HCV infects 170 million persons worldwide and is a serious global health problem. Genotype-3a is the dominant genotype in newly diagnosed infections within the UK and has a high response rate to interferon therapy, with up to 70% patients achieving a sustained virological response (SVR). The reason(s) for this are unknown; therefore the aim was to assess host and viral factors that determine treatment outcome of subtype-3a infection. Full-length subtype-3a viral sequence analysis identified 2 novel regions of hypervariability within E2 - HVR495 and HVR575, that are subject to positive selection pressure. A 5 amino-acid insertion found only in subtype-3a and a putative glycosylation site were contained within HVR575. These data suggest that HVR495 and HVR575 may serve as major antigenic sites in subtype-3a HCV infection. Successful treatment of chronic subtype-3a infection was not associated with pre-treatment quasispecies diversity and complexity, PePHD, HVR495 or HVR575 sequence. Different patterns of quasispecies variation were observed in patients that failed treatment. Subtype-3a specific CD8+ T-cell responses in chronic infection target non-structural proteins, in contrast to pre-dominant genotype-1 core-specific CD4+ T-cell responses. SVR was associated with a decline in subtype-3a specific and non-specific T-cell responses, and also total lymphocyte counts, which all recovered after treatment. These data do not support the theory that clearance of subtype-3a is associated with an enhancement of antiviral T-cell responses. Overlapping peptides detected a greater number of subtype-3a T-cell responses compared with peptides representing putative predicted CD8 epitopes. Therefore subtype-3a HCV is distinct from genotype-1 in terms of genome sequence, effect of treatment on quasispecies and subtype-3a specific T-cell responses, further emphasising the importance in understanding this distinct subtype.

For both influenza viruses and hepatitis C viruses, T cell responses to conserved antigens are one strategy for the human host to control the spread of infection. Such T cell responses can be generated with the use of viral vectored vaccines. Initially I show that the viral vectored vaccine MVA-NP+M1 can boost memory T cell responses to influenza A virus in adults aged over 50 years old. However within this group, MVA-NP+M1 had reduced immunogenicity in adults who were aged over 70 years old. The influenza virus-specific T cell responses comprised both CD4 and CD8 T cells, and were capable of secreting multiple Th1 cytokines. I then show that MVA-NP+M1 can be safely co-administered alongside seasonal influenza vaccine. The combination does not interfere with the peak T cell response that normally occurs 1 week following MVA-NP+M1. There was a statistically significant increase in antibodies to the H3N2 strain when the vaccines were co-administered, suggesting that the MVA-NP+M1 can act as an adjuvant. The efficacy of MVA-NP+M1 in humans had been previously evaluated in an influenza virus challenge study. I used a whole blood transcriptome approach to improve the classification of outcomes following influenza virus challenge. For subjects with laboratory-confirmed influenza, individuals with moderate/severe symptoms were found to have a distinct transcriptional signature comprising over 2,000 genes. I used a machine learning algorithm to reduce this variation down to just six genes (CCL2, SEPT4, LAMP3, RTP4, MT1G and OAS3). I validated this finding using expression data from an independently conducted challenge experiment. Data from these six genes was successfully able to predict symptomatic and asymptomatic cases with 89% and 100% accuracy respectively. To induce T cell responses to hepatitis C virus, I used the vaccines ChAd3-NSmut and MVA-NSmut in a prime-boost regimen. While the combination was highly immunogenic in healthy young adults, MVA-NSmut alone was unable to prime immune responses. The magnitude of T cell responses to the vaccine immunogen was correlated with the breadth of the T cell responses to different epitopes. Re-administration of the same two vaccines after a short time interval (8 weeks) did not improve upon previous peaks in T cell response. However with a longer time interval (> 34 weeks), some individuals were able to achieve higher frequencies of virus-specific T cells compared to the first round of vaccines. A whole blood transcriptome approach was used to study gene expression in volunteers vaccinated with ChAd3-NSmut and MVA-NSmut. Vaccination with MVA-NSmut results in a very strong, but relatively short-lived host gene expression signature. In contrast, the transcriptional response seen following ChAd3-NSmut was much less pronounced. A comparison of the functional analysis of gene lists from both vaccines showed that similar pathways were being activated and repressed.

