Elevated Serum Levels of Interferon‐γ–Inducible Protein–10 in Patients Coinfected with Hepatitis C Virus and HIV

Coinfection with hepatitis C virus (HCV) and human immunodeficiency virus (HIV) is associated with an accelerated course of HCV infection and a faster progression to severe liver disease. We have investigated whether the development of liver disease in coinfected patients is associated with specific chemokine and cytokine production. Four cohorts--HCV/HIV-coinfected patients, HCV-monoinfected patients, HIV-monoinfected patients, and healthy control subjects--were studied. Serum levels of the 10-kDa interferon- gamma -inducible protein (IP-10) were higher in all 3 groups of infected patients than in control subjects (P<.0001). HCV/HIV-coinfected patients had significantly higher IP-10 levels than monoinfected patients. In HCV-monoinfected patients, liver fibrosis scores and liver enzyme levels were positively correlated with IP-10 levels. Elevated IP-10 levels are associated with and may contribute to liver damage in both HCV-monoinfected and HCV/HIV-coinfected patients.

Hepatitis C (chronic)

INTRODUCTION

60-85% of people infected with hepatitis C virus will go on to develop chronic hepatitis C, which is now believed to affect 3% of the world's population.

METHODS AND OUTCOMES

We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of interventions in treatment-naïve people with chronic infection, but without liver decompensation? What are the effects of interventions in people with chronic infection, but without liver decompensation, who have not responded to interferon treatment? What are the effects of interventions in people with chronic infection, but without liver decompensation, who relapse after interferon treatment? What are the effects of interventions in people with chronic hepatitis C infection, who also have HIV? We searched: Medline, Embase, The Cochrane Library and other important databases up to May 2006 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).

RESULTS

We found 24 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.

CONCLUSIONS

In this systematic review we present information relating to the effectiveness and safety of the following interventions: interferon monotherapy, interferon alfa plus ribavirin, and peginterferon monotherapy or with ribavirin.

Hereditary hemochromatosis should be considered a conformational disorder

Hereditary hemochromatosis (HH) is a genetic disease associated with iron overload, in which individuals homozygous for the mutant C282Y HFE associated allele are at risk of developing liver disease, diabetes and arthritis. Conformational diseases are a class of disorders associated with the expression of misfolded protein and examples include conditions such as Alzheimer's, Parkinson's, Z alpha 1-antitrypsin deficiency and Huntington's diseases. HFE C282Y is a mutant protein that does not fold correctly forming aggregates and is retained in the Endoplasmic Reticulum (ER). Consequently, we propose that HH associated with the C282Y HFE mutation should be considered a conformational disorder.

Expression of hereditary hemochromatosis C282Y HFE protein in HEK293 cells activates specific endoplasmic reticulum stress responses

BACKGROUND

Hereditary Hemochromatosis (HH) is a genetic disease associated with iron overload, in which individuals homozygous for the mutant C282Y HFE associated allele are at risk for the development of a range of disorders particularly liver disease. Conformational diseases are a class of disorders associated with the expression of misfolded protein. HFE C282Y is a mutant protein that does not fold correctly and consequently is retained in the Endoplasmic Reticulum (ER). In this context, we sought to identify ER stress signals associated with mutant C282Y HFE protein expression, which may have a role in the molecular pathogenesis of HH.

RESULTS

Vector constructs of Wild type HFE and Mutant C282Y HFE were made and transfected into HEK293 cell lines. We have shown that expression of C282Y HFE protein triggers both an unfolded protein response (UPR), as revealed by the increased GRP78, ATF6 and CHOP expression, and an ER overload response (EOR), as indicated by NF-kappaB activation. Furthermore, C282Y HFE protein induced apoptotic responses associated with activation of ER stress. Inhibition studies demonstrated that tauroursodeoxycholic acid, an endogenous bile acid, downregulates these events. Finally, we found that the co-existence of both C282Y HFE and Z alpha 1-antitrypsin protein (the protein associated with the liver disease of Z alpha 1-antitrypsin deficiency) expression on ER stress responses acted as potential disease modifiers with respect to each other.

CONCLUSION

Our novel observations suggest that both the ER overload response (EOR) and the unfolded protein response (UPR) are activated by mutant C282Y HFE protein.

