli, we identified several compounds and target classes that are potentially able to treat intestinal fibrosis. This phenotypic screening platform offers significant improvements over conventional methods for identifying a wide range of drug targets.

Association between Immunologic Markers and Cirrhosis in Individuals from a Prospective Chronic Hepatitis C Cohort

Background: Chronic hepatitis C virus (HCV) infection can affect immune response and inflammatory pathways, leading to severe liver diseases such as cirrhosis and hepatocellular carcinoma (HCC). Methods: In a prospective cohort of chronically HCV-infected individuals, we sampled 68 individuals who developed cirrhosis, 91 controls who did not develop cirrhosis, and 94 individuals who developed HCC. Unconditional odds ratios (ORs) from polytomous logistic regression models and canonical discriminant analyses (CDAs) were used to compare categorical (C) baseline plasma levels for 102 markers in individuals who developed cirrhosis vs. controls and those who developed HCC vs. cirrhosis. Leave-one-out cross validation was used to produce receiver operating characteristic curves to assess predictive ability of markers. Lastly, biological pathways were assessed in association with cirrhotic development compared to controls. Results: After multivariable adjustment, DEFA-1 (OR: C2v.C1 = 7.73; p < 0.0001), ITGAM (OR: C2v.C1 = 4.03; p = 0.0002), SCF (OR: C4v.C1 = 0.19; p-trend = 0.0001), and CCL11 (OR: C4v.C1 = 0.31; p-trend= 0.002) were all associated with development of cirrhosis compared to controls; these markers, together with clinical/demographics variables, improved prediction of cirrhosis from 55.7% (in clinical/demographic-only model) to 74.9% accuracy. A twelve-marker model based on CDA results further increased prediction of cirrhosis to 88.0%. While six biological pathways were found to be associated with cirrhosis, cell adhesion was the only pathway associated with cirrhosis after Bonferroni correction. In contrast to cirrhosis, DEFA-1 and ITGAM levels were inversely associated with HCC risk. Conclusions: Pending validation, these findings highlight the important role of immunological markers in predicting HCV-related cirrhosis even 11 years post-enrollment.

Chemokine CXCL10 Modulates the Tumor Microenvironment of Fibrosis-Associated Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) constitutes a devastating health burden. Recently, tumor microenvironment-directed interventions have profoundly changed the landscape of HCC therapy. In the present study, the function of the chemokine CXCL10 during fibrosis-associated hepatocarcinogenesis was analyzed with specific focus on its impact in shaping the tumor microenvironment. C57BL/6J wild type (WT) and Cxcl10 knockout mice (Cxcl10^−/−) were treated with diethylnitrosamine (DEN) and tetrachloromethane (CCl₄) to induce fibrosis-associated HCCs. Cxcl10 deficiency attenuated hepatocarcinogenesis by decreasing tumor cell proliferation as well as tumor vascularization and modulated tumor-associated extracellular matrix composition. Furthermore, the genetic inactivation of Cxcl10 mediated an alteration of the tumor-associated immune response and modified chemokine/chemokine receptor networks. The DEN/CCl₄-treated Cxcl10^−/− mice presented with a pro-inflammatory tumor microenvironment and an accumulation of anti-tumoral immune cells in the tissue. The most striking alteration in the Cxcl10^−/− tumor immune microenvironment was a vast accumulation of anti-tumoral T cells in the invasive tumor margin. In summary, our results demonstrate that CXCL10 exerts a non-redundant impact on several hallmarks of the tumor microenvironment and especially modulates the infiltration of anti-tumorigenic immune cells in HCC. In the era of microenvironment-targeted HCC therapies, interfering with CXCL10 defines a novel asset for further improvement of therapeutic strategies.

Induction of Collagen I by CXCL10 in Ovarian Theca-Stroma Cells via the JNK Pathway

Premature ovarian insufficiency (POI) poses a great threat to reproductive-age women. Ovarian fibrogenesis is a basic histologic feature of POI. Ovarian theca-stroma cells are responsible for ovarian fibrosis, but few studies have focused on the ovarian microenvironment. The role and mechanism of chemokines in the development of POI remain unclear. Here, we evaluated C-X-C motif chemokine ligand 10 (CXCL10) in biochemical POI patients, POI patients, and a POI mouse model. CXCL10 levels in serum and follicular fluid were higher in both bPOI and POI patients than in controls. An increased level of CXCL10 was also observed in a POI mouse model. CXCL10 concentrations in serum and follicular fluid were positively associated with follicle-stimulating hormone and negatively associated with antral follicle count. Our study for the first time found that CXCL10 induced COL1A1 and COL1A2 production, two subunits of collagen I in mouse theca-stroma cells by activating the JNK/c-Jun pathway. Inhibition of JNK and c-Jun attenuated the increases of COL1A1 and COL1A2 caused by CXCL10. Moreover, CXCL10 had no effects on hormone synthesis, proliferation, and apoptosis in human luteinized granulosa (hGL) cells. Our findings revealed a potential diagnostic value of CXCL10 in the early stage of POI and shed new insights into the biological function of CXCL10 in ovarian fibrosis.

Regulation and functional roles of chemokines in liver diseases

Inflammation is a major contributor to the pathogenesis of almost all liver diseases. Low-molecular-weight proteins called chemokines are the main drivers of liver infiltration by immune cells such as macrophages, neutrophils and others during an inflammatory response. During the past 25 years, tremendous progress has been made in understanding the regulation and functions of chemokines in the liver. This Review summarizes three main aspects of the latest advances in the study of chemokine function in liver diseases. First, we provide an overview of chemokine biology, with a particular focus on the genetic and epigenetic regulation of chemokine transcription as well as on the cell type-specific production of chemokines by liver cells and liver-associated immune cells. Second, we highlight the functional roles of chemokines in liver homeostasis and their involvement in progression to disease in both human and animal models. Third, we discuss the therapeutic opportunities targeting chemokine production and signalling in the treatment of liver diseases, such as alcohol-associated liver disease and nonalcoholic steatohepatitis, including the relevant preclinical studies and ongoing clinical trials.

Distinct Immune Imprints of Post-Liver Transplantation Hepatitis C Persist Despite Viral Clearance

Recurrence or de novo infection of hepatitis C virus (HCV) after liver transplantation (LT) has been associated with progressive graft hepatitis that can be improved by treatment with novel direct-acting antivirals. Cases of rejection episodes have been described during and after HCV treatment. The evolution of innate and adaptive immune response during and after cure of HCV LT is unknown. We studied 74 protein biomarkers in the plasma of LT patients receiving antiviral therapy. In addition, deep immune phenotyping of both the myeloid and lymphoid immune cell subsets in peripheral blood mononuclear cells was performed. We found that LT patients with active HCV infection displayed distinct alterations of inflammatory protein biomarkers, such as C-X-Cmotif chemokine 10 (CXCL10), caspase 8, C-C motif chemokine 20 (CCL20), CCL19, interferon γ, CUB domain-containing protein 1 (CDCP1), interleukin (IL)-18R1, CXCL11, CCL3, IL8, IL12B, tumor necrosis factor-beta, CXCL6, osteoprotegerin, IL10, fms-related tyrosine kinase 3 ligand, hepatocyte growth factor, urokinase-type plasminogen activator, neurotrophin-3, CCL4, IL6, tumornecrosis factor receptor superfamily member 9, programmed death ligand 1, IL18, and monocyte chemotactic protein 1, and enrichment of peripheral immune cell subsets unlike patients without HCV infection who received transplants. Interestingly, patients who cleared HCV after LT did not normalize the altered inflammatory milieu nor did the peripheral immune cell subsets normalize to what would be seen in the absence of HCV recurrence. Overall, these data indicate that HCV-specific imprints on inflammatory analytes and immune cell subsets after LT are not completely normalized by therapy-induced HCV elimination. This is in line with the clinical observation that cure of HCV after LT did not trigger rejection episodes in many patients.