Hepatitis C Virus (HCV) infection represents a worldwide pandemic and is currently the leading cause of cirrhosis and liver transplantation. After transplantation recurrence is almost universal with 96% of patients testing positive for viral RNA and exhibiting histological evidence of infection within the first year. Type I interferons (IFN) and interferon inducible genes are responsible for the innate antiviral state and single nucleotide polymorphisms (SNPs) within these genes may affect the patients ability to respond post-transplantation. We hypothesize the elucidation of associations between SNPs in Type-I Interferon and Interferon inducible genes and HCV recurrence post-liver transplantation might help to identify HCV patients with different prognosis and improve liver transplant recipient selection. 100 HCV positive patients were genotyped using Allelic Discrimination on an ABI Prism 7700 sequence detector (Applied Biosystems) for SNPs in IFNB1, OAS-1, and ISG-15 to establish a relationship between SNPs and clinical complications post-transplantation. Quantitative real-time polymerase chain reaction (QPCR) was also run to determine the relationship between SNPs or disease state and the level of RNA expression. Results were collected and analyzed using Fishers exact test, Kaplan-Meir method, and the log-rank test. Results obtained indicated that SNPs in OAS-1 are associated with HCV recurrence within 12 months post-orthotopic liver transplantation (OLT) and OAS-1 SNP genotypes were significantly associated with the development of fibrosis within the first year. Additionally we observed an association between the SNP genotypes of OAS-1 and ISG-15 and CMV infection post-OLT. A significant distribution of ISG-15 genotypes was also found to correlate with acute rejection. These findings might help identify patients at high risk of developing complications within the first year.

The leading causes of liver disease are Hepatitis C virus infection and chronic alcohol abuse. Alcohol accelerates liver disease in HCV but the mechanisms are poorly understood. The identification of molecular gene expression profiles on human liver tissue was performed using microarrays. Samples were obtained from alcoholic-cirrhotic, HCV-cirrhotic, HCV/alcohol-cirrhotic and control non-cirrhotic liver tissue. Probe set expression summaries were calculated using RMA. Probe set level linear models were fit where probe set expression was modeled by HCV status, alcohol status, and the interaction between HCV and Alcohol. HCV cirrhosis was associated with up-regulation of genes related to viral and immune response, apoptosis and inflammation. There were down-regulation of genes in the ubiquititin-proteasome system in alcoholic cirrhosis. The interaction of HCV and alcohol revealed negative interaction for genes involved in apoptosis and immune response. There was a negative estimate for genes involved in class II restricted antigen presentation.

Hepatitis C virus (HCV) is a major global pathogen estimated to infect over 170 million people worldwide. A recent study has shown that vaccination with adenoviral vectors, based on rare human and simian serotypes encoding the non-structural (NS) proteins of HCV, induces highly potent, multi-specific and durable T cell responses in healthy human volunteers. In this thesis I assess the safety and immunogenicity of these vaccines (ChAd3–NSmut and Ad6-NSmut), for the first time in HCV infected patients. This work also explores whether vaccine-induced T cell responses target in vivo circulating HCV antigens and common naturally occurring epitope variants. Patients with treatment naive chronic genotype 1 HCV infection were vaccinated (i.m.) with ChAd3-NSmut and Ad6-NSmut in a heterologous prime boost schedule, either with or without current IFN and ribavirin (IFN/RBV). Epitope-specific T cell responses were defined by fine mapping using HCV peptides. Circulating viral genomic sequence was determined in vaccinated patients at baseline and at any point of viral relapse. Cross-reactivity of vaccine-induced T cell responses was determined in T cell assays, using peptides corresponding to both circulating host virus and common population HCV epitope variants. An in vitro dendritic cell /T cell priming model was used to identify possible candidates for a cross-reactive vaccine immunogen at the most immunodominant epitope, NS3₁₄₀₆. 33 patients were vaccinated. Vaccination was well tolerated. At the highest vaccine dose (2.5 x 10¹⁰vp) vaccine-induced T cell responses were detectable in 11/20 patients receiving concurrent IFN/RBV and 2/4 patients receiving vaccination alone. In total 14 antigenic targets were identified, 2 of which have not previously been described. However, T cell responses were of lower magnitude and more narrowly focused than those observed in healthy volunteers vaccinated with the same regimen. Analysis of viral sequence showed that in many cases vaccine-induced T cells did not target the circulating virus. At the most immunodominant epitope (NS3₁₄₀₆), T cells induced by vaccination failed to target common circulating genotype 1 HCV variants. An in vitro model suggested that in order to target all genotype 1 sequences at this epitope, it would be necessary to insert both a genotype 1a and 1b version of this epitope into a vaccine immunogen. Vaccination with adenoviral vectors induces T cell responses in patients with chronic HCV infection, however immune responses are attenuated compared with healthy volunteers. Ultimately a successful therapeutic or prophylactic vaccine strategy will rely on inducing responses that target conserved or cross-reactive epitopes.

