The transforming growth factor-beta high-producer genotype is associated with response to hepatitis C virus-specific therapy in HIV-positive patients with acute hepatitis C

Lack of association between single-nucleotide polymorphisms of pro- and anti-inflammatory cytokines and HTLV-1-associated myelopathy / tropical spastic paraparesis development in patients from Rio de Janeiro, Brazil

Background

HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a progressive neurological and inflammatory disease, associated with HTLV-1 infection. HAM/TSP neurological disease is a consequence of an inflammatory reaction, and adaptive immune responses, through the secretion of anti-inflammatory and pro-inflammatory cytokines, play an important role in the outcome of infection and disease progression. Studies addressing the association between cytokines functional single nucleotide polymorphisms and HAM/TSP development are scarce.

Methods

The genetic polymorphisms of cytokine genes were evaluated in HAM/TSP patients (n = 68) and in asymptomatic HTLV-1 positive carriers (n = 83) from Rio de Janeiro, Brazil, in a case-control study. HTLV-1 infected patients were genotyped for SNPs in five cytokine genes: TNFA-308G/A, IL6-174G/C, IFNG + 874 T/A, TGFB at the codons + 10 T/C and + 25G/C, IL10-592C/A and -819C/T, and -1082A/G and proviral load (PVL) was quantified. Associations between genotypes, haplotypes, clinical outcome and pro viral load were evaluated.

Results

Lack of association between the cytokine polymorphisms and disease outcome was observed. The genotypes TNFA-308GG, IL6-174GG/GC, IL10-592AA and -819CC and TGFb1 high producers phenotypes were correlated with higher PVL in HAM/TSP patients versus asymptomatic carriers.

Conclusions

We did not observe association between cytokine polymorphisms and risk for HAM/TSP development in Brazilian HTLV-1 infected individuals, regardless of differences in PVL between HAM/TSP versus asymptomatic carriers in specific cytokine polymorphisms.

Host Genetic Factors and Dendritic Cell Responses Associated with the Outcome of Interferon/Ribavirin Treatment in HIV-1/HCV Co-Infected Individuals

HIV-1/HCV co-infection is a significant health problem. Highly active antiretroviral treatment (HAART) against HIV-1 has proved to be fairly successful. On the other hand, direct acting antiviral drugs against HCV have improved cure rates but high cost and development of drug resistance are important concerns. Therefore PEGylated interferon (PEG-IFN) and ribavirin (RBV) still remain essential components of HCV treatment, and identification of host factors that predict IFN/RBV treatment response is necessary for effective clinical management of HCV infection. Impaired dendritic cell (DC) and T cell responses are associated with HCV persistence. It has been shown that IFN/RBV treatment enhances HCV-specific T cell functions and it is likely that functional restoration of DCs is the underlying cause. To test this hypothesis, we utilized an antibody cocktail (consisting of DC maturation, adhesion and other surface markers) to perform comprehensive phenotypic characterization of myeloid DCs (mDCs) and plasmacytoid DCs (pDCs) in a cohort of HIV-1/HCV co-infected individuals undergoing IFN/RBV treatment. Our results show that pre-treatment frequencies of mDCs are lower in non-responders (NRs) compared to responders (SVRs) and healthy controls. Although, the treatment was able to restore the frequency of mDCs in NRs, it downregulated the frequency of CCR7⁺, CD54⁺ and CD62L⁺ mDCs. Pre-treatment frequencies of pDCs were lower in NRs and decreased further upon treatment. Compared to SVRs, NRs exhibited higher ratio of PD-L1⁺/CD86⁺ pDCs prior to treatment; and this ratio remained high even after treatment. These findings demonstrate that enumeration and phenotypic assessment of DCs before/during therapy can help predict the treatment outcome. We also show that before treatment, PBMCs from SVRs secrete higher amounts of IFN-γ compared to controls and NRs. Upon genotyping IFNL3 polymorphisms rs12979860, rs4803217 and ss469415590, we found rs12979860 to be a better predictor of treatment outcome. Collectively, our study led to identification of important correlates of IFN/RBV treatment response in HIV-1/HCV co-infected individuals.

