Histological features and HLA class II alleles in hepatitis C virus chronically infected patients with persistently normal alanine aminotransferase levels

Association between the Genetic Polymorphisms of CCL2, CCL5, CCL8, CCR2, and CCR5 with Chronic Hepatitis C Virus Infection in the Chinese Han Population

Background: Hepatitis C virus (HCV) infection is a global public health burden. Chronic HCV infection leads to the development of fibrosis, cirrhosis, liver cancer, and liver failure over time.Methods: A total of 250 patients with chronic HCV infection and 299 healthy blood donors were recruited. Sixteen candidate single nucleotide polymorphisms (SNPs) in chemokine (C-C motif) ligand 2 (CCL2), CCL5, CCL8, C-C chemokine receptor 2 (CCR2), and CCR5 were genotyped in all participants.Results: The rs1024610 AA genotype was significantly associated with decreased susceptibility to chronic HCV infection. Aspartate aminotransferase (AST) levels, AST/platelet ratio index, and the fibrosis 4 score were significantly lower in the CCL2 rs1024610 T allele and haplotype ATGC carriers. Moreover, expression levels of collagen IV (C-IV) and laminin (LN) were significantly higher in patients with the CCL5 rs2280788 C allele compared to the non-carriers. Similarly, the expression levels of C-IV, LN, and hyaluronic acid were significantly higher in patients with the CCL5 haplotype, TGCT. No significant differences were identified between the SNPs/haplotypes and plasma levels of CCL2, CCL5, CCL8, CCR2, and CCR5 in the healthy controls, and the rs1024610 allele alteration had no effect on CCL2 promoter activity.Conclusions: This is the first study to report an association between CCL2 rs1024610 and the risk of chronic HCV infection in the Chinese Han population. rs1024610 and ATGC haplotype in CCL2 were reasonable candidate markers of liver abnormalities. rs2280788 and TGCT haplotype in CCL5 are likely to play a significant role in liver fibrosis during chronic HCV infection.

Genetic Factors That Affect Spontaneous Clearance of Hepatitis C or B Virus, Response to Treatment, and Disease Progression

Hepatitis C virus (HCV) and hepatitis B virus (HBV) infections can lead to cirrhosis, end-stage liver disease, and hepatocellular carcinoma. Over the past decade, studies of individuals infected with these viruses have established genetic associations with the probability of developing a chronic infection, risk of disease progression, and likelihood of treatment response. We review genetic and genomic methods that have been used to study risk of HBV and HCV infection and patient outcomes. For example, genome-wide association studies have linked a region containing the interferon lambda genes to spontaneous and treatment-induced clearance of HCV. We review the genetic variants associated with HCV and HBV infection, and how these variants affect specific expression or activities of their products. Further studies of these variants could provide insights into risk factors for and mechanisms of chronic infection and disease progression, as well as new strategies for treatment.

Effect of HLA on hepatitis C virus clearance and persistence in anti-HCV-positive end-stage renal disease patients

BACKGROUND/AIMS

The efficacy of immune response against hepatitis C virus (HCV) is determined by human leukocyte antigen (HLA) molecules of the host which present HCV antigens to CD4 + and CD8 + T lymphocytes. In this study, we aimed to investigate the possible relationship between the frequencies of certain HLA class I-II alleles and the natural history of HCV in patients with end-stage renal disease (ESRD).

SETTINGS AND DESIGN

This is a retrospective cohort study conducted in a university hospital.

PATIENTS AND METHODS

The present study comprised 189 ESRD patients (candidates for renal transplantation) who had positive anti-HCV antibody test. The results concerning HCV and HLA status were gathered from patients' files. The viral persistence was compared between the groups that were determined by HLA sub-typing.

STATISTICAL ANALYSIS

Statistical evaluation was performed using Mann-Whitney U-test, Chi-square test, and Fisher's exact test. Level of error was set at 0.05 for all statistical evaluations, and P values < 0.05 were considered statistically significant.

RESULTS

We found possible association between the course of HCV infection and specific HLA alleles. HLA class I CwFNx016 and HLA class II DRBFNx0110 alleles were observed more frequently in the viral clearance group (P < 0.05). The HLA class I BFNx0138 allele group was more prone to develop chronic hepatitis C (P < 0.01).

CONCLUSIONS

These findings suggest that HLA class I CwFNx016 and HLA class II DRBFNx0110 alleles may be associated with immunological elimination of HCV in Turkish patients on hemodialysis. HLA sub-typing could help predict the prognosis of HCV infection.

Major Histocompatibility Class II Pathway Is Not Required for the Development of Nonalcoholic Fatty Liver Disease in Mice

Single-nucleotide polymorphisms within major histocompatibility class II (MHC II) genes have been associated with an increased risk of drug-induced liver injury. However, it has never been addressed whether the MHC II pathway plays an important role in the development of nonalcoholic fatty liver disease, the most common form of liver disease. We used a mouse model that has a complete knockdown of genes in the MHC II pathway (MHCII(Δ/Δ)). Firstly we studied the effect of high-fat diet-induced hepatic inflammation in these mice. Secondly we studied the development of carbon-tetra-chloride- (CCl4-) induced hepatic cirrhosis. After the high-fat diet, both groups developed obesity and hepatic steatosis with a similar degree of hepatic inflammation, suggesting no impact of the knockdown of MHC II on high-fat diet-induced inflammation in mice. In the second study, we confirmed that the CCl4 injection significantly upregulated the MHC II genes in wild-type mice. The CCl4 treatment significantly induced genes related to the fibrosis formation in wild-type mice, whereas this was lower in MHCII(Δ/Δ) mice. The liver histology, however, showed no detectable difference between groups, suggesting that the MHC II pathway is not required for the development of hepatic fibrosis induced by CCl4.

Protective effect of HLA-DRB1 11 and predisposition of HLA-C 04 in the development of severe liver damage in Brazilian patients with chronic hepatitis C virus infection

The objective of this study was to investigate human leucocyte antigen (HLA) genes in patients chronically infected with hepatitis C virus (HCV) and to analyse the possible role of these genes in the progression of chronic hepatitis C. One hundred and forty-five (145) Brazilian patients infected only with HCV genotype 1 were evaluated. HLA class I (A, B, C) and class II (DRB1, DQA1, DQB1) typing were carried out by PCR-SSO, through Luminex technology. Associations were found with protection against development of liver damage by both DRB1 11 (5.0% versus 18.2%, P=0.0016, OR=0.23, CI 95% = 0.09-0.58; Pc=0.0208) and DRB1 11-DQA1 05-DQB1 03 haplotype (4.2% versus 15.3%, P=0.0032; OR = 0.24, CI 95% = 0.08-0.64). Liver damage was associated with HLA-C 04 in patients with <20 years of infection (38.4% versus 9.1%, P = 0.002, OR = 6.25, CI 95%=1.97-19.7; Pc=0.0238). It is concluded that HLA alleles can influence the development of liver damage in HCV type-1 chronically infected Brazilian patients.