Hepatitis B (prevention)

INTRODUCTION

Nearly a third of the world's population has been infected by hepatitis B at some point, and at least 350 million people have become chronic carriers. Progressive liver damage occurs in up to 25% of carriers. In areas of high endemicity, transmission occurs largely in childhood, from an infected mother to her baby, or between members of a household.

METHODS AND OUTCOMES

We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of vaccination against hepatitis B infection in countries with high endemicity; and in countries with low endemicity? We searched: Medline, Embase, The Cochrane Library and other important databases up to November 2006 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).

RESULTS

We found 46 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.

CONCLUSIONS

In this systematic review we present information relating to the effectiveness and safety of the following interventions: selective vaccination of high-risk individuals; selective vaccination of people with chronic liver disease not caused by hepatitis B; universal vaccination of adolescents; universal vaccination of infants.

The impact of inherited prothrombotic risk factors on individuals chronically infected with hepatitis C virus from a single source

Intrahepatic thrombotic events have been postulated to play a key role in the pathogenesis of hepatic fibrosis. Genetic and acquired thrombotic risk factors may therefore contribute to the varying rates of fibrosis progression observed in patients with chronic hepatitis C virus (HCV) infection. The aim of this study was to assess the impact of inherited mutations in factor V and factor II (prothrombin) on hepatic fibrosis progression rates in individuals infected with HCV. Two hundred and ten Irish women infected with HCV genotype 1b, contracted from a single source (HCV-contaminated anti-D immunoglobulin) were genotyped for the factor V Leiden G1691A and prothrombin G20210A polymorphisms, and compared with Irish Caucasoid controls. Index and subsequent liver biopsies were scored (Ishak scoring system) by a single pathologist. Statistical analysis was performed using SPSS. Factor V Leiden and prothrombin G20210A heterozygosity were determined in 3.7% and 1.85%, respectively, of the study population. There was no association between these polymorphisms and fibrotic score on the index biopsy, or degree of change in fibrotic score on subsequent biopsies. The mean fibrotic score for factor V wild type was 1.06 vs 0.71 for the heterozygotes (P = 0.89). The mean change in fibrotic scores between subsequent biopsies was 0.72 for factor V wild type vs 0.50 for heterozygotes (P = 0.68). Similarly, there was no significant difference in fibrotic score for those with the prothrombin G20210A polymorphism (P = 0.936). Alanine aminotransferase levels for factor V wild type were significantly lower than those for the heterozygotes, 45.9 vs 57 (P = 0.032). Factor V Leiden and prothrombin G20210A heterozygosity rates were infrequently detected in this HCV cohort and were similar to rates seen in a Caucasian Irish control population. In this cohort, neither factor V Leiden nor prothrombin G20210A polymorphisms had a significant impact on fibrotic scores or degree of change between subsequent biopsies. These data do not support a key role for thrombotic risk factors in fibrogenesis in HCV-infected patients.

Development of in vitro correlate assays of immunity to infection with Yersinia pestis

Pneumonic plague is a severe, rapidly progressing disease for which there is no effective vaccine. Since the efficacy of new vaccines cannot be tested in humans, it is essential to develop in vitro surrogate assays that are valid predictors of immunity. The F1 capsule antigen stimulates a protective immune response to most strains of Yersinia pestis. However, strains of Y. pestis that are F1- but still virulent have been isolated, and an in vitro assay, the results which can predict protection against both F1+ and F1- strains, is needed. The virulence antigen (V) is an essential virulence factor of Y. pestis and stimulates protective antibodies. We investigated potential correlates of plague immunity that are based on anti-V antibody-mediated neutralization of Yersinia-induced macrophage cytotoxicity. The neutralizing activity of sera from mice vaccinated with an F1-V fusion candidate vaccine was determined. The decrease in the level of the apoptosis-specific enzyme caspase-3 significantly predicted survival in one- and two-dose vaccination experiments. Sera from F1-V-vaccinated nonhuman primates were evaluated with macrophage assays based on caspase-3 and on other markers manifested at the different stages in cell death. Using murine- and human-derived macrophages in microscopic and fluorescence-activated-cell-sorting-based live/dead staining assays of terminal necrosis, we demonstrated a strong association between in vitro neutralization of macrophage cytotoxicity induced by serum-treated Yersinia and in vivo protection against lethal infection. These results provide a strong base for the development of reliable in vitro correlate bioassays that are predictive of protective immunity to plague.

