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1.
Cad. Saúde Pública (Online) ; 36(2): e00036619, 2020. graf
Artículo en Inglés | LILACS | ID: biblio-1055632

RESUMEN

Abstract: Cost-effectiveness analysis is essential in health decision making. Several countries use it as synthesis of evidence to incorporate health technologies. The protease inhibitors (PI) boceprevir (BOC) and telaprevir (TVR) are indicated for chronic hepatitis C treatment and were incorporated in guidelines worldwide. Pre-marketing clinical trials showed higher sustained virological response rates in relation to previous therapies, but the incorporation of PIs generated a significant financial impact. The aim of this study was to discuss the relevance of cost-effectiveness analysis through a study that involved the inclusion of PIs in a clinical protocol. The analysis was part of a real-life study that included patients infected with hepatitis C virus genotype 1 treated in a tertiary university hospital in Brazil. Triple therapies (TT) with ribavirin (RBV), peginterferon α-2a (Peg-INF α-2a) and BOC or TVR were compared to dual therapy with RBV and Peg-INF α-2a. Sensitivity analysis of the cost-effectiveness ratio indicated an 88.2% chance of TTs presenting a higher cost per cure. The incremental cost-effectiveness ratios (ICER) exceeded the Brazilian gross domestic product (GDP) per capita by three times in all proposed scenarios. The sensitivity of ICER showed an 88.4% chance of TT not being cost-effective. The impact of PI incorporation was negative and the conduct about this could have been different if a previous cost-effectiveness analysis had been conducted.


Resumo: A análise de custo-efetividade tem sido essencial para a tomada de decisões em saúde. Diversos países utilizam esse tipo de análise como síntese das evidências para incorporar as tecnologias em saúde. Os inibidores de protease (IPs) boceprevir (BOC) e telaprevir (TVR) são indicados para o tratamento da hepatite C crônica e foram incorporados nas diretrizes internacionais. Os ensaios clínicos pré-marketing demonstraram taxas mais altas de resposta virológica sustentada em relação às terapias anteriores, mas a incorporação dos IPs gerou um impacto financeiro significativo. O estudo teve como objetivo discutir a relevância da análise de custo-efetividade, através de um estudo que envolveu a inclusão de IPs em um protocolo clínico. A análise fez parte de um estudo de vida real que incluiu pacientes com infecção pelo vírus da hepatite C, genótipo 1, tratados em um hospital universitário terciário no Brasil. As terapias triplas (TTs) com ribavirina (RBV), peg-interferon α-2a (Peg-INF α-2a) e BOC ou TVR foram comparadas às terapias duplas com RBV e Peg-INF α-2a. A análise de sensibilidade da custo-efetividade indicou odds de 88,2% de TTs apresentarem custo mais elevado por paciente curado. Em todos os cenários propostos, as razões de custo-efetividade incremental (ICERs) superaram em três vezes o produto interno bruto (PIB) per capita brasileiro. A sensibilidade da ICER mostrou probabilidade de 88,4% das TTs não serem custo-efetivas. O impacto da incorporação dos IPs foi negativo, e a conduta teria sido diferente se tivesse sido realizada uma análise prévia de custo-efetividade.


Resumen: El análisis de coste-efectividad ha sido esencial para la toma de decisiones en salud. Diversos países utilizan este tipo de análisis como síntesis de evidencias para incorporar tecnologías en salud. Los inhibidores de proteasa (IPs) boceprevir (BOC) y telaprevir (TVR) se indican para el tratamiento de la hepatitis C crónica y fueron incorporados en directrices internacionales. Los ensayos clínicos pre-marketing demostraron tasas más altas de respuesta virológica sostenida, respecto a las terapias anteriores, pero la incorporación de los IPs generó un impacto financiero significativo. El objetivo del estudio fue discutir la relevancia del análisis de coste-efectividad, a través de un estudio que implicó la inclusión de IPs en un protocolo clínico. El análisis formó parte de un estudio de vida real que incluyó a pacientes con infección por el virus de la hepatitis C, genotipo 1, tratados en un hospital universitario terciario en Brasil. Las terapias triples (TTs) con ribavirina (RBV), peg-interferon α-2a (Peg-INF α-2a) y BOC o TVR se compararon con las terapias dobles con RBV y Peg-INF α-2a. El análisis de sensibilidad del coste-efectividad indicó odds de 88,2% de que las TTs presentaran un coste más elevado por paciente curado. En todos los escenarios propuestos, las razones de coste-efectividad incremental (ICERs) superaron tres veces el producto interno bruto (PIB) per cápita brasileño. La sensibilidad de la ICER mostró una probabilidad de que un 88,4% de las TTs no eran costo-efectivas. El impacto de la incorporación de los IPs fue negativo, y el resultado habría sido diferente si se hubiese realizado un análisis previo de coste-efectividad.


