GASPAR LISBOA NETO
Projetos de Pesquisa
Unidades Organizacionais
LIM/52 - Laboratório de Virologia, Hospital das Clínicas, Faculdade de Medicina
3 resultados
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- Resistance mutations are rare among protease inhibitor treatment-naive hepatitis C genotype-1 patients with or without HIV coinfection(2015) LISBOA-NETO, Gaspar; NOBLE, Caroline F.; PINHO, Joao R. Rebello; MALTA, Fernanda M.; GOMES-GOUVEA, Michele S.; ALVARADO-MORA, Monica V.; SILVA, Mariliza H. da; LEITE, Andrea G. B.; PICCOLI, Leonora Z.; RODRIGUES, Flaviane K.; CARRILHO, Flair J.; MENDES-CORREA, Maria C.Background: HCV has a high replication rate and a lack of proofreading activity, leading to a greatly diverse viral population. This diversity may lead to emergence of resistant strains in direct-acting antiviral therapy. The frequency of naturally occurring HCV protease inhibitor (PI) mutations has been addressed in many countries, but there are few data on the prevalence of these mutations in Brazilian patients. Methods: We evaluated the sequence of HCV NS3 protease gene in 247 patients (135 HCV-monoinfected and 112 HIV-HCV-coinfected patients). HCV RNA was extracted from plasma and a fragment of 765 base pairs from the NS3 region was amplified and sequenced with Sanger-based technology. Results: HIV-HCV-coinfected patients were more likely to be older than 40 years and have an HCV subtype-1a infection. Overall, 21.9% of patients had at least one amino acid substitution in the NS3 region; 14 patients (5.7%) harboured at least one resistance mutation (T54S, V55A, Q80R) and the Q80K mutation was not found in our case series. There was no difference between monoinfected and coinfected patients regarding the frequency of natural polymorphisms and resistance mutations. Conclusions: Baseline HCV NS3 amino acid substitutions identified herein are considered mostly natural polymorphisms with no clinical impact on PI-based therapy. The identified resistance mutations may be associated with low-level resistance to PIs in vitro. Q80K substitution seems to be a rare event in Brazil. HIV coinfection was not associated with a greater frequency of such substitutions in the studied sample.
- Characterization of clinical predictors of naturally occurring NS3/NS4A protease polymorphism in genotype 1 hepatitis C virus mono and HIV co-infected patients(2017) NETO, Gaspar Lisboa; MALTA, Fernanda M.; GOMES-GOUVEA, Michele S.; NOBLE, Caroline F.; ROMANO, Camila M.; PINHO, Joao R. Rebello; SILVA, Mariliza H.; LEITE, Andrea G. B.; PICCOLI, Leonora Z.; CARRILHO, Flair J.; MENDES-CORREA, Maria C.Spontaneously occurring resistance may impair the success of protease inhibitors based regimens in HCV treatment. This study aimed to evaluate associations between amino acid substitutions in NS3/NS4A domain and clinical features of 247 HCV mono or HCV/HIV co-infected patients. Fourteen samples (5.7%) harbored at least one resistance-associated substitution (RAS). The following RASs were detected in NS3 region: T54S (6-2.4%), V55A (7-2.8%), and Q80R (2-0.8%). S122G occurred in 86.9% of HCV genotype 1b samples with either natural polymorphisms or RASs. Advanced liver fibrosis and HIV co-infection were not related to NS3/NS4A amino acid substitutions.
- Natural occurrence of NS5B inhibitor resistance-associated variants in Brazilian patients infected with HCV or HCV and HIV(2017) NOBLE, Caroline Furtado; MALTA, Fernanda; LISBOA-NETO, Gaspar; GOMES-GOUVEA, Michele Soares; LEITE, Andrea Gurgel Batista; CASTRO, Vanessa Fusco Duarte de; SANTANA, Rubia Anita Ferraz; CARRILHO, Flair Jose; MENDES-CORREA, Maria Cassia; PINHO, Joao Renato RebelloResistance-associated variants (RAVs) represent a challenge to the success of new HCV therapies. The aim of this study was to describe the prevalence of naturally occurring NS5B RAVs in Brazilian direct acting antivirals (DAA)-na < ve patients infected with HCV genotype 1, or co-infected with HIV. Patient enrollment and sample collection were performed between 2011 and 2013. Using Sanger-based sequencing, 244 sequences were obtained. RAVs detected in HCV-1a sequences were V321A (1.6 %), M414V (1.3 %), A421V (21.4-23.7 %), A421G (1.3 %) and Y448H (1.3 %); and in HCV-1b sequences were L159F (16.1 %), C316N (7.1-16.3 %) and A421V (3.2-6.3 %). Understanding the real RAVs scenario in patients is fundamental to establishing the most effective therapeutic strategy and in minimizing the risks for their selection.