The impact of diabetes mellitus on fibrosis progression in patients transplanted for hepatitis C

Despite the recognition of numerous factors for aggressive hepatitis C virus (HCV) recurrence after liver transplantation (LT) our understanding of this phenomenon is incomplete. We tested the hypothesis that diabetes mellitus (DM) was implicated. One hundred sixty-three patients undergoing primary LT for HCV from 1990 to 2004 were evaluated and biopsies were scored according to the modified Ishak score. Severe recurrence of HCV was defined as a fibrosis score > or = 4 within 6 years of LT. Risk factors assessed included recipient, donor and transplant variables. Fifty-four patients (33.1%) had a fibrosis score > or = 4 at the end of the study period. Factors associated with progression to severe fibrosis was donor age (p = 0.008) especially donor age >55 (p = 0.038, HR 2.43), pre-LT DM (p = 0.039, HR 2.68) and DM post-LT (p = 0.004, HR 3.28). The combination of receiving a liver from a donor older than 55 years and having DM post-LT was associated with an 8.38-fold risk of progression to severe fibrosis (p = 0.000124) when compared to patients not diabetic post-LT who received livers from donors aged <55 years. These data indicate that diabetic status is one of the more important variables determining the severity of HCV recurrence and is synergistic with donor age. This observation may provide an additional management opportunity to modify the impact of HCV recurrence.

HLA class I allelic diversity and progression of fibrosis in patients with chronic hepatitis C

Patients infected with HIV-1 who are heterozygous at HLA class I loci present greater variety of antigenic peptides to CD8+ cytotoxic T lymphocytes, slowing progression to AIDS. A similar broad immune response in chronic hepatitis C (CHC) infection could result in greater hepatic injury. Although specific HLA class II alleles may influence outcome in CHC patients, the role of HLA class I heterogeneity is generally less clearly defined. Our aims were to determine whether HLA class I allelic diversity is associated with disease severity and progression of fibrosis in CHC. The study population consisted of 670 adults with CHC, including 155 with advanced cirrhosis, and 237 non-HCV-infected controls. Serological testing for HLA class I antigens was performed via microlymphocytotoxicity assay. Peptide expression was defined as heterozygous (i.e., a different allele at each locus) or homozygous. Fibrosis staging was determined using METAVIR classification. Heterozygosity at the B locus (fibrosis progression rate [FPR] 0.08 vs. 0.06 units/yr; P = .04) and homozygosity at the A locus (FPR 0.10 vs. 0.08 units/yr; P = .04) predicted a higher median FPR. Age at infection, genotype, and duration of infection were also predictors of FPR. A higher proportion of patients with stage F2-F4 expressed HLA-B18 compared with controls (OR 2.2, 95% CI 1.17-4.23; P = .02). These differences were not observed in patients with advanced cirrhosis. HLA zygosity at 1, 2, or 3 alleles was not associated with fibrosis stage, liver inflammation, or treatment outcome. In conclusion, HLA class I allelic diversity has a minor influence on FPRs and disease severity in CHC.

Liver transplantation for HCV-related cirrhosis in a patient with gastric mucosa-associated lymphoma (MALToma) pretreated with rituximab

End-stage liver disease due to chronic hepatitis C virus (HCV) infection is now the most frequent indication for liver transplantation. HCV infection is associated with extrahepatic disease including cryoglobulinemia and lymphoma. The number of patients requiring liver transplantation (LT) for cirrhosis secondary to HCV infection has increased over the past 10 years; consequently, associated extrahepatic manifestations (in particular hematological malignancies) will be more commonly observed in this patient group. The management of patients with both end-stage liver disease and significant HCV-related extrahepatic disease is undefined. We report a 59-year-old man in whom extranodal marginal-zone B-cell lymphoma arising in gastric mucosa-associated lymphoid tissue (MALToma) was successfully eradicated by rituximab administration and gastrectomy at LT for HCV-related cirrhosis. Our experience with rituximab in this patient suggests that it can be used safely in the setting of severe liver disease due to HCV infection. Rituximab may be useful in preventing progression of NHL until surgical extirpation is possible.