Variations at multiple genes improve interleukin 28B genotype predictive capacity for response to therapy against hepatitis C infection

OBJECTIVE

To identify genetic factors that predict sustained virological response (SVR) to pegylated interferon (Peg-IFN)/ribavirin (RBV) in HIV/hepatitis C virus (HCV) genotype 1 or 4-coinfected patients and that enhance the predictive capacity of IL28B genotype in this population.

DESIGN

Prospective cohort study.

SETTING

Five tertiary care centers in Spain.

PATIENTS

Two hundred and five HIV/HCV genotype 1 or 4-coinfected patients who received a complete course of Peg-IFN/RBV for 48 weeks.

MAIN OUTCOME MEASURES

All individuals were genotyped for 144 single-nucleotide polymorphisms (SNPs).

RESULTS

One hundred and sixty-two (79%) patients bore HCV genotype 1. Overall SVR was achieved by 73 (36%) individuals. SNPs at the following genes were associated with SVR: IL28B, low-density lipoprotein receptor (LDLR), transforming growth factor β (TGF-β), aquaporine 2 (AQP-2), very-low-density lipoprotein receptor, Sp110 nuclear body protein, interferon alpha/beta receptor 1, 2'-5'-oligoadenylate synthase 1 and apolipoprotein B. There was a strong synergy between SNPs at IL28B, TGF-β and AQP-2 genes: the number of patients reaching SVR with all three favorable genotypes versus unfavorable genotypes were 22 (78.6%) versus 1 (7.1%) (P = 2.1 × 10). HCV baseline viral load, IL28B, TGF-β, AQP-2 and LDLR haplotypes were independently associated with SVR.

CONCLUSION

A number of genetic factors modify the predictive capacity of IL28B genotype. These can be used to identify HCV genotype 1 or 4-infected patients with a very high or a very low probability to respond to bitherapy with Peg-IFN/RBV. Predictive models based on these factors could be helpful to tailor direct acting antiviral-based therapy.

Role of viral and host factors in interferon based therapy of hepatitis C virus infection

The current standard of care (SOC) for hepatitis C virus (HCV) infection is the combination of pegylated interferon (PEG-IFN), Ribavirin and protease inhibitor for HCV genotype 1. Nevertheless, this treatment is successful only in 70-80% of the patients. In addition, the treatment is not economical and is of immense physical burden for the subject. It has been established now, that virus-host interactions play a significant role in determining treatment outcomes. Therefore identifying biological markers that may predict the treatment response and hence treatment outcome would be useful. Both IFN and Ribavirin mainly act by modulating the immune system of the patient. Therefore, the treatment response is influenced by genetic variations of the human as well as the HCV genome. The goal of this review article is to summarize the impact of recent scientific advances in this area regarding the understanding of human and HCV genetic variations and their effect on treatment outcomes. Google scholar and PubMed have been used for literature research. Among the host factors, the most prominent associations are polymorphisms within the region of the interleukin 28B (IL28B) gene, but variations in other cytokine genes have also been linked with the treatment outcome. Among the viral factors, HCV genotypes are noteworthy. Moreover, for sustained virological responses (SVR), variations in core, p7, non-structural 2 (NS2), NS3 and NS5A genes are also important. However, all considered single nucleotide polymorphisms (SNPs) of IL28B and viral genotypes are the most important predictors for interferon based therapy of HCV infection.

Dendritic Cells in HIV-1 and HCV Infection: Can They Help Win the Battle?