Asunto(s)
Humanos , Antivirales/uso terapéutico , Análisis Costo-Beneficio , Hepatitis C Crónica/tratamiento farmacológico , Oligopéptidos , Antivirales/economía , Polietilenglicoles , Ribavirina , Proteínas Recombinantes , Brasil , Prolina/análogos & derivados , Interferón-alfa , Hepacivirus , Años de Vida Ajustados por Calidad de Vida , Hepatitis C Crónica/economía , Quimioterapia Combinada , Interferón alfa-2 , Genotipo
2.
Rev. Soc. Bras. Med. Trop ; 51(6): 731-736, Nov.-Dec. 2018. tab
Artículo en Inglés | LILACS | ID: biblio-977101

RESUMEN

Abstract INTRODUCTION: Chronic hepatitis C is a leading cause of liver disease. Infection triggers an immediate immune response in the host that is mediated by humoral/cellular mechanisms. T cells respond to infection via secretion of cytokines, which inhibit or stimulate one another, leading to cytokine imbalance and ultimately affecting treatment. Studies using interferon (IFN) and ribavirin (RBV) showed that TCD8+ cells and cytokine levels are associated with sustainable virological response (SVR). However, studies that investigated the effects of triple therapy (TT) are limited. METHODS: The study included hepatitis C virus (HCV)+ RNA, naives, genotype 1, ≥18 years, and advanced fibrosis (F≥3) patients. Samples were collected at baseline and after 12 weeks (W12) of TT. Six cytokines were analyzed by flow cytometry. RESULTS: Of 31 patients, four were excluded (two deaths, one interrupted TT, and one F2 patient). Of the 27 remaining patients, 21 (78%) were cirrhotic. SVR was achieved in 63% of the patients. The patients had a mean age of 55.11 ± 10.03 years. Analyses at baseline showed that the chemokine CCL5/Regulated on Activation, Normal T Cell Expressed and Secreted (RANTES) (p=0.04) and interleukin (IL)-6 (p=0.02), which was associated with SVR. RANTES (p=0.04) and IL-8 (p=0.01) levels were associated with SVR at W12. CONCLUSIONS Similar to patterns observed during double therapy, IL-6, IL-8, and RANTES levels were associated with SVR in TT, indicating the potential role of interferon in immune response to hepatitis C virus.


Asunto(s)
Humanos , Masculino , Femenino , Oligopéptidos/administración & dosificación , Antivirales/administración & dosificación , Prolina/análogos & derivados , Citocinas/sangre , Hepatitis C Crónica/tratamiento farmacológico , Prolina/administración & dosificación , Estudios Prospectivos , Resultado del Tratamiento , Carga Viral , Hepatitis C Crónica/sangre , Quimioterapia Combinada , Citometría de Flujo , Genotipo , Persona de Mediana Edad
3.
Rev. Soc. Bras. Med. Trop ; 51(2): 146-154, Mar.-Apr. 2018. tab, graf
Artículo en Inglés | LILACS | ID: biblio-897067

