Chimeric Antigen Receptor T Cell Therapy for Hepatocellular Carcinoma: Where Do We Stand?

Hepatocellular carcinoma (HCC) remains a global health challenge that urgently calls for innovative therapeutic strategies. Chimeric antigen receptor T cell (CAR T) therapy has emerged as a promising avenue for HCC treatment. However, the therapeutic efficacy of CAR T immunotherapy in HCC patients is significantly compromised by some major issues including the immunosuppressive environment within the tumor, antigen heterogeneity, CAR T cell exhaustion, and the advanced risk for on-target/off-tumor toxicity. To overcome these challenges, many ongoing preclinical and clinical trials are underway focusing on the identification of optimal target antigens and the decryption of the immunosuppressive milieu of HCC. Moreover, limited tumor infiltration constitutes a significant obstacle of CAR T cell therapy that should be addressed. The continuous effort to design molecular targets for CAR cells highlights the importance for a more practical approach for CAR-modified cell manufacturing. This review critically examines the current landscape of CAR T cell therapy for HCC, shedding light on the changes in innate and adaptive immune responses in the context of HCC, identifying potential CAR T cell targets, and exploring approaches to overcome inherent challenges. Ongoing advancements in scientific research and convergence of diverse treatment modalities offer the potential to greatly enhance HCC patients' care in the future.

The role of gut barrier dysfunction in postoperative complications in liver transplantation: pathophysiological and therapeutic considerations

PURPOSE

Gut barrier dysfunction is a pivotal pathophysiological alteration in cirrhosis and end-stage liver disease, which is further aggravated during and after the operational procedures for liver transplantation (LT). In this review, we analyze the multifactorial disruption of all major levels of defense of the gut barrier (biological, mechanical, and immunological) and correlate with clinical implications.

METHODS

A narrative review of the literature was performed using PubMed, PubMed Central and Google from inception until November 29th, 2023.

RESULTS

Systemic translocation of indigenous bacteria through this dysfunctional barrier contributes to the early post-LT infectious complications, while endotoxin translocation, through activation of the systemic inflammatory response, is implicated in non-infectious complications including renal dysfunction and graft rejection. Bacterial infections are the main cause of early in-hospital mortality of LT patients and unraveling the pathophysiology of gut barrier failure is of outmost importance.

CONCLUSION

A pathophysiology-based approach to prophylactic or therapeutic interventions may lead to enhancement of gut barrier function eliminating its detrimental consequences and leading to better outcomes for LT patients.

Adrenal insufficiency in liver diseases - pathophysiology and underlying mechanisms

Relative adrenal insufficiency (RAI) is common in critically ill patients with cirrhosis, but it has been also documented in non-critically ill patients. Its pathophysiology is complex and not well understood yet. In this review, we aimed to present potential mechanisms and causal pathways implicated in the pathogenesis of RAI in cirrhosis. There is accumulating evidence supporting a suboptimal baseline adrenal function in cirrhosis mainly due to decreased cortisol synthesis and metabolism rates from the adrenal gland. Apart from this peripheral impairment, more recent studies suggest that there is a greater defect in the central stimulation of the hypothalamic-pituitary-adrenal (HPA) axis (hypothalamus/pituitary gland). Pro-inflammatory mediators, which are elevated in cirrhosis, have been also implicated through suppression of the HPA axis, decrease in cortisol synthesis and tissue glucocorticoid resistance. All abovementioned support the hepatoadrenal syndrome hypothesis that during episodes of acute decompensation there is suboptimal adrenocortical response that leads to worse outcomes. In conclusion, the complex pathophysiology of adrenal dysfunction in cirrhosis has not been fully elucidated yet and further research is needed in order to better understand this rather common entity in cirrhosis.

Exploring the role of IL-1β in inflammatory bowel disease pathogenesis

Interleukin 1β (IL-1β) is a significant mediator of inflammation and tissue damage in IBD. The balance between IL-1β and its endogenous inhibitor-IL-1Ra-, plays a critical role in both initiation and regulation of inflammation. However, the precise role of IL-1β as a causative factor in IBD or simply a consequence of inflammation remains unclear. This review summarizes current knowledge on the molecular and cellular characteristics of IL-1β, describes the existing evidence on the role of this cytokine as a modulator of intestinal homeostasis and an activator of inflammatory responses, and also discusses the role of microRNAs in the regulation of IL-1β-related inflammatory responses in IBD. Current evidence indicates that IL-1β is involved in several aspects during IBD as it greatly contributes to the induction of pro-inflammatory responses through the recruitment and activation of immune cells to the gut mucosa. In parallel, IL-1β is involved in the intestinal barrier disruption and modulates the differentiation and function of T helper (Th) cells by activating the Th17 cell differentiation, known to be involved in the pathogenesis of IBD. Dysbiosis in the gut can also stimulate immune cells to release IL-1β, which, in turn, promotes inflammation. Lastly, increasing evidence pinpoints the central role of miRNAs involvement in IL-1β-related signaling during IBD, particularly in the maintenance of homeostasis within the intestinal epithelium. In conclusion, given the crucial role of IL-1β in the promotion of inflammation and immune responses in IBD, the targeting of this cytokine or its receptors represents a promising therapeutic approach. Further research into the IL-1β-associated post-transcriptional modifications may elucidate the intricate role of this cytokine in immunomodulation.

Low Urinary Free Cortisol as a Risk Factor for Patients with Variceal Bleeding

Background and Objectives: Specificity and reliability issues of the current cortisol assessment methods lead to limitations on the accurate assessment of relative adrenal insufficiency. Although free cortisol provides a more accurate evaluation of adrenal cortisol production, the expense and time-consuming nature of these assays make them impractical for routine use. Research has, thus, focused on alternative methods, such as indirectly measuring free cortisol using Coolens' equation or directly assessing salivary cortisol concentration, which is considered a more favorable approach despite associated challenges like sampling issues and infection risks. The aim of this study was to explore correlations between 24 h urinary free cortisol (UFC), free plasma cortisol, serum total cortisol, and salivary cortisol as potential reliable indices of free cortisol in the setting of variceal bleeding. Additionally, we assessed the predictive value of UFC for 6-week mortality and 5-day treatment failure in patients with liver cirrhosis and variceal bleeding. Materials and Methods: A total of 40 outpatients with liver cirrhosis and variceal bleeding were enrolled. Free cortisol levels in serum, saliva, and urine were assessed using the electrochemiluminescence immunoassay method. For the measurement of plasma-free cortisol, a single quadrupole mass spectrometer was employed. The quantification of free cortisol was fulfilled by analyzing the signal response in the negative ESI-MS mode. Results: UFC was significantly correlated to free plasma cortisol. Negative correlations were demonstrated between UFC, the Child-Pugh (CP) score, and C reactive protein (CRP) levels. In the multivariate analysis, CP stage C was associated with 6-week mortality risk and portal vein thrombosis with 5-day treatment failure using Cox regression and binary logistic regression analyses, respectively. Patients who experienced rebleeding, infection, or death (or any combination of these events) presented with lower levels of UFC. Conclusions: This study suggests that low levels of UFC may impose a risk factor for patients with liver cirrhosis and variceal bleeding. The use of UFC as an index of adrenal cortisol production in variceal bleeding warrants further investigation.