In der Promotion wird die Entwicklung, Optimierung und Validierung einer Reversed-phase-Chromatography Methode zur Messung des Ribavirinplasmaspiegels beschrieben. Diese wurde mit einer Solid Phase Extraction zur Probenvorbereitung kombiniert. Zudem finden sich zahlreiche Auswertungen von gemessenen Patienenchromatogrammen zu ausgewählten, klinisch relevanten Fragestellungen, wie beispielsweise die Darstellung des Ribavirinplasmaspiegels im Tagesverlauf, im Verlauf der ersten sechs Therapiewochen, im Vergleich von Männern und Frauen, sowie bei einem niereninsuffizienten Patienten. Zu den erhobenen Ergebnissen wird Stellung genommen, und daraus resultierende Schlussfolgerungen bezüglich einer zukünftigen Optimierung der Hepatitis-C-Therapie kommentiert. / The doctorate program will describe the development, optimization and validation of a reversed phase chromatography method for measuring ribavirinplasma levels. This has been combined with solid phase extraction for preparing samples. In addition, numerous analyses of patients’ chromatograms are included relative to clinically relevant questions such as the depiction of ribavirinplasma levels during the course of a day, during the course of the first six weeks of therapy, in comparison to other men and women as well as patients suffering from kidney insufficiencies. The collected data will be commented on, as well as the resulting implications relative to a future optimization of hepatitis-C therapy.

INTRODUCTION: Mortality associated with hepatitis C virus (HCV) infection is increasing, yet only a small percentage of HCV-infected individuals are aware of their infections, complete treatment, and achieve a cure, defined as a sustained virologic response. In March 2015, the Section of General Internal Medicine at Boston Medical Center (BMC), New England’s largest safety-net hospital, implemented the Adult Primary Care HCV Treatment and Triage Program to increase access to treatment. We are unaware of prior studies that have explored a pharmacist-centered primary care-based HCV treatment model in the era of newer direct-acting antiviral (DAA) medications. OBJECTIVES: To gain a deeper understanding of the roles of each program staff member, as well as an understanding of how primary care providers (PCPs) who refer patients to the program perceive and interact with the program. Such an understanding will help promote implementation and dissemination of the program. METHODS: We conducted in-depth semi-structured interviews with six staff members and with five PCPs in the Section of General Internal Medicine at BMC who refer patients to the program. We asked staff members about their roles and their perception of the program’s impact on patient linkage to HCV treatment. We probed PCPs about their experiences with HCV screening, referral, and follow-up processes, and differences in accessing HCV treatment for their patients prior to and following the implementation of the program. We audiotaped and transcribed interviews, and identified major themes through qualitative analysis. RESULTS: We identified five major themes that characterize how the HCV treatment program delivers care: 1) efficiency (“So here I feel like…they get evaluated…they get treated. Boom, it’s done”); 2) clear and open communication (“…one of the strengths of our program is that we have…a lot of direct contact with patients…”); 3) personalized medicine (“…I've set up the pill box for them [patients]…we tailor it to whatever they need”); 4) high patient engagement (“So if I get a referral for a patient…I call the patient three times. If I haven’t heard from the patient…I send them a letter and I tell the PCP”); 5) patient empowerment through education (“I think patient education is the best thing…if the patient is involved then… they’ll do what they need to do”). Additionally, the public health social worker and the pharmacist play key roles in the program. The social worker supports patients throughout treatment and addresses psychosocial barriers to treatment engagement (“I had a patient…who stopped taking his medication because his apartment was infested with bed bugs…[Social worker] got the patient furniture for free and got an exterminator…”). The pharmacist provides medication management during face-to-face patient visits (“…I go over everything imaginable...proper adherence…adverse effects, interactions…”). CONCLUSIONS: The HCV treatment program at BMC is a promising model to deliver HCV treatment to urban, underserved patient populations. Our findings suggest that public health social workers and pharmacists may be one approach to increasing access to HCV treatment in primary care settings in the era of DAA medications. Further study of the program’s efficacy in improving HCV outcomes is warranted.