RESUMEN

Abstract INTRODUCTION: Licensed for chronic hepatitis C treatment in 2011, the protease inhibitors (PIs) telaprevir (TVR) and boceprevir (BOC), which have high sustained viral responses (SVR), ushered a new era characterized by the development of direct-action drugs against the hepatitis C virus (HCV). The aim of this study was to analyze the effectiveness and safety of BOC and TVR administered with pegylated interferon and ribavirin and to share the experience of a Brazilian reference center. METHODS: A retrospective descriptive study was conducted in patients with HCV genotype 1 infection who started treatment between July 2013 and December 2015. Data were collected using a computerized system. RESULTS: A total of 115 subjects were included, of which 58 (50.4 %) had liver cirrhosis and 103 (89.6 %) used TVR. The overall SVR rate was 61.7 % (62.1 % for TVR and 58.3 % for BOC). The presence of cirrhosis was associated with a lower SVR rate, whereas patients who relapsed after prior therapy had a greater chance of showing SVR than did non-responders. The incidence of adverse drug reactions (ADRs) was high. Almost all patients (~100 %) presented with hematologic events. Furthermore, treatment had to be discontinued in 15 subjects (13 %) due to severe ADRs. CONCLUSIONS: In conclusion, the SVR rates in our study were lower than those reported in pre-marketing studies but were comparable to real-life data. ADRs, particularly hematological ADRs, were more common compared to those in previous studies and resulted in a high rate of treatment discontinuity.


Asunto(s)
Humanos , Masculino , Femenino , Adulto , Anciano , Antivirales/administración & dosificación , Inhibidores de Proteasas/administración & dosificación , Hepacivirus/genética , Hepatitis C Crónica/tratamiento farmacológico , Oligopéptidos/administración & dosificación , Oligopéptidos/efectos adversos , Antivirales/efectos adversos , Polietilenglicoles/administración & dosificación , Polietilenglicoles/efectos adversos , Inhibidores de Proteasas/efectos adversos , Ribavirina/administración & dosificación , Ribavirina/efectos adversos , Proteínas Recombinantes/administración & dosificación , Proteínas Recombinantes/efectos adversos , Prolina/administración & dosificación , Prolina/análogos & derivados , Prolina/efectos adversos , Estudios Retrospectivos , Resultado del Tratamiento , Interferón-alfa/administración & dosificación , Interferón-alfa/efectos adversos , Hepacivirus/efectos de los fármacos , Hepatitis C Crónica/genética , Hepatitis C Crónica/virología , Quimioterapia Combinada , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos , Interferón alfa-2 , Genotipo , Persona de Mediana Edad
4.
Rev. Soc. Bras. Med. Trop ; 51(1): 14-20, Jan.-Feb. 2018. tab
Artículo en Inglés | LILACS | ID: biblio-897052

RESUMEN

Abstract INTRODUCTION: In 2013, combination therapy using peginterferon, ribavirin, and boceprevir or telaprevir was introduced to treat hepatitis C virus genotype 1 infection in Brazil. The effectiveness of this therapy in four Brazilian regions was evaluated. METHODS: Clinical and virological data were obtained from patients of public health institutions in five cities, including sustained virological response (SVR) and side effects. Patients with advanced fibrosis (F3/4), moderate fibrosis (F2) for > 3 years, or extra-hepatic manifestations were treated according to Ministry of Health protocol. Treatment effectiveness was verified by using bivariate and multivariate analysis; p-values of < 0.05 were considered significant. RESULTS: Of 275 patients (64.7% men; average age, 57 years old), most (61.8%) were treatment-experienced; 53.9% had subgenotype 1a infection, 85.1% had advanced fibrosis, and 85.5% were treated with telaprevir. SVR was observed in 54.2%. Rapid virological response (RVR) was observed in 54.6% of patients (data available for 251 patients). Overall, 87.5% reported side effects and 42.5% did not complete treatment. Skin rash, severe infection, and death occurred in 17.8%, 2.5%, and death in 1.4% of cases, respectively. SVR was associated with treatment completion, RVR, and anemia. CONCLUSIONS: The effectiveness of hepatitis C virus triple therapy was lower than that reported in phase III clinical trials, possibly owing to the prioritized treatment of patients with advanced liver fibrosis. The high frequency of side effects and treatment interruptions observed supported the decision of the Brazilian authorities to suspend its use when safer and more effective drugs became available in 2015.


