Improving Diagnosis of Hepatitis C Virus Infection Using Hepatitis C Core Antigen Testing in a Resource-Poor Setting

Abstract INTRODUCTION: We compared the hepatitis C virus (HCV) core antigen test with the HCV RNA assay to confirm anti-HCV results to determine whether the HCV core antigen test could be used as an alternative confirmatory test to the HCV RNA test. METHODS: Sera from 156 patients were analyzed for anti-HCV and HCV core antigen using a chemiluminescent microparticle immunoassay (Architect i2000SR) and for HCV RNA using the artus HCV RG RT-PCR Kit (QIAGEN) in a Rotor-Gene Q instrument. RESULTS: The diagnostic sensitivity, specificity, and positive and negative predictive values of the HCV core antigen assay compared to the HCV RNA test were 77.35%, 100%, 100%, and 89.38%, respectively. HCV core antigen levels showed a good correlation with those from HCV RNA quantification (r =0.872). However, 13 samples with a viral load of less than 4000 IU/mL were negative in the HCV core antigen assay. All gray-zone reactive samples were also RNA positive and were positive on repeat testing. CONCLUSIONS: The Architect HCV core antigen assay is highly specific and has an excellent positive predictive value. At the present level of sensitivity (77%), the study is still relevant in a low-income setting in which most of the HCV-positive patients would go undiagnosed, since HCV RNA testing is not available and/or not affordable. HCV core antigen testing can also help determine the true burden of infection in a population, considering the fact that almost 50% of the anti-HCV positive cases are negative for HCV RNA.

IgG1 and IgG4 antibodies against core and NS3 antigens of hepatitis C virus

Abstract INTRODUCTION: IgG subclasses involved in the immune response to hepatitis C virus (HCV) antigens have been rarely studied. We investigated the immune response mediated by IgG1 and IgG4 antibodies against the recombinant core and NS3 antigens in patients with chronic hepatitis C. METHODS: Sixty patients infected with HCV genotype 1 without antiviral treatment and 60 healthy subjects participated in the study. Serum levels of alanine aminotransferase, HCV viremia, and the presence of cryoglobulinemia and liver fibrosis were determined. We investigated the serum IgG1 and IgG4 antibodies against recombinant HCV core and NS3 non-structural protein antigens using amplified indirect ELISA. RESULTS: Anti-core and anti-NS3 IgG1 antibodies were detected in 33/60 (55%) and 46/60 (77%) patients, respectively, whereas only two healthy control samples reacted with an antigen (NS3). Anti-core IgG4 antibodies were not detected in either group, while 30/60 (50%) patients had anti-NS3 IgG4 antibodies. Even though there were higher levels of anti-NS3 IgG4 antibodies in patients with low viremia (< 8 × 105 IU/mL), IgG1 and IgG4 antibody levels did not correlate with ALT levels, the presence of cryoglobulinemia, or degree of hepatic fibrosis. High production of anti-core and anti-NS3 IgG1 antibodies was observed in chronic hepatitis C patients. In contrast, IgG4 antibodies seemed to only be produced against the NS3 non-structural antigen and appeared to be involved in viremia control. CONCLUSIONS: IgG1 antibodies against structural and non-structural antigens can be detected in chronic hepatitis C, while IgG4 antibodies seem to be selectively stimulated by non-structural HCV proteins, such as the NS3 antigen.

Early predictive efficacy of core antigen on antiviral outcomes in genotype 1 hepatitis C virus infected patients

Response-guided therapy is of limited use in developing countries because hepatitis C virus RNA detection by sensitive molecular methods is time- and labor-consuming and expen- sive. We evaluated early predictive efficacy of serum hepatitis C virus core antigen kinetics on sustained virologic response in patients with genotype 1 hepatitis C virus during pegylated interferon plus ribavirin treatment. For 478 patients recruited, hepatitis C virus RNAs were detected at baseline, and at weeks 4, 12, 24, 48, and 72 using Cobas TaqMan. Architect hepatitis C virus core antigen was performed at baseline, and weeks 4 and 12. Predictive values of hepatitis C virus core antigen on sustained virologic response were compared to hepatitis C virus RNA. In the first 12 weeks after treatment initiation the dynamic patterns of serum hepatitis C virus core antigen and hepatitis C virus RNA levels were similar in sustained virologic response, relapse, and null response patients groups. Although areas under the receiver operating characteristics curves of hepatitis C virus core antigen were lower than those of hepatitis C virus RNA at the same time points, modeling analysis showed that undetectable hepatitis C virus core antigen (rapid virological response based on hepatitis C virus core antigen) had similar positive predictive value on sustained virologic response to hepatitis C virus RNA at week 4 (90.4% vs 93.3%), and hepatitis C virus core antigen decrease greater than 1 log10 IU/mL (early virological response based on hepatitis C virus core antigen) had similar negative predictive value to hepatitis C virus RNA at week 12 (94.1% vs 95.Z%). Analysis on the validation group demonstrated a positive predictivevalue of 97.5% in rapid virological response based on hepatitis C virus core antigen and a negative predictive value of 100% in early virological response based on hepatitis C virus core antigen. In conclusion, hepatitis C virus core antigen is comparable to hepatitis C virus RNA in predicting sustained virologic response of chronic genotype 1 hepatitis C virus infected patients, and can be used to guide anti-hepatitis C virus treatment, especially in resource-limited areas.