Creeping Fat in the Pathogenesis of Crohn's Disease: An Orchestrator or a Silent Bystander?

Although the phenomenon of hypertrophied adipose tissue surrounding inflamed bowel segments in Crohn's disease has been described since 1932, the mechanisms mediating the creeping fat formation and its role in the pathogenesis of the disease have not been fully unraveled. Recent advances demonstrating the multiple actions of adipose tissue beyond energy storage have brought creeping fat to the forefront of scientific research. In Crohn's disease, dysbiosis and transmural injury compromise the integrity of the intestinal barrier, resulting in an excessive influx of intraluminal microbiota and xenobiotics. The gut and peri-intestinal fat are in close anatomic relationship, implying a direct reciprocal immunologic relationship, whereas adipocytes are equipped with an arsenal of innate immunity sensors that respond to invading stimuli. As a result, adipocytes and their progenitor cells undergo profound immunophenotypic changes, leading to adipose tissue remodeling and eventual formation of creeping fat. Indeed, creeping fat is an immunologically active organ that synthesizes various pro- and anti-inflammatory cytokines, profibrotic mediators, and adipokines that serve as paracrine/autocrine signals and regulate immune responses. Therefore, creeping fat appears to be involved in inflammatory signaling, which explains why it has been associated with a higher severity or complicated phenotype of Crohn's disease. Interestingly, there is growing evidence for an alternative immunomodulatory function of creeping fat as a second barrier that prevents an abnormal systemic inflammatory response at the expense of an increasingly proliferating profibrotic environment. Further studies are needed to clarify how this modified adipose tissue exerts its antithetic effect during the course of Crohn's disease.

Epigenetic Regulation in Lean Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD), the most prominent cause of chronic liver disease worldwide, is a rapidly growing epidemic. It consists of a wide range of liver diseases, from steatosis to nonalcoholic steatohepatitis, and predisposes patients to liver fibrosis, cirrhosis, and even hepatocellular carcinoma. NAFLD is strongly correlated with obesity; however, it has been extensively reported among lean/nonobese individuals in recent years. Although lean patients demonstrate a lower prevalence of diabetes mellitus, central obesity, dyslipidemia, hypertension, and metabolic syndrome, a percentage of these patients may develop steatohepatitis, advanced liver fibrosis, and cardiovascular disease, and have increased all-cause mortality. The pathophysiological mechanisms of lean NAFLD remain vague. Studies have reported that lean NAFLD demonstrates a close association with environmental factors, genetic predisposition, and epigenetic modifications. In this review, we aim to discuss and summarize the epigenetic mechanisms involved in lean NAFLD and to introduce the interaction between epigenetic patterns and genetic or non genetic factors. Several epigenetic mechanisms have been implicated in the regulation of lean NAFLD. These include DNA methylation, histone modifications, and noncoding-RNA-mediated gene regulation. Epigenetics is an area of special interest in the setting of lean NAFLD as it could provide new insights into the therapeutic options and noninvasive biomarkers that target this under-recognized and challenging disorder.

The Influence of Single Nucleotide Polymorphisms on Vitamin D Receptor Protein Levels and Function in Chronic Liver Disease

Single nucleotide polymorphisms (SNPs) in the vitamin D receptor (VDR) gene have been associated with chronic liver disease. We investigated the role of VDR SNPs on VDR protein levels and function in patients with chronic liver disease. VDR expression levels were determined in peripheral T lymphocytes (CD3+VDR+), monocytes (CD14+VDR+), and plasma from patients (n = 66) and healthy controls (n = 38). Genotyping of SNPs and the determination of expression of VDR/vitamin D-related genes were performed by using qPCR. The effect of FokI SNP on vitamin D-binding to VDR was investigated by molecular dynamics simulations. CD14+VDR+ cells were correlated with the MELD score. The ApaI SNP was associated with decreased CD3+VDR+ levels in cirrhotic patients and with higher liver stiffness in HCV patients. The BsmI and TaqI SNPs were associated with increased VDR plasma concentrations in cirrhotic patients and decreased CD14+VDR+ levels in HCV patients. The FokI SNP was associated with increased CD3+VDR+ levels in cirrhotic patients and controls. VDR polymorphisms were significantly related to the expression of genes critical for normal hepatocyte function and immune homeostasis. VDR expression levels were related to the clinical severity of liver disease. VDR SNPs may be related to the progression of chronic liver disease by affecting VDR expression levels.

Alexithymic characteristics and interoceptive abilities are associated with disease severity and levels of C-reactive protein and cytokines in patients with inflammatory bowel disease

Background

Alexithymia and atypical gut-brain signaling have been linked to the pathophysiology of inflammatory bowel disease (IBD). We herein assessed IBD patients' alexithymia levels and interoceptive abilities, and detected potential correlations with psychological distress, symptom severity and disease activity, and inflammation indices.

Methods

Adult IBD outpatients and healthy controls were recruited. Alexithymia was assessed using the Toronto Alexithymia Scale, interoceptive accuracy using the Heartbeat Counting Test (cardiac interoception) and the Water Load Test-II (gastric interoception), and interoceptive sensibility using the Multidimensional Assessment of Interoceptive Awareness (MAIA).

