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.

Evaluation of the total hepatitis C virus core antigen assay in determining viraemia in Egyptian patients with chronic hepatitis C

Hepatitis C virus [HCV] is an important etiologic agent for chronic liver diseases in Egypt. Positivity of anti-HCV antibodies indicates past or current infection and in contrast to molecular detection of HCV-RNA does not give any indication about viral replication. Several problems still persist when RT-PCR is used for screening of patients. Recently, the availability of an anti-core antigen monoclonal antibody allowed development of an enzyme-linked immunosorbent assay [ELISA] detecting and quantifying total HCV core Ag [C-Ag] in peripheral blood of HCV-infected patients. The aim of this study is to evaluate the usefulness of the total HCV C-Ag in determining viremia compared to HCV-RNA detected by RT-PCR among anti-HCV positive Egyptian patients. In this study, 143 anti-HCV antibody positive patients were tested for HCV-RNA by PCR and HCV-Core antigen to evaluate the sensitivity and specificity of the latter. Among those 116 cases [81.11%] were HCV-RNA+ve and 111 [77.68] cases were HCV-Core Ag +ve, while 27 cases [18.84%] were HCV- RNA negative and 32[22.32%] were HCV-Core Ag -ve. Out of 116 patients who were HCV- RNA +ve, 111 [95.65%] were HCV-Core Ag +ve also, while 5 [4.35%] cases all with low viral load were negative. The sensitivity, specificity, PPV and NPV of HCV-Core Ag when referred to HCV-RNA were 95.7%, 100%, 100% and 84.4% respectively. Thus positive total HCV Core Ag could be a useful test in clinical practice to determine HCV viremia with a sensitivity and specificity close to that of PCR assays. However, a negative test is not reliable to exclude low viral load

Significance of the hepatitis C virus (HCV) core antigen as an alternative plasma marker of active HCV infection.

PURPOSE: To evaluate the role of core antigen (Ortho trak-C assay) as a marker of active HCV infection in comparison to HCV RNA as detected by reverse transcription polymerase chain reaction (RT-PCR). METHODS: This evaluation was carried out during January 2000 to December 2003 in HCV infected individuals who were treatment naomicronve or were on anti-viral therapy. Additionally, sequential plasma samples from patients on clinical follow-up were included in this study. A total of 167 samples from 61 patients were tested by trak-C and RT-PCR. HCV RNA detection was achieved by a RT-PCR. Trak-C assay results were also compared in a limited proportion of these samples with known HCV viral load and genotype. RESULTS: Of 167 samples tested, 56.9% were RNA positive and 43.1% were RNA negative while 50.3% were trak-C positive and 49.7% were trak-C negative, yielding a sensitivity of 85.3% and a specificity of 95.8% for the trak-C assay (Kappa co-efficient = 0.8). The concentration of HCVcAg and HCV RNA showed significant correlation (n=38, r=0.334, P =0.04). The trak-C assay detected the most prevalent HCV genotypes in India without significant difference (P =0.335). The difference between mean absorbance values of HCV RNA positive samples compared to HCV RNA negative samples in the trak-C assay was highly significant (P < 0.000). Qualitative results of trak-C assay and RT-PCR were comparable in 93% of follow-up samples. CONCLUSIONS: Trak-C assay can be recommended for confirmation of HCV infection and follow-up in laboratories with resource-poor facilities.

Evaluation of the HCV core antigen assay as a second-line supplemental test for diagnosis of active hepatitis c infection

Hepatitis C virus core [HCV] antigen assays have been produced to exclude infectious donations collected the preseroconversion window phase. For the same purpose, we evaluated the specificity and sensitivity of a novel hepatitis C virus core antigen detection immunoassay and the applications of this assay in clinical diagnosis. Samples were collected from 30 anti-HCV antibody negative healthy subjects [Gi], and 46 anti-HCV antibody positive patients [G2]. All included samples were subjected to HCV core antigen and HCV-RNA PCR. Among the 46 anti-HCV Ab positive samples, HCV core antigen was positive in 38 samples from 40 samples positive for HCV-RNA with sensitivity of 95% [38/40]. All the 30 anti-HCV Ab negative samples [n=30] were negative for both HCV core antigen and HCV-RNA with specificity of 100% .There was no significant variation in the sensitivity of HCV core antigen between genotype 1 [100%] and genotype 4 [94.5%]. Viral load in HCV core antigen positive samples [906653 +/- 133803] was significantly increased than that of HCV core antigen negative samples [16342 +/- 5245] with P value<0.05. HCV core antigen assay is a useful method in screening strategy of HCV infection and provides a reliable means of distinguishing between current and cleared HCV infections that is well correlated with HCV-RNA testing

Prevalence of HCV infection in patients on haemodialysis: survey by antibody and core antigen detection.