Should we treat HCV carriers with normal ALT levels? The '5Ws' dilemma

Approximately 30% of patients with chronic HCV infection have persistently normal ALT levels. Although formerly referred to as 'healthy' or 'asymptomatic' HCV carriers, and thus historically excluded from antiviral treatment, it has now become clear that the majority of these patients have some degree of histological liver damage that may be significant in up to 20% of cases and might progress towards a more severe degree of liver fibrosis. A significant proportion of patients experience periods of increased serum ALT associated with enhanced disease progression. However, controversies still exist in clinical practice regarding the definition of 'persistent' ALT normality, the virological and histological features of these subjects, the need for liver biopsy, the role of noninvasive tools for the assessment of liver fibrosis, the natural history and the usefulness of antiviral treatment. The advent of new therapeutic options (pegylated interferon plus ribavirin) has shifted treatment targets towards the eradication of underlying infection, with therapy decision based on age, severity of disease and likelihood of response rather than on aminotransferase levels. This review is aimed at approaching the main unresolved issues on this topic, trying to give evidence-based answers to the more frequently asked questions from patients and their physicians.

Dysfunction of Immune Systems and Host Genetic Factors in Hepatitis C Virus Infection with Persistent Normal ALT

Patients with chronic hepatitis C (CHC) virus infection who have persistently normal alanine aminotransferase levels (PNALT) have mild inflammation and fibrosis in comparison to those with elevated ALT levels. The cellular immune responses to HCV are mainly responsible for viral clearance and the disease pathogenesis during infection. However, since the innate and adaptive immune systems are suppressed by various kinds of mechanisms in CHC patients, the immunopathogenesis of CHC patients with PNALT is still unclear. In this review, we summarize the representative reports about the immune suppression in CHC to better understand the immunopathogenesis of PNALT. Then, we summarize and speculate on the immunological aspects of PNALT including innate and adaptive immune systems and genetic polymorphisms of HLA and cytokines.

Hepatitis C virus infection causes hypolipidemia regardless of hepatic damage or nutritional state: An epidemiological survey of a large Japanese cohort

AIM

  Infection with hepatitis C virus (HCV) is the leading cause of liver cirrhosis that develops into hepatocellular carcinoma. Previous studies have shown in vitro that lipids within hepatocytes are crucially important for a series of HCV infection-proliferation-release processes. On the other hand, in the patients with HCV, the serum total cholesterol (Total-C) and low-density lipoprotein cholesterol (LDL-C) levels have been reported to be lower. We conducted an epidemiological survey of a large cohort and investigated whether the lower serum lipid levels were caused by a direct or the secondary effects of HCV infection (i.e. hepatic damage or nutritional disorder).

METHODS

  Among 146 857 participants (male, 34%; female, 66%) undergoing public health examinations between 2002 and 2007 in Ibaraki Prefecture, Japan, the HCV positive rates determined by HCV antibody/antigen and/or RNA tests were 1.37% and 0.67% in males and females, respectively.

RESULTS

  In addition to Total-C and LDL-C, serum high-density lipoprotein cholesterol and triglyceride concentrations were also significantly lower in the HCV positive subjects compared with the negative subjects, regardless of sex, age or nutritional state evaluated by body mass index. Multivariate analysis showed that HCV infection was the strongest among the factors to be significantly associated with the lower level of these lipids. Particularly, the hypolipidemia was also confirmed in the HCV positive subjects with normal aminotransferase levels (alanine aminotransferase ≤30 and aspartate aminotransferase ≤30).

CONCLUSION

  This epidemiological survey in a large Japanese cohort suggests that the HCV infection itself might directly cause hypolipidemia, irrespective of host factors including age, hepatic damage and nutritional state.

Genes and hepatitis C: susceptibility, fibrosis progression and response to treatment

Hepatitis C virus contact and infection show three different phenotypes: spontaneous viral clearance (SVC), chronic hepatitis C (CHC) and sustained virological response (SVR) following antiviral treatment. Many factors, including genetics, influence the evolution of these three phenotypes. We performed a literature search (PubMed) up to 31 January 2010 without language restriction to identify relevant studies on genes and hepatitis C. Additional studies were sought by reviewing the reference lists of the identified articles. Meta-analysis (using Meta-disk 1.4) was conducted to evaluate the association of single nucleotide polymorphism (SNP) in the IL28B region and SVR. The candidate gene approach showed strong relationships between human leucocyte antigen class II (DQB1(*) 0301 and DRB1(*) 1101) and SVC. A cirrhosis risk score involving 7 SNPs has been validated recently. The set of odds ratios of studies demonstrated an association between SNP (rs12987960/rs8099917) in the IL28B and SVR in CHC treated with peginterferon plus ribavirin (OR: 4.6; 95% CI: 2.9-7.3). The overall distribution of protective allele correlated with ethnic differences in SVR (Asians, Europeans, Hispanic and Afro-Americans) together with SVC, but not with fibrosis stage or viral load. These polymorphisms did not influence SVR in very-easy-to-treat patients such as genotype 2/3, rapid virological responders or patients with acute hepatitis C. While the genetic fingerprint for fibrosis progression remains elusive, IL28b polymorphism predicts SVC and SVR. However, nearly half of patients achieving SVR did not show favourable genotype. Further genetic signals are warranted to complete the puzzle of factors influencing hepatitis C.

The association of HLA class II DR B1 alleles with HCV infection in Egyptian children

BACKGROUND AND STUDY AIMS

Human leucocyte antigens (HLA) class II appear to play an important role in the individual's immune response to viral infection. The aim of this study is to assess the relationship between HLA class II antigens with the clinical, laboratory and histopathological state of the liver in Egyptian children and adolescents with chronic hepatitis C virus (HCV) infection.

PATIENTS AND METHODS

The study included 46 chronically infected HCV children and adolescents without - hepatitis B virus (HBV) nor human immunodeficiency virus - (HIV). Their mean age was 10.4±4.23years (3-17). HLA-DRB typing was done by polymerase chain reaction (PCR) for the patients and 20 control subjects. Biochemical and haematological parameters were assessed as well as a liver biopsy was taken from the included patients.

RESULTS

The most frequent alleles demonstrated among patients were DRB1∗03, DRB1∗04 and DRB1∗13 (45.6%, 39.1% and 26.1%), respectively. Analysis of DRB1 frequencies between patients and control revealed that DRB1*15 is significantly reduced among patients when compared with the control group (p<0.01). Patients possessing the allele DRB1*03 had significantly reduced platelet count (p=0.03), and this allele was presented to a greater extent in patients with minimal grade of inflammation. Patients with DRB1*04 had significantly low serum albumin (p=0.04) and patients with DRB1*13 had significantly high serum aspartate aminotransferase (AST) levels (p=0.05).

CONCLUSION

In Egyptian HCV-infected children, special HLA patterns were found; HLA DRB1*03 was present in nearly half of the patients, while the frequency of HLA DRB1*15 was significantly reduced among the cases in comparison to the control subjects.