Results

Forty-one patients with Crohn's disease (CD), 16 with ulcerative colitis (UC), and 50 healthy controls were included. In CD patients, the level of externally oriented thinking and total alexithymia score were correlated with disease activity (P=0.027 and P=0.047, respectively), while in UC patients difficulties in identifying emotions were linked to disease activity (P=0.007). In CD patients, the Noticing, Not-Worrying and Emotional Awareness MAIA subscale score were correlated with C-reactive protein levels (P=0.005, P=0.048 and P=0.005), the Noticing subscale score with interleukin (IL)-1β levels (r=-0.350, P=0.039), the Not-Distracting subscale score with IL-6 levels (r=-0.402, P=0.017), and the Emotional Awareness subscale score with IL-1β (r=-0.367, P=0.030) and IL-6 (r=-0.379, P=0.025) levels. Finally, in UC patients, the Not-Worrying subscale score was significantly associated with IL-6 levels (r=-0.532, P=0.049), while difficulties in identifying emotions were linked to IL-8 levels (r=0.604, P=0.022).

Conclusion

Emotional and interoceptive processing is associated with IBD disease activity, suggesting a potential implication for IBD pathophysiology.

Creeping Fat in Crohn's Disease-Surgical, Histological, and Radiological Approaches

During the course of Crohn's disease, the response of mesenteric adipose tissue to the production of inflammatory mediators and bacterial invasion through the intestinal mucosa results in the formation of creeping fat. Creeping fat describes the arresting finger-like projections that surround the inflamed bowel. In this review, the microscopic and macroscopic features of creeping fat and histological evidence for the importance of this tissue are discussed. Moreover, the most recent insights into the radiological assessment of creeping fat in patients with Crohn's disease are reported. Advances in imaging techniques have revolutionized the possibility of visualization and quantification of adipose tissue depots with excellent accuracy. Visceral fat has been significantly correlated with various Crohn's-disease-related outcomes. Despite the difficulties in distinguishing physiologic perienteric fat from creeping fat, the growing interest in fat-wrapping in Crohn's disease has rejuvenated radiologic research. With regard to the noninvasive fat-wrapping assessment, a novel CT enterography-based mesenteric creeping fat index has been developed for the mitigation of the confounding effect of normal retroperitoneal and perienteric adipose tissue. Research on machine learning algorithms and computational radiomics in conjunction with mechanistic studies may be the key for the elucidation of the complex role of creeping fat in Crohn's disease.

Exploring the Role of Vitamin D and the Vitamin D Receptor in the Composition of the Gut Microbiota

The microbiome has a major impact on human physiology and plays a critical role in enhancing or impairing various physiological functions such as regulation of the immune system, metabolic activities, and biosynthesis of vitamins and hormones. Variations in the gut microbial community play a critical role in both health and disease. Regulation of calcium and bone metabolism, as well as cellular functions such as proliferation, apoptosis, differentiation, and immune modulation, are among the known effects of vitamin D. These biological functions are primarily carried out through the binding of vitamin D to the vitamin D receptor (VDR), a member of the nuclear receptor superfamily. The immunomodulatory properties of vitamin D suggest that this molecule plays an important role in various diseases. Maintenance of immune homeostasis appears to occur in part through the interaction of the gut microbiota with vitamin D. Increasing evidence points to the central role of vitamin D in maintaining mucosal barrier function, as vitamin D deficiency has been associated with disruption of gut barrier integrity, translocation of bacteria into the bloodstream, and systemic inflammation. In parallel, a bidirectional interaction between vitamin D and the gut microbiota has been demonstrated as data show upregulation of intestinal VDR expression and downregulation of inflammatory markers in response to fermentation products. The aim of this review is to provide an overview of the evidence of a link between the gut microbiome and vitamin D, with a focus on data from experimental models and translational data from human studies related to vitamin D-induced changes in gut microbiota composition.

Alterations in gut immunological barrier in SARS-CoV-2 infection and their prognostic potential

Although coronavirus disease 2019 (COVID-19) is primarily associated with mild respiratory symptoms, a subset of patients may develop more complicated disease with systemic complications and multiple organ injury. The gastrointestinal tract may be directly infected by SARS-CoV-2 or secondarily affected by viremia and the release of inflammatory mediators that cause viral entry from the respiratory epithelium. Impaired intestinal barrier function in SARS-CoV-2 infection is a key factor leading to excessive microbial and endotoxin translocation, which triggers a strong systemic immune response and leads to the development of viral sepsis syndrome with severe sequelae. Multiple components of the gut immune system are affected, resulting in a diminished or dysfunctional gut immunological barrier. Antiviral peptides, inflammatory mediators, immune cell chemotaxis, and secretory immunoglobulins are important parameters that are negatively affected in SARS-CoV-2 infection. Mucosal CD4+ and CD8+ T cells, Th17 cells, neutrophils, dendritic cells, and macrophages are activated, and the number of regulatory T cells decreases, promoting an overactivated immune response with increased expression of type I and III interferons and other proinflammatory cytokines. The changes in the immunologic barrier could be promoted in part by a dysbiotic gut microbiota, through commensal-derived signals and metabolites. On the other hand, the proinflammatory intestinal environment could further compromise the integrity of the intestinal epithelium by promoting enterocyte apoptosis and disruption of tight junctions. This review summarizes the changes in the gut immunological barrier during SARS-CoV-2 infection and their prognostic potential.

Vitamin D and Microbiome: Molecular Interaction in Inflammatory Bowel Disease Pathogenesis

Studies of systemic autoimmune diseases point to characteristic microbial patterns in various diseases, including inflammatory bowel disease (IBD). Autoimmune diseases, and IBD in particular, show a predisposition to vitamin D deficiency, leading to alterations in the microbiome and disruption of intestinal epithelial barrier integrity. In this review, we examine the role of the gut microbiome in IBD and discuss how vitamin D-vitamin D receptor (VDR)-associated molecular signaling pathways contribute to the development and progression of IBD through their effects on gut barrier function, the microbial community, and immune system function. The present data demonstrate that vitamin D promotes the proper function of the innate immune system by acting as an immunomodulator, exerting anti-inflammatory effects, and critically contributing to the maintenance of gut barrier integrity and modulation of the gut microbiota, mechanisms that may influence the IBD development and progression. VDR regulates the biological effects of vitamin D and is related to environmental, genetic, immunologic, and microbial aspects of IBD. Vitamin D influences the distribution of the fecal microbiota, with high vitamin D levels associated with increased levels of beneficial bacterial species and lower levels of pathogenic bacteria. Understanding the cellular functions of vitamin D-VDR signaling in intestinal epithelial cells may pave the way for the development of new treatment strategies for the therapeutic armamentarium of IBD in the near future.

Shifting gears: Study of immune system parameters of male habitual marathon runners

Aim

Marathon is a running event in which athletes must cover a distance of 42.195 km. In addition to participating in marathons, marathoners have incorporated extensive running into their lifestyle. In the present study, we investigated the effect of long-term strenuous exercise in the form of marathon running on the immune system.

