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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A study of pharmacogenomics for therapeutic and prognostic guidance towards hepatitis C virus (HCV) for patients co-infected with HIV

Yuen, King-tai, 袁敬弟 January 2013 (has links)
The cost effectiveness of using novel HCV treatment option, telaprevir and boceprevir, should depend on patients’ respond to conventional PEG-INFα and ribavirin therapy. The study of pharmacogenomics, interleukin-28B (IL-28B) polymorphisms, accompanied with the information of HCV genotypes are suggested to have the strongest predictive value of treatment outcomes and prognosis of disease in individuals infected with HCV who are undergoing conventional PEG-INFα and ribavirin therapy. It is extremely valuable in HCV/HIV co-infected patients as these groups of patients require a complex treatment regimen and demonstrate poor sustained viral response (SVR) rate. The development of a fast and promising IL-28B genotyping assay is urgently needed. A total of 47 blood samples randomly selected from HCV and HIV co-infected patients were used in this investigation. The aims of this study are to evaluate and compare the performance of newly developed IL-28B HybProbe real-time PCR assay using LightCycler® system against Sanger Sequencing method in determining IL-28B polymorphisms on rs12979860 and rs8099917 and to estimate the prevalence of IL-28B polymorphisms among HCV/HIV co-infected patients in Hong Kong. In addition, the genotypic distribution of HCV among the same patient group is identified by using in-house Sanger Sequencing method. It was found that the newly developed IL-28B real-time HybProbe assay resulted in 100% concordance with the traditionally used Sanger Sequencing method. The allele frequencies of C and T were 96% and 4% in rs12979860 and T and G were 97% and 3% in rs8099917 respectively. The CC and TT wild type are predominating in rs12979860 and rs8099917 with frequencies of 93.62% and 95.74% respectively. The most favorable compound genotype CC/TT with both homozygous wild types on both SNPs was the most predominant type with a high prevalence of 93.61%. Among all the samples, 50% samples were found to be HCV genotype 1, 41.18% were genotype 6 and 8.82% were genotype 3. A simple and efficient IL-28B real-time HybProbe assay was developed in this study and proved to show excellent performance on IL-28B genotyping although further optimization is suggested before it can be applied in the clinical setting. The favourable wild type genotypes of rs12979860 and rs8099917 accounted for the most predominant genotypes which is similar to other findings obtained from an Asian population. A comparatively high prevalence of HCV genotype 6 was found in the HCV/HIV co-infected group. Future study with the information of treatment outcomes (HCV viral load) can further evaluate the predictive value of IL-28B polymorphisms on SVR in different HCV genotypes. / published_or_final_version / Medical Sciences / Master / Master of Medical Sciences
2

Geographies of hepatitis C : exploring the extent to which geographic accessibility to healthcare influences outcomes amongst individuals infected with Hepatitis C in NHS Tayside, Scotland

Astell-Burt, Thomas January 2010 (has links)
Millions of people are infected with the Hepatitis C Virus (HCV) worldwide. In the UK, many individuals continue to live with undiagnosed HCV infection and are increasingly at risk of developing life-threatening cirrhosis and liver cancer. Of those that are diagnosed, only some are referred to an HCV specialist centre where vital treatment could cure their infection. Of those that are referred, only a proportion have actually attended and stayed in follow-up with a specialist centre. Geographic access to healthcare may be an important factor in these trends, but has so far received little attention in the context of HCV. This thesis examines the influence of geographic access to primary and specialist healthcare on HCV detection, trends of referral, chances of specialist centre utilisation and the odds of staying in follow-up. It also explores association between geographic access and the type of location in which diagnoses were made with the risk of mortality from liver-related causes. HCV detection was lower amongst those with poorer geographic access to primary healthcare, but further analyses suggest this trend is due to selection, not causation. Individuals with the furthest to travel were less likely to be referred to an HCV specialist centre, compared to those who lived closer. Travel-time was not a significant predictor of utilisation of HCV specialist centres, but with patients in more remote areas less likely to be referred, it is probable that the utilisation result is biased due to selection. Liver-related mortality was higher for patients diagnosed in hospitals, but the risk of death was not associated with a lack of geographic access to healthcare.
3

AVALIAÇÃO DA EFETIVIDADE DO PROGRAMA DE TRATAMENTO DA HEPATITE C CRÔNICA EM USUÁRIOS DA FARMÁCIA ESTADUAL DE MEDICAMENTOS EXCEPCIONAIS DO MARANHÃO (FEME). / EVALUATION OF THE EFFECTIVENESS OF THE TREATMENT PROGRAM HEPATITIS C CHRONIC IN USERS OF THE STATE PHARMACY OF EXCEPTIONAL MEDICINES OF MARANHÃO (FEME).