Association of human leucocyte antigen Class I (HLA-A and HLA-B) with chronic hepatitis C virus infection in Egyptian patients

Egypt has the highest prevalence of hepatitis C virus (HCV) in the world, ranging from 6% to 28% with an average of approximately 13.8% in the general population. It has been reported that human leucocyte antigen (HLA) alleles are associated with the outcome of HCV infection, but this associations showed ethnic and geographical differences. The objective of this study is to investigate the association between the frequencies of HLA Class I and chronic HCV infection in Egyptian patients and to find out whether there is a relation between certain HLA Class I antigens and HCV viral load, degree of fibrosis, activity and alanine aminotransferase (ALT) level. A case control study was conducted on 100 patients with chronic HCV infection and 150 healthy controls. HLA-A and HLA-B typing by complement-dependent micro-lympho-cytotoxicity assay was performed for both groups. HLA-A11 antigen was significantly increased in patients with chronic HCV infection versus controls (OR 3.98; 95% CI = 1.85-8.89; P = 0.001; and Pc = 0.021). HLA-B12, HLA-B13, HLA-B17 and HLA-B40 were higher in patients, and HLA-A32 and HLA-B14 were higher in controls, although the significance was lost after correction for multiple testing. HLA-A9 was significantly associated with low viral load (P = 0.008, Pc = 0.048). The results of this work implicate that HLA-A11 antigen may influence chronic HCV infection and may play a role in viral persistence. Different HLA Class I antigens are not associated with degree of liver fibrosis, grades of activity or level of ALT. However, HLA-A9 is associated with low HCV viral load in chronic HCV Egyptian patients.

Hepatitis C virus NS4 protein impairs the Th1 polarization of immature dendritic cells

Dendritic cells (DCs) in chronic hepatitis C patients display impaired function, although the details remain unclear. To investigate the hepatitis C virus (HCV) protein that has the most impact on DC function, we compared five recombinant proteins and seven HCV protein genes in modulating DC phenotype and function. Immature DCs (iDCs) were established from healthy donor peripheral blood monocytes with granulocyte-macrophage colony stimulating factor (GM-CSF) and IL-4. Lipopolysaccharide was used to establish mature DCs (mDCs). Cells were then pulsed with HCV recombinant proteins or transfected with HCV plasmids and subsequently assayed for cell surface marker expression by flow cytometry. For cytokine and proliferative T-cell response analysis, DCs were cultured with autologous CD4 T cells and tuberculin purified protein derivative (PPD). Mean fluorescent intensity of CD86 was reduced in HCV protein-pulsed iDCs. Proliferative T-cell responses and Th1 cytokine concentrations were reduced with HCV nonstructural proteins (NS), particularly with HCV NS4. HCV nonstructural proteins, particularly NS4, change the iDC phenotype and reduce antigen-specific T-cell stimulatory function with Th1 cytokine reductions.

HCV carriers with normal alanine aminotransferase levels: healthy persons or severely ill patients? Dealing with an everyday clinical problem

Approximately 30% of patients with chronic HCV infection show persistently normal ALT levels. Although formerly referred to as 'healthy' or 'asymptomatic' HCV carriers, and thus historically excluded from antiviral treatment, it has now become clear that the majority of these patients have some degree of histological liver damage that may be significant in up to 20% of patients and might progress toward a more severe degree of liver fibrosis. A significant proportion of patients (> or =20%) experience periods of increased serum ALT (flare) associated with enhanced disease progression. However, controversies still exist in clinical practice regarding the definition of 'persistent' ALT normality, the virological and histological features of these subjects, the need for liver biopsy, the role of non invasive tools for the assessment of liver fibrosis (transient hepatic elastography, fibroscan), and the natural history and optimal management of chronic hepatitis C with normal ALT. The advent of new therapeutic options (pegylated interferons plus ribavirin) has shifted treatment targets toward eradication of underlying infection, with therapy decision based on age, severity of disease and likelihood of response rather than on aminotransferase levels. This review does approach the main unresolved issues on this topic in the form of a dialog between a hepatologist and a patient with HCV infection but normal alanine aminotransferase levels, trying to give evidence-based answers to the more frequently asked questions from patients and their physicians.

Association between liver cirrhosis due to HBV infection and HLA-DRB1 gene polymorphism in Fujian Province

AIM: To investigate the association between HLA-DRB1 gene polymorphism and the genetic susceptibility to HBV-induced liver cirrhosis in Fujian Han population.

METHODS: Genotyping of HLA-DRB1 gene was performed in 93 patients with HBV-induced cirrhosis and 84 healthy individuals using sequencing-based typing. The distribution of alleles in control group was checked by Hardy-Weinberg genetic equilibrium; association between disease and frequencies of alleles were analyzed using genetic statistical methods to find the gene polymorphisms.

RESULTS: The frequency of HLA-DRB1*04 allele was significantly higher in patient group than in control group (OR = 2.536, 95%CI: 1.292-4.97, P = 0.0068). However, the frequency of HLA-DRB1*1101 allele was significantly lower in patient group than in control group (OR = 0.339, 95%CI: 0.119-0.964, P = 0.0425). Significant difference was found in genotype of HLA-DRB1 04 between the case group and the control group (OR = 3.456, 95%CI: 1.553-7.692, χ² = 9.227, P = 0.0024). There was significant dose-response relationship between liver cirrhosis and the genotype of HLA-DRB1 04 (OR = 2.457, 95%CI: 1.274-4.737, χ² = 7.197, P = 0.0073).

CONCLUSION: HLA-DRB1*04 allele and HLA-DRB1*1101 allele may be the susceptibility and resistant genes in the patients with liver cirrhosis respectively.

The association between the genetic polymorphism of HLA-DQA1, DQB1, and DRB1 and serum alanine aminotransferase levels in chronic hepatitis C in the Chinese population

BACKGROUND AND AIM

To investigate a possible association between HLA genes with serum alanine aminotransferase (ALT) levels and evaluate whether the HLA-DQA1, DQB1, and DRB1 genes could influence the development of liver damage in chronic hepatitis C.

METHODS

A total of 145 patients with chronic hepatitis C virus (HCV) infection (36 patients with persistently normal ALT values; 109 patients with elevated ALT levels) and 160 uninfected healthy controls were examined for HLA-DQA1, DQB1, and DRB1 molecules by using polymerase chain reaction-sequencing based typing (PCR-SBT).

RESULTS

Among the patients chronically infected with HCV, the frequencies of DQA1*0501, DQB1*0301, and DRB1*0401 alleles were significantly increased in the normal ALT group compared with those with abnormal ALT levels, whereas that of DQB1*0201 was significantly lower. As compared to uninfected healthy controls, DQA1*0501, DQB1*0301, and DRB1*0401 allele frequencies were also statistically higher in the normal ALT group, whereas that of DQB1*0201 was the inverse. The haplotype frequencies of DQA1*0301-DQB1*0301, DQA1*0501-DQB1*0301, and DRB1*1101-DQB1*0301 were found to be significantly higher in the normal ALT group. Multivariate logistic regression indicated that female sex, and the DQB1*0301 allele and DRB1*0401 allele were independently associated with normal ALT values, whereas DQB1*0201 allele was the inverse.