Persistent infections with human immunodeficiency virus type 1 (HIV-1) and hepatitis C virus (HCV) are a major cause of morbidity and mortality worldwide. As sentinels of our immune system, dendritic cells (DCs) play a central role in initiating and regulating a potent antiviral immune response. Recent advances in our understanding of the role of DCs during HIV-1 and HCV infection have provided crucial insights into the mechanisms employed by these viruses to impair DC functions in order to evade an effective immune response against them. Modulation of the immunological synapse between DC and T-cell, as well as dysregulation of the crosstalk between DCs and natural killer (NK) cells, are emerging as two crucial mechanisms. This review focuses on understanding the interaction of HIV-1 and HCV with DCs not only to understand the immunopathogenesis of chronic HIV-1 and HCV infection, but also to explore the possibilities of DC-based immunotherapeutic approaches against them. Host genetic makeup is known to play major roles in infection outcome and rate of disease progression, as well as response to anti-viral therapy in both HIV-1 and HCV-infected individuals. Therefore, we highlight the genetic variations that can potentially affect DC functions, especially in the setting of chronic viral infection. Altogether, we address if DCs’ potential as critical effectors of antiviral immune response could indeed be utilized to combat chronic infection with HIV-1 and HCV.

Cytokines genes polymorphisms in chronic hepatitis C: impact on susceptibility to infection and response to therapy

BACKGROUND

Cytokines play a key role in the regulation of immune responses. In hepatitis C virus infection, the production of abnormal cytokine levels appears to contribute in the progression of the disease, viral persistence, and affects response to therapy. Cytokine genes polymorphisms located within the coding/regulatory regions have been shown to affect the overall expression and secretion of cytokines. The aim of the study was to evaluate the association of of IL28B rs12979860, TGF-β1-509, TNF-α 308, and IL-10-1082 polymorphisms with the susceptibility to hepatitis C virus genotype 4 infection and response to pegylated interferon-α and ribavirin therapy.

METHODS

IL28B, TGF-β1 and TNF-α genes polymorphisms were genotyped using polymerase chain reaction (PCR)-based restriction fragment length polymorphism assay while IL-10 gene polymorphism was detected by sequence specific primer-PCR in 220 healthy individuals and 440 hepatitis C infected patients (220 sustained virological response and 220 non-responder to combination therapy).

RESULTS

IL28 B CT and TT, TGF-β1 CT and TT and TNF-α AG and AA genotypes were significantly associated with susceptibility to hepatitis C infection and response to therapy. While no association was found between IL-10 gene polymorphism and susceptibility to HCV infection and response to treatment.

CONCLUSIONS

These results suggested that inheritance of IL28B CT and TT, TGF-β1 CT and TT and TNF-α AG and AA genotypes which appear to affect the cytokine production may be associated with susceptibility to HCV infection and resistance to combined antiviral therapy.

Case definitions for acute hepatitis C virus infection: a systematic review

BACKGROUND & AIMS

Case definitions for recent hepatitis C virus (HCV) infection vary considerably between studies. The aim of this systematic review was to characterize case definitions for recent HCV and explore the heterogeneity in studies performed to date.

METHODS

A systematic literature search of MEDLINE, SCOPUS, and ISI Web of Knowledge was performed covering all studies of recent HCV infection cited between January 2000 and June 2011. The criteria used by each study to define cases of recent HCV infection were extracted, structured, and analyzed.

RESULTS

Overall, 195 articles were included, with 87% (n=169) providing a clear case definition for recent HCV infection. The most frequently used individual criteria for defining a case included HCV antibody seroconversion (77%), alanine aminotransferase (ALT) elevation (68%), and HCV RNA detection (63%). In studies using HCV antibody seroconversion, the window period between the last negative and the first positive antibody test varied widely across studies (4 weeks to 4 years). Considerable diversity was also observed with respect to the ALT threshold used to characterize ALT elevations, ranging from 2 to 20 times the upper limit of normal. HCV antibody seroconversion was used as a single criterion in 41% of the studies, while all other studies used at least two criteria (range: 2-9). Epidemiology/surveillance studies mostly used a more sensitive case definition, whereas treatment studies, natural history studies, and diagnosis studies used more specific case definitions.

CONCLUSIONS

Marked heterogeneity in case definitions for recent HCV infection was observed. Although a single case definition for recent HCV is not warranted, a degree of standardization within specific study categories would enable improved cross-study comparison and more uniform evaluation of HCV prevention and management strategies.