TEIXEIRA, Fábio Gomes 18 October 2011 (has links)
Submitted by Maria Aparecida (cidazen@gmail.com) on 2017-11-13T14:21:15Z No. of bitstreams: 1 Fábio Gomes Teixeira.pdf: 415617 bytes, checksum: 372db933a02a007f513b9a2d77a17362 (MD5) / Made available in DSpace on 2017-11-13T14:21:15Z (GMT). No. of bitstreams: 1 Fábio Gomes Teixeira.pdf: 415617 bytes, checksum: 372db933a02a007f513b9a2d77a17362 (MD5) Previous issue date: 2011-10-18 / Cohort study using retrospective data to evaluate the effectiveness of the treatment program for chronic hepatitis C in users of Farmácia Estadual de Medicamentos Excepcionais do Maranhão (FEME) to determine the rate of sustained virologic response (SVR) and correlate it with demographic, clinical, laboratory, histological and virological features of patients and to identify the rates of discontinuation of treatment. We analyzed data from 256 patients treated for chronic hepatitis C in FEME for the period January 2005 to July 2009, being an SVR by intention to treat 57%. Males predominated (66%). The mean age was 52.5 years, with a predominance of non-white individuals in relation to whites. Genotype 1 was the most common (77%) and 150 (58.6%) patients had viral load above 400,000 UI/ml. With respect to the treatment regimen, pegylated interferon associated with ribavirin was used by 80.5% of patients, the rate of discontinuation of treatment of 13,3%. They were identified as factors independently associated with SVR: white, non-cirrhotic, have not a genotype 1 and viral load below 400,000 IU / ml. These findings demonstrate the effectiveness of treatment provided by FEME, which makes it possible to cure most patients, preventing progression to end-stage liver disease and its disastrous consequences. The factors associated with SVR have seen in other studies, leads us to believe that the results are reliable and that the program is fulfilling the role it has set itself. / Estudo de coorte com dados retrospectivos com o objetivo de avaliar a efetividade do programa de tratamento da hepatite C crônica em usuários da Farmácia Estadual de Medicamentos Excepcionais do Maranhão (FEME), determinar a taxa de resposta virológica sustentada (RVS) e correlacioná-la com características demográficas, clínicas, laboratoriais, histológicas e virológicas dos pacientes, além de identificar as taxas de interrupção do tratamento. Foram analisados os dados de 256 pacientes, tratados para hepatite C crônica na FEME no período de Janeiro de 2005 a Julho de 2009, encontrando-se uma RVS por intenção de tratar de 57%. O sexo masculino foi predominante (66%). A média de idade encontrada foi de 52,5 anos, havendo predomínio de indivíduos não brancos em relação aos brancos. O genótipo 1 foi o mais comum (77%) e 150 (58,6%) pacientes apresentaram carga viral superior a 400.000 UI/ml. Com relação ao esquema de tratamento, o interferon peguilado associado ribavirina foi utilizado por 80,5% dos pacientes, sendo a taxa de interrupção do tratamento de 13,3%. Foram identificados como fatores independentemente associados à RVS : cor branca, não cirróticos, ter genótipo não 1 e carga viral abaixo de 400.000 UI/ml. Estes achados demonstram a efetividade do tratamento fornecido pela FEME, que possibilita a cura da maioria dos pacientes, prevenindo a progressão para doença hepática terminal e suas consequências desastrosas. A RVS associada a fatores já vistos em outros estudos, nos faz acreditar que os resultados são confiáveis e que o programa está cumprindo o papel a que se propôs.
4

Srovnání adherence a úspěšnosti antiretrovirové léčby virové hepatitidy C u uživatelů a neuživatelů drog / Comparison of adherence and outcome of antiviral therapy of viral hepatitis C in drug users and non-users