CONCLUSIONS

These results suggest that particular HLA alleles may have an influence on the serum ALT level of chronic HCV infection as a host genetic factor in the Chinese population. The DQA1*0501, DQB1*0301, and DRB1*0401 alleles, and the DQA1*0301-DQB1*0301, DQA1*0501-DQB1*0301, and DRB1*1101-DQB1*0301 haplotypes seem to be associated with low hepatitis activity; whereas DQB1*0201 allele is closely correlated with the progression of liver injury in chronic HCV infection.

Host genetic factors and antiviral immune responses to hepatitis C virus

Human genome variations explain some of the heterogeneity in the immune response to antigenic stimuli. Such differences in response to hepatitis C virus (HCV) antigens can account for the ability of the immune response to clear HCV after an acute infection or to develop more rapidly progressive liver disease. Several studies have examined polymorphisms in several candidate immune-response genes for their relation to these HCV outcomes. Results of some of these studies complement knowledge gained from immunology studies, and others offer new insights into HCV biology. This review summarizes published studies on variation in immune-response genes and HCV outcomes.

Disease progression in chronic hepatitis C: modifiable and nonmodifiable factors

The hepatic complications of chronic hepatitis C (CHC) usually occur only after progression to cirrhosis has taken place. Progression to cirrhosis, however, is extremely variable and depends on a broad set of host and viral factors that modify the rate at which fibrosis develops in a given individual. Despite their inherent limitations, studies of the natural history of CHC have identified several nonmodifiable factors associated with disease progression. These include age at acquisition of infection, sex, and race. More recent reports suggest important roles for host genetic polymorphisms and viral factors. Of greater immediate relevance to patients and their clinicians are the potentially modifiable factors, which include excessive alcohol consumption; smoking (tobacco and marijuana); insulin resistance; and coinfection with hepatitis B virus, human immunodeficiency virus type 1, or schistosomiasis. Unfortunately, to date, there are no reliable predictive models that can accurately estimate the risk of CHC disease progression.

Guidelines for the antiviral therapy of hepatitis C virus carriers with normal serum aminotransferase based on platelet counts

AIM

We aimed to identify the candidates for antiviral therapy, among patients who are hepatitis C virus (HCV) carriers with normal serum aminotransferase (ALT), focused on the inhibition of hepatocellular carcinoma (HCC).

METHODS

Four hundred and sixty-four HCV carriers with normal serum ALT and 129 HCV carriers with persistently normal ALT (PNALT) and platelet (PLT) counts >/=150 000/muL who received liver biopsies were enrolled. HCV carriers with normal serum ALT were divided into four groups according to their ALT levels (</=30 U/L or 31-40 U/L) and PLT counts (>/=150 000/muL or <150 000/muL).

RESULTS

In 129 HCV carriers with PNALT, the rate of progression of fibrosis stage was 0.05/year and no HCC was detected during the follow up for 10 years. Approximately 20% of patients with ALT </=40 U/L and PLT counts >/=150 000/muLwere at stage F2-3; however, approximately 50% of patients with ALT </= 40 U/L and PLT counts <150 000/muL were at stage F2-4. An algorithm for the management of HCV carriers with normal serum ALT was advocated based on ALT and PLT counts.

CONCLUSION

The combination of ALT and PLT counts is useful for evaluating the fibrosis stage in HCV carriers with normal serum ALT. Most patients with PLT counts <150 000/muL are candidates for antiviral therapy, especially those with ALT levels >/=31 U/L when we focus on the inhibition of the development of HCC.

Long-term follow-up of the hepatitis C HENCORE cohort: response to therapy and occurrence of liver-related complications

The aims of the study were to verify the long-term effect of time on viral clearance in hepatitis C virus (HCV) patients and to find out factors possibly associated with disease progression. A total of 1641 patients recruited from eight European centres in 1996-1997 were re-analysed 5-7 years after inclusion. The occurrence of decompensated cirrhosis, hepatocellular carcinoma (HCC) and liver transplantation was analysed in relation to different host and viral factors. Ninety-three per cent of the HCV patients who had cleared the virus (spontaneously or after antiviral therapy) remained HCV-RNA-negative during follow up and may be considered as 'cured'. Among patients who were sustained responders at inclusion, 2.3% developed liver complications during follow up, and 31% of non-responders did. Advanced age at infection and presence of the human leucocyte antigen (HLA) DRB1*1201-3 allele were possibly associated with a higher rate of progression to decompensated cirrhosis or HCC. Decompensated cirrhosis might be further associated with male gender, non-response to previous therapy, and lack of HLA DRB1*1301 allele, whereas HCC seems to be associated with the presence of the HLA DQ02 allele. Long-term follow up of HCV patients indicates that virological response persists over time and is associated with a very low incidence of liver complications. Advanced age at inclusion, advanced age at infection, viral genotype 1, non-response to previous therapy and possibly some specific HLA alleles are factors independently associated with a faster rate of progression towards liver complications. The large proportion of patients lost to follow up stresses the need for a strengthened and optimized management of HCV patients.

Immunopathogenesis of hepatitis C virus infection and hepatic fibrosis: New insights into antifibrotic therapy in chronic hepatitis C

Fibrosis and cirrhosis represent the consequences of a sustained wound-healing response to chronic liver injury of any cause. Chronic hepatitis C virus (HCV) has emerged as a leading cause of cirrhosis in the USA and throughout the world. HCV may induce fibrogenesis directly by hepatic stellate cell activation or indirectly by promoting oxidative stress and apoptosis of infected cells. The ultimate result of chronic HCV injury is the accumulation of extracellular matrix with high density type I collagen within the subendothelial space of Disse, culminating in cirrhosis with hepatocellular dysfunction. The treatment of hepatitis C with the combination of pegylated interferon and ribavirin is still both problematic and costly, has suboptimal efficacy, serious side effects and a high level of intolerance, and is contraindicated in many patients. Hence, new approaches have assumed greater importance, for which there is an urgent need. The sustained progress in understanding the pathophysiology of hepatic fibrosis in the past two decades has increased the possibility of developing drugs specifically targeting the fibrogenic process. Future efforts should identify genetic markers associated with fibrosis risk in order to tailor the treatment of HCV infection based on genetically regulated pathways of injury and/or fibrosis. Such advances will expand the arsenal to overcome liver fibrosis, particularly in patients with hepatic diseases who have limited treatment options, such as those patients with chronic hepatitis C who have a high risk of fibrosis progression and recurrent HCV disease after liver transplantation.

Disease progression in Chinese chronic hepatitis C patients with persistently normal alanine aminotransaminase levels

BACKGROUND

Although chronic hepatitis C virus-infected patients with persistently normal alanine aminotransaminase levels usually have mild liver disease, disease progression can still occur. However, it is uncertain which group of patients is at risk of disease progression.