Development of a reliable and valid nutritional knowledge questionnaire for urban South African adolescents

OBJECTIVES

We wanted to develop a valid and reliable nutritional knowledge test for urban South African adolescents who were participating in the Birth-to-Twenty cohort study. The questionnaire was intended for use every second year, from ages 13 to 14 y until age 20 y.

METHODS

The initial steps involved the development of a conceptual framework and identification of nutritional concepts in collaboration with nutritional experts, and this defined the construct of the questionnaire. The South African national teaching curriculum objectives for nutritional education and other relevant issues were selected as the desired concepts, and most items were phrased in accordance with the recently developed South African Food-Based Dietary Guidelines. Thereafter, 140 items (questions) were developed and in turn assessed by an expert panel, and the result was that only 88 items remained. This was done to ensure content and face validity of the items. The 88 items were constructed into a questionnaire and piloted for appropriateness and understanding by adolescents, ages 13 to 14 y, as a means of assessing face validity by non-experts. The edited preliminary questionnaire (still with 88 items) was administered to a nutrition expert group (n = 71) versus a non-expert group (n = 82), referred to as sample 1, for the purposes of performing item analysis and assessing construct validity of the questionnaire. The result of the analysis, a 63-item questionnaire, was administered to adolescents at three school grade levels, 8 (n = 128), 10 (n = 143), and 12 (n = 98), referred to as sample 2, which was representative of the grades in which the Birth-to-Twenty group will be in when the questionnaire is administered. The questionnaire was administered to the sample to assess its content validity and internal consistency reliability. The final questionnaire had 60 items, and its construct, content, and internal consistency reliability were reassessed.

RESULTS

The final 60-item questionnaire displayed a significant difference (P < 0.0001) in the mean scores of the expert and non-expert groups tested. It had internal consistencies (Cronbach's alpha) of 0.71, 0.79, and 0.82 for grades 8, 10, and 12 respectively, and an overall value of 0.77 for all groups combined. However, it was less than 0.7 for most grade 8 pupils and for all grades at a historically disadvantaged school.

CONCLUSION

A nutritional knowledge questionnaire with construct, face, and content validities and internal consistency was developed for use in South African adolescents to evaluate their nutritional knowledge. Internal consistency was low in children at a disadvantaged school and those in grade 8 compared with multiracial groups at a multiracial school. It is recommended that pupils at disadvantaged schools be assisted by trained interviewers when taking the test.

Distinct subpopulations of gamma delta T cells are present in normal and tumor-bearing human liver

Gamma delta T cells are thought to mediate immune responses at epithelial surfaces. We have quantified and characterized hepatic and peripheral blood gamma delta T cells from 11 normal and 13 unresolved tumor-bearing human liver specimens. gamma delta T cells are enriched in normal liver (6.6% of T cells) relative to matched blood (0.9%; P = 0.008). The majority express CD4(-)CD8(-) phenotypes and many express CD56 and/or CD161. In vitro, hepatic gamma delta T cells can be induced to kill tumor cell lines and release interferon-gamma, tumor necrosis factor-alpha, interleukin-2 and interleukin-4. Analysis of V gamma and V delta chain usage indicated that V delta 3(+) cells are expanded in normal livers (21.2% of gamma delta T cells) compared to blood (0.5%; P = 0.001). Tumor-bearing livers had significant expansions and depletions of gamma delta T cell subsets but normal cytolytic activity. This study identifies novel populations of liver T cells that may play a role in immunity against tumors.

Outcomes of liver transplantation in HIV-infected individuals: the impact of HCV and HBV infection