Methods & Results

We collected peripheral blood samples from 37 male marathoners before/after a race and 37 age/sex/body mass index (BMI)-matched healthy sedentary controls. Hematological and biochemical tests revealed race-induced leukocytosis attributable to neutrophilia and significant increases in plasma lactate dehydrogenase (LDH), creatine phosphokinase (CPK), and cortisol concentrations. Phenotypic analysis of lymphocytes revealed race-induced significant decrease in the number of lymphocytes, memory helper T (Th) cells, naive, memory and activated cytotoxic T (Tc) cells, natural killer (NK), NKT, and B1 cells, and a significant increase in the number of activated Th and regulatory Th cells (Tregs). Compared with controls, marathoners maintained significantly lower levels of memory and activated Th cells and higher levels of activated Tc and B1 cells. Measurement of plasma cytokine levels revealed a pro-inflammatory cytokine polarization that increased after the race. Examination of gene expression of cytokines and Th-cell signature transcription factors in peripheral blood mononuclear cells revealed a significant decrease in tumor necrosis factor α (TNF-α) and interleukin (IL)-17, and a significant increase in IL-6, IL-10 and forkhead box P3 (FoxP3) after the race. Compared with controls, marathoners maintained significantly higher levels of TNF-α. Assessment of the suppressive capacity of Tregs in co-cultures of isolated effector Th cells and Tregs showed significantly increased suppressive capacity of marathoners' Tregs after the race.

Conclusions

Compared with controls, marathoners live with permanent changes in certain immune parameters. Marathoners exhibit a stable pro-inflammatory cytokine polarization that increases after the race and is counterbalanced by increased numbers of Tregs overexpressing FoxP3 and having increased suppressive capacity.

Molecular Mechanisms Underlying IL-33-Mediated Inflammation in Inflammatory Bowel Disease

Interleukin-33 (IL-33) is a cytokine defined by its pleiotropic function, acting either as a typical extracellular cytokine or as a nuclear transcription factor. IL-33 and its receptor, suppression of tumorigenicity 2 (ST2), interact with both innate and adaptive immunity and are considered critical regulators of inflammatory disorders. The IL-33/ST2 axis is involved in the maintenance of intestinal homeostasis; on the basis of their role as pro- or anti-inflammatory mediators of first-line innate immunity, their expression is of great importance in regard to mucosal defenses. Mucosal immunity commonly presents an imbalance in inflammatory bowel disease (IBD). This review summarizes the main cellular and molecular aspects of IL-33 and ST2, mainly focusing on the current evidence of the pro- and anti-inflammatory effects of the IL-33/ST2 axis in the course of ulcerative colitis and Crohn's disease, as well as the molecular mechanisms underlying the association of IL-33/ST2 signaling in IBD pathogenesis. Although IL-33 modulates and impacts the development, course, and recurrence of the inflammatory response, the exact role of this molecule is elusive, and it seems to be associated with the subtype of the disease or the disease stage. Unraveling of IL-33/ST2-mediated mechanisms involved in IBD pathology shows great potential for clinical application as therapeutic targets in IBD treatment.

Vitamin D–VDR Novel Anti-Inflammatory Molecules—New Insights into Their Effects on Liver Diseases

There is consistent evidence that vitamin D deficiency is strongly associated with liver dysfunction, disease severity, and poor prognosis in patients with liver disease. Vitamin D and its receptor (VDR) contribute to the regulation of innate and adaptive immune responses. The presence of genetic variants of vitamin D- and VDR-associated genes has been associated with liver disease progression. In our recent work, we summarized the progress in understanding the molecular mechanisms involved in vitamin D–VDR signaling and discussed the functional significance of VDR signaling in specific cell populations in liver disease. The current review focuses on the complex interaction between immune and liver cells in the maintenance of liver homeostasis and the development of liver injury, the interplay of vitamin D and VDR in the development and outcome of liver disease, the role of vitamin D- and VDR-associated genetic variants in modulating the occurrence and severity of liver disease, and the therapeutic value of vitamin D supplementation in various liver diseases. The association of the vitamin D–VDR complex with liver dysfunction shows great potential for clinical application and supports its use as a prognostic index and diagnostic tool.

Urinary free cortisol is a reliable index of adrenal cortisol production in patients with liver cirrhosis

BACKGROUND

The measurement of total and free cortisol has been studied as a clinical index of adrenal cortisol production in patients with liver cirrhosis. Correlations between free plasma and salivary cortisol have previously been reported in stable cirrhotic patients. Urinary free cortisol constitutes an index of adrenal cortisol production; however, it has never been used in assessing adrenal function in patients with liver cirrhosis.

AIMS

The aim of this observational study was to determine associations between urinary free cortisol, serum total, salivary, measured and calculated plasma free cortisol levels in cirrhotics, determining which of them can be used as an indirect index of free cortisol levels. Moreover, we investigated the potential use of 24 h urinary free cortisol as a prognostic factor for mortality.

METHODS

Seventy-eight outpatients with liver cirrhosis were included. Serum, salivary and urinary free cortisol were measured using the electrochemiluminenscence immunoassay. Plasma free cortisol determination was conducted using a single quadrupole mass spectrometer. The quantification of free cortisol was achieved by determining the signal response on negative ESI-MS mode.

RESULTS

Twenty-four hour urinary free cortisol levels correlated with free cortisol determined by mass spectrometer, total cortisol and calculated free cortisol levels. Patients with low levels of urinary free cortisol presented a significantly higher mortality rate compared to those with high levels. The factors associated with death risk were determined by Cox regression. In the multivariate analysis, two models were applied; in the first model, CP score, PVT and urinary free cortisol were found to be significantly related to patients' survival, whereas in the second, MELD score, ascites and urinary free cortisol were independently related to survival.

CONCLUSIONS

This study suggests that 24 h urinary free cortisol could be considered as a potential index of adrenal cortisol production in patients with liver cirrhosis and it potentially detects patients with a high mortality risk.

The impact of metabolic health on non-alcoholic fatty liver disease (NAFLD). A single center experience

BACKGROUND

The role of patients' metabolic clinical and biochemical profile in NAFLD has not been extensively explored.

AIMS

The aim of the study was to assess the role of metabolic health in NAFLD patients and to examine liver disease progression in these populations.