AIM

To examine the severity of liver disease on liver biopsy in Chinese patients with persistently normal alanine aminotransaminase levels, and their disease progression over time.

METHODS

Eighty-two patients with persistently normal alanine aminotransaminase levels were followed up longitudinally. The median time of follow-up was 8.1 years. Forty-seven of the 82 patients (57.3%) had a second liver biopsy.

RESULTS

At the time of analysis, six of the 82 patients (7.3%) developed decompensated liver cirrhosis. Patients with an initial fibrosis stage F2 or F3 [6/23 (26.1%) vs. 0/59 (0%), P < 0.0001] or inflammatory grade A2 or A3 [5/40 (12.5%) vs. 1/42 (2.4%), P = 0.04] were more likely to develop decompensated liver cirrhosis. On multivariate analysis, initial fibrosis stage F2 or F3 was independently associated with progression to decompensated liver cirrhosis (relative risk 2.3, 95% confidence interval 0.03-2.5, P = 0.02).

CONCLUSION

Chinese chronic hepatitis C virus patients with persistently normal alanine aminotransaminase levels with moderate to severe fibrosis at initial evaluation are more likely to develop decompensated liver cirrhosis.

A comparative review of HLA associations with hepatitis B and C viral infections across global populations

Hepatitis B (HBV) and hepatitis C (HCV) viral infection or co-infection leads to risk of development of chronic infection, cirrhosis and hepatocellular carcinoma (HCC). Immigration and globalization have added to the challenges of public health concerns regarding chronic HBV and HCV infections worldwide. The aim of this study is to review existing global literature across ethnic populations on HBV and HCV related human leukocyte antigen (HLA) associations in relation to susceptibility, viral persistence and treatment. Extensive literature search was conducted to explore the HLA associations in HBV and HCV infections reported across global populations over the past decade to understand the knowledge status, weaknesses and strengths of this information in different ethnic populations. HLA DR13 is consistently associated with HBV clearance globally. HLADRB1*11/*12 alleles and DQB1*0301 are associated with HBV persistence but with HCV clearance worldwide. Consistent association of DRB1*03 and *07 is observed with HCV susceptibility and non-responsiveness to HBV vaccination across the population. HLA DR13 is protective for vertical HBV and HCV transmission in Chinese and Italian neonates, but different alleles are associated with their susceptibility in these populations. HLA class I molecule interactions with Killer cell immunoglobulin like receptors (KIR) of natural killer (NK) cells modulate HCV infection outcome via regulating immune regulatory cells and molecules. HLA associations with HBV vaccination, interferon therapy in HBV and HCV, and with extra hepatic manifestations of viral hepatitis are also discussed. Systematic studies in compliance with global regulatory standards are required to identify the HLA specific viral epitope, stage specific T cell populations interacting with different HLA alleles during disease progression and viral clearance of chronic HBV or HCV infections among different ethnic populations. These studies would facilitate stage specific therapeutic strategies for clearance of HBV and HCV infections or co-infections across global populations and aid in identification of HBV-HCV combined vaccine. HLA associations of chronic HBV or HCV development with confounding host factors including alcohol, drug abuse, insulin resistance, age and gender are lacking and warrant detailed investigation across global populations.

Generic human leukocyte antigen class II (DRB1 and DQB1) alleles in patients with paracoccidioidomycosis

Human leukocyte antigen (HLA) class II alleles are involved in antigen processing and in the presentation of antigens to T lymphocytes. Few studies have investigated HLA genes in paracoccidioidomycosis. In the present investigation, we analyzed the distribution of the HLA class II alleles DRB1 and DQB1 in 45 healthy volunteers and in 80 patients with paracoccidioidomycosis. The patients presented with various clinical forms of the disease, and allele distribution was evaluated individually in each presentation type. In patients with the unifocal chronic form of the disease, a mild clinical presentation in which lesions are restricted or localized, the HLA allele most commonly seen was DRB1*11 (p<0.039). This suggests that the participation of HLA antigens may influence the outcome of the host-parasite interaction in paracoccidioidomycosis, regulating the immune response to Paracoccidioides brasiliensis antigens.

The changing epidemiology and natural history of hepatitis C virus infection

Injection drug use remains the predominant mode of transmission of hepatitis C virus (HCV) infection. Growing numbers of persons who have been chronically infected with HCV for 20 or more years are coming to medical attention and are at risk for serious complications of chronic infection, including cirrhosis and hepatocellular carcinoma. Factors linked with the development of advanced fibrosis and cirrhosis include age at infection, duration of infection, heavy alcohol use, coinfections with HIV or hepatitis B virus, and male sex. Emerging risk factors for disease progression include steatosis, insulin resistance (and factors associated with the metabolic syndrome), and host genetics.

Review article: management of patients with chronic hepatitis C virus infection and "normal" alanine aminotransferase activity

BACKGROUND

Hepatitis C virus infection, a major cause of chronic liver disease, occurs with normal serum alanine aminotransferase activity in approximately 25% of patients. These patients have historically remained untreated but substantial evidence indicates liver damage, progression of disease and impaired quality of life in some individuals.

AIM

To review the current management of patients with chronic hepatitis C and normal alanine aminotransferase activity.

METHODS

This review represents the summary of discussions at a Clinical Workshop with a comprehensive literature searching of available databases (PubMed and Embase).

RESULTS

Current limits defining normal serum alanine aminotransferase activity are not representative of a "healthy" status. Most patients with hepatitis C and normal alanine aminotransferase levels have histologically proven liver damage that, although generally mild, may be significant (> or =F2) in up to 20% of patients and progresses at approximately 50% of the rate in patients with elevated alanine aminotransferase levels. Some patients have persistently normal alanine aminotransferase activity and may have a more benign outcome, but a significant proportion (> or =20%) experience periods of increased serum alanine aminotransferase activity which may be associated with enhanced disease progression.

CONCLUSIONS

A treatment approach that considers host and virus-related variables and optimizes patient and cost benefits may therefore provide more effective management of patients with chronic hepatitis C and normal alanine aminotransferase activity.

Liver biopsy findings for HIV-infected patients with chronic hepatitis C and persistently normal levels of alanine aminotransferase

BACKGROUND

Severe liver fibrosis is common in patients coinfected with human immunodeficiency virus (HIV) and hepatitis C virus (HCV) who have a high alanine aminotransferase (ALT) level. However, little is known about the frequency, liver biopsy findings, and significance of a persistently normal ALT level in coinfected patients.

METHODS

We analyzed clinical data and histological findings for 256 patients coinfected with HIV and HCV, 24 (9.4%) of whom had an ALT level within the normal range on > or =2 separate occasions within a 6-month period.