Immunomodulation of CXCL10 Secretion by Hepatitis C Virus: Could CXCL10 Be a Prognostic Marker of Chronic Hepatitis C?

Chemokine (C-X-C motif) ligand (CXCL)10 and other CXCR3 chemokines are involved in the pathogenesis of acute and "chronic hepatitis C virus (HCV) infection" (CHC). Here, we review the scientific literature about HCV and CXCL10. The combination of circulating CXCL10 and single nucleotide polymorphisms (SNPs) in IL-28B can identify patients with acute HCV infection most likely to undergo spontaneous HCV clearance and those in need of early antiviral therapy. In CHC, the HCV and intrahepatic interferon- (IFN-) γ drive a raised CXCL10 expression by sinusoidal endothelium and hepatocytes, thereby inducing the recruitment of CXCR3-expressing T cells into the liver; thus, CXCL10 plays an important role in the development of necroinflammation and fibrosis. Increased CXCL10 was significantly associated with the presence of active vasculitis in HCV-associated cryoglobulinemia, or with autoimmune thyroiditis in CHC. Pretreatment CXCL10 levels are predictive of early virological response and sustained virological response (SVR) to IFN-α and ribavirin and may be useful in the evaluation of candidates for therapy. The occurrence of SNPs adjacent to IL-28B (rs12979860, rs12980275, and rs8099917), and CXCL10 below 150 pg/mL, independently predicted the first phase viral decline and rapid virological response, which in turn independently predicted SVR. Directly acting antiviral agents-mediated clearance of HCV is associated with the loss of intrahepatic immune activation by IFN-α, associated by decreased levels of CXCL10. In conclusion, CXCL10 is an important marker of HCV clearance and successful therapy in CHC patients. Whether CXCL10 is a novel therapeutic target in CHC will be evaluated.

Elevated serum levels of sialyl Lewis X (sLeX) and inflammatory mediators in patients with breast cancer

PURPOSE

The carbohydrate sialyl Lewis^X (sLe^X) mediates cell adhesion, is critical in the normal function of immune cells, and is frequently over-expressed on cancer cells. We assessed the association, differential levels, and prognostic value of sLe^X and inflammatory cytokines/chemokines in breast cancer sera.

METHODS

We retrospectively measured sLe^X and a panel of cytokines/chemokines in the sera of 26 non-invasive ductal carcinoma in situ (DCIS), 154 invasive non-metastatic breast cancer (non-MBC), 63 metastatic breast cancer (MBC) patients, and 43 healthy controls. Differences in sLe^X and inflammatory cytokines among and between patient groups and healthy controls were assessed with nonparametric tests and we performed survival analysis for the prognostic potential of sLe^X using a cut-off of 8 U/mL as previously defined.

RESULTS

Median serum sLe^X was significantly higher than controls for invasive breast cancer patients (MBC and non-MBC) but not DCIS. In univariate analysis, we confirmed patients with serum sLe^X > 8 U/mL have a significantly shorter progression-free survival (PFS) (P = 0.0074) and overall survival (OS (P = 0.0003). Similarly, patients with high serum MCP-1 and IP-10 had shorter OS (P = 0.001 and P < 0.001, respectively) and PFS (P = 0.010 and P < 0.001, respectively). sLe^X, MCP-1 and IP-10 remained significant in multivariate survival analysis.

CONCLUSION

Elevated serum sLe^X was associated with invasive cancer but not DCIS. High serum sLe^X levels were associated with inflammatory mediators and may play a role in facilitating local invasion of breast tumor. Furthermore, serum MCP-1, IP-10 and sLe^X may have prognostic value in breast cancer.

Circulating CXCL10 in cirrhotic portal hypertension might reflect systemic inflammation and predict ACLF and mortality

BACKGROUND & AIMS

CXCR% ligands play an important role in hepatic injury, inflammation and fibrosis. While CXCL9 and CXCL11 are associated with survival in patients receiving transjugular intrahepatic portosystemic shunt (TIPS), the role of CXCL10 in severe portal hypertension remains unknown.

METHODS

A total of 89 cirrhotic patients were analysed. CXCL10 protein levels were measured in portal and hepatic blood at TIPS insertion and 2 weeks later in 24 patients. CXCL10 and IL8 levels were assessed in portal, hepatic, cubital vein and right atrium blood in a further 25 patients at TIPS insertion. Furthermore, real-time PCR determined hepatic CXCL10-mRNA in 40 cirrhotic patients.

RESULTS

Hepatic CXCL10 showed no association with decompensation. By contrast, circulating CXCL10-levels were higher in portal than in hepatic vein blood, suggesting an extrahepatic source of CXCL10 in cirrhosis. However, CXCL10 protein in blood samples from portal, hepatic, cubital veins and right atrium correlated excellently with each other and with IL-8 levels. Higher CXCL10 circulating levels were associated with presence of ascites and higher Child scores. Higher CXCL10 circulating protein levels were associated with acute decompensation, acute-on-chronic liver failure (ACLF) and independently with mortality. Moreover, a decrease in CXCL10 protein levels after TIPS insertion was associated with better survival in each cohort and analysed together.

DISCUSSION

Circulating CXCL10 possibly reflects systemic inflammation and it is correlated with acute decompensation, ACLF and complications in patients with severe portal hypertension receiving TIPS. CXCL10 predicts survival in these patients and a decrease in CXCL10 after TIPS may be considered a good prognostic factor.

The association of CCL3 and CCL4 polymorphisms with HCV clearance in Chinese Han population

AIM

To explore the association of CCL3 (rs1063340) and CCL4 (rs1049807) polymorphisms with hepatitis C virus (HCV) clearance and sustained virologic response (SVR).

METHODS

Two populations were enrolled in the current study; one was a general population including 1585 untreated individuals, with HCV infection and the other was a treatment population comprising 353 HCV-infected patients treated with pegylated interferon-α and ribavirin (pegIFN-α/RBV). Two single nucleotide polymorphisms (SNPs) were genotyped, and the relationship between HCV clearance and treatment outcome was analysed.