METHODS

The medical charts of 569 patients diagnosed with fatty liver were thoroughly reviewed; 344 patients were excluded because of other chronic liver diseases. Metabolically healthy people were defined as those who met none of the following criteria: blood pressure ≥ 130/85 mmHg or under hypertension treatment, fasting glucose ≥ 100 mg/dl or under diabetes treatment, serum triglycerides > 150 mg/dl, high density lipoprotein-cholesterol <40/50 mg/dl for men/women. Study participants were followed-up over a median period of 22 months.

RESULTS

The present observational case-control study included 225 NAFLD patients; 14 (6.2%) were metabolically healthy. Metabolically healthy participants were younger (p = 0.006), had lower age at diagnosis (p = 0.002), lower levels of γ-GT (p = 0.013), fasting glucose (p <0.001) and triglycerides (p <0.001) and higher HDL-cholesterol (p = 0.005) compared to metabolically non-healthy. By the last follow up assessment, 8 metabolically healthy patients had developed dyslipidemia; 1 patient (14.4%) had presented liver disease progression compared to 8 patients (10.5%) from the unhealthy group (p = 0.567). In multivariate analysis, diabetes mellitus (p = 0.017) and hemoglobin levels (p = 0.009) were the sole independent predictors of disease progression. No significant difference was observed in liver disease progression-free survival rates among the two patient groups (p = 0.503).

CONCLUSIONS

Metabolically healthy NAFLD patients presented with a favorable biochemical profile; however, they were diagnosed with NAFLD at a younger age and the liver disease progression risk was similar to that of metabolically unhealthy patients. These findings suggest that metabolically healthy NAFLD may not constitute a benign condition and patients could potentially be at increased risk of metabolic syndrome and liver disease progression.

Endotoxin Translocation and Gut Barrier Dysfunction Are Related to Variceal Bleeding in Patients With Liver Cirrhosis

Background

Bacterial infections are associated with the risk of variceal bleeding through complex pathophysiologic pathways.

Objectives

The primary objective of the present case-control study was to investigate the role of bacterial translocation and intestinal barrier dysfunction in the pathogenesis of variceal bleeding. A secondary objective was to determine independent predictors of key outcomes in variceal bleeding, including bleeding-related mortality.

Methods

Eighty-four (n = 84) consecutive patients participated in the study, 41 patients with acute variceal bleeding and 43 patients with stable cirrhosis, and were followed up for 6 weeks. Peripheral blood samples were collected at patient admission and before any therapeutic intervention.

Results

Child-Pugh (CP) score (OR: 1.868; p = 0.044), IgM anti-endotoxin antibody levels (OR: 0.954; p = 0.016) and TGF-β levels (OR: 0.377; p = 0.026) were found to be significant predictors of variceal bleeding. Regression analysis revealed that albumin (OR: 0.0311; p = 0.023), CRP (OR: 3.234; p = 0.034) and FABP2 levels (OR:1.000, p = 0.040), CP score (OR: 2.504; p = 0.016), CP creatinine score (OR: 2.366; p = 0.008), end-stage liver disease model (MELD), Na (OR: 1.283; p = 0.033), portal vein thrombosis (OR: 0.075; p = 0.008), hepatocellular carcinoma (OR: 0.060; p = 0.003) and encephalopathy (OR: 0.179; p = 0.045) were significantly associated with 6-week mortality.

Conclusions

Bacterial translocation and gut barrier impairment are directly related to the risk of variceal bleeding. Microbiota-modulating interventions and anti-endotoxin agents may be promising strategies to prevent variceal bleeding.

The role of vitamin D receptor polymorphisms in the course of chronic hepatitis C infection

Background

Vitamin D and its receptor (VDR) exert important immunoregulatory functions that contribute to liver homeostasis. The aim of this study was to investigate the influence of FokI, ApaI, BsmI and TaqI VDR polymorphisms on cirrhosis development and laboratory variables in patients with chronic hepatitis C (CHC).

Methods

A total of 48 patients were enrolled in this retrospective, observational study and underwent genotype analysis; their medical records were examined to obtain relevant data.

Results

The cumulative rate of progression to cirrhosis during the course of CHC was 31.3% after a median period of 11 years from diagnosis. Importantly, in multivariate analysis, FokI ff (adjusted hazard ratio [aHR] 13.6, 95% confidence interval [CI] 2.51-73.73; P=0.002) and ApaI aa (aHR 4.69, 95%CI 1.13-19.43; P=0.033) genotypes were independently associated with progression to cirrhosis. The presence of the aa genotype was also associated with higher liver stiffness measurements measured by transient elastography compared to the AA/Aa genotype (12.3kPa interquartile range [IQR] 9.6-17.3 vs. 7.1kPa IQR 5.6-11.1; P=0.012). In addition, higher HCV RNA and lower serum albumin levels were observed in patients with the tt genotype of the TaqI polymorphism compared to TT/Tt carriers, and in patients with the aa genotype compared to AA/Aa carriers. In haplotype analysis, no association was found between any haplotype and disease progression.

Conclusions

In patients with CHC, laboratory parameters are influenced by VDR polymorphisms and the development of cirrhosis is related to homozygosity for the dominant trait of ApaI and FokI variants.

The Role of Leptin in Childhood Immune Thrombocytopenia (ITP): An Anti-Inflammatory Agent?

To investigate the effect of leptin in childhood ITP, we measured plasma leptin in 39 children with acute ITP, after treatment and in remission, and in 33 healthy age/BMI-matched controls. We also cultured ITP and control peripheral blood mononuclear cells (PBMCs) with recombinant leptin to assess its direct effect on pro/anti-inflammatory cytokine gene expression. A significant increase in leptin was observed in children with active disease compared to controls. A significant inverse correlation of leptin with platelet count was also observed in children with acute ITP. Leptin remained high after treatment with IVIg, whereas steroid treatment lowered leptin below control levels. In remission, leptin was in the control range. Cytokine gene expression was significantly increased in children with acute ITP compared with controls, with highest expression for IFN-γ and IL-10. IVIg/steroid treatment significantly decreased IFN-γ and IL-10 expression. In remission, IFN-γ and IL-10 expression remained low. Addition of leptin to PBMCs isolated from patients in remission resulted in a significant increase in IL-10 gene expression compared to controls. Further experiments with purified T-cells and monocytes identified monocytes as the source of leptin-induced IL-10. We suggest that leptin acts as an active anti-inflammatory agent in childhood ITP by promoting IL-10 secretion by monocytes.