RESULTS

The proportion of patients demonstrating advanced stages of fibrosis (F3 and F4) was 78 (33.7%) of 232 patients in the high ALT level group, compared with 0 (0%) of 24 patients in the persistently normal ALT level group (P<.001). Among patients with persistently normal ALT levels, 23 (96%) had any grade of fibrosis, and 7 (29%) had stage F2 of fibrosis. No differences were found between both groups with respect to age, sex, HIV transmission category, Centers for Disease Control and Prevention clinical category, CD4+ cell count (both nadir and baseline values), type of antiretroviral therapy, years since onset of HCV infection, alcohol use, or HCV load. However, the proportion of patients infected with HCV genotype 3 was significantly higher among patients with high ALT levels than in patients with persistently normal ALT levels (61 [26.9%] of 232 patients vs. 1 [4.2%] of 24 patients; P=.04).

CONCLUSIONS

Histological abnormalities are significantly milder in patients coinfected with HIV and HCV who have persistently normal ALT levels than those found in patients with high ALT levels. However, a subgroup of patients with persistently normal ALT levels may have significant cases of fibrosis. Liver biopsy may be recommendable in patients coinfected with HIV and HCV who have persistently normal ALT levels, to determine the extent of liver fibrosis and, consequently, to assess suitability for treatment.

The economics of treating chronic hepatitis C patients with peginterferon alpha-2a (40 kDa) plus ribavirin presenting with persistently normal aminotransferase

Peginterferon alpha-2a (40 kDa) plus ribavirin is effective at achieving sustained viral response compared with no treatment in patients with chronic hepatitis C (CHC) and persistently normal aminotransferase levels (PNALT). The cost-effectiveness of treating CHC in the setting of PNALT has not been assessed. Disease progression in patients with PNALT was simulated in a Markov model. The rate of fibrosis progression, quality of life and costs for each health state were based on literature estimates. The perspective of the Italian National Health Service was adopted and costs (euro 2003) and benefits were discounted at 3%. Sensitivity analyses were performed on important parameters. The primary analysis compared combination therapy with peginterferon alpha-2a (40 kDa) plus ribavirin to no treatment in a cohort of patients with mean age 45 years, and was based on findings from a multinational, randomized trial in patients with PNALT. In genotype 1 patients, the risk of cirrhosis at 30 years is forecast to fall from 32% with no treatment to 19% with combination therapy, increasing quality-adjusted life years (QALYs) by 0.74 years at an incremental cost per QALY gained of euro 16,831. The 30-year risk of cirrhosis in genotype 2 or 3 is projected to fall to 9% with combination therapy, an increase in QALYs of 1.34 years, at an incremental cost per QALY gained of euro 3,000. Thus treatment of PNALT with peginterferon alpha-2a (40 kDa) plus ribavirin is projected to reduce the incidence of cirrhosis, increase life expectancy and have an acceptable cost-effectiveness ratio from a societal perspective.

Human leukocyte antigen class II DQB1*0301, DRB1*1101 alleles and spontaneous clearance of hepatitis C virus infection: a meta-analysis

AIM

To assess the associations of human leukocyte antigen (HLA) class II DQB1*0301 and/or DRB1*1101 allele with spontaneous hepatitis C virus (HCV) clearance by meta-analysis of individual dataset from all studies published till date.

METHODS

To clarify the impact of HLA class II polymorphisms on viral clearance, we performed a meta-analysis of the published data from 11 studies comparing the frequencies of DQB1*0301 and DRB1*1101 alleles in individuals with spontaneous resolution to those with persistent infection. As we identified the heterogeneity between studies, summary statistical data were calculated based on a random-effect model.

RESULTS

Meta-analyses yielded summary estimates-odds ratio (OR) of 2.36 [95%CI (1.62, 3.43), P<0.00001] and 2.02 [95%CI (1.56, 2.62), P<0.00001] for the effects of DQB1*0301 and DRB1*1101 alleles on spontaneous clearance of HCV, respectively.

CONCLUSION

These results support the hypothesis that specific HLA class II alleles might influence the susceptibility or resistance to persistent HCV infection. Both DQB1*0301 and DRB1*1101 are protective alleles and present HCV epitopes more effectively to CD4(+)T lymphocytes than others, and subjects with these two alleles are at a lower risk of developing chronic HCV infection. Large, multi-ethnic confirmatory and well-designed studies are needed to determine the host genetic determinants of HCV infection.

Hepatitis C -- identifying patients with progressive liver injury

Hepatitis C follows a variable course with some patients developing progressive liver fibrosis, cirrhosis and hepatocellular carcinoma, while others have minimal or no significant liver disease after decades of infection. Studies have identified both host and viral factors associated with disease progression. The importance of general factors such as age at infection, gender, immune status and alcohol consumption has long been recognized; however recently, polymorphisms in a wide array of genes have also been shown to be associated with progressive fibrosis. How specific viral proteins may contribute to disease progression has also been studied. This review highlights what is currently known about the factors associated with progressive liver injury in patients with hepatitis C. A greater understanding of the determinants of disease progression will hopefully lead to improved utilization of existing treatments and ultimately may aid in identification of new therapeutic targets.

Hepatitis C virus-related hepatocellular carcinoma and B-cell lymphoma patients show a different profile of major histocompatibility complex class II alleles

Comparison of human leukocyte antigen (HLA) frequencies in patients with hepatitis C virus (HCV)-associated hepatocellular carcinoma (HCC) and in patients with HCV-associated non-Hodgkin's lymphoma (NHL) has not been addressed previously. To this aim, we investigated the distribution of HLA class II alleles in two selected groups of HCV-infected patients. Group 1 included 50 patients with HCV-associated NHL; group 2 included 29 patients with HCV-associated HCC. A control group included 144 hospitalized patients without NHL or HCC and who were negative for HCV, hepatitis B virus, and human immunodeficiency virus antibodies. Polymerase chain reaction sequence DRB1 and DQB1 specific-primer methods were used. DRB1*1101/DQB1*0301 haplotype, which mainly favors the spontaneous clearance of HCV infection, was lower in HCC subjects than in controls, whereas HLA-DRB1*1104/DQB1*0301, was higher in NHL patients. These findings suggest different pathogenic pathways in HCC and in NHL development. In patients with HCV-associated HCC, a major protective role of DQB1*0301 allele, rather than DRB1*11, was found, probably because of a better HLA class II-associated virus clearance. By contrast, the same allele as HLA-DRB1*04 showed an increase in HCV-associated NHL. These data suggest that NHL and HCC development may be associated to a different response with respect to chronic HLA class II-restricted antigen presentation (perhaps a switch toward CD4+Th2 response in NHL?) or, alternatively, that these alleles could be in linkage disequilibrium to unrelated gene(s), or are in synergy with other immunomodulatory genes that may confer increased risk for NHL.