Le Virus de l’Hépatite C (HCV) est un problème majeur de santé publique qui touche plus de 170 millions de personnes dans le monde. Le HCV cible essentiellement les hépatocytes où il effectue son cycle de réplication qui peut-être divisé en trois étapes majeures : l’entrée de la particule virale qui aboutit à la libération de l’ARN viral dans le cytoplasme, la traduction/réplication du génome viral et l’assemblage/sécrétion des particules néosynthétisées. Durant ma thèse, nous nous sommes intéressés à l’étape d’entrée qui est un processus complexe multiséquentiel faisant intervenir de nombreux facteurs cellulaires. Le virus se lie d’abord à la surface cellulaire via des facteurs d’attachement puis interagit avec des facteurs d’entrée spécifiques tels que la tétraspanine CD81, le récepteur scavenger B1 et les protéines de jonctions serrées CLDN-1, -6, -9 et OCLN. La particule virale est ensuite internalisée via une endocytose dépendante de la clathrine, puis sous l’action du pH acide des endosomes les enveloppes virale et cellulaire fusionnent permettant la libération de la capside virale dans le cytoplasme de la cellule infectée. Parmi les facteurs cellulaires impliqués dans l’entrée du HCV, deux protéines de la famille des tétraspanines ont été identifiées, CD81 et CD63. Les tétraspanines sont des protéines transmembranaires capables de former des microdomaines enrichis en tétraspanines en interagissant entre elles ainsi qu’avec des protéines dites partenaires. Nous avons testé l’implication dans l’entrée virale des tétraspanines exprimées dans les hépatocytes. Ainsi, nous avons montré que CD151 semble également important pour l’entrée du HCV. CD151 aurait un rôle indirect sur l’entrée en jouant sur l’organisation membranaire, en empêchant CD81 de former des clusters qui restreignent l’entrée du virus. Nous avons aussi étudié le rôle que pouvait jouer les polymorphismes de facteurs d’entrée sur l’entrée virale. Sur une cohorte de patients toxicomanes infectés par le HIV mais non infectés par le HCV, deux mutations ont été identifiées, R209Q dans CLDN-6 et P24A dans OCLN, qui n’étaient pas présentes dans les populations contrôles ou coinfectées par le HCV. Chez les patients toxicomanes, il est très rare que les patients infectés par le HIV ne le soient pas par le HCV, suggérant une résistance naturelle de ces patients à l’infection. Nous avons émis l’hypothèse que ces deux mutations pouvaient bloquer l’entrée du HCV. Cependant, la caractérisation de ces mutations a montré qu’elles n’avaient pas d’effet fonctionnel in vitro. Enfin, nous avons exploré l’effet de la Monensine, un ionophore polyéther, sur l’infection par le HCV. Cette molécule augmente le pH des endosomes via ses capacités de transfert d’ions à travers les membranes cellulaires. Nous avons montré qu’elle inhibe l’entrée du HCV en bloquant la fusion. De manière intéressante, la transmission cellule-cellule, un mécanisme d’entrée du virus encore mal caractérisé, était également bloquée par la Monensine, suggérant une étape de fusion dépendante du pH pour cette voie. Nous avons généré des mutants de résistance à la Monensine, notamment le clone FL-8 qui portait deux mutations dans les glycoprotéines d’enveloppe, Y297H dans E1 et I399T dans E2. Les particules virales portant ces deux mutations infectaient les cellules de manière indépendante du pH, présentaient des propriétés physicochimiques différentes et ne se transmettaient plus de cellule à cellule. En conclusion ces études soulignent l’importance de l’organisation membranaire pour l’entrée du virus via certains facteurs cellulaires tels que CD151. Par