Natural history of grade 1 ascites in patients with liver cirrhosis

Background

No evidence is available on the natural history of grade 1 ascites and its progression to grade 2/3 in patients with liver cirrhosis. The aim of the current study was to address this issue, to assess the development of main comorbid disorders closely related to ascites progression, and to identify the predictive factors for survival in this setting.

Methods

Consecutive Caucasian cirrhotic patients with grade 1 ascites were retrospectively analyzed. None of patients was under treatment with diuretics at diagnosis. Control groups consisted of 145 cirrhotics with grade 2/3 ascites and 175 cirrhotics without ascites.

Results

Diuretics were initiated in 58 patients with grade 1 ascites at baseline by the attending physician. At the last follow up, 29 patients had no ascites, 33 patients had grade 1 and 38 patients had grade 2/3 ascites. No variable was found to be an independent predictor of grade 2/3 ascites. Seven patients developed spontaneous bacterial peritonitis while under treatment with diuretics; at that time only 1 patient had grade 1 ascites. The mortality rate was similar among all examined groups.

Conclusions

This study suggests that the presence of grade 1 ascites does not constitute a precursor of grade 2/3 ascites in patients with cirrhosis. Thus, patients with grade 1 ascites do not require specific treatment with diuretics.

Transcription factor Ets-2 regulates the expression of key lymphotropic factors

Transcription factor Ets-2 downregulates the expression of cytokine genes and HIV-1 in resting T-cells. Herein, we studied whether Ets-2 regulates the expression of lymphotropic factors (LFs) NFAT2, NF-κΒ/p65, c-Jun, c-Fos, which regulate the activation/differentiation of T-cells, and kinase CDK10, which controls Ets-2 degradation and repression activity. In silico analysis revealed Ets-2 binding sites on the promoters of NFAT2, c-Jun, c-Fos. The T-cell lines Jurkat (models T-cell signaling/activation) and H938 (contains the HIV-1-LTR) were transfected with an Ets-2 overexpressing vector, in the presence/absence of mitogens. mRNA and protein levels were assessed by qPCR and Western immunoblotting, respectively. Ets-2 overexpression in unstimulated Jurkat increased NFAT2 and c-Jun mRNA/protein, c-Fos mRNA and NF-κΒ/p65 protein, and decreased CDK10 protein. In unstimulated H938, Ets-2 upregulated NFAT2, c-Jun and CDK10 mRNA/protein and NF-κΒ/p65 protein. In stimulated Jurkat, Ets-2 increased NFAT2, c-Jun and c-Fos mRNA/protein and decreased CDK10 mRNA/protein. In stimulated H938 Ets-2 increased NFAT2, c-Jun and c-Fos protein and reduced CDK10 protein levels. Furthermore, Ets-2 overexpression modulated the expression of pro- and anti-apoptotic genes in both cell lines. Ets-2 upregulates the expression of key LFs involved in the activation of cytokine genes or HIV-1 in T-cells, either through its physical interaction with gene promoters or through its involvement in signaling pathways that directly impact their expression. The effect of Ets-2 on CDK10 expression in H938 vs Jurkat cells dictates that, additionally to Ets-2 degradation, CDK10 may facilitate Ets-2 repression activity in cells carrying the HIV-1-LTR, contributing thus to the regulation of HIV latency in virus-infected T-cells.

The role of the gut microbiota in the treatment of inflammatory bowel diseases

The human intestinal microbiota coevolves with its host through a symbiotic relationship and exerts great influence on substantial functions including aspects of physiology, metabolism, nutrition and regulation of immune responses leading to physiological homeostasis. Over the last years, several studies have been conducted toward the assessment of the host-gut microbiota interaction, aiming to elucidate the mechanisms underlying the pathogenesis of several diseases. A defect on the microbiota-host crosstalk and the concomitant dysregulation of immune responses combined with genetic and environmental factors have been implicated in the pathogenesis of inflammatory bowel diseases (IBD). To this end, novel therapeutic options based on the gut microbiota modulation have been an area of extensive research interest. In this review we present the recent findings on the association of dysbiosis with IBD pathogenesis, we focus on the role of gut microbiota on the treatment of IBD and discuss the novel and currently available therapeutic strategies in manipulating the composition and function of gut microbiota in IBD patients. Applicable and emerging microbiota treatment modalities, such as the use of antibiotics, prebiotics, probiotics, postbiotics, synbiotics and fecal microbiota transplantation (FMT) constitute promising therapeutic options. However, the therapeutic potential of the aforementioned approaches is a topic of investigation and further studies are needed to elucidate their position in the present treatment algorithms of IBD.

Role of NLRP3 inflammasome in inflammatory bowel diseases

Inflammasomes are multiprotein intracellular complexes which are responsible for the activation of inflammatory responses. Among various subtypes of inflammasomes, NLRP3 has been a subject of intensive investigation. NLRP3 is considered to be a sensor of microbial and other danger signals and plays a crucial role in mucosal immune responses, promoting the maturation of proinflammatory cytokines interleukin 1β (IL-1β) and IL-18. NLRP3 inflammasome has been associated with a variety of inflammatory and autoimmune conditions, including inflammatory bowel diseases (IBD). The role of NLRP3 in IBD is not yet fully elucidated as it seems to demonstrate both pathogenic and protective effects. Studies have shown a relationship between genetic variants and mutations in NLRP3 gene with IBD pathogenesis. A complex interaction between the NLRP3 inflammasome and the mucosal immune response has been reported. Activation of the inflammasome is a key function mediated by the innate immune response and in parallel the signaling through IL-1β and IL-18 is implicated in adaptive immunity. Further research is needed to delineate the precise mechanisms of NLRP3 function in regulating immune responses. Targeting NLRP3 inflammasome and its downstream signaling will provide new insights into the development of future therapeutic strategies.

Interleukin 12/interleukin 23 pathway: Biological basis and therapeutic effect in patients with Crohn's disease

Considering that both innate and adaptive immune responses are involved in the pathogenesis of Crohn’s disease (CD), novel therapeutic options have significantly been developed. Biological agents represent an important addition to the conventional treatments for immuno-inflammatory conditions, acting as antagonists of adhesion molecules or various inflammatory cytokines. The interleukin 12 (IL-12)/IL-23 common pathway has been found to play a determinant role in the induction of inflammation in adaptive immune responses. In particular, IL-23 promotes the differentiation of naïve T helper cells into Th17 phenotype with the concomitant secretion of several inflammatory cytokines such as IL-17 and IL-22, whereas IL-12 induces the Th1 polarization and production of critical cytokines such as interferon-γ and tumor necrosis factor. Nowadays, there is increased interest regarding the role of IL-23 as a therapeutic target of CD through the blockage of IL-23 mediated pathways. In this editorial, we focus on the role of IL-12/IL-23 pathway in the regulation of mucosal immunity and in the induction and maintenance of chronic inflammation. In parallel, we critically discuss the available data regarding the therapeutic effect of the IL-12/IL-23 inhibitors and especially of ustekinumab, a human monoclonal antibody which has been recently approved by the United States Food and Drug Administration for the management of moderate-to-severe CD and its potential to be used as first-line therapy in everyday clinical practice.