Asunto(s)
Humanos , Masculino , Femenino , Adulto , Anciano , Inhibidores de Proteasas/administración & dosificación , Hepacivirus/genética , Hepatitis C Crónica/tratamiento farmacológico , Oligopéptidos/administración & dosificación , Ribavirina/administración & dosificación , Prolina/administración & dosificación , Prolina/análogos & derivados , Protocolos Clínicos , Interferones/administración & dosificación , Resultado del Tratamiento , Hepatitis C Crónica/virología , Quimioterapia Combinada , Respuesta Virológica Sostenida , Genotipo , Persona de Mediana Edad
5.
Clinics ; 72(6): 378-385, June 2017. tab, graf
Artículo en Inglés | LILACS | ID: biblio-840088

RESUMEN

OBJECTIVE: To evaluate the effectiveness and safety of first-generation protease inhibitors for the treatment of genotype 1 hepatitis C virus-infected patients at Brazilian reference centers. METHODS: This multicenter cross-sectional study included hepatitis C virus genotype 1 monoinfected patients treated with Peg-interferon, ribavirin, and either boceprevir (n=158) or telaprevir (n=557) between July 2013 and April 2014 at 15 reference centers in Brazil. Demographic, clinical, virological, and adverse events data were collected during treatment and follow-up. RESULTS: Of the 715 patients, 59% had cirrhosis and 67.1% were treatment-experienced. Based on intention-to-treat analysis, the overall sustained viral response was 56.6%, with similar effectiveness in both groups (51.9% for boceprevir and 58% for telaprevir, p=0.190). Serious adverse events occurred in 44.2% of patients, and six deaths (0.8%) were recorded. Cirrhotic patients had lower sustained viral response rates than non-cirrhotic patients (46.9% vs. 70.6%, p<0.001) and a higher incidence of serious adverse events (50.7% vs. 34.8%, p<0.001). Multivariate analysis revealed that sustained viral response was associated with the absence of cirrhosis, viral recurrence after previous treatment, pretreatment platelet count greater than 100,000/mm3, and achievement of a rapid viral response. Female gender, age>65 years, diagnosis of cirrhosis, and abnormal hemoglobin levels/platelet counts prior to treatment were associated with serious adverse events. CONCLUSION: Although serious adverse events rates were higher in this infected population, sustained viral response rates were similar to those reported for other patient cohorts.


Asunto(s)
Humanos , Masculino , Femenino , Persona de Mediana Edad , Anciano , Antivirales/administración & dosificación , Hepacivirus/genética , Hepatitis C Crónica/tratamiento farmacológico , Inhibidores de Proteasas/administración & dosificación , Brasil , Estudios Transversales , Genotipo , Hepatitis C Crónica/virología , Interferón-alfa/administración & dosificación , Oligopéptidos/administración & dosificación , Polietilenglicoles/administración & dosificación , Prolina/administración & dosificación , Prolina/análogos & derivados , Proteínas Recombinantes/administración & dosificación , ARN Viral/genética , Resultado del Tratamiento
6.
Ann. hepatol ; 16(2): 312-317, Mar.-Apr. 2017. tab, graf
Artículo en Inglés | LILACS | ID: biblio-887238

RESUMEN

ABSTRACT The addition of the new protease inhibitors (PIs) to peg-interferon (IFN) and ribavirin (RBV), approved for chronic hepatitis C, has clearly improved sustained virological response (SVR) rates although several adverse events have been reported with this regimens, including mild hematological toxicity. Moreover, severe pancytopenia and aplastic anemia during triple therapy with telaprevir has recently been described in seven patients. We report here two cases of severe agranulocytosis/aplastic anemia using boceprevir or simeprevir in interferon-based combination and 2 additional cases of severe myelosupression in IFN-free therapy with sofosbuvir and simeprevir plus RBV. Our observations suggest that PIs could have a sort of class-effect in developing severe hematologic toxicity or, at least, an additive interaction with other potentially myelotoxic agents such as IFN or RBV that are used in the classical regimens against HCV. Unfortunately, the mechanisms behind this phenomenon are currently unknown. In conclusion, given the lifethreatening character of these complications, close monitoring is mandatory in patients under PIs based therapy to promptly detect serious hematological toxicities and to carefully evaluate treatment discontinuation. Prospective studies assessing the usefulness of RBV in the era of new IFN-free combinations are needed.