ailleurs, nous avons mis en évidence que la transmission cellule-cellule était dépendante du pH et que des mutations ponctuelles dans E1 et E2 permettent une fusion indépendante du pH. En revanche, des polymorphismes naturels de CLDN-6 et OCLN n’affectent pas leur capacité à supporter l’entrée virale. / Hepatitis C Virus (HCV) is a global health problem with over 170 million infected people worldwide. HCV targets mainly the hepatocytes and its lifecycle is divided into three steps. Viral particle entry leads to the release of viral genomic RNA into the cytoplasm where translation and replication take place. Then, new viral particles are assembled and secreted. During my thesis, we focused on the entry step. Indeed, HCV entry is a complex multistep process that requires numerous cellular factors. First, the virus interacts with attachment factors and then interacts with specific cellular factors including the tetraspanin CD81, the scavenger receptor B1 and the tight junction proteins CLDN-1, -6, -9 and OCLN. The viral particle is next internalized through a clathrin-dependent endocytosis. Finally, fusion at low pH occurs between viral and endosomal membranes leading to the release of the capsid into the cytoplasm. Among cellular factors involved in HCV entry, two members of the tetraspanin superfamily were identified, CD81 and CD63. Tetraspanins are transmembrane proteins able to organize themselves in tetraspanin-enriched microdomains through tetraspanin-tetraspanin interactions and interactions with partner proteins. We tested the involvement in HCV entry of tetraspanins expressed in hepatocytes. Interestingly, we showed that CD151 is also involved in HCV entry. CD151 seems to play an indirect role in HCV entry through regulating membrane organization, especially by preventing CD81 clustering, which is unfavourable to HCV entry. We also studied the effect of some entry factors polymorphisms on viral entry. In a cohort of drug users infected by HIV but not by HCV, we identified two mutations, R209Q in CLDN-6 and P24A in OCLN, not found in control or coinfected patients. It is very rare for drug users patients infected by HIV not to be infected by HCV, suggesting a natural resistance of these patients to HCV infection. We hypothesized that the two mutations identified might impair HCV entry. However, the characterization of these mutations showed that they did not have a functional effect in vitro. Finally, we investigated the effect of Monensin, a polyether ionophore, on viral entry. This molecule increases endosomal pH through its ions transfer properties across cell membranes. We showed that Monensin inhibits HCV entry through impairing the fusion step. Interestingly, HCV cell-to-cell transmission, another poorly characterized entry pathway, was also blocked by Monensin, suggesting that a pH-dependent fusion step is also required for this transmission route. We generated resistant mutants to Monensin, notably the FL-8 mutant carrying two mutations in envelope glycoproteins, namely Y297H in E1 and I399T in E2. Viral particles expressing these two mutations infected cells in a pH-independent manner, displayed different biophysical properties and were not cell-to-cell transmitted. To conclude, these studies highlight the importance of membrane organization for viral entry through cell factors like CD151. We also pointed out that cell-to-cell transmission is a pH-dependent process. In addition, point mutations in E1 and E2 are sufficient to enable HCV to be pH-independent for its entry. However, polymorphisms in CLDN-6 and OCLN seem to have no effect on viral entry.