Inflammatory response of endothelial cells to hepatitis C virus recombinant envelope glycoprotein 2 protein exposure

The hepatitis C virus (HCV) encodes approximately 10 different structural and non-structural proteins, including the envelope glycoprotein 2 (E2). HCV proteins, especially the envelope proteins, bind to cell receptors and can damage tissues. Endothelial inflammation is the most important determinant of fibrosis progression and, consequently, cirrhosis. The aim of this study was to evaluate and compare the inflammatory response of endothelial cells to two recombinant forms of the HCV E2 protein produced in different expression systems (Escherichia coli and Pichia pastoris). We observed the induction of cell death and the production of nitric oxide, hydrogen peroxide, interleukin-8 and vascular endothelial growth factor A in human umbilical vein endothelial cells (HUVECs) stimulated by the two recombinant E2 proteins. The E2-induced apoptosis of HUVECs was confirmed using the molecular marker PARP. The apoptosis rescue observed when the antioxidant N-acetylcysteine was used suggests that reactive oxygen species are involved in E2-induced apoptosis. We propose that these proteins are involved in the chronic inflammation caused by HCV.

Hepatitis C: datos epidemiológicos de Tucumán y Argentina / Hepatitis C: epidemiological data from Tucumán and Argentina

Hemos entrado en un nuevo siglo, un nuevo milenio y al mismo tiempo en la 2a. década de la hepatitis C. En la actualidad existen en Tucumán y Argentina algunos estudios retrospectivos y otros probables a corto plazo, pero todavía son insuficientes para predecir estadísticamente cuál será la progresión de la enfermedad. Se encontró que en Tucumán y ciertas regiones de Argentina la prevalencia de hepatitis C es menor del 1 por ciento. Los factores de riesgo asociados a la misma en Tucumán son en su mayoría debido a transfusiones y la relevancia de la patología alcohólica en su progreso a la cronicidad. Los resultados obtenidos avalan la necesidad de que los gobiernos se interesen en el problema que la hepatitis C representa para la salud pública, destinando medios y recursos para el tratamiento gratuito en los sistemas sociales y también para investigación. Los datos epidemiológicos son cruciales en la prevención de la hepatitis C. Para contener la expansión de VHC primero debemos reconocer que la enfermedad existe, conocer su epidemiología, su cuadro clínico y los factores de riesgo para así evitar su contagio. La primera defensa contra cualquier enfermedad es el conocimiento.

Seroprevalencia de anti-VHC, coexistencia de AG-HBS, anti HBC y HIV, and algunos factores de riesgo en donantes anti VHC / The anti-HCV seroprevalence, the coexistence of AG-HBS, anti-HBC and VIH, and some risk factors in positive anti-HCV donors

La seroprevalencia de Anti-VHC, la coexistencia de Ag-HBs, Anti-HBc, HIV y algunos factores de riesgo en donantes Anti-VHC positivo del Banco de Sangre "Jesús Boada Boada" de Barquisimeto durante enero-junio de 1999, se determinó a través de un estudio descriptivo transversal,donde la población y muestra estuvo conformada por el total de donantes voluntarios de sangre (3381), de los cuales 47 resultaron Anti-VHC positivo según la prueba ABBOTT HCV EIA 3.0. Se encontró una seroprevalencia de 1,21 por ciento; el 17.02 por ciento resultaron positivos también para Anti-HBc y 4.26 por ciento tienen positividad simultanea Ag-Hbs y Anti-HBc. Se realizó a 27 donantes voluntarios seropositivos visitas domiciliarias para citarlos al Ambulatorio Urbano tipo II "Pueblo Nuevo" donde se aplicó una encuesta estructural mediante la entrevista. el 88,89 por ciento pertenecen al sexo masculino, el 77,78 por ciento se ubica entre los 15 y 35 años; entre los principales factores de riesgo se encontró que el 81,48 por ciento estuvo en contacto con agujas e instrumental no estéril ó de esterilidad dudosa, 59.09 por ciento tuvo heridas accidentales en barberías, el 76 por ciento con vida sexual activa 3 ó más parejas sexuales y el 100 por ciento son heterosexuales, con ocupación de bajo riesgo para adquirir la infección, desconocen la seropositividad de sus parejas sexuales y del grupo familiar con el cual conviven

Evolution of hepatitis C virus-specific T cell responses and cytokine production in chronic hepatitis C patients treated with high doses of interferon-alpha