RESULTS

The general population comprised 995 persistent HCV cases (both HCV RNA and anti-HCV were positive) and 590 spontaneous clearance cases (HCV RNA was negative, but anti-HCV was positive). An association between the SNPs and HCV clearance was not found in our study. The treatment population consisted of 235 patients who achieved SVR and 118 non-responders. Variants of both SNPs (rs1063340-C and rs1049807-G) were associated with a reduction in SVR following IFN treatment (dominant model: P = 0.026 for rs1063340 and P = 0.048 for rs1049807). In addition, the ancestral alleles of rs1063340 and rs1049807 increased the likelihood of virus clearance by 62% compared to both the derived and minor alleles of the two SNPs (P = 0.040).The interaction analysis showed that the level of glucose interacted with the association of rs1063340 and SVR.

CONCLUSIONS

Our results suggested that genetic variants at the CCL3 and CCL4 loci may be marker SNPs for risk of HCV treatment outcome.

Atypical Chemokine Receptor 1 Polymorphism can not Affect Susceptibility to Hepatitis C Virus

Background:

Hepatitis C virus has infected 130 to 150 million individuals globally. Atypical chemokine receptor 1 has become a focus of research because of its diverse roles in different diseases. However, little is known regarding the association of atypical chemokine receptor 1 polymorphism with susceptibility to hepatitis C virus.

Aims:

To determine the association of an atypical chemokine receptor 1 polymorphism (rs12075) with hepatitis C virus susceptibility.

Study Design:

Case-control study.

Methods:

We collected blood samples from 231 patients infected with hepatitis C virus and 239 blood donors as control subjects. Genotyping of atypical chemokine receptor 1 was performed using a 5ˊ-nuclease assay with TaqMan-minor groove binding probes. Comparisons between hepatitis C virus-infected patients and control subjects were assessed using Fisher’s exact test.

Results:

The genotype frequencies of FY*A/FY*A, FY*A/FY*B and FY*B/FY*B were 86.1%, 13.9% and 0% in the patient group, and 86.2%, 13.4% and 0.4% in the control group, respectively. The difference in atypical chemokine receptor 1 genotype frequencies between hepatitis C virus-infected patients and control group was not significant (p=1.00, OR=1.004, 95% CI=0.594-1.695). FY*A and FY*B allele frequencies were 93.1% and 6.9% in the patient group, and 92.9% and 7.1% in the control group, respectively. The difference in atypical chemokine receptor 1 allele frequencies between hepatitis C virus-infected patients and the control group was not significant (p=1.00, OR=0.972, 95% CI=0.589-1.603).

Conclusion:

Our result indicates that atypical chemokine receptor 1 polymorphism (rs12075) does not affect susceptibility to hepatitis C virus.

Predictive Value of Serum IFN-γ inducible Protein-10 and IFN-γ/IL-4 Ratio for Liver Fibrosis Progression in CHB Patients

Noninvasive serum markers for assessment of liver fibrosis in chronic hepatitis B (CHB) patients have not been well-studied. The present study was to evaluate the predictive value of serum interferon gamma-inducible protein-10 (IP-10/CXCL10) and the interferon (IFN)-γ/interleukin (IL)-4 ratio for liver fibrosis progression in CHB patients. A total of 180 CHB patients were categorized into four groups: no fibrosis, mild fibrosis, moderate fibrosis, and severe fibrosis. Serum and intrahepatic levels of IP-10, IFN-γ, and IL-4 were examined, from which the IFN-γ/IL-4 ratio was calculated. We found that the serum IP-10 levels were positively correlated with the severity of liver fibrosis, whereas the IFN-γ/IL-4 ratio was negatively associated with the progression of hepatic fibrosis. Multivariate logistic regression analysis revealed that the serum IP-10 was an independent predictor for significant fibrosis. For predicting significant fibrosis, the IP-10 cut-off value of 300 ng/mL had a sensitivity of 92.7% and a specificity of 68.6%. When the IP-10 level was combined with the IFN-γ/IL-4 ratio, the specificity and positive predictive value were 93.8% and 94.6%, respectively; thus, the discriminatory ability was much improved. In conclusion, the serum IP-10 level and the IFN-γ/IL-4 ratio have great potential to predict significant fibrosis among CHB patients.

Combined Detection of Serum IL-10, IL-17, and CXCL10 Predicts Acute Rejection Following Adult Liver Transplantation

Discovery of non-invasive diagnostic and predictive biomarkers for acute rejection in liver transplant patients would help to ensure the preservation of liver function in the graft, eventually contributing to improved graft and patient survival. We evaluated selected cytokines and chemokines in the sera from liver transplant patients as potential biomarkers for acute rejection, and found that the combined detection of IL-10, IL-17, and CXCL10 at 1-2 weeks post-operation could predict acute rejection following adult liver transplantation with 97% specificity and 94% sensitivity.

Senescence in chronic allograft nephropathy

Despite increasing numbers of patients on dialysis, the numbers of renal transplants performed yearly have remained relatively static. During the last 50 years, there have been many advances in the pharmacology of prevention of organ rejection. However, most patients will suffer from a slow but steady decline in renal function leading to graft loss. The most common cause of long-term graft loss is chronic allograft nephropathy (CAN). Therefore, elucidating and understanding the mechanisms involved in CAN is crucial for achieving better posttransplant outcomes. It is thought that the development of epithelial to mesenchymal transition (EMT) in proximal tubules is one of the first steps towards CAN, and has been shown to be a result of cellular senescence. Cells undergoing senescence acquire a senescence associated secretory phenotype (SASP) leading to the production of interleukin-1 alpha (IL-1α), which has been implicated in several degenerative and inflammatory processes including renal disease. A central mediator in SASP activation is the production of reactive oxygen species (ROS), which are produced in response to numerous physiological and pathological stimuli. This review explores the connection between SASP and the development of EMT/CAN in an effort to suggest future directions for research leading to improved long-term graft outcomes.

Early non-invasive selection of patients at high risk of severe hepatitis C recurrence after liver transplantation

BACKGROUND

The early identification of patients at high risk of severe post liver transplant hepatitis C recurrence is relevant, as these patients may be treated using interferon (IFN)-free regimens.

METHODS

In a retrospective study with prospectively collected data, we investigated whether the use of several non-invasive methods (fibrosis 4 index [FIB-4], AST-to-platelets ratio index [APRI], enhanced liver fibrosis test [ELF], IFN-γ-inducible protein 10 [IP-10], and transient elastography by Fibroscan) and their combinations 6 months after transplantation could identify those recipients at higher risk of severe recurrence, defined by the presence of significant fibrosis (F ≥2) and/or portal hypertension (hepatic venous pressure gradient ≥6 mmHg) 12 months after transplant. Seventy-two hepatitis C virus (HCV)-infected liver transplant patients and 10 recipients in whom HCV was eradicated before transplantation were included in the study.

RESULTS

The levels of all biomarkers were significantly higher in HCV-infected recipients than in controls. Among HCV recipients, levels of biomarkers were significantly higher in patients with severe recurrence. Although there were no statistically significant differences between biomarkers, APRI, ELF, and FIB-4 obtained the highest area under the ROC curve values. The combination of serum biomarkers with Fibroscan increased the negative and positive predictive values, although diagnostic accuracy of individual tests was not significantly improved.

CONCLUSIONS

Patients at higher risk of severe HCV recurrence can be identified early, 6 months after transplantation, using readily available non-invasive methods.