Věchetová, Sonja January 2016 (has links)
3456 ABSTRACT: Background: VHC is a widespread serious chronic infectious disease. Most of the patients affected by the disease consist of IDUs. Treatment of VHC is now perceived as an important preventive element for the spread of the disease in IDUs population. Adherence to treatment is absolutely crucial for the successful completion of treatment. Adherence to treatment is often questioned by clinicians who treat VHC in patients using addictive substances. Objectives: To compare the efficacy of treatment of VHC in patients with a history of drug in patients without a history of drug, to compare treatment adherence among patients without a drug history and patients with drug history, to map out the factors affecting adherence to treatment and to find a place in the therapeutic team for expertise of addictologist. Material and Methods: Data from documentation of 258 patients that were treated in 2006- 2015 for viral hepatitis C at the Department of Infectious Diseases at the University Hospital Brno have been processed with using the statistical and analytical methods and in compliance with ethical rules retrospectively. Adherence to treatment (defined as the completion or early termination of treatment due to non-compliance with the treatment regime by the patient) and the effectiveness of treatment, as...
5

"More than a liver" - the role of the social work practitioner in hepatitis C treatment centres

Mouton, Marlize, National Centre in HIV Social Research, Faculty of Arts & Social Sciences, UNSW January 2008 (has links)
Hepatitis C is a fast growing infectious disease in Australia and is often associated with related psycho-social and mental health problems. The conventional treatment process for hepatitis C is challenging due to a number of reasons. This study explored social workers’ perceptions of the contribution of their role in hepatitis C treatment centres in relation to the treatment experience of patients. The roles that social workers fulfill, their contribution to the multidisciplinary team and towards a culturally competent service, were explored. Furthermore the knowledge, skills and values required for providing a competent service in a hepatitis C treatment setting was explored. The broad theoretical frameworks that inform social work practice were considered, especially the biopsycho-social model, the strengths perspective, the critically reflexive approach and communications theory. This qualitative study used a semi-structured interview method for data collection. Ten social workers in hepatitis C treatment clinics participated in the study. The findings highlight the needs of patients and how social worker participants described helping to address and meet these needs by employing their knowledge, skills and values through their social work roles and interventions in a team context in a multicultural and multi-faceted work environment. A major challenge that social workers described was to keep patients on treatment despite debilitating side effects that diminish patients' motivation to complete treatment. A shortcoming in the service was described to be the limited psychiatric support available at many treatment centres. The findings lead to a number of recommendations to improve social work services in hepatitis C treatment settings. More research was recommended in areas such as motivational techniques, psychiatric support, and effective group work strategies. The need for increased funding for social work positions in the hepatitis C field was also highlighted. It is anticipated that findings of this study can be applied to hepatitis C treatment in broader settings such as prisons, drug and alcohol settings and general practice. This research will contribute to literature in the field of hepatitis C treatment models and in the field of social work practice in hepatitis C contexts.
6

"More than a liver" - the role of the social work practitioner in hepatitis C treatment centres

Mouton, Marlize, National Centre in HIV Social Research, Faculty of Arts & Social Sciences, UNSW January 2008 (has links)
Hepatitis C is a fast growing infectious disease in Australia and is often associated with related psycho-social and mental health problems. The conventional treatment process for hepatitis C is challenging due to a number of reasons. This study explored social workers’ perceptions of the contribution of their role in hepatitis C treatment centres in relation to the treatment experience of patients. The roles that social workers fulfill, their contribution to the multidisciplinary team and towards a culturally competent service, were explored. Furthermore the knowledge, skills and values required for providing a competent service in a hepatitis C treatment setting was explored. The broad theoretical frameworks that inform social work practice were considered, especially the biopsycho-social model, the strengths perspective, the critically reflexive approach and communications theory. This qualitative study used a semi-structured interview method for data collection. Ten social workers in hepatitis C treatment clinics participated in the study. The findings highlight the needs of patients and how social worker participants described helping to address and meet these needs by employing their knowledge, skills and values through their social work roles and interventions in a team context in a multicultural and multi-faceted work environment. A major challenge that social workers described was to keep patients on treatment despite debilitating side effects that diminish patients' motivation to complete treatment. A shortcoming in the service was described to be the limited psychiatric support available at many treatment centres. The findings lead to a number of recommendations to improve social work services in hepatitis C treatment settings. More research was recommended in areas such as motivational techniques, psychiatric support, and effective group work strategies. The need for increased funding for social work positions in the hepatitis C field was also highlighted. It is anticipated that findings of this study can be applied to hepatitis C treatment in broader settings such as prisons, drug and alcohol settings and general practice. This research will contribute to literature in the field of hepatitis C treatment models and in the field of social work practice in hepatitis C contexts.
7

"More than a liver" - the role of the social work practitioner in hepatitis C treatment centres