Characteristic sequence changes of hepatitis C virus genotype 2b associated with sustained biochemical response to IFN therapy

In hepatitis C virus (HCV) genotype 2b infection, viral eradication (sustained viral response; sVR) is obtained in about 40% by interferon monotherapy, whereas a considerable proportion of non-sVR patients exhibit sustained biochemical response (sBR) showing normal biochemical values despite persistent viraemia. However, the mechanism of sBR has not yet been established. In this study, we analysed serial changes in full-length sequences of HCV genotype 2b before and after interferon (IFN) therapy in five patients with sBR and five with no response (NR; persistent viraemia and abnormal biochemical values after IFN therapy). The overall substitution rate of amino acids in the full-length HCV genome was higher in the sBR group than in the NR group [2.22 +/- 0.48 (10(-3) changes/site/year) vs 1.04 +/- 0.30: P = 0.002]. When the genetic changes were analysed for individual HCV proteins, the sBR group had significantly higher substitution rates of amino acid in NS4A [8.82 +/- 2.80 (10(-3) changes/site/year) vs 0: P = 0.001]. These amino acid changes in sBR were mainly located in the binding motifs of HLA class I molecules including those frequently found in the Japanese population. These results demonstrated that the greater amino acid changes of HCV arising during interferon therapy are associated with the establishment of sBR. Although functional significance of these changes awaits further investigation, the finding that amino acid changes in NS4A in sBR patients are mainly located in the HLA class I binding motifs illustrated the potential roles of the escape mutations of HCV genome from CTLs in the decreasing activities of hepatitis in sBR.

Liver Function Tests

Liver diseases are common, and currently represent the 12th leading cause of death in the United States. However, numerous hepatic disorders exist, and differential diagnosis often is difficult. Moreover, because laboratory testing is routine, an abnormal serum transaminase or alkaline phosphatase in patients without clinical symptoms is not uncommon. Although liver function tests are critical in recognizing the presence of liver disease and its specific diagnosis, the interpretation of the tests may be confusing and difficult. Furthermore, not all persons with one or more test abnormalities actually have liver disease. In this review, liver function tests and an approach to their interpretation are discussed.

Host genetic determinants in hepatitis C virus infection

In addition to viral and environmental/behavioural factors, host genetic diversity is believed to contribute to the spectrum of clinical outcomes in hepatitis C virus (HCV) infection. This paper reviews the literature with respect to studies of host genetic determinants of HCV outcome and attempts to highlight trends and synthesise findings. With respect to the susceptibility to HCV infection, several studies have replicated associations of the HLA class II alleles DQB1(*)0301 and DRB1(*)11 with self-limiting infection predominantly in Caucasian populations. Meta-analyses yielded summary estimates of 3.0 (95% CI: 1.8-4.8) and 2.5 (95% CI: 1.7-3.7) for the effects of DQB1(*)0301 and DRB1(*)11 on self-limiting HCV, respectively. Studies of genetics and the response to interferon-based therapies have largely concerned single-nucleotide polymorphisms and have been inconsistent. Regarding studies of genetics and the progression of HCV-related disease, there is a trend with DRB1(*)11 alleles and less severe disease. Studies of extrahepatic manifestations of chronic HCV have shown an association between DQB1(*)11 and DR3 with the formation of cryoglobulins. Some important initial observations have been made with respect to genetic determinants of HCV outcome. Replication studies are needed for many of these associations, as well as biological data on the function of many of these polymorphisms.

Impact of antiretroviral treatment on progression of hepatic fibrosis in HIV/hepatitis C virus co-infected patients

BACKGROUND

The impact of immune reconstitution on liver fibrosis in HIV/hepatitis C virus (HCV) patients is unknown. In this case-control study, we investigated the impact of HIV infection on the severity of liver fibrosis and identified related factors.

METHODS

We studied 116 HIV/HCV patients and 235 HCV only patients all untreated for HCV. Each co-infected patient was matched with two singly-infected patients according to gender, age at contamination and duration of infection. Liver biopsy was analysed using the METAVIR score.

RESULTS

Alcohol consumption and route of contamination differed between HCV-infected and HCV/HIV co-infected patients. Among co-infected patients, a F3-F4 Metavir score was significantly more frequent than in mono-infected patients. Co-infected patients with severe fibrosis (F3-F4) had higher transaminase, ferritin levels and lower CD4 T-cell count than patients with none to moderate fibrosis (F0-F2). Although median duration of treatment with nucleoside analogues, non-nucleoside analogues and protease inhibitors were comparable in both groups, the delay between the presumed date of contamination and treatment initiation with highly active antiretroviral therapy (HAART) was significantly longer for patients with severe fibrosis than those with none to moderate fibrosis. Finally, the mean rate of fibrosis progression was significantly slower among patients exposed to HAART.

CONCLUSION

Early antiretroviral therapy in co-infected HIV-HCV patients may slow liver fibrosis progression.

Factors influencing the rate of fibrosis progression in chronic hepatitis C

Alcohol consumption, age at infection, and male gender have been identified as risk factors for faster fibrosis progression in patients with chronic hepatitis C (CHC). Yet the influence of liver steatosis, light to moderate alcohol consumption, or iron overload on this progression remains controversial. To analyze the effect of individual risk factors and their interaction on fibrosis progression in a group of patients with CHC and a definite date of infection, we studied 133 consecutive untreated patients. Covariates included were age, body mass index (BMI), gender, age at infection, alcohol intake, serum lipids, glycemia, serum ALT, AST, GGT, iron, and ferritin, grade and stage (METAVIR and Scheuer), and hepatic stainable iron (Perl's stain). The rate of fibrosis progression was inferred from the METAVIR score. By logistic regression analysis, hepatic steatosis (odds ratio [OR], 3.035; 95% confidence interval [CI], 1.16-7.93), serum ferritin levels higher than 290 ng/ml (OR, 5.5; 1.6-18.65), and light to moderate ethanol intake (1-50 g/day) (OR, 5.22; 1.5-17.67) were independently associated with faster fibrosis progression. There was no effect of interaction between these variables on the rate of fibrosis progression. Liver steatosis, serum ferritin levels, and light to moderate alcohol intake are associated with faster fibrosis progression in chronic hepatitis C. Combination of these factors did not further accelerate this progression. The impact of modification of these factors on progression should be tested in longitudinal studies.

Natural history of initially mild chronic hepatitis C

The hepatitis C virus is a leading cause of chronic liver disease, cirrhosis and hepatocellular carcinoma in western countries. Chronic hepatitis C is highly heterogeneous and many patients present with a mild form of liver disease. Population-based studies have indeed demonstrated that around 50% of hepatitis C virus carriers have persistently normal ALT and two-third have mild histological liver lesions. Studies on the natural history of initially mild chronic disease indicate that the short-term outcome is always benign. However, progression of liver fibrosis can be observed at long-term (>5-7 years) follow-up, particularly in those cases who have elevated and/or fluctuating transaminase levels. Observational prospective studies and outcome modelling projections indicate that the risk of liver disease progression towards severe fibrosis/cirrhosis is minimal at 10-15 years in hepatitis C virus carriers with persistently normal ALT, around 5-10% in patients with elevated ALT and F0 (no fibrosis) in the initial biopsy but >30-40% in chronic carriers with elevated ALT and F1 (portal fibrosis) in the initial biopsy. Cofactors like age at infection, alcohol, coinfections and liver steatosis accelerate disease progression. On the basis of these findings, patients with initially mild chronic hepatitis C and elevated ALT should be proposed for antiviral therapy in the absence of contraindications.