Inflammatory molecules expression pattern for identifying pathogen species in febrile patient serum

Inflammatory molecules, such as cytokines and chemokines, have been considered markers for bacterial or viral infection in serum of patients in numerous studies. The aim of the present study was to investigate whether we were able to identify the pathogen species through patterns of inflammatory molecules. A total of 132 patients with elevated body temperature (tympanic temperature, >38.3°C) were recruited for this study. The concentrations of various inflammatory molecules in the patients' serum were evaluated using a cytometric bead array. Higher concentrations of interleukin (IL)-6 and IL-8 were detected in bacterial infection groups (patients with positive and negative blood cultures), as compared with the viral infection group. Viral infection (including influenza and dengue viral infections) was associated with higher concentrations of interferon-γ-inducible protein 10 (IP-10), as compared with the bacterial infection group. In addition, IL-8 levels in the gram-negative bacteria group were higher, as compared with the gram-positive bacteria group. However, IL-8 was insufficient for bacterial species identification. By contrast, dengue virus infection induced the highest serum level of IP-10 among all groups. In conclusion, detection of the patterns of inflammatory molecules may aid the subsequent management and treatment modalities in hospitals, although evaluation of these molecules alone may be insufficient for identifying the pathogen species.

Chemokine (C-X-C motif) ligand 11 levels predict survival in cirrhotic patients with transjugular intrahepatic portosystemic shunt

BACKGROUND & AIMS

Chemokines, such as CXCR3-ligands, have been identified to play an important role during hepatic injury, inflammation and fibrosis. While CXCL9 is associated with survival in patients receiving transjugular intrahepatic portosystemic shunt (TIPS), the role of CXCL11 in severe portal hypertension remains unknown.

METHODS

CXCL11-levels were measured in 136 patients with liver diseases, and 63 healthy controls. In further 47 cirrhotic patients receiving TIPS, CXCL11 levels were measured in portal and hepatic veins at TIPS insertion by cytometric bead array. CXCL11-levels were measured in 23 patients in cubital vein and right atrium, whereas in 24 patients in portal and hepatic blood at an invasive reevaluation.

RESULTS

CXCL11-levels were increased with the severity of liver fibrosis. CXCL11-levels from portal, hepatic and cubital veins and right atrium showed a highly significant correlation among each other in these patients. Furthermore, levels of CXCL11 from the right atrium were significantly higher than those from cubital vein. Interestingly, patients with alcoholic cirrhosis had significantly lower CXCL11-levels, than other aetiologies of cirrhosis. After TIPS, CXCL11 levels correlated with the degree of portal pressure and patients with higher CXCL11-levels in portal and hepatic veins showed higher mortality. Multivariate analysis revealed hepatic CXCL11-levels before TIPS, creatinine and age as independent predictors for survival in TIPS patients, whereas MELD score and low portal CXCL11-levels after TIPS predicted long-term survival.

CONCLUSION

CXCL11 levels are mainly increased in patients with non-alcoholic cirrhosis and high portal pressure. Moreover, levels of CXCL11 might predict long-time survival of cirrhotic patients bearing TIPS.

Interferon-γ, interleukin-10 and interferon-inducible protein 10 (CXCL10) as serum biomarkers for the early allograft dysfunction after liver transplantation

Orthotopic liver transplantation (LTP) is nowadays a standard procedure, and provides the chance of survival of patients with end-stage non-treatable chronic liver disease or acute liver failure. Despite long-term survival with a good quality of life in the majority of patients, about 20% develop early allograft dysfunction (EAD), which leads to death or the need for re-transplantation. Therefore, the early diagnosis of EAD and evaluation of its risk factors are very important. Many primary pathological processes leading to EAD are accompanied by the release of different mediators and by a change of biochemical parameters detectable in the peripheral blood. The aim of this study was to investigate cytokines as well as soluble mediators in the serum of patients with and without EAD from our LTP bank, and to evaluate their predictive and prognostic values for EAD. We demonstrated for the first time that the level of IFNγ during the nearest preoperative period may serve as a predictive parameter for EAD. We additionally found that IL-10 and CXCL10 (IP-10) levels in the early postoperative period can be prognostic for EAD. We believe our data expand the spectrum of predictive and prognostic parameters for EAD in LTP.

Biomarkers in HCV Infection

Liver-related biomarkers have been developed and validated mainly in patients with chronic hepatitis C for the prediction of liver fibrosis or cirrhosis, which is a final pathway of chronic liver injury. They are noninvasive, traceable, and easy-to-use. Biomarkers provide implications related to screening, diagnosis, treatment, and prognosis of chronic hepatitis. For the improvement of performance and coverage, biomarker panels, imaging biomarkers, and even genetic biomarkers have been developed. With the advancement of genomics and proteomics, earlier and more precise prediction is expected in the near future. In this review, multiple biomarker panels for the estimation of the degree of fibrosis in chronic hepatitis C, biomarkers for the screening and diagnosis of hepatitis C, biomarkers for the treatment of hepatitis C, biomarkers for the prediction of complications related to the chronic hepatitis C, and future perspectives will be summarized.

CXCL9 is a prognostic marker in patients with liver cirrhosis receiving transjugular intrahepatic portosystemic shunt

BACKGROUND & AIMS

Inflammation, collagen deposition and tissue remodelling are involved in the pathogenesis and complications of cirrhosis with portal hypertension. CXCL9 and other chemokines play an important role in these processes and have been associated with liver injury and complications of liver disease in humans. However, their predictive value in patients with cirrhosis and portal hypertension remains to be established.

METHODS

103 patients with liver cirrhosis who had received TIPS (transjugular intrahepatic portosystemic shunt) were included into this study. The TIPS indication was either refractory ascites or recurrent bleeding. Before and after the TIPS procedure portal and hepatic venous blood samples were obtained in 78 patients. In 25 patients blood samples were obtained from the portal vein, hepatic vein, right atrium and cubital vein at TIPS insertion. Serum levels of CXCL9 were measured by cytometric bead array and correlated with clinical parameters and overall outcome.

RESULTS

Portal venous levels of CXCL9 decreased after TIPS. Child-Pugh score, refractory ascites, renal dysfunction and alcoholic aetiology of cirrhosis were associated with increased CXCL9 levels. Importantly, low levels of CXCL9 in portal and hepatic vein samples were prognostic factors for the survival of patients receiving TIPS during long-time follow-up.

CONCLUSIONS

The CXCR3 ligand CXCL9 affects the liver and/or is released by the liver and thereby might contribute to hepatic and extrahepatic organ dysfunction. Elevated levels of CXCL9 are associated with shorter survival in cirrhotic patients with severe portal hypertension receiving TIPS. This chemokine should be further evaluated as a novel biomarker for the outcome in patients with cirrhosis and portal hypertension and its modulation as a new therapeutic strategy.