O vÃrus da hepatite C (VHC) e a esteatose sÃo importantes causas de doenÃa hepÃtica crÃnica no mundo. Apesar de comum, a fisiopatologia da esteatose, e seu papel na progressÃo da fibrose em pacientes com VHC, permanece desconhecida. O objetivo deste trabalho foi quantificar esteatose macrovesicular e microvesicular e correlacionÃ-las com dados clÃnicos e histopatolÃgicos. O estudo analisou biÃpsias hepÃticas de pacientes portadores do VHC sem tratamento prÃvio. A fibrose e atividade necroinflamatÃria foram avaliadas segundo os escores de METAVIR e Ishak; as classificaÃÃes de Kleiner e Brunt foram utilizadas como suporte para o diagnÃstico de esteatohepatite realizado pelo patologista. Ademais, o nÃmero de hepatÃcitos com esteatose macrovesicular e esteatose microvesicular foram quantificados a partir do nÃmero total de hepatÃcitos. A fibrose e atividade necroinflamatÃria foram classificadas e semi-quantificadas. Foi encontrada associaÃÃo significante da fibrose avaliada pelo sistema de Ishak entre a esteatose macrogoticular e microgoticular (p= 0,017 e p= 0,0113, respectivamente). A atividade inflamatÃria global (classificaÃÃo Metavir ) apresentou correlaÃÃo linear com a piora da fibrose (< 0,001). A fibrose avaliada pelo sistema de Metavir se correlacionou com o IMC. A presenÃa de VHC associado à esteatohepatite apresentou correlaÃÃo significante com as mÃdias das AST/ALT, e com a fibrose de Ishak e Metavir, quando comparado aos dados dos pacientes com VHC, sem esteatohepatite (p = 0,006; p = 0,012; p = 0,0098 e p = 0,014, respectivamente). Em nosso trabalho, concluÃmos que a fibrose de Ishak esteve associado a esteatose macrogoticular e microgoticular. Igualmente, se demonstrou que a presenÃa da esteatohepatite esteve fortemente associado a fibrose. / The hepatitis C virus (HCV) and steatosis are important causes of chronic hepatic disease in the world. Although common, the pathofisiology of steatosis and its role in the progression of fibrosis in patients with HCV is uncertain. Our objective was to quantify the macrovacuolar and microvesicular steatosis and to correlate them with clinical and histophatologic data. The study included needle biopsy of the liver of patients with HCV without previous treatment. The fibrosis and necroinflammatory activity of hepatic damage by HCV were evaluated by METAVIR and Ishakâs scores; Kleinerâs and Bruntâs classification were used as a support for diagnosis of the steatohepatitis by the pathologist. Furthermore, the number of hepatocytes with the macrovacuolar and microvesicular steatosis was quantified in a total number of hepatocytes. Fibrosis and necroinflammatory activity were categorized and semi quantified. A significant association of the fibrosis was found and it was evaluated by the Ishak system between the macrogoticular and the microgoticular steatosis (p=0,017 e p= 0,0113, respectively). The global inflammatory activity (Metavir classification) has presented a linear correlation with the worsening of the fibrosis (< 0,001). The fibrosis which was evaluated by the Metavir system has been correlated with the BMI. The presence of HCV associated with the steatohepatitis has presented a significant correlation with the average of AST/ALT and with the Ishak and Metavir fibrosis, when compared to the data of the patients with HCV, without steatohepatitis (p= 0,006; p= 0,012; p= 0,0098 and p= 0,014, respectively) In our research we conclude that the Ishak fibrosis has been associated with the macrogoticular and microgoticular steatosis. Equally, it was demonstrated that the presence of the steatohepatitis was strongly associated to the fibrosis.