Asunto(s)
Humanos , Inhibidores de Proteasas/efectos adversos , Enfermedades de la Médula Ósea/inducido químicamente , Enfermedades de la Médula Ósea/terapia , Prolina/análogos & derivados , Hepatitis C/tratamiento farmacológico , Simeprevir/efectos adversos , Anemia Aplásica/inducido químicamente , Anemia Aplásica/terapia , Índice de Severidad de la Enfermedad , Examen de la Médula Ósea , Prolina/efectos adversos , Valor Predictivo de las Pruebas , Factores de Riesgo , Resultado del Tratamiento , Hepatitis C/diagnóstico , Resultado Fatal , Quimioterapia Combinada
7.
Braz. j. med. biol. res ; 49(7): e5300, 2016. tab, graf
Artículo en Inglés | LILACS | ID: lil-785056

RESUMEN

The aim of this study was to determine risk factors for adverse events (AE)-related treatment discontinuation and severe anemia among patients with chronic hepatitis C virus (HCV) genotype 1 infection, treated with first-generation protease inhibitor (PI)-based therapy. We included all patients who initiated treatment with PI-based therapy at a Brazilian university hospital between November 2013 and December 2014. We prospectively collected data from medical records using standardized questionnaires and used Epi Info 6.0 for analysis. Severe anemia was defined as hemoglobin ≤8.5 mg/dL. We included 203 patients: 132 treated with telaprevir (TVR) and 71 treated with boceprevir (BOC). AE-related treatment discontinuation rate was 19.2% and anemia was the main reason (38.5%). Risk factors for treatment discontinuation were higher comorbidity index (OR=1.85, CI=1.05-3.25) for BOC, and higher bilirubin count (OR=1.02, CI=1.01-1.04) and lower BMI (OR=0.98, CI=0.96-0.99) for TVR. Severe anemia occurred in 35 (17.2%) patients. Risk factors for this outcome were lower estimated glomerular filtration rate (eGFR; OR=0.95, CI=0.91-0.98) for patients treated with TVR, and higher comorbidity index (OR=2.21, CI=1.04-4.67) and ribavirin dosage (OR=0.84, CI=0.72-0.99) for those treated with BOC. Fifty-five (57.3%) patients treated with TVR and 15 (27.3%) patients treated with BOC achieved sustained virological response (SVR). Among patients who received TVR and interrupted treatment due to AE (n=19), only 26.3% (n=5) achieved SVR (P=0.003). Higher number of comorbidities, lower eGFR and advanced liver disease are associated with severe anemia and early treatment cessation, which may compromise SVR achievement.


Asunto(s)
Humanos , Masculino , Femenino , Adulto , Persona de Mediana Edad , Anciano , Adulto Joven , Anemia/etiología , Hepatitis C Crónica/tratamiento farmacológico , Oligopéptidos/administración & dosificación , Prolina/análogos & derivados , Inhibidores de Proteasas/administración & dosificación , Antivirales/administración & dosificación , Tasa de Filtración Glomerular , Hepatitis C Crónica/complicaciones , Hepatitis C Crónica/virología , Interferón-alfa/administración & dosificación , Modelos Logísticos , Oligopéptidos/efectos adversos , Polietilenglicoles/administración & dosificación , Prolina/administración & dosificación , Prolina/efectos adversos , Estudios Prospectivos , Inhibidores de Proteasas/efectos adversos , Proteínas Recombinantes/administración & dosificación , Ribavirina/administración & dosificación , Factores de Riesgo , Índice de Severidad de la Enfermedad , Estadísticas no Paramétricas , Respuesta Virológica Sostenida , Factores de Tiempo , Insuficiencia del Tratamiento
8.
Braz. j. infect. dis ; 18(4): 454-456, Jul-Aug/2014.
Artículo en Inglés | LILACS | ID: lil-719308