Recurrent HCV after liver transplantation-mechanisms, assessment and therapy

Chronic HCV infection is the leading indication for liver transplantation. However, as a result of HCV recurrence, patient and graft survival after liver transplantation are inferior compared with other indications for transplantation. HCV recurrence after liver transplantation is associated with considerable mortality and morbidity. The development of HCV-related fibrosis is accelerated after liver transplantation, which is influenced by a combination of factors related to the virus, donor, recipient, surgery and immunosuppression. Successful antiviral therapy is the only treatment that can attenuate fibrosis. The advent of direct-acting antiviral agents (DAAs) has changed the therapeutic landscape for the treatment of patients with HCV. DAAs have improved tolerability, and can potentially be used without PEG-IFN for a shorter time than previous therapies, which should result in better outcomes. In this Review, we describe the important risk factors that influence HCV recurrence after liver transplantation, highlighting the mechanisms of fibrosis and the integral role of hepatic stellate cells. Indirect and direct assessment of fibrosis, in addition to new antiviral therapies, are also discussed.

Transplantation and inflammation: implications for the modification of chemokine function

Oxidative stress is a major and recurring cause of damage during inflammation, especially following organ transplantation. Initial ischaemia–reperfusion injury causes the production of many reactive oxygen and nitrogen species, and subsequent recruitment and activation of inflammatory cells can lead to further oxidative stress. This stress is well known to cause damage at the cellular level, for example by induction of senescence leading to the production of a characteristic senescence-associated secretory phenotype. Chemokines are an important component of the senescence-associated secretory phenotype, recruiting further leucocytes and reinforcing the stress and senescence responses. As well as inducing the production of proteins, including chemokines, oxidative stress can alter proteins themselves, both directly and by induction of enzymes capable of modification. These alterations can lead to important modifications to their biological activity and also alter detection by some antibodies, potentially limiting the biological relevance of some immunochemical and proteomic biomarkers. Peroxynitrite, a reactive nitrogen species generated during inflammation and ischaemia, can cause such modifications by nitrating chemokines. Matrix metalloproteinases, released by many stressed cells, can cleave chemokines, altering function, while peptidylarginine deiminases can inactivate certain chemokines by citrullination. This review discusses the relationship between inflammation and post-translational modification, focusing on the functional modulation of transplant-relevant pro-inflammatory chemokines.

Noninvasive allograft imaging of acute rejection: evaluation of (131)I-anti-CXCL10 mAb

The purpose of this study was to investigate the use of iodine-131-labeled anti-CXCL10 mAb as tracer targeted at CXCL10 to detect acute rejection (AR) with mice model. Expression of CXCL10 was proved by RT-PCR, ELISA, and immunochemistry staining. All groups were submitted to whole-body autoradioimaging and ex vivo biodistribution studies after tail vein injection of (131)I-anti-CXCL10 mAb. The highest concentration/expression of CXCL10 was detected in allograft tissue compared with allograft treated with tacrolimus and isograft control. Tacrolimus could obviously inhibit the rejection of allograft. Allograft could be obviously imaged at all checking points, much clearer than the other two groups. The biodistribution results showed the highest uptake of radiotracer in allograft. T/NT (target/nontarget) ratio was 4.15 ± 0.25 at 72 h, apparently different from allograft treated with tacrolimus (2.29 ± 0.10), P < 0.05. These data suggest that CXCL10 is a promising target for early stage AR imaging and (131)I-CXCL10 mAb can successfully image AR and monitor the effect of immunosuppressant.

Pretreatment serum macrophage inflammatory protein (MIP)-1 levels predict sustained virological responses to re-treatment in patients with chronic hepatitis C virus infection

BACKGROUND

There are few predictors of the virological response in patients who are re-treated with antiviral therapies. In this study, we evaluated the levels of chemokines that bind to C-C chemokine receptor type 5 (CCR5) and their impact on combination therapy in both treatment-naïve and treatment-experienced patients chronically infected with hepatitis C virus (HCV).

METHODS

Longitudinal analysis of CCR5 chemokines was performed using the multiplex Bio-Rad 27-plex assay in 56 treatment-naïve and 24 treatment-experienced patients with chronic HCV infection during combination therapy with peginterferon alfa and ribavirin. A group of healthy donors was included as the control (n=11).

RESULTS

The pretreatment level of macrophage inflammatory protein 1 (MIP-1) was determined to be an independent predictor, with an ideal predictive threshold for sustained virological response of 95.23 pg/ml. A rapid decline in HCV RNA was observed in patients with a pretreatment MIP-1 level of <95.23 pg/ml, while a slow reduction was measured in patients with levels of ≥95.23 pg/ml (p=0.014). Of note, the dynamics of MIP-1 further indicated that a lower level at baseline and at treatment week 12 was significantly associated with a favorable outcome of antiviral therapy (p=0.014), especially in treatment-experienced patients (p=0.04), while a higher level of MIP-1beta correlated with the elevation of transaminases.

CONCLUSIONS

Serum MIP-1 is an independent and effective predictor of early and sustained virological response in chronically HCV-infected patients undergoing re-treatment.

Roles for chemokines in liver disease

Sustained hepatic inflammation is an important factor in progression of chronic liver diseases, including hepatitis C or non-alcoholic steatohepatitis. Liver inflammation is regulated by chemokines, which regulate the migration and activities of hepatocytes, Kupffer cells, hepatic stellate cells, endothelial cells, and circulating immune cells. However, the effects of the different chemokines and their receptors vary during pathogenesis of different liver diseases. During development of chronic viral hepatitis, CCL5 and CXCL10 regulate the cytopathic versus antiviral immune responses of T cells and natural killer cells. During development of nonalcoholic steatohepatitis, CCL2 and its receptor are up-regulated in the liver, where they promote macrophage accumulation, inflammation, fibrosis, and steatosis, as well as in adipose tissue. CCL2 signaling thereby links hepatic and systemic inflammation related to metabolic disorders and insulin resistance. Several chemokine signaling pathways also promote hepatic fibrosis. Recent studies have shown that other chemokines and immune cells have anti-inflammatory and antifibrotic activities. Chemokines and their receptors can also contribute to the pathogenesis of hepatocellular carcinoma, promoting proliferation of cancer cells, the inflammatory microenvironment of the tumor, evasion of the immune response, and angiogenesis. We review the roles of different chemokines in the pathogenesis of liver diseases and their potential use as biomarkers or therapeutic targets.

Early periportal sinusoidal fibrosis is an accurate marker of accelerated HCV recurrence after liver transplantation

BACKGROUND & AIMS

Significant liver fibrosis (F ⩾ 2) and portal hypertension (hepatic venous pressure gradient [HVPG] ⩾ 6 mmHg) 1 year after liver transplantation (LT) are predictors of severe hepatitis C recurrence. Periportal sinusoidal fibrosis (SF) is an early expression of the fibrogenic process in response to liver injury. We aimed to evaluate whether SF in early liver biopsies represents an early and accurate marker for identifying patients with severe HCV recurrence after LT.

METHODS

A total of 101 HCV LT patients with early biopsy (<6 months), and HVPG measurement and/or liver biopsy one year after LT were included. Early biopsies were stained with Sirius Red and SF was graded semi-quantitatively. Results were compared between groups (significant SF vs. non-significant SF) and correlated with the development of severe HCV recurrence one year after LT.