Mouton, Marlize, National Centre in HIV Social Research, Faculty of Arts & Social Sciences, UNSW January 2008 (has links)
Hepatitis C is a fast growing infectious disease in Australia and is often associated with related psycho-social and mental health problems. The conventional treatment process for hepatitis C is challenging due to a number of reasons. This study explored social workers’ perceptions of the contribution of their role in hepatitis C treatment centres in relation to the treatment experience of patients. The roles that social workers fulfill, their contribution to the multidisciplinary team and towards a culturally competent service, were explored. Furthermore the knowledge, skills and values required for providing a competent service in a hepatitis C treatment setting was explored. The broad theoretical frameworks that inform social work practice were considered, especially the biopsycho-social model, the strengths perspective, the critically reflexive approach and communications theory. This qualitative study used a semi-structured interview method for data collection. Ten social workers in hepatitis C treatment clinics participated in the study. The findings highlight the needs of patients and how social worker participants described helping to address and meet these needs by employing their knowledge, skills and values through their social work roles and interventions in a team context in a multicultural and multi-faceted work environment. A major challenge that social workers described was to keep patients on treatment despite debilitating side effects that diminish patients' motivation to complete treatment. A shortcoming in the service was described to be the limited psychiatric support available at many treatment centres. The findings lead to a number of recommendations to improve social work services in hepatitis C treatment settings. More research was recommended in areas such as motivational techniques, psychiatric support, and effective group work strategies. The need for increased funding for social work positions in the hepatitis C field was also highlighted. It is anticipated that findings of this study can be applied to hepatitis C treatment in broader settings such as prisons, drug and alcohol settings and general practice. This research will contribute to literature in the field of hepatitis C treatment models and in the field of social work practice in hepatitis C contexts.
8

"More than a liver" - the role of the social work practitioner in hepatitis C treatment centres

Mouton, Marlize, National Centre in HIV Social Research, Faculty of Arts & Social Sciences, UNSW January 2008 (has links)
Hepatitis C is a fast growing infectious disease in Australia and is often associated with related psycho-social and mental health problems. The conventional treatment process for hepatitis C is challenging due to a number of reasons. This study explored social workers’ perceptions of the contribution of their role in hepatitis C treatment centres in relation to the treatment experience of patients. The roles that social workers fulfill, their contribution to the multidisciplinary team and towards a culturally competent service, were explored. Furthermore the knowledge, skills and values required for providing a competent service in a hepatitis C treatment setting was explored. The broad theoretical frameworks that inform social work practice were considered, especially the biopsycho-social model, the strengths perspective, the critically reflexive approach and communications theory. This qualitative study used a semi-structured interview method for data collection. Ten social workers in hepatitis C treatment clinics participated in the study. The findings highlight the needs of patients and how social worker participants described helping to address and meet these needs by employing their knowledge, skills and values through their social work roles and interventions in a team context in a multicultural and multi-faceted work environment. A major challenge that social workers described was to keep patients on treatment despite debilitating side effects that diminish patients' motivation to complete treatment. A shortcoming in the service was described to be the limited psychiatric support available at many treatment centres. The findings lead to a number of recommendations to improve social work services in hepatitis C treatment settings. More research was recommended in areas such as motivational techniques, psychiatric support, and effective group work strategies. The need for increased funding for social work positions in the hepatitis C field was also highlighted. It is anticipated that findings of this study can be applied to hepatitis C treatment in broader settings such as prisons, drug and alcohol settings and general practice. This research will contribute to literature in the field of hepatitis C treatment models and in the field of social work practice in hepatitis C contexts.
9

Examining the impact of healthcare and harm reduction services on drug use and hepatitis C virus infection risk among people who inject drugs