Lack of TGF-β production by hepatitis C virus-specific T cells during HCV acute phase is associated with HCV clearance in HIV coinfection

BACKGROUND & AIMS

Immunity and genetic factors govern the recovery from acute hepatitis C virus (HCV) infection. No predictive factors have been yet identified in patients coinfected with the human immunodeficiency virus (HIV). We investigated whether early T cell responses to HCV producing transforming-growth-factor beta (TGF-β) predict the outcome of acute HCV coinfection, independently of the IL-28B gene polymorphism.

METHODS

Intracellular cytokine staining assays against HCV-core, E1, NS2, and NS4 overlapping peptides were used for the analysis of peripheral HCV-specific TGF-β-producing T cells. Patients were genotyped for IL-28B polymorphisms. Healthy donors' samples were tested as controls. Twenty-four acute hepatitis C-HIV+ patients were followed-up for 15 months defining two groups: (A) Recovered (n=16, 5 spontaneous recoveries, 11 sustained virologic response after treatment), (B) Chronic HCV (n=8, 4 spontaneous chronic course, 4 therapeutic failures).

RESULTS

During the acute pretreatment phase, core/NS2-specific TGF-β-producing CD4+ and/or CD8+ T cells were detected in 8/24 (33%) patients. Lack of anti-HCV TGF-β+ cells was characteristic of healthy donors and Group A, except for 2 cases, with frequencies significantly lower than in Group B (p=0.04 and 0.01), and was associated with recovery in 14/16 cases. Presence of anti-HCV TGF-β+ cells was associated with persistent viremia in 6/8 cases (p=0.005). This profile remained stable over time. Such TGF-β production was independent of the rs129679860 SNP (p=1.0) which was not associated with recovery (p=1.0).

CONCLUSIONS

During acute hepatitis C, pre-therapeutic HCV-specific TGF-β-producing T cells are a new marker independent of the IL-28B gene polymorphism, predicting the lack of spontaneous or therapeutic HCV clearance.

Interferon combination therapy for HIV/hepatitis C virus coinfection

IFN-α has been the cornerstone of chronic hepatitis C virus (HCV) treatment for over a decade. Yet, rates of sustained virologic response of HCV infection to interferon-based therapy, particularly in difficult-to-treat populations, have been disappointingly low. This is particularly true in HIV/HCV coinfection, in which less than a third of patients typically respond to therapy. New HCV protease inhibitors, most of which will need to be administered with pegylated interferon, are in development, but comprehensive, long-term data for their use in coinfected patients is not yet available. Understanding the basis of this population's poor response to interferon-based therapy is crucial to future exploration of new therapeutic options, immunotherapy and prognosis in HIV/HCV-coinfected population.

Prospects for personalizing antiviral therapy for hepatitis C virus with pharmacogenetics

Chronic hepatitis C virus (HCV) infection is a major cause of liver disease worldwide. HCV infection is currently treated with IFNα plus ribavirin for 24 to 48 weeks. This demanding therapy fails in up to 50% of patients, so the use of pharmacogenetic biomarkers to predict the outcome of treatment would reduce futile treatment of non-responders and help identify patients in whom therapy would be justified. Both IFNα and ribavirin primarily act by modulating the immune system of the patient, and HCV uses multiple mechanisms to counteract the antiviral effects stimulated by therapy. Therefore, response to therapy is influenced by variations in human genes governing the immune system and by differences in HCV genes that blunt antiviral immune responses. This article summarizes recent advances in understanding how host and viral genetic variation affect outcome of therapy. The most notable human associations are polymorphisms within the IL28B gene, but variations in human leukocyte antigen and cytokine genes have also been associated with treatment outcome. The most prominent viral genetic association with outcome of therapy is that HCV genotype 1 is much less sensitive to treatment than genotypes 2 and 3, but genetic differences below the genotype level also influence outcome of therapy, presumably by modulating the ability of viral genes to blunt antiviral immune responses. Pharmacogenetic prediction of the outcome of IFN-based therapy for HCV will require integrating the efficacies of the immunosuppressive mechanisms of a viral isolate, and then interpreting the viral resistance potential in context of the genetic profile of the patient at loci associated with outcome of therapy. Direct-acting inhibitors of HCV that will be used in combination with IFNα are nearing approval, so genetic prediction for anti-HCV therapy will soon need to incorporate viral genetic markers of viral resistance to the new drugs.