Prognostic significance of vitamin D receptor (VDR) gene polymorphisms in liver cirrhosis

Several polymorphisms in the vitamin D receptor (VDR) are associated with the occurrence of chronic liver disease. Here, we investigated the association between BsmI, ApaI, TaqI and FokI VDR polymorphisms and the severity of liver cirrhosis in relation to serum cytokine and lipopolysaccharide binding protein (LBP) levels and their role on survival in cirrhotic patients. We found that patients harboring the BB genotype had higher MELD score, and they were mainly at CP stage C; patients harboring the AA genotype had increased LBP, IL-1β and IL-8 levels, and they were mostly at CP stage C; TT genotype carriers had higher MELD score and they were mainly at CP stage C and FF genotype carriers had lower IL-1β levels when compared to Bb/bb, Aa/aa, Tt/tt and Ff/ff genotypes respectively. In the multivariate analysis ApaI, BsmI and TaqI polymorphisms were independently associated with liver cirrhosis severity. In the survival analysis, the independent prognostic factors were CP score, MELD and the FF genotype. Our results indicate that the ApaI, TaqI and BsmI polymorphisms are associated with the severity of liver cirrhosis, through the immunoregulatory process. Survival is related to the FF genotype of FokI polymorphism, imparting a possible protective role in liver cirrhosis.

Role of band ligation for secondary prophylaxis of variceal bleeding

AIM

To summarize and critically examine the role of band ligation in secondary prophylaxis of variceal bleeding in patients with cirrhosis.

METHODS

A literature review was performed using the MEDLINE and PubMed databases. The search terms consisted of the words “endoscopic band ligation” OR “variceal band ligation” OR “ligation” AND “secondary prophylaxis” OR “secondary prevention” AND “variceal bleeding” OR “variceal hemorrhage” AND “liver cirrhosis”. The data collected from relevant meta-analyses and from the most recent randomized studies that were not included in these meta-analyses were used to evaluate the role of endoscopic band ligation in an effort to demonstrate the most recent advances in the treatment of esophageal varices.

RESULTS

This study included 11 meta-analyses published from 2002 to 2017 and 10 randomized trials published from 2010 to 2017 that evaluated the efficacy of band ligation in the secondary prophylaxis of variceal bleeding. Overall, the results proved that band ligation was superior to endoscopic sclerotherapy. Moreover, the use of β-blockers in combination with band ligation increased the treatment effectiveness, supporting the current recommendations for secondary prophylaxis of variceal bleeding. The use of transjugular intrahepatic portosystemic shunt was superior to combination therapy regarding rebleeding prophylaxis, with no difference in the survival rates; however, the results concerning the hepatic encephalopathy incidence were conflicting. Recent advances in the management of secondary prophylaxis of variceal bleeding have targeted a decrease in portal pressure based on the pathophysiological mechanisms of portal hypertension.

CONCLUSION

This review suggests that future research should be conducted to enhance current interventions and/or to develop innovative treatment options with improved clinical endpoints.

Νon-invasive screening for esophageal varices in patients with liver cirrhosis

Esophageal varices are one of the main complications of liver cirrhosis. Upper gastrointestinal endoscopy is the gold standard for the detection of esophageal varices. Many less invasive methods for screening of varices have been investigated and the most recent Baveno VI guidelines suggest that endoscopy is not necessary in patients with liver stiffness <20 kPa and platelets >150,000/μL. A critical review of the literature was performed concerning non-invasive or minimally invasive methods of screening for esophageal varices. Liver and spleen elastography, imaging methods including computed tomography, magnetic resonance imaging and ultrasound, laboratory tests and capsule endoscopy are discussed. The accuracy of each method, and its advantages and limitations compared to endoscopy are analyzed. There are data to support the Baveno VI guidelines, but there is still a lack of large prospective studies and low specificity has been reported for the liver stiffness and platelet count combination. Spleen elastography has shown promising results, as there are data to support its superiority to liver elastography, but it needs further assessment. Computed tomography has shown high diagnostic accuracy and can be part of the diagnostic work up of cirrhotic patients in the future, including screening for varices.

Ets-2 Acts As a Transcriptional Repressor of the Human Immunodeficiency Virus Type 1 through Binding to a Repressor-Activator Target Sequence of 5'-LTR

HIV-1 is transcriptionally active in activated T helper (Th)-cells and inactive in naive or resting memory Th-cells. Ets-2 is a preinduction transcriptional repressor of the IL-2 gene in naive Th-cells and a candidate transcriptional repressor of HIV-1 in the same cells, because the −279 to −250 upstream region of HIV-1-LTR [repressor–activator target sequence (RATS)], that participates in HIV-1-LTR transcriptional silencing, encompasses the AAGGAG Ets-2 binding site. In this proof of concept study, we investigated whether Ets-2 represses the expression of HIV-1. To assess whether Ets-2 can repress HIV-1 transcriptional activation acting through RATS, we transfected Jurkat cells with an Ets-2 overexpression plasmid (pCDNA3-ets-2) or Ets-2 silencing plasmids (ets-2-shRNA) and, as target genes, plasmids carrying the whole HIV-1-LTR sequence (HIV-1-LTR-CAT) or two copies of the RATS sequence (2× RATS-CAT) or a point mutation in the Ets-2 binding site (2× mutantRATS-CAT) or CMV-CAT (control). Ets-2 overexpression resulted in a significant reduction of HIV-1-LTR-CAT and 2× RATS-CAT activities in stimulated cells, but not of the 2× mutantRATS-CAT or CMV-CAT. Ets-2 silencing led to increased activities of HIV-1-LTR-CAT and 2× RATS-CAT in unstimulated cells, but had no effect on the activities of 2× mutantRATS-CAT and CMV-CAT. To assess Ets-2 binding to HIV-1-LTR–RATS in naive Th-cells, we isolated naive Th-cell nuclear proteins and passed them through an Ets-2 antibody column; electrophoretic mobility shift assays were performed using an RATS probe mixed with consecutive protein eluates. Ets-2 bound to the HIV-1-LTR–RATS in a dose-dependent manner. To assess Ets-2 binding to RATS in vivo, Jurkat cells were transfected with 2× RATS-CAT and stained for the Ets-2 protein and the RATS sequence by combining immunofluorescence and fluorescence in situ hybridization techniques. In unstimulated cells, Ets-2 bound to RATS, whereas no binding was observed in stimulated cells. To test for RATS specificity, the same experiments were performed with 2× mutantRATS-CAT, and no binding of Ets-2 was observed. The results were corroborated by chromatin immunoprecipitation assays performed with the same cells. Our results show that Ets-2 is a transcriptional repressor of HIV-1. Repression of HIV-LTR-RATS mediated by Ets-2 may account for the low-level transcription and replication of HIV-1 in naive Th-cells, and contribute to the viral latency and maintenance of viral reservoirs in patients, despite long-term therapy.