Artenie, Andreea Adelina 10 1900 (has links)
L’infection par le virus de l’hépatite C (VHC) est l’un des principaux problèmes de santé publique chez les utilisateurs de drogues injectables (UDI). Actuellement, plusieurs outils sont disponibles pour réduire le fardeau du VHC dans cette population. Ceux-ci incluent des programmes de réduction des méfaits, tels que le traitement par un opioïde agoniste (TAO), pouvant réduire le risque d'infection par le VHC, ainsi que des traitements antiviraux extrêmement efficaces pour éradiquer le virus parmi les infectés. Plus récemment, il y a eu un intérêt national et international à éliminer le VHC en tant que menace pour la santé publique d'ici 2030, tout en priorisant les UDI dans les efforts de prévention et traitement. Parallèlement à ce mouvement, plus globalement, le fardeau des méfaits liés aux pratiques d’injection chez les UDI, tels que la surdose, soulignent la nécessité d’adopter une vision plus large sur leur santé. Dans l’ensemble, cette thèse vise à combler certaines lacunes dans les connaissances vis-à-vis de l’élimination du VHC chez les UDI. Premièrement, puisque le lien entre l’adéquation du dosage des TAO et le risque d’infection au VHC est peu connu, j’examine cette relation dans un échantillon d’UDI suivis dans la cohorte HEPCO à Montréal. Les résultats indiquent que le risque d'infection par le VHC ne serait pas systématiquement réduit chez toutes les personnes recevant des TAO, mais plutôt que ce risque varie en fonction de la dose prescrite et de l’adéquation du dosage telle que perçue par le patient. Ces résultats soulignent qu’un élargissement de l'accès aux TAO ne serait pas suffisant pour atteindre les objectifs de prévention et d'élimination du VHC, et que l’adéquation du dosage devrait être prise en compte dans le cadre de nos efforts de prévention. Deuxièmement, l’accès aux traitements antiviraux est faible chez les UDI, en partie à cause des préoccupations des prestataires et des décideurs politiques qui craignent une augmentation de la consommation de drogues et des comportements à risque après le traitement. En capitalisant sur deux études différentes - la cohorte IMPACT à Montréal et les essais SIMPLIFY / D3FEAT menés dans plusieurs pays - je montre que les comportements liés à la drogue diminuent ou restent stables après le traitement du VHC. Ensemble, ces deux études suggèrent que les préoccupations liées à une consommation élevée de drogue ou à une hausse des comportements à risque après le traitement ne seraient pas fondées. Ainsi, ces résultats appuient davantage une augmentation de l’accès au traitement chez les UDI. Troisièmement, allant au-delà du VHC en tant que problématique principale, en capitalisant une fois de plus sur les données collectées dans HEPCO, j’examine les associations entre trois facteurs - le TAO, le logement et le revenu - et la fréquence d’injection chez les UDI. Puisque la consommation de drogues est dynamique dans le temps, j'examine dans quelle mesure ces trois facteurs sont liés à la fréquence d’injection chez des UDI ayant des trajectoires d’injection variées. Nos résultats indiquent que la stabilité socioéconomique et le TAO seraient systématiquement liés à une fréquence d'injection inférieure chez les UDI, quelles que soit leurs trajectoires d’injection sous-jacentes. Globalement, ces résultats suggèrent qu’il y aurait des moyens de soutenir tous les UDI à atteindre de petits changements comportementaux qui pourraient réduire les risques liés aux pratiques d’injection, qu’ils soient ou non en mesure d’arrêter l’injection de drogues. En conclusion, alors que presque tous les pays ont lancé un effort mondial pour éliminer le VHC, des efforts sont nécessaires pour optimiser les programmes de réduction des méfaits bien établis afin de réduire la transmission du VHC, et d’accroître l’accès au traitement chez ceux qui sont infectés, tout en considérant les besoins et les préoccupations des communautés touchées. Cette thèse a fourni des données permettant d’éclairer (i) l’optimisation des TAO dans la prévention de la transmission du VHC, (ii) l’élargissement de l’accès au traitement du VHC et (iii) l’accès à des logements et revenus stables afin de réduire plus globalement les risques liés aux pratiques d’injection chez les UDI. Ainsi, ces résultats pourraient aider à réduire le fardeau du VHC chez les UDI et à soutenir le progrès vers l'élimination du VHC. / Infection with hepatitis C virus (HCV) is one of the main public health concerns affecting people who inject drugs (PWID). Although no effective prophylactic vaccine currently exists to prevent acquisition of HCV, a number of other tools are available to curb the HCV burden among PWID. These include harm-reduction programs, such as opioid agonist treatment (OAT), which can reduce the risk of HCV infection among those susceptible, and highly effective antiviral therapies to eradicate the virus among those who are infected. In recent years, there has been national and international interest in eliminating HCV as a public health threat by 2030, prioritising PWID in prevention and treatment efforts given that they are the population most affected. In parallel to this global effort, the high prevalence of injection-related harms among PWID that are unrelated to HCV, such as overdose, highlight a need to adopt a broader view on drug user health. Overall, this thesis is concerned with addressing some of the knowledge gaps and barriers that remain to achieving HCV elimination in PWID. First, because little is known about the importance of OAT dosage in influencing the risk of HCV acquisition, I examine this relationship in a sample of PWID followed in the Hepatitis Cohort (HEPCO) in Montreal. Findings indicate that the risk of HCV infection may not be systematically reduced for everyone receiving OAT and rather, that the risk of infection varies considerably according to the level of the prescribed OAT dosage and patient-perceived dosage adequacy. These findings suggest that simply scaling-up OAT access may not be sufficient to achieving the HCV elimination goals, and that the dosage of treatment should be considered as part of prevention efforts. Second, uptake of HCV treatment is low among PWID, partly due to concerns among providers and policymakers that drug use and injection risk behaviours may increase following treatment, thereby negating the benefits of therapy. Capitalising on two different studies - the IMPACT Cohort in Montreal and the SIMPLIFY/D3FEAT trials conducted in several countries - I illustrate that drug-related behaviours decrease or remain stable following HCV treatment. Together, these two studies suggest that concerns of escalating drug use or risk behaviours following HCV treatment are unfounded, further supporting the importance of expanding access to therapy among PWID. Third, moving beyond HCV as the primary focus of research, and capitalising once more on data collected in HEPCO, I examine the associations between three factors- OAT, housing and income, and patterns of injection frequency among PWID. Recognizing that injection patterns are dynamic over time, I examine the extent to which these three factors relate to injection frequencies among PWID with diverse trajectories of injection drug use, followed over a period of 7.5 years. Our findings indicate that socioeconomic stability and OAT are consistently associated with a lower injection frequency among all PWID, irrespective of their underlying injection trajectory and whether or not they are on a path to cessation. These findings suggest that there may be ways to support PWID in making small behavioral changes that could reduce their risks of injection-related harms, irrespective of whether or not they are in a position to stop injecting. In conclusion, at a time when many countries have embarked onto a global effort to eliminate HCV, efforts are needed to ensure that well-evidenced harm-reduction programs are optimised to reduce transmission of HCV, treatment for HCV infection is scaled-up among those who are infected ,and efforts do not overlook the basic needs and concerns of affected communities. This thesis provided data to help inform (i) optimisation of OAT provision for the prevention of HCV transmission, (ii) expanded access to HCV treatment, and (iii) access to stable housing and income to reduce the risk of injection-related harms among PWID. Ultimately, findings could contribute to reducing the HCV burden among PWID, helping move towards HCV elimination and, more broadly, improving the overall health of this marginalised group.
10