Acute hepatitis C in HIV-infected men who have sex with men: an emerging sexually transmitted infection

Since 2000 outbreaks of acute hepatitis C virus (HCV) among HIV-positive men who have sex with men (MSM) who denied injecting drug use have been reported from Europe, the United States, Canada and Australia. Given the burden of liver disease, in particular HCV, on the morbidity and mortality in HIV patients in the era of combination antiretroviral therapy, the rapid and significant rise in the incidence of HCV in the HIV-infected MSM population in high-income countries is alarming. This relates to a significant change in the epidemiology of HCV that has occurred, with HCV emerging as a sexually transmitted infection within this population. Work to date suggests that this permucosal HCV transmission results from high-risk sexual and noninjecting drug use behaviours, reopening the discussion on the importance of sexual transmission. Given this occurs almost exclusively in HIV-infected MSM, HIV probably has a critical role mediated either through behavioural and/or biological factors. Finally, the management of acute HCV in HIV infection is complicated by concomitant HIV infection and combination antiretroviral therapy. This review will synthesize the most recent epidemiological, immunological and management issues that have emerged as a result of the epidemic of acute HCV among HIV-infected MSM.

Acute hepatitis C: analysis of a 126-case prospective, multicenter cohort

OBJECTIVES

To analyze the data (epidemiology, mode of transmission, course, and outcome) of a large series of patients with acute hepatitis C (AHC) in France.

METHODS

Prospective multicenter register, observational study.

RESULTS

A cohort of 126 patients with AHC was prospectively enrolled between 1999 and 2007. Fifteen (12%) were HIV coinfected. Suspected modes of hepatitis C virus transmission were drug use (38%), sexual contact (21%), nosocomial transmission (18%), and occupational exposure (12%). For 40% of the patients, AHC was revealed by jaundice. Spontaneous viral clearance occurred in 40% of the 72 patients observed for 3 months without treatment. Only jaundice and nosocomial/occupational transmission were predictive of spontaneous viral clearance. Ninety patients were treated with standard or pegylated interferon-alpha alone (58%) or in combination with ribavirin (42%), for 24 weeks or less in 90%. In intention-to-treat, a sustained viral response was obtained in 58 of 78 (74%) hepatitis C virus monoinfected patients [19 of 22 (86%) with 24 weeks of pegylated interferon-alpha alone], but only six of 12 (50%) of HIV coinfected patients.

CONCLUSION

AHC remains rare, and drug and sexual transmission are predominant. A 3-month follow-up after diagnosis avoids treatment for four out of 10 patients. Antiviral treatment is highly effective, 24 weeks of pegylated interferon-alpha alone being a good option.

Advances in sexually transmitted infections of the gastrointestinal tract

The gastrointestinal mucosa is a target of many sexually transmitted infections, and major advances have increased our understanding of the consequences of such infections within the gastrointestinal system. HIV-1 is associated with a marked loss of mucosal CD4(+) T cells that express CC-chemokine receptor 5. This process seems to be more rapid and more severe in mucosa-associated lymphoid tissue than in the peripheral blood. Mechanistic insights into the underlying cause of acute and chronic gastrointestinal damage with HIV infection-microbial translocation, defects in intestinal epithelial barrier function and activation of a systemic immune response-have also been achieved. Increased understanding of the pathogenesis of mucosal HIV-1 infection may identify therapeutic targets to restore immunological function and the integrity of the intestinal mucosal epithelial barrier. The increasing prevalence of lymphogranuloma venereum in Europe, mostly in HIV-positive men who have sex with men, suggests a change in the epidemiology of what was previously considered to be a 'tropical' disease. The increasing incidence of acute HCV infection transmitted via sexual contact has also been fueled by high-risk sexual behaviors among men who have sex with men, many of whom are also HIV-positive. The first part of this Review discusses the pathogenesis and gastrointestinal complications of HIV infection, and the second part summarizes advances in our understanding of other sexually transmitted infections of the gastrointestinal system.