Distribution of the HLA class I allele in chronic hepatitis C and its association with serum ALT level in chronic hepatitis C

An essential process for resolution of viral infections is the efficient recognition and elimination of intracellular virus. Recognition of viral antigens in the form of short peptides associated with HLA class I molecule is a major task of CD8+ cytotoxic T lymphocytes. In this study, we have evaluated the frequency of the HLA class I alleles in patients with chronic hepatitis C. HLA-B51, -B52, -B55, -B56, -B61, B70, -Cw1, -Cw3, and -Cw4 are less frequent in patients with chronic hepatitis C than in Japanese individuals. The frequency of HLA-A2 is slightly lower in the patients but tends to be higher in patients with normal alanine aminotransferase (ALT) level than in those with elevated ALT level (p = 0.07). Other HLA alleles are not significantly different between two groups. Comparison of HLA homozygosity at HLA-A and -B or -C or at two or three loci did not show a significant association with levels of serum ALT or with the clinical outcome of interferon therapy in patients with hepatitis C. These results suggest a possibility that the alterations of host response, which depends on genetic background, influence disease activities of HCV infection.

Persistence of hepatitis C virus in a white population: Associations with human leukocyte antigen class 1

The aim of this study was to define novel associations between human leukocyte antigen (HLA) class 1 alleles and persistence or clearance of the hepatitis C virus (HCV) in a white population. All individuals in the study were seropositive for anti-HCV antibodies. Viral status was determined by the Roche HCV Amplicor test. HLA-A, -B, -C allelic group profile was molecularly defined by reverse line probe hybridization. The strongest individual allelic group associations with persistent HCV infection were HLA A*11 (p = 0.044) and Cw*04 (p = 0.006). However, only the HLA C*04 association survived correction for multiple comparisons. Further analysis of alleles in linkage with HLA Cw*04 revealed that the haplotype HLA A*11, Cw*04 was present in 11 individuals, 10 of whom were viremic (p = 0.05). No gene dosage effect was observed. No association between HLA class 1 allelic groups and aviremia and virus load was evident in this white population. HLA B*44 is associated with low virus load in human immunodeficiency virus disease, but this association was not evident in this HCV-infected population. Novel HLA class 1 alleles associated with persistence of HCV have been identified.

The influence of the human genome on chronic viral hepatitis outcome

The mechanisms that determine viral clearance or viral persistence in chronic viral hepatitis have yet to be identified. Recent advances in molecular genetics have permitted the detection of variations in immune response, often associated with polymorphism in the human genome. Differences in host susceptibility to infectious disease and disease severity cannot be attributed solely to the virulence of microbial agents. Several recent advances concerning the influence of human genes in chronic viral hepatitis B and C are discussed in this article: a) the associations between human leukocyte antigen polymorphism and viral hepatic disease susceptibility or resistance; b) protective alleles influencing hepatitis B virus (HBV) and hepatitis C virus (HCV) evolution; c) prejudicial alleles influencing HBV and HCV; d) candidate genes associated with HBV and HCV evolution; d) other genetic factors that may contribute to chronic hepatitis C evolution (genes influencing hepatic stellate cells, TGF-beta1 and TNF-alpha production, hepatic iron deposits and angiotensin II production, among others). Recent discoveries regarding genetic associations with chronic viral hepatitis may provide clues to understanding the development of end-stage complications such as cirrhosis or hepatocellular carcinoma. In the near future, analysis of the human genome will allow the elucidation of both the natural course of viral hepatitis and its response to therapy.

Screening of NS5ATP1 interacting proteins in leukocytes by yeast-two hybrid technique

AIM: To investigate the biological function of NS5ATP1 and to screen proteins in leukocytes interacting with NS5ATP1 by yeast-two hybrid.

METHODS: The NS5ATP1 gene was amplified by polymerase chain reaction (PCR) and NS5ATP1 bait plasmid was constructed by using yeast-two hybrid system 3, then the constructed vector was transformed into yeast AH109. The transformed yeast mated with yeast Y187 containing leukocytes cDNA library plasmid in 2×YPDA medium. Diploid yeast was plated on synthetic dropout nutrient medium (SD/-Trp-Leu-His-Ade) and synthetic dropout nutrient medium (SD/-Trp-Leu-His-Ade) containing x--gal for selecting two times and screening. After extracting and sequencing of plasmid from blue colonies, the results were analyzed by bioinformatics.

RESULTS: Ten colonies were sequenced, among which two colonies were human HLA-B27 mRNA, two homo sapiens arsA arsenite transporter, ATP-binding, homolog 1(bacterial) (ASNA1) gene, one homo sapiens haplotype E22i mitochondrion, one homo sapiens pyrin (MEFV) gene, one homo sapiens cofilin 1, one homo sapiens chromosome 15, one s homo sapiens chromosome 17, clone RP11-353N14, and one new gene.

CONCLUSION: Genes of NS5ATP1 interacting proteins in leukocytes are successfully cloned and the results bring some new clues for studying the biological functions of NS5ATP1 and associated proteins.

Impact of human immunodeficiency virus (HIV) infection on the progression of liver fibrosis in hepatitis C virus infected patients

OBJECTIVES

To compare the rate of hepatic fibrosis progression in hepatitis C virus (HCV) infected and human immunodeficiency virus (HIV)-HCV coinfected patients, and to identify factors that may influence fibrosis progression.

PATIENTS AND METHODS

A total of 153 HCV infected and 55 HCV-HIV coinfected patients were identified from two London hospitals. Eligible patients had known dates of HCV acquisition, were HCV-RNA positive, and had undergone a liver biopsy, which was graded using the Ishak score. Univariate and multivariate logistic regression analyses were used to identify factors associated with fibrosis progression rate and the development of advanced fibrosis (stages 3 and 4).

RESULTS

The estimated median fibrosis progression rate was 0.17 units/year (interquartile range (IQR) 0.10-0.25) in HIV-HCV coinfected and 0.13 (IQR 0.07-0.17) in HCV monoinfected patients (p=0.01), equating to an estimated time from HCV infection to cirrhosis of 23 and 32 years, respectively. Older age at infection (p<0.001), HIV positivity (p=0.019), higher alanine aminotransferase (ALT) level (p=0.039), and higher inflammatory activity (p<0.001) on first biopsy were all independently associated with more rapid fibrosis progression. ALT was correlated with histological index (r=0.35, p<0.001). A CD4 cell count < or =250 x 10(6)/l was independently associated with advanced liver fibrosis (odds ratio 5.36 (95% confidence interval 1.26-22.79)) and was also correlated with a higher histological index (r=-0.42, p=0.002).

CONCLUSION

HIV infection modifies the natural history of HCV by accelerating the rate of fibrosis progression by 1.4 fold, and the development of advanced fibrosis threefold. A low CD4 cell count was independently associated with advanced disease and correlated with higher histological index, which suggests that early antiretroviral therapy may be of benefit in slowing HCV progression in coinfected patients.