Submitted by admin tede (tede@pucgoias.edu.br) on 2018-05-28T19:39:54Z No. of bitstreams: 1 Marina Brandão Braz Albuquerque.pdf: 605500 bytes, checksum: 1405379cffb1283fb04eb721d76cc92a (MD5) / Made available in DSpace on 2018-05-28T19:39:54Z (GMT). No. of bitstreams: 1 Marina Brandão Braz Albuquerque.pdf: 605500 bytes, checksum: 1405379cffb1283fb04eb721d76cc92a (MD5) Previous issue date: 2018-03-27 / The use of hepatic biopsy to assess the stay of the level of fibrosis continues to be gold standard but may present some risks during the procedure and high cost. Given that the WHO suggested the use of APRI and FIB-4 indexes to evaluate hepatic fibrosis in patients with chronic hepatitis C, because they are low-cost exams that can replace the use of hepatic biopsy. Objectives: Assess the level of hepatic fibrosis before and after treatment of hepatitis C by means of APRI and FIB 4 methods. Methods: This is a cross-descriptive study, carried out by reviewing medical records of patients attending the STD/AIDS and Viral Hepatitis clinics in the period from March 2016 to December 2017. The level of fibrosis was defined according to PCDT 2015 in significant fibrosis values of APRI > 1.5 and FIB-4 > 3.25; and absence of fibrosis APRI ≤ 0.5 and FIB-4 ≤ 1.5. Patients who did not fit within the triage were defined as indeterminate. The correlation between the improvement of fibrosis and the variables was performed: gender, age and genotype. Results: 45 selected patients were assisted in the clinic, 23 of them (51.1%) were male. The average age of the patients was 57.13. The infection by genotype 1a was more prevalent n = 19 (42.2%). Among the 45 patients, 28 were within the classifications between absence and advanced by the APRI before the treatment and 17 were defined as indeterminate. In the FIB-4, 26 patients were classified between absence and advanced fibrosis and 19 defined as indeterminate. After the treatment 25 patients were classified by APRI and 20 by FIB- 4. Only the FIB-4 index had significant correlation (P < 0.05) with age and improvement in fibrosis. Conclusions: Both tests can be used to verify the staging of hepatic fibrosis and assist in daily practice, but some results may be in the indeterminate zone. In these cases, it is necessary to carry out complementary tests to better define the degree of fibrosis. / O uso da biópsia hepática para avaliar o estadiamento do grau de fibrose continua sendo padrão-ouro, contudo pode apresentar alguns riscos durante o procedimento, além de elevado custo. Diante disso, a OMS sugeriu o uso dos índices APRI e FIB-4 para avaliar a fibrose hepática em pacientes portadores de hepatite C crônica, visto que os exames têm baixo custo e podem substituir a biópsia hepática. Objetivos: Avaliar o grau de fibrose hepática pelos métodos APRI e FIB 4 antes e após tratamento de hepatite C. Métodos: Trata-se de estudo descritivo transversal, realizado por meio da revisão de prontuários médicos de pacientes atendidos no Ambulatório de DST/AIDS e Hepatites Virais em Aparecida de Goiânia no período de março de 2016 a dezembro de 2017. O grau de fibrose foi assim definido conforme PCDT 2015: fibrose significativa com valores de APRI >1,5 e FIB-4 >3,25; ausência de fibrose com APRI ≤0,5 e FIB-4 ≤1,5. Os pacientes que não se enquadravam na classificação foram definidos como indeterminados. Foi realizada a correlação entre a melhora da fibrose e as variáveis: gênero, idade e genótipo. Resultados: Foram selecionados para o estudo 45 pacientes atendidos na unidade, dos quais 23 (51,1%) eram do sexo masculino. A média de idade dos pacientes foi de 57,13 anos. A infecção pelo genótipo 1a foi mais prevalente, n= 19 (42,2%). Dos 45 pacientes, 28 estavam inseridos nas classificações entre fibrose ausente e avançada pelo APRI antes do tratamento e 17 foram definidos como indeterminados. No FIB-4, 26 pacientes foram classificados entre ausência e fibrose avançada e 19 foram definidos como indeterminados. Após o tratamento, 25 pacientes foram classificados pelo APRI e 20 pelo FIB-4. Apenas o índice FIB-4 mostrou correlação significativa (p<0,05) entre idade e melhora na fibrose. Conclusões: Ambos os testes podem ser utilizados para verificar o estadiamento da fibrose hepática e auxiliar na prática diária, porém alguns resultados podem estar na zona indeterminada. Neste caso é necessária a realização de testes complementares para definir melhor o grau de fibrose.