RESUMEN

Approximately 170 million people are infected with hepatitis C, and the sustained virological response rate to treatment with pegylated interferon and ribavirin is 30-50%. In an attempt to improve the chances of cure, boceprevir is being added to therapy, but it is associated with an increased incidence of adverse events. We herein report a case of acute pancreatitis developed during treatment with pegylated interferon, ribavirin and boceprevir. Boceprevir was the most likely cause of drug-associated pancreatitis after the most common causes were ruled out, since this adverse event had not occurred when the patient had previously been exposed to pegylated interferon and ribavirin and there was no recurrence of the episode of pancreatitis when these two drugs were reintroduced. Acute pancreatitis is a rare adverse event associated with boceprevir therapy, but a potentially fatal event. Sequential determination of pancreatic enzymes should be considered during hepatitis C treatment with boceprevir.


Asunto(s)
Adulto , Humanos , Masculino , Antivirales/efectos adversos , Pancreatitis/inducido químicamente , Prolina/análogos & derivados , Enfermedad Aguda , Antivirales/uso terapéutico , Quimioterapia Combinada , Hepatitis C Crónica/tratamiento farmacológico , Interferón-alfa/uso terapéutico , Pancreatitis/diagnóstico , Polietilenglicoles/uso terapéutico , Prolina/efectos adversos , Proteínas Recombinantes/uso terapéutico , Ribavirina/uso terapéutico
9.
J. bras. med ; 102(1)jan.-fev. 2014. graf, ilus, tab
Artículo en Portugués | LILACS | ID: lil-712210

RESUMEN

A infecção pelo vírus da hepatite C (HCV) é importante causa de hepatite crônica, cirrose e carcinoma hepatocelular, sendo razão para a indicação de transplante hepático no mundo industrializado (Sherlock, 1995). Várias estratégias de tratamento da hepatite C foram empregadas ao longo dos últimos anos. O interferon peguilado em monoterapia ou combinado à ribavirina tornou-se tratamento padrão. Em 2011, foram introduzidos os inibidores de protease. Em dezembro de 2013, uma nova geração de drogas tem conferido resultados auspiciosos à terapia.


The hepatitis C virus infection (HCV) is an important cause of chronic hepatitis, cirrhosis and hepatocellular carcinoma, which leads indication for liver transplantation in the industrialized world (Sherlock, 1995). Many treatment strategies for hepatitis C were used for the latest years. Pegylated interferon monotherapy or combined to the ribavirin became a standard treatment. In 2011, protease inhibitors were introduced. In December 2013, a new generation drugs have been presented auspicious results to the therapy.


Asunto(s)
Humanos , Masculino , Femenino , Hepacivirus , Hepatitis C Crónica/tratamiento farmacológico , Hepatitis C Crónica/virología , Inhibidores de Proteasas/uso terapéutico , Antivirales/uso terapéutico , Quimioterapia Combinada , Inhibidores de Proteasas/administración & dosificación , Interferón-alfa/administración & dosificación , Interferón-alfa/uso terapéutico , Oligopéptidos/administración & dosificación , Oligopéptidos/uso terapéutico , Prolina/análogos & derivados , Ribavirina/administración & dosificación , Ribavirina/uso terapéutico
10.
Braz. j. infect. dis ; 17(2): 194-204, Mar.-Apr. 2013. ilus, tab
Artículo en Inglés | LILACS | ID: lil-673199

RESUMEN

The standard of care therapy of chronic hepatitis C with the combination of pegylated interferon and ribavirin for 24 or 48 weeks was a remarkable accomplishment of the past decade. However, sustained virological responses rates of about 80% (genotypes 2-3) and 50% (geno 3 type 1) were not satisfactory especially for patients infected with genotype 1. Important advances in the biology of HCV have made possible the development of the direct-acting antiviral agents boceprevir and telaprevir with substantial increase in the rates of sustained virological response with shorter duration of therapy for a large number of patients. However, the complexity of triple therapy is higher and several new side effects are expected suggesting greater expertise in the patient management. Anemia and disgeusia are frequent with boceprevir while cutaneous rash, ranging from mild to severe, is expected with telaprevir. Higher risk of drug-drug interactions demand further clinical consideration of the previous well-known adverse events of pegylated interferon and ribavirin. Identification and prompt management of these potential new problems with boceprevir and telaprevir are crucial in clinical practice for optimizing treatment and assuring safety outcomes to HCV-genotype 1 patients.