Liver transplantation (LT) in human immunodeficiency virus (HIV)-positive individuals is considered to be an experimental therapy with limited reported worldwide experience, and little long-term survival data. Published data suggest that the short-term outcome is encouraging in selected patients. Here, we report our experience in 14 HIV-infected liver allograft recipients, and compare outcomes between those coinfected with hepatitis C virus (HCV) and the non-HCV group. A total of 14 HIV-infected patients (12 male, 2 female, age range 26-59 years) underwent LT between January 1995 and April 2003. Indications for LT were HCV (n = 7), hepatitis B virus (HBV; n = 4), alcohol-induced liver disease (n = 2), and seronegative hepatitis (n = 1); 3 patients presented with acute liver failure. At LT, CD4 cell counts (T-helper cells that are targets for HIV) ranged from 124 to 500 cells/microL (mean 264), and HIV viral loads from <50 to 197,000 copies/mL. Nine of 12 patients were exposed to highly active antiretroviral therapy (HAART) before LT. In the non-HCV group (n = 7), all patients are alive, all surviving more than 365 days (range 668-2,661 days). No patient has experienced HBV recurrence, and graft function is normal in all 7 patients. However, 5 of 7 HCV-infected patients died after LT at 95-784 days (median 161 days). A total of 4 patients died of complications due to recurrent HCV infection and sepsis, despite antiviral therapy in 3 of them. A total of 3 patients experienced complications relating to HAART therapy. In conclusion, outcome of LT in HIV-infected patients with HBV or other causes of chronic liver disease indicates that LT is an acceptable therapeutic option in selected patients. However, longer follow-up in larger series is required before a conclusive directive can be provided for HCV / HIV coinfected patients requiring LT.

Mitochondrial toxicity associated with HAART following liver transplantation in an HIV-infected recipient

Antiretroviral therapy is not uncommonly associated with drug toxicities, and hepatotoxicity occurs in approximately 20% of individuals prescribed antiretroviral therapy. Mitochondrial toxicity causing lactic acidosis is a rare but fatal complication that has been described in some HIV-infected patients treated with nucleoside analogue reverse transcriptase inhibitors. In this report, we describe the course of an HIV-infected patient receiving antiretroviral therapy who developed lactic acidosis after liver transplantation for HCV-induced liver disease.

Hepatitis B virus genotype A and D and clinical outcomes of liver transplantation for HBV-related disease

Hepatitis B virus (HBV) genotypes have been associated with specific patterns of disease and response to antiviral therapy. We investigated the effect of HBV genotype on HBV recurrence and mortality after liver transplantation (LT). Pretransplant sera of 45 hepatitis B surface antigen (HBsAg) positive adults were submitted for HBV genotyping by a reverse-phase hybridization line probe assay with genotype-specific probes. Data were correlated with clinical outcomes after transplantation. Genotype A (n =15), D (n = 13) and A/D (n = 12) accounted for 89% of all genotypes. Coinfection with two HBV genotypes was encountered in 14 (31.1%) patients. Eighteen patients (40 %) developed HBV recurrence at a median of 10 months posttransplant (range, 1-53) and 10 patients (22 %) died at a median of 24 months (range, 3-63). Genotype D patients were more likely to develop HBV recurrence or die compared with genotype A patients, although this did not reach statistical significance. Dual infection with genotype A/D resulted in mortality similar to that of genotype A but recurrence similar to that of genotype D. Active viral replication at time of transplantation was the only independent factor (P = 0.03) that predicted HBV recurrence. In conclusion, HBV genotype A and D did not have a significant impact on clinical outcomes of LT for HBV-related liver disease in patients of European origin. These data do not support routine HBV genotyping in liver transplantation.

Localization of T and B lymphocytes in histologically normal adult human donor liver

BACKGROUND/AIMS

Donor liver suitable for successful transplantation often has one or more of a range of mild abnormalities including inflammation. Passenger leukocytes documented in donor liver are thought to result from inflammatory stimuli in response to ischemic, drug or alcohol related damage. The aim was to identify donor livers, which were free of any evidence of damage, and to determine if, and where, leukocytes were present in these pristine livers.

METHODOLOGY

Eight of eighteen donor livers, examined by hematoxylin and eosin staining, were found to be free of any evidence of pathological damage. Sections from these livers were stained with antibodies against CD3 (T cell marker), CD20 (B cell marker) and CD45 (common leukocyte antigen).

RESULTS

Each of these livers were found to have significant numbers of T lymphocytes, located mainly in the portal tracts but also scattered throughout the parenchyma. A similar distribution of B cells was detected but at much lower levels.

CONCLUSIONS

The presence of lymphocytes in the human liver is usually considered a hallmark of pathology. The demonstration of significant lymphocyte populations in pristine liver, particularly in the parenchyma, supports the hypothesis that the human liver harbors tissue-resident lymphocytes.

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.