RESULTS

Patients with early significant SF had older donor age and higher necroinflammatory activity (NIA). The presence of early significant SF enabled identification of 78.9% and 90.6% of patients with F ⩾ 2 and HVPG ⩾ 6 mmHg, respectively, one year after LT. Donor age and NIA were independent predictors of significant fibrosis (F ⩾ 2) one year after LT, whereas donor age, ALT (3 months), NIA, and SF grade were independent predictors of portal hypertension (HVPG ⩾ 6).

CONCLUSIONS

Significant SF in early biopsies is a good predictor of severe hepatitis C recurrence. This histological finding, when combined with simple variables, may be useful to select the best candidates for early antiviral therapy after LT.

Expression profiles of circulating cytokines, chemokines and immune cells in patients with hepatitis B virus infection

BACKGROUND

Immune cells and molecules play a vital role in initiating, maintaining, regulating immunological homeostasis and inflammation in many pathological and physiological processes; however, the changes on expressions and functions of these cells and molecules in hepatitis B virus (HBV) infection have not been elucidated well.

OBJECTIVES

The current study aimed to determine the expression pattern of different cytokines, chemokines, immune cells in HBV infection and their association with disease progression.

PATIENTS AND METHODS

Sixty-nine patients with chronic HBV infection were enrolled. Five immune cell subsets and 46 cytokines and chemokines were analyzed by flow cytometry and Luminex 200.

RESULTS

In comparison to healthy individuals and asymptomatic HBV carriers, expression of CXCL9, CXCL10, CXCL11, and IL-10 were elevated in patients with chronic active HBV and had positive correlation with ALT levels. In contrast, G-CSF, MCP-3, and IFN-γ levels were significantly decreased in patients with chronic active HBV infection in contrast to carriers and healthy individuals; however, these down regulations did not show any correlation with either virological findings or liver inflammation. Although the proportion of CD4(+) CD25 (high) regulatory T cells (Tregs) was higher in patients with HBV infection than in healthy controls, no correlations were found between Tregs and other cytokines or chemokines.

CONCLUSIONS

CXCR3-associated chemokines might contribute to liver inflammation in chronic hepatitis B, while MCP-3 and G-CSF were inhibited by HBV infection. Host immune response was suppressed as manifested by an increase in CD4(+) CD25(high) Tregs and IL-10 as well as a decrease in IFN-γ. Exploiting the expression pattern of cytokine and chemokine may help to develop a better understanding of chronic HBV infection pathogenesis.

Omega-3 fatty acids and/or fluvastatin in hepatitis C prior non-responders to combination antiviral therapy - a pilot randomised clinical trial

BACKGROUND & AIMS

Hepatitis C virus (HCV) utilises cholesterol and lipoprotein metabolism for replication and infectivity. Statins and omega-3 (n-3) polyunsaturated fatty acids (PUFA) have been shown to have antiviral properties in vitro. This open label pilot study evaluated the efficacy of fluvastatin (Lescol(®) 40-80 mg) and n-3 PUFA (Omacor(®) 1 g and 2-4 g) on HCV-RNA and lipoviral particles (LVP) in difficult to treat prior non-responders.

METHODS

Patients (n = 60) were randomly allocated in a factorial design to: no active drug; low-dose n-3 PUFA; high-dose n-3 PUFA; fluvastatin; low-dose n-3 PUFA + fluvastatin; or high-dose n-3 PUFA + fluvastatin. 50/60 completed study drugs for 12 weeks and followed up to week 24. Comparison was made between fluvastatin (n = 24) vs no fluvastatin (n = 26) and n-3 PUFA high-dose (n = 17) vs low-dose (n = 17) vs none (n = 16). The primary outcomes were change in total HCV-RNA, LVP and ALT at week 12 compared with baseline. Secondary outcome was change in interferon-gamma-inducible protein-10 (IP10) as a measure of interferon activation.

RESULTS

35% had compensated cirrhosis and 45% were prior null responders. There was no significant change in total HCV RNA, LVP, non-LVP or LVP ratio in patients receiving fluvastatin or n-3 PUFAs. ALT was not significantly different in those treated with fluvastatin or n-3 PUFAs. 12 weeks of low-dose n-3 PUFA decreased median IP10 concentration by -39 pg/ml (-111, 7.0 pg/ml Q1-Q3).

CONCLUSIONS

Fluvastatin and n-3 PUFAs have no effect on plasma HCV-RNA or LVP. The effect of low-dose n-3 PUFA on IP10 warrants further prospective evaluation as a supplemental therapy to enhance interferon sensitivity.

Hepatitis C recurrence: the Achilles heel of liver transplantation

Hepatitis C virus (HCV) infection is the most common indication for liver transplantation worldwide; however, recurrence post transplant is almost universal and follows an accelerated course. Around 30% of patients develop aggressive HCV recurrence, leading to rapid fibrosis progression (RFP) and culminating in liver failure and either death or retransplantation. Despite many advances in our knowledge of clinical risks for HCV RFP, we are still unable to accurately predict those most at risk of adverse outcomes, and no clear consensus exists on the best approach to management. This review presents a critical overview of clinical factors shown to influence the course of HCV recurrence post transplant, with particular focus on recent data identifying the important role of metabolic factors, such as insulin resistance, in HCV recurrence. Emerging data for genetic markers of HCV recurrence and their usefulness for predicting adverse outcomes will also be explored.

The role of chemokines in acute and chronic hepatitis C infection

Hepatitis C imposes a significant burden on global healthcare. Chronic infection is associated with progressive inflammation of the liver which typically manifests in cirrhosis, organ failure and cancer. By virtue of elaborate evasion strategies, hepatitis C virus (HCV) succeeds as a persistent human virus. It has an extraordinary capacity to subvert the immune response enabling it to establish chronic infections and associated liver disease. Chemokines are low molecular weight chemotactic peptides that mediate the recruitment of inflammatory cells into tissues and back into the lymphatics and peripheral blood. Thus, they are central to the temporal and spatial distribution of effector and regulatory immune cells. The interactions between chemokines and their cognate receptors help shape the immune response and therefore, have a major influence on the outcome of infection. However, chemokines represent a target for modulation by viruses including the HCV. HCV is known to modulate chemokine expression in vitro and may therefore enable its survival by subverting the immune response in vivo through altered leukocyte chemotaxis resulting in impaired viral clearance and the establishment of chronic low-grade inflammation. In this review, the roles of chemokines in acute and chronic HCV infection are described with a particular emphasis placed on chemokine modulation as a means of immune subversion. We provide an in depth discussion of the part played by chemokines in mediating hepatic fibrosis while addressing the potential applications for these chemoattractants in prognostic medicine.