PURPOSE: The present study was undertaken to determine the prevalence of HCV infection by antibody testing and HCV core antigen (HCVcAg) determination by ELISA in haemodialysis patients and to evaluate the HCV c Ag assay in the detection of HCV infected patients on haemodialysis. MATERIALS AND METHODS: A total of 151 chronic renal failure patients on haemodialysis from May 2003 to October 2004 were studied. One hundred patients out of 151 were followed for 2-5 months. All the patients were tested for anti HCV and HCV core antigen once a month. Anti HCV ELISA positive specimens were confirmed by RIBA. RESULTS: The overall prevalence of HCV infection was 13.23%. Antibody positivity was observed in 9.93% and HCVcAg alone was detected in 2.64%. One patient (0.66%) was initially positive for core antigen and later seroconverted. CONCLUSIONS: Screening for HCV antibodies alone does not exclude infection with HCV in patients on haemodialysis and HCVcAg may be a useful test for identifying HCV infected patients on haemodialysis in the early phase of infection before seroconversion.

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

Hepatitis B and C virus markers among new entrant medical students.

AIM: To investigate the presence of hepatitis B and C virus markers in new entrant medical students at the Faculty of Medicine, University of Kelaniya. METHOD: 456 students (mean age 24 years, SD 3.5, 257 men) were investigated before they were exposed to clinical work, using a questionnaire to assess sociodemographic factors and possible risk factors for contracting hepatitis B or C. Blood samples were tested for HBs Ag and anti HBs (n = 456), and anti-HCV (n = 162 randomly selected samples) with a third generation sandwich radioimmunoassay technique. RESULTS: The students were from 20 of the 25 districts in the country, although their distribution was not inform. A past history of hepatitis or jaundice was obtained from 24 (5.3%) and 6 (1.3%) students respectively. None of them had been vaccinated against hepatitis B. At least one risk factor for hepatitis B or C was present in 32 (7%) of them. None of the samples were positive for HBsAg or anti-HCV, and only two (0.44%) were positive for anti-HBs. CONCLUSION: Our results support the view that exposure to hepatitis B and C seems to be uncommon in this country, at least up to young adulthood. As most new entrant medical students are not immune to these infections there is a strong case to vaccinate them against hepatitis B before they are exposed to clinical work.

correlation between the presence of anti-HCV antibodies and HCV antigens in donors plasma, as determined by serological methods

Forty eight serum samples obtained from donor's and hepatitis patients, were included in this study to demonstrate the correlation between the antigens of the HCV and their antibodies in the plasma of the donors by using serological techniques. HCV-Ags were isolated and purified by using sucrose gradient technique, from serum samples positive for HCV-Ab. The HCV-Ags in serum samples and in fractions were detected by PHA assay, whereas, the antibodies Were detected by UBI.HCV EIA 4.0. The results indicates a 37.5% correlation beween the HCV-Ags and HCV-Ab is in the serum samples included in this study, also it indicate possibility of HCV transmission by routes other than that of blood transfusion and possiblity of finding a greater number of asymptomatic carriers. The results also demonstrates 70.8% of the samples were HCV positive whereas only 29.16% were HBV positive

Hepatitis B and C virus infection prevalence among women in Manila, the Philippines.

A seroepidemiological survey of HBsAg, HBeAg, anti-HBs, anti-HBc, anti-HBe and anti-HCV positivities was conducted in 1997 in Manila, The Philippines. Adult women (21 to 59 years of age) were invited to donate peripheral blood for the study, and 50 people volunteered. They were nonsmokers, nonhabitual drinkers, and mostly married; none of them was a professional blood donor. The serum assay showed that all subjects were negative for HBsAg and HBeAg. Overall, a half (50%) of the study subjects were positive for any one of the HBV infection markers (i.e. HBV+). The older group (25 women at 36-59 years of age) showed significantly higher prevalence than the younger group (25 women at 21-35 years of age) of positivity to all three HBV antibody markers and therefore HBV positivity also. None of the study subjects was positive for anti-HCV. Comparison of the present findings with the results reported in the literature for the 1980s suggests that the risk of HBV infection and most probably that of HCV infection also has decreased in this 10-year period in the Philippines.