Response to hepatitis B vaccination in patients with liver cirrhosis

Hepatitis B vaccination is strongly recommended for all infants and children but also for adults who are at risk of HBV infection. Attempts to immunize patients with liver cirrhosis have been proven relatively ineffective, and several strategies have already been used to improve the immune response in this group. The primary aim of this review is to examine, discuss, and summarize the immunogenicity of hepatitis B vaccination in patients with liver cirrhosis. MEDLINE search identified 11 studies (n = 961). The dose of the vaccine and the schedule of the vaccination varied. The response rates to the HBV vaccination ranged from 16% to 87% among patients with cirrhosis regardless of the number and vaccine dose. In particular, patients who received the standard dose of vaccination achieved seroprotection rates ranged from 16% to 79% (mean response rate 38%) and those who received a double dose achieved relatively better seroprotection rates (range: 26%-87%; mean response rate 53%). The overall mean response rate to the HBV vaccination was 47%. In conclusion, cirrhotic patients achieve lower seroprotection rates after the completion of HBV vaccination series. Several strategies have tried to improve the immunogenicity; however, there is a great need for additional studies to further explore (1) the immune response in relation to poor vaccination responsiveness confounding factors, (2) novel strategies to improve immunogenicity, and (3) the immune mechanism underlying the differences in response rates to HBV vaccination.

Risk of hepatitis B reactivation in patients treated with direct-acting antivirals for hepatitis C

The recent introduction of direct-acting antiviral drugs (DAAs) for treatment of the hepatitis C virus (HCV) has greatly improved the management of HCV for infected patients. These viral protein inhibitors act rapidly, allowing HCV clearance and increasing the sustained virological response rates. However, hepatitis B virus (HBV) reactivation has been reported in HCV/HBV co-infected patients. Hepatitis B reactivation refers to an abrupt increase in the HBV and is well-documented in patients with previously undetected HBV DNA due to inactive or resolved HBV infection. Reactivation can occur spontaneously, but in most cases, it is triggered by various factors. Reactivation can be transient, without clinical symptoms; however, it usually causes a hepatitis flare. HBV reactivation may occur regardless of HCV genotype and type of DAA regimen. HBV screening is strongly recommended for co-infected HCV/HBV patients before initiation and during DAA therapy regardless of HBV status, HCV genotype and class of DAAs used. HBV reactivation can be prevented with pretreatment screening and prophylactic treatment when necessary. Additional data are required to evaluate the underlying mechanisms of HBV reactivation in this setting.

Anti-Xa activity in patients with hepatocellular carcinoma

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Transcription Factor Ets-2 Acts as a Preinduction Repressor of Interleukin-2 (IL-2) Transcription in Naive T Helper Lymphocytes

IL-2 is the first cytokine produced when naive T helper (Th) cells are activated and differentiate into dividing pre-Th0 proliferating precursors. IL-2 expression is blocked in naive, but not activated or memory, Th cells by the transcription factor Ets-2 that binds to the antigen receptor response element (ARRE)-2 of the proximal IL-2 promoter. Ets-2 acts as an independent preinduction repressor in naive Th cells and does not interact physically with the transcription factor NFAT (nuclear factor of activated T-cells) that binds to the ARRE-2 in activated Th cells. In naive Th cells, Ets-2 mRNA expression, Ets-2 protein levels, and Ets-2 binding to ARRE-2 decrease upon cell activation followed by the concomitant expression of IL-2. Cyclosporine A stabilizes Ets-2 mRNA and protein when the cells are activated. Ets-2 silences directly constitutive or induced IL-2 expression through the ARRE-2. Conversely, Ets-2 silencing allows for constitutive IL-2 expression in unstimulated cells. Ets-2 binding to ARRE-2 in chromatin is stronger in naive compared with activated or memory Th cells; in the latter, Ets-2 participates in a change of the IL-2 promoter architecture, possibly to facilitate a quick response when the cells re-encounter antigen. We propose that Ets-2 expression and protein binding to the ARRE-2 of the IL-2 promoter are part of a strictly regulated process that results in a physiological transition of naive Th cells to Th0 cells upon antigenic stimulation. Malfunction of such a repression mechanism at the molecular level could lead to a disturbance of later events in Th cell plasticity, leading to autoimmune diseases or other pathological conditions.

Epidemiology of hepatitis C in Greece

Hepatitis C is a global health issue and constitutes a major cause of chronic liver disease worldwide. In this article, a comprehensive literature search was conducted for the prevalence of hepatitis C virus (HCV) infection in Greece, since data on the HCV prevalence, viremia and genotypes are important for developing strategies to manage or eliminate HCV infection. In addition, the pattern of HCV infection was analyzed according to the geographic region and the risk factors. These differences reflect not only distinct epidemiological characteristics among populations, but also differences on the strategy of data acquisition and quantification. Although there are not enough data, the estimation of the current prevalence of Hepatitis C in Greece ranges from 0.5% to 2%. The most important risk factors for HCV infection include blood product transfusion, intravenous drug use, chronic hemodialysis, organ transplantation, occupational exposure, sexual transmission, and vertical transmission. Because of lack of vaccine or effective post-exposure prophylaxis for HCV, the main focus of prevention is to recognize and control these risk factors. HCV infection in Greece is closely associated with the development of chronic liver disease, cirrhosis, and primary hepatocellular carcinoma. As far as the genotype distribution is concerned genotype 1 estimated to be 45%-47% and it constitutes the prevalent genotype in Greece, followed by genotype 3.