Asunto(s)
Humanos , Antivirales/efectos adversos , Hepatitis C Crónica/tratamiento farmacológico , Oligopéptidos/efectos adversos , Prolina/análogos & derivados , Inhibidores de Proteasas/efectos adversos , Interacciones Farmacológicas , Quimioterapia Combinada , Genotipo , Hepacivirus/genética , Prolina/efectos adversos
12.
Gastroenterol. latinoam ; 22(2): 148-151, abr.-jun. 2011. tab, graf
Artículo en Español | LILACS | ID: lil-661807

RESUMEN

The patient who fails to an interferon based treatment with or without ribavirin represents a major challenge for the clinician. In the initial evaluation a detailed history of the first course of treatment is critical, since it largely determines the likelihood of response to retreatment. In addition, the use of adequate doses of ribavirin and excellent adherence are key for a successful therapy. During re-treatment, a viral load detectable at 12 weeks at any level is considered an indication to discontinue treatment because of the low probability of achieving sustained response. There are new direct antiviral agents (protease inhibitors) that have been shown to increase response rate in patients who previously failed treatment, nevertheless, these drugs have limitations, such as high cost, activity restricted to certain genotypes, additional adverse effects and low response in previous null-responders. There is great optimism in the development of multiple new therapies with different mechanisms of action that promise to significantly increase the chances of eradicating the virus in these difficult to treat patients.


El paciente que ha fallado a un tratamiento sobre la base de interferón, con o sin ribavirina representa un desafío importante para el clínico. En su enfrentamiento inicial es clave una historia detallada del primer curso de tratamiento, ya que en gran parte determina la posibilidad de respuesta a un re-tratamiento. Por otro lado, el uso de dosis adecuadas de ribavirina y una excelente adherencia son claves en el éxito de la terapia. Durante un re-tratamiento, una carga viral a las 12 semanas detectable en cualquier nivel se considera indicación de suspender el tratamiento por la baja probabilidad de lograr respuesta sostenida. Se debe considerar que existen nuevas drogas antivirales directas (inhibidores de proteasa) que han demostrado aumentar la tasa de respuesta en pacientes que previamente han fallado al tratamiento, no obstante, estas drogas tienen limitaciones tales como alto costo, efectividad restringida a algunos genotipos, efectos adversos adicionales y baja respuesta en pacientes respondedores nulos a un tratamiento previo. Existe gran optimismo en el desarrollo de múltiples nuevas terapias con diferentes mecanismos de acción que prometen aumentar en forma significativa la posibilidad de erradicar el virus en este grupo de pacientes difícil de tratar.


Asunto(s)
Humanos , Antivirales/uso terapéutico , Hepatitis C/tratamiento farmacológico , Interferón-alfa/uso terapéutico , Oligopéptidos/uso terapéutico , Prolina/uso terapéutico , Ribavirina/uso terapéutico , Prolina/análogos & derivados , Quimioterapia Combinada , Relación Dosis-Respuesta a Droga , Retratamiento
13.
Experimental & Molecular Medicine ; : 684-692, 2011.
Artículo en Inglés | WPRIM | ID: wpr-190966