OBJECTIVE: To assess the evolution of in vitro T cell response to hepatitis C virus (HCV) Core, E1, E2 and NS3 antigens in 10 patients with chronic hepatitis C, before, during and after a high dose interferon alpha (IFN-alpha) therapy, and to evaluate the influence of IFN-alpha on the in vivo and in vitro production of tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma). METHODS: T cell response to HCV antigens was evaluated by lymphoproliferation assays. In vivo and in vitro cytokine production was evaluated at weeks 0, 4, 8, and 12 of IFN-alpha therapy by enzyme immunoassays. RESULTS: In general, of all HCV antigens tested throughout the follow-up, those belonging to the Core region were the most immunostiumlatory. This observation was valid in IFN-alpha responders as well as IFN-alpha non-responders. The lymphoproliferative response to HCV antigens increased during IFN-alpha therapy. Serum levels of TNF-alpha were significantly increased in HCV patients, and six out of ten patients showed increased IFN-gamma serum levels. A significant decrease of IFN-gamma levels was observed during therapy and the same trend was seen for TNF-alpha. Mitogen-stimulated TNF-alpha and IFN-gamma production before therapy did not differ from that of normal controls, however, the cytokine production was reduced at week 4 of therapy, corresponding with a clinical improvement. A return to pretreatment values was observed after 8 weeks of therapy. CONCLUSIONS: a) Core antigens are the most immunostimulatory HCV antigens at the T cell level in chronic hepatitis C patients; b) High dose IFN-alpha therapy induces an increase in lymphoproliferative response to HCV antigens; c) Serum levels of TNF-alpha are increased in HCV patients; d) High dose IFN-alpha therapy induces a decrease in serum levels of IFN-gamma; e) High dose IFN-alpha therapy induces a transiently decreased mitogen-induced TNF-alpha and IFN-gamma production.

Comportamiento de la Hepatitis C en donantes de sangre / Hepatitis c in blood donors

Se realizó un estudio prospectivo de los donantes habituales de sangre de los bancos municipales de 10 de Octubre y Guanabacoa durante el año 1999, donde se encontraron 50 pacientes con el antígeno C positivo para la hepatitis. Estos pacientes fueron remitidos a nuestro hospital, donde se confeccionó historia clínica completa, se realizaron las pruebas funcionales hepáticas, ultrasonido, laparoscopia con biopsia y se trataron con interferón. Se observó que el 100 porciento eran asintomáticos, un 30 porciento mostró ligero aumento de la TGP. El 80 porciento presentó hepatomegalia detectable en el ultrasonido. Al realizarles la histopatología, el 72 porciento poseía una hepatitis crónica. El 60 porciento de la muestra recibió tratamiento con interferón alfa mostrando negativización del antígeno C de la hepatitis, pero a pesar de esto continuaron evolucionando a la cronicidad

Excreción de porfirinas e infección crónica por virus C de la hepatitis / Porphyrin excretion and chronic infection by hepatitis C virus

Eighteen patients with cirrhosis Child-Pough A, eight infected with hepatitis C virus, were studied. Urinary excretion of Ù aminolevulinic acid, porphobilinogen, coproporphyrins, uroporphyrins and fecal excretion of coproporphyrins and protoporphyrins were measured. Red blood cell protoporphyrin was also measured. There were no differences in the measured parameters between patients with or without hepatitis C virus infection. No patient had uroporphyrin excretion values over the normal range. Some patients had slight elevations in some parameters, but always below the values observed in porphyrias. In these group of patients, hepatitis C virus infection of its associated liver diasease do not cause detectable alterations in porphyrin metabolism

Prevalencia de marcadores de hepatitis b y c en diferentes grupos poblacionales de la Región Metropolitana de Honduras / Prevalence of hepatitis b and c markers in differents populations of Metropolitan Region of Honduras

La Hepatitis Viral es considerada una causa importante de morbilidad y mortalidad en el mundo entero. Con el desarrollo de nuevas pruebas serológicas ha sido posible determinar en una forma más precisa las tasas de portadores de estas infecciones virales. Para determinar la prevalencia de Hepatitis C en los grupos poblacionales seleccionados los investigadores estudiaron 1041 muestras de suero provenientes de estos grupos mencionados anteriormente, en el Departamento de Microbiología, UNAH, Tegucigalpa, Honduras; durante el segundo semestre de 1994. La seroprevalencia de antígeno de superficie de la Hepatitis B (HBsAg), Anticuerpos dirigidos contra el antígeno nuclear de Hepatitis B (Anti-HBc) y Anticuerpos contra Hepatitis C (Anti-HCV), fue determinada por métodos serológicos con ensayos inmunoenzimáticos comerciales de acuerdo a las instrucciones del fabricante (Ortho Diagnostic). Para propósitos de análisis se dividió el grupo estudiado en dos grandes grupos; grupo I sin riesgo y grupo II de riesgo. Conociendo que la Hepatitis B ocurre con mayor frecuencia en adultos cuyas ocupaciones, estilo de vida y comportamiento (particularmente homosexualidad y actividades sexuales promiscuas) los ubica a un mayor riesgo de contraer la infección

Seroprevalencia de marcadores de hepatis B y C en trabajadores del área de salud

Introducción : La vía percutánea es una de las más frecuentes y efectivas formas de contagio con los virus B y C. Por lo tanto los trabajadores del área tienen un riesgo importante de contagio. El presente estudio se realizó para evaluar la seroprevalencia de marcadores de infección con estos virus, y para medir la frecuencia