TNFR1 determines progression of chronic liver injury in the IKKγ/Nemo genetic model

Death receptor-mediated hepatocyte apoptosis is implicated in a wide range of liver diseases including viral and alcoholic hepatitis, ischemia/reperfusion injury, fulminant hepatic failure, cholestatic liver injury, as well as cancer. Deletion of NF-κB essential modulator in hepatocytes (IKKγ/Nemo) causes spontaneous progression of TNF-mediated chronic hepatitis to hepatocellular carcinoma (HCC). Thus, we analyzed the role of death receptors including TNFR1 and TRAIL in the regulation of cell death and the progression of liver injury in IKKγ/Nemo-deleted livers. We crossed hepatocyte-specific IKKγ/Nemo knockout mice (Nemo(Δhepa)) with constitutive TNFR1(-/-) and TRAIL(-/-) mice. Deletion of TNFR1, but not TRAIL, decreased apoptotic cell death, compensatory proliferation, liver fibrogenesis, infiltration of immune cells as well as pro-inflammatory cytokines, and indicators of tumor growth during the progression of chronic liver injury. These events were associated with diminished JNK activation. In contrast, deletion of TNFR1 in bone-marrow-derived cells promoted chronic liver injury. Our data demonstrate that TNF- and not TRAIL signaling determines the progression of IKKγ/Nemo-dependent chronic hepatitis. Additionally, we show that TNFR1 in hepatocytes and immune cells have different roles in chronic liver injury-a finding that has direct implications for treating chronic liver disease.

Chronic chorioamnionitis is the most common placental lesion in late preterm birth

OBJECTIVES

The pathogenesis of late preterm birth remains elusive for the mechanisms of disease responsible. Placental examination can often provide important clues for the pathogenesis of pregnancy complications. This study was conducted to determine placental pathologic findings according to the gestational age and the clinical circumstances of preterm birth.

STUDY DESIGN

Placental pathologic findings and obstetrical and neonatal outcomes were reviewed in a consecutive preterm birth cohort from a single tertiary center (N = 1206). Placentas of term births (N = 300) were used as normal controls.

RESULTS

Acute chorioamnionitis (22.7% vs. 16.7%), maternal vascular underperfusion (6.4% vs. 0.5%), and chronic chorioamnionitis (20.8% vs. 10.5%) were significantly more frequent in preterm births than in term births (P < 0.05, for each). Among preterm births, chronic chorioamnionitis was the most common pathology of late preterm birth (gestational age <37 and ≥34 weeks), while acute chorioamnionitis was the most common lesion of extremely preterm birth (gestational age <28 weeks). While the frequency of acute chorioamnionitis decreased with advancing gestation, that of chronic chorioamnionitis increased (P < 0.001, for each). The upward trend of the frequency of chronic chorioamnionitis was related to advancing gestation in both spontaneous and indicated preterm births (P < 0.001, for each).

CONCLUSIONS

Chronic chorioamnionitis is a common pathology of late preterm birth. It is suggested that chronic chorioamnionitis, a feature of maternal anti-fetal rejection, is an important etiology of preterm birth, especially of late preterm birth.

Progression of liver fibrosis in post-transplant hepatitis C: mechanisms, assessment and treatment

Liver fibrosis results from an excessive wound healing response in most chronic liver diseases, such as hepatitis C. Despite great advances in antiviral therapy in recent years, progressive liver fibrosis remains a major problem for patients with recurrent hepatitis C after liver transplantation. Liver biopsy remains a central tool in the management of HCV-positive liver transplant recipients, but reliable non-invasive methods for the assessment of liver fibrosis, such as ultrasound elastography, are increasingly being incorporated in the management of post-transplant patients, helping predict prognosis, guide treatment decisions, and stratify patients for emerging antifibrotic therapies. In this manuscript, we will review the natural history as well as tools to monitor fibrosis progression in the HCV-positive liver transplant recipient, the mechanisms underlying rapid fibrosis progression in up to 30% of these patients, the effect of antiviral therapies and highlight promising antifibrotic approaches.

Recurrent diseases following liver transplantation: current concepts

PURPOSE OF REVIEW

Liver transplantation is the treatment of choice for patients with chronic end-stage liver disease. The posttransplant setting is complex, and an improved long-term graft and patient survival adds to the complexity. There are often multiple causes of graft dysfunction and the associated morbidity and disorder are varied. This review focuses on the current concepts of several recurrent diseases, emphasizing the interpretation of the posttransplant liver biopsies in long-term survivors as challenging and clinically more relevant then ever. It confirms the importance and the necessity of clinico-pathologic correlation in the posttransplant setting.

RECENT FINDINGS

The long-term graft and patient survival following liver transplantation has improved significantly over the past decade. The spectrum of histopathologic patterns seen in liver biopsies and our understanding of them have evolved and expanded considerably, so much so, that both pathologists and clinicians alike now recognize new and emerging disease patterns not previously encountered in the nontransplant setting.

SUMMARY

Typical histopathologic features are usually easily identified and interpreted in liver biopsies. There are, however, a number of atypical histopathologic patterns, especially in the setting of recurrent diseases, often modified by immunosuppression, or altered by other immune-mediated processes, autoimmunity, or hepatotoxicity. Several conditions and entities, especially in the late posttransplant setting, including atypical allograft rejection, idiopathic posttransplant hepatitis, the spectrum of changes seen in recurrent hepatitis C, nodular regenerative hyperplasia, and de-novo disease occurrence, to name a few, have all been recognized in the past several years.

Management of recurrent hepatitis C in orthotopic liver transplant recipients

End-stage liver disease and hepatocellular carcinoma from chronic hepatitis C are the most common indications for orthotopic liver transplantation and the incidence of both are projected to increase over the next decade. Recurrent hepatitis C virus infection of the allograft is associated with an accelerated progression to cirrhosis, graft loss, and death. This article presents an overview of the natural history of hepatitis C virus recurrence in liver transplant recipients and guidance on optimal management strategies.

Proapoptotic effects of the chemokine, CXCL 10 are mediated by the noncognate receptor TLR4 in hepatocytes

Aberrant expression of the chemokine CXC chemokine ligand (CXCL)10 has been linked to the severity of hepatitis C virus (HCV)-induced liver injury, but the underlying molecular mechanisms remain unclear. In this study, we describe a yet-unknown proapoptotic effect of CXCL10 in hepatocytes, which is not mediated through its cognate chemokine receptor, but the lipopolysaccharide receptor Toll-like receptor 4 (TLR4). To this end, we investigated the link of CXCL10 expression with apoptosis in HCV-infected patients and in murine liver injury models. Mice were treated with CXCL10 or neutralizing antibody to systematically analyze effects on hepatocellular apoptosis in vivo. Direct proapoptotic functions of CXCL10 on different liver cell types were evaluated in detail in vitro. The results showed that CXCL10 expression was positively correlated with liver cell apoptosis in humans and mice. Neutralization of CXCL10 ameliorated concanavalin A-induced tissue injury in vivo, which was strongly associated with reduced liver cell apoptosis. In vitro, CXCL10 mediated the apoptosis of hepatocytes involving TLR4, but not CXC chemokine receptor 3 signaling. Specifically, CXCL10 induced long-term protein kinase B and Jun N-terminal kinase activation, leading to hepatocyte apoptosis by caspase-8, caspase-3, and p21-activated kinase 2 cleavage. Accordingly, systemic application of CXCL10 led to TLR4-induced liver cell apoptosis in vivo.

CONCLUSION

The results identify CXCL10 and its noncognate receptor, TLR4, as a proapoptotic signaling cascade during liver injury. Antagonism of the CXCL10/TLR4 pathway might be a therapeutic option in liver diseases associated with increased apoptosis.