RESUMEN

Recent epidemiologic studies clearly showed that early intensive glucose control has a legacy effect for preventing diabetic macrovascular complications. However, the cellular and molecular processes by which high glucose leads to macrovascular complications are poorly understood. Vascular smooth muscle cell (VSMC) dysfunction due to high glucose is a characteristic of diabetic vascular complications. Activation of nuclear factor-kappaB (NF-kappaB) may play a key role in the regulation of inflammation and proliferation of VSMCs. We examined whether VSMC proliferation and plasminogen activator inhibitor-1 (PAI-1) expression induced by high glucose were mediated by NF-kappaB activation. Also, we determined whether selective inhibition of NF-kappaB would inhibit proliferation and PAI-1 expression in VSMCs. VSMCs of the aorta of male SD rats were treated with various concentrations of glucose (5.6, 11.1, 16.7, and 22.2 mM) with or without an inhibitor of NF-kappaB or expression of a recombinant adenovirus vector encoding an IkappaB-alpha mutant (Ad-IkappaBalphaM). VSMC proliferation was examined using an MTT assay. PAI-1 expression was assayed by real-time PCR and PAI-1 protein in the media was measured by ELISA. NF-kappaB activation was determined by immunohistochemical staining, NF-kappaB reporter assay, and immunoblotting. We found that glucose stimulated VSMC proliferation and PAI-1 expression in a dose-dependent manner up to 22.2 mM. High glucose (22.2 mM) alone induced an increase in NF-kappaB activity. Treatment with inhibitors of NF-kappaB such as MG132, PDTC or expression of Ad-IkappaB-alphaM in VSMCs prevented VSMC proliferation and PAI-1 expression induced by high glucose. In conclusion, inhibition of NF-kappaB activity prevented high glucose-induced VSMC proliferation and PAI-1 expression.


Asunto(s)
Animales , Masculino , Ratas , Aorta/citología , Enfermedades Cardiovasculares/prevención & control , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Complicaciones de la Diabetes/prevención & control , Regulación de la Expresión Génica/efectos de los fármacos , Glucosa/inmunología , Leupeptinas/farmacología , Músculo Liso Vascular/citología , Miocitos del Músculo Liso/citología , FN-kappa B/antagonistas & inhibidores , Inhibidor 1 de Activador Plasminogénico/genética , Prolina/análogos & derivados , Ratas Sprague-Dawley , Tiocarbamatos/farmacología
14.
Mem. Inst. Oswaldo Cruz ; 104(8): 1055-1062, Dec. 2009. ilus
Artículo en Inglés | LILACS | ID: lil-538164

RESUMEN

Proline racemase is an important enzyme of Trypanosoma cruzi and has been shown to be an effective mitogen for B cells, thus contributing to the parasite's immune evasion and persistence in the human host. Recombinant epimastigote parasites overexpressing TcPRAC genes coding for proline racemase present an augmented ability to differentiate into metacyclic infective forms and subsequently penetrate host-cells in vitro. Here we demonstrate that both anti T. cruzi proline racemase antibodies and the specific proline racemase inhibitor pyrrole-2-carboxylic acid significantly affect parasite infection of Vero cells in vitro. This inhibitor also hampers T. cruzi intracellular differentiation.


Asunto(s)
Animales , Isomerasas de Aminoácido/antagonistas & inhibidores , Inhibidores Enzimáticos/farmacología , Interacciones Huésped-Parásitos/fisiología , Prolina/análogos & derivados , Trypanosoma cruzi/enzimología , Chlorocebus aethiops , Microscopía Electrónica de Rastreo , Prolina/farmacología , Trypanosoma cruzi/fisiología , Trypanosoma cruzi/ultraestructura , Células Vero
15.
Indian J Biochem Biophys ; 1989 Apr; 26(2): 126-8
Artículo en Inglés | IMSEAR | ID: sea-28862

RESUMEN

A method has been described for the detection and estimation of 3,4-dehydroproline using initial oxidation with isatin or H2O2 and subsequent reaction with p-dimethylamino benzaldehyde (Ehrlich reagent). The method is sensitive enough to detect as low as 0.6 micrograms of 3,4-dehydroproline/sq. cm on paper chromatogram. 3,4-dehydroproline could also be estimated by the classical H2O2-oxidation procedure employed for hydroxyproline apparently yielding the same chromophore on a molar basis. However, when estimated by the chloramine-T oxidation method, its sensitivity was only 1/100th of that of 4-hydroxyproline. The usefulness of these procedures in the detection and estimation of 3,4-dehydroproline has been described.


Asunto(s)
Fenómenos Químicos , Química , Cromatografía en Papel/métodos , Prolina/análogos & derivados
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