Characterization of Hepatitis C Virus Infection of Hepatocytes and Astrocytes

Liu, Ziqing January 2014 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Approximately 2.8% of the world population is currently infected with hepatitis C virus (HCV). Neutralizing antibodies (nAbs) are often generated in chronic hepatitis C patients yet fail to control the infection. In the first two chapters of this study, we focused on two alternative routes of HCV transmission, which may contribute to HCV’s immune evasion and establishment of chronic infection. HCV was transmitted via a cell-cell contact-mediated (CCCM) route and in the form of exosomes. Formation of HCV infection foci resulted from CCCM HCV transfer and was cell density-dependent. Moreover, CCCM HCV transfer occurred rapidly, involved all four known HCV receptors and intact actin cytoskeleton, and led to productive HCV infection. Furthermore, live cell imaging revealed the temporal and spatial details of the transfer process. Lastly, HCV from HCV-infected hepatocytes and patient plasma occurred in both exosome-free and exosome-associated forms and the exosome-associated HCV remained infectious, even though HCV infection did not significantly alter exosome secretion. In the third chapter, we characterized HCV interaction with astrocytes, one of the putative HCV target cells in the brain. HCV infection causes the central nervous system (CNS) abnormalities in more than 50% of chronically infected subjects but the underlying mechanisms are largely unknown. We showed that primary human astrocytes (PHA) were very inefficiently infected by HCV, either in the free virus form or through cell-cell contact. PHA expressed all known HCV receptors but failed to support HCV entry. HCV IRES-mediated translation was functional in PHA and further enhanced by miR122 expression. Nevertheless, PHA did not support HCV replication regardless of miR122 expression. To our great surprise, HCV exposure induced robust IL-18 expression in PHA and exhibited direct neurotoxicity. In summary, we showed that CCCM HCV transfer and exosome-mediated HCV infection constituted important routes for HCV infection and dissemination and that astrocytes did not support productive HCV infection and replication, but HCV interactions with astrocytes and neurons alone might be sufficient to cause CNS dysfunction. These findings provide new insights into HCV infection of hepatocytes and astrocytes and shall aid in the development of new and effective strategies for preventing and treating HCV infection.

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