Autocrine CCL2, CXCL4, CXCL9 and CXCL10 signal in retinal endothelial cells and are enhanced in diabetic retinopathy

This study aimed at examining the presence and role of chemokines (angiogenic CCL2/MCP-1 and angiostatic CXCL4/PF-4, CXCL9/Mig, CXCL10/IP-10) in proliferative diabetic retinopathy (PDR). Regulated chemokine production in human retinal microvascular cells (HRMEC) and chemokine levels in vitreous samples from 40 PDR and 29 non-diabetic patients were analyzed. MCP-1, PF-4, Mig, IP-10 and VEGF levels in vitreous fluid from PDR patients were significantly higher than in controls. Except for IP-10, cytokine levels were significantly higher in PDR with active neovascularization and PDR without traction retinal detachment (TRD) than those in inactive PDR, PDR with TRD and control subjects. Exploratory regression analysis identified associations between higher levels of IP-10 and inactive PDR and PDR with TRD. VEGF levels correlated positively with MCP-1 and IP-10. Significant positive correlations were observed between MCP-1 and IP-10 levels. In line with these clinical findings Western blot analysis revealed increased PF-4 expression in diabetic rat retinas. HRMEC produced MCP-1, Mig and IP-10 after stimulation with IFN-γ, IL-1β or lipopolysaccharide. IFN-γ synergistically enhanced Mig and IP-10 production in response to IL-1β or lipopolysaccharide. MCP-1 was produced by HRMEC in response to VEGF treatment and activated HRMEC via the ERK and Akt/PKB pathway. On the other hand, phosphorylation of ERK induced by VEGF and MCP-1 was inhibited by PF-4, Mig and IP-10. In accordance with inhibition of angiogenic signal transduction pathways, PF-4 inhibited in vitro migration of HRMEC. Thus, regulatory roles for chemokines in PDR were demonstrated. In particular, IP-10 might be associated with the resolution of active PDR and the development of TRD.

Mitochondrial dysfunction and the inflammatory response

Inflammation has been linked to multiple degenerative and acute diseases as well as the aging process. Moreover, mitochondrial alterations play a central role in these processes. Mitochondria have an important role in pro-inflammatory signaling; similarly, pro-inflammatory mediators may also alter mitochondrial function. Both of these processes increase mitochondrial oxidative stress, promoting a vicious inflammatory cycle. Additionally, damage-associated molecular patterns derived from mitochondria could contribute to inflammasome formation and caspase-1 activation, while alterations in mitochondrial autophagy may cause inflammation. Strategies aimed at controlling excessive oxidative stress within mitochondria may represent both preventive and therapeutic interventions in inflammation.

Chemokines in tissue fibrosis

Fibrosis or scarring of diverse organs and tissues is considered as a pathologic consequence of a chronically altered wound healing response which is tightly linked to inflammation and angiogenesis. The recruitment of immune cells, local proliferation of fibroblasts and the consecutive accumulation of extracellular matrix proteins are common pathophysiological hallmarks of tissue fibrosis, irrespective of the organ involved. Chemokines, a family of chemotactic cytokines, appear to be central mediators of the initiation as well as progression of these biological processes. Traditionally chemokines have only been considered to play a critical role in orchestrating the influx of immune cells to sites of tissue injury. However, within the last years, further aspects of chemokine biology including fibroblast activation and angiogenesis have been deciphered in tissue fibrosis of many different organs. Interestingly, certain chemokines appear to mediate common effects in liver, kidney, lung, and skin of various animal models, while others mediate tissue specific effects. These aspects have to be kept in mind when extrapolating data of animal studies to early human trials. Nevertheless, the further understanding of chemokine effects in tissue fibrosis might be an attractive approach for identifying novel therapeutic targets in chronic organ damage associated with high morbidity and mortality. This article is part of a Special Issue entitled: Fibrosis: Translation of basic research to human disease.

The interferon signaling pathway genes as biomarkers of hepatitis C virus disease progression and response to treatment

Hepatitis C virus is an ever-increasing worldwide health problem with over 350,000 individuals succumbing to hepatitis C virus-related liver diseases each year. The ability to determine the outcome of an acute-phase illness may be useful in terms of implementing treatment strategies; however, to date, the predictive associations in the literature have centered around candidate gene analysis. Much greater advancements have been made in describing biomarkers from the activation of the host innate immune response, such as the interferon system, for prediction of treatment outcome in chronic hepatitis C with the advent of genome-wide association studies. Recent times has seen a major breakthrough in the field with the description of the IL28B genotype as an independent association factor for pegylated IFN-α2b/ribavirin treatment response. The ability to couple this with other easily measured biomarkers such as the interferon-stimulated gene CXCL10, serum concentration may make this predictive marker set very useful in the clinical setting.

Elevated circulating osteoprotegerin and reduced matrix-metalloprotease-9 in post-menopausal women with chronic Hepatitis C virus infection

The failure of the immune response to clear the Hepatitis C virus (HCV) results in chronic inflammation that leads to liver cirrhosis. In general, women have a better prognosis than men and this may be associated with increased levels of anti-inflammatory mediators that are positively regulated by female sex hormones. Our aim was to determine if a cohort of Irish women who acquired infection through administration of HCV genotype 1b-contaminated anti-D immunoglobulin from a single source, had altered levels of circulating cytokine levels compared to women who spontaneously resolved infection, men with HCV infection or age-matched healthy controls. Twenty post-menopausal women and 20 men with chronic HCV infection (genotype 1), 20 post-menopausal women who resolved infection and age and sex-matched controls were recruited for the study. Levels of circulating cytokines were assessed by ELISA. Circulating IL-6, Oncostatin-M, TNF-α, CXCL10, CCL18, VEGF and GM-CSF did not differ between groups. Both men and women with HCV had significantly elevated levels of circulating Osteoprotegerin (OPG). However, male but not female HCV patients had elevated levels of circulating Matrix Metalloprotease-9 (MMP-9). An increased OPG: MMP-9 ratio in the circulation of females compared to males with chronic HCV may help protect against HCV-associated liver disease and explain the slow progress of liver disease in this cohort.

Profibrogenic chemokines and viral evolution predict rapid progression of hepatitis C to cirrhosis

Chronic hepatitis C may follow a mild and stable disease course or progress rapidly to cirrhosis and liver-related death. The mechanisms underlying the different rates of disease progression are unknown. Using serial, prospectively collected samples from cases of transfusion-associated hepatitis C, we identified outcome-specific features that predict long-term disease severity. Slowly progressing disease correlated with an early alanine aminotransferase peak and antibody seroconversion, transient control of viremia, and significant induction of IFN-γ and MIP-1β, all indicative of an effective, albeit insufficient, adaptive immune response. By contrast, rapidly progressive disease correlated with persistent and significant elevations of alanine aminotransferase and the profibrogenic chemokine MCP-1 (CCL-2), greater viral diversity and divergence, and a higher rate of synonymous substitution. This study suggests that the long-term course of chronic hepatitis C is determined early in infection and that disease severity is predicted by the evolutionary dynamics of hepatitis C virus and the level of MCP-1, a chemokine that appears critical to the induction of progressive fibrogenesis and, ultimately, the ominous complications of cirrhosis.