Evaluation of a recombinant multiepitope antigen for diagnosis of hepatitis C virus: A lower cost alternative for antigen production.

BACKGROUND: The most of the hepatitis C-infected patients remain undiagnosed until they develop severe liver damage or submitted for serological screening. OBJECTIVE: To evaluate a recombinant multiepitope protein for detection of IgG anti-hepatitis C virus. METHOD: A synthetic gene was cloned, expressed in Escherichia coli, and the recombinant protein was purified. Human serum panel consisted of 88 positives (20 HCV genotyped) and 376 negatives for hepatitis C, 6 positives for human acquired immunodeficiency virus, 6 syphilis positives, 6 hepatitis B positives were tested by IgG antihepatitis C virus using the protein by enzyme-linked immunosorbent assay. In addition, 20 positive (all genotyped samples) and 20 negative samples were also tested by immunoblot and dot blot assays. RESULTS: Positive hepatitis C sera were strongly reactive against the protein by immunoblot assay. In the dot blot assay, positive sera were reactive until 1:1000 dilution and there were no false positive results in the hepatitis C negative sera. In the enzyme-linked immunosorbent assay, positive and negative sera had significant discrimination. No cross-reaction was observed in samples positive for syphilis; human acquired immunodeficiency virus and hepatitis B. All 20 genotyped samples were positive by the three methods. CONCLUSION: The multiepitope protein used here has a lower cost compared to production of each antigen separately and could be an alternative for the serological diagnosis of hepatitis C.

Kinetics of hepatitis C virus load and hemodialysis: is there any influence of the reuse of dialysis membrane on HCV viremia?

BACKGROUND: Patients with chronic kidney disease (CKD) on regular hemodialysis are at increased risk of acquiring hepatitis C virus (HCV). Although controversial, a distinct dynamic of the HCV load has been reported in this group - a lower HCV viremia compared to non-uremic patients. The reasons for this remain unclear, but the host immune response related to the hemodialysis procedure and the reuse of dialysis membranes are the most investigated factors. METHODS: We analyzed the kinetics of HCV RNA viremia in 21 hemodialysis patients infected with genotype 1, through a highly sensitive quantitative method (real-time polymerase chain reaction), immediately before and at the end of the first use and the last reuse of the cellulose diacetate dialysis membrane. RESULTS: Initial HCV load did not correlate with demographic or biochemical parameters, but higher HCV viremia was associated with a longer time on hemodialysis (r = 0.44, p = 0.04). Although not significant, HCV RNA decreased in 11/21 (52.3%) patients after the first dialysis session (median 279,000 vs 176,000 IU/ml, p = 0.91). However, a significant increase in HCV RNA viremia was observed in 17/21 (80.9%) patients after the tenth session (median 187,000 vs 342,000 IU/ml, p = 0.009). CONCLUSIONS: Except for the first session of hemodialysis, we did not confirm a decrease in HCV viremia related to the time on hemodialysis or with the reuse of the dialysis membrane. Factors other than the reuse of the dialysis membrane might be involved in the multifaceted kinetics of HCV RNA in CKD patients on hemodialysis.

Occult hepatitis B virus infection in immunocompromised patients.

Occult hepatitis B infection is characterized by hepatitis B virus (HBV) DNA in the serum in the absence of hepatitis B surface antigen (HBsAg). We assessed occult HBV infection prevalence in two groups of immunocompromised patients (maintenance hemodialysis patients and HIV-positive patients) presenting HBsAg-negative and anti-HBc positive serological patterns, co-infected or not by HCV. Thirty-four hemodialysis anti-HIV negative patients, 159 HIV-positive patients and 150 blood donors who were anti-HBc positive (control group) were selected. HBV-DNA was detected by nested-PCR. Occult hepatitis B infection was not observed in the hemodialysis patients group but was found in 5% of the HIV-patients and in 4% of the blood donors. Immunosuppression in HIV positive patients was not a determining factor for occult HBV infection. In addition, no significant relationship between HBV-DNA and HCV co-infection in the HIV-positive patient group was found. A lack of significant associations was also observed between positivity for HBV-DNA and CD4 count, viral load and previous lamivudine treatment in these HIV-positive patients.

Occult hepatitis B virus infection in immunocompromised patients

Occult hepatitis B infection is characterized by hepatitis B virus (HBV) DNA in the serum in the absence of hepatitis B surface antigen (HBsAg). We assessed occult HBV infection prevalence in two groups of immunocompromised patients (maintenance hemodialysis patients and HIV-positive patients) presenting HBsAg-negative and anti-HBc positive serological patterns, co-infected or not by HCV. Thirty-four hemodialysis anti-HIV negative patients, 159 HIV-positive patients and 150 blood donors who were anti-HBc positive (control group) were selected. HBV-DNA was detected by nested-PCR. Occult hepatitis B infection was not observed in the hemodialysis patients group but was found in 5 percent of the HIV-patients and in 4 percent of the blood donors. Immunosuppression in HIV positive patients was not a determining factor for occult HBV infection. In addition, no significant relationship between HBV-DNA and HCV co-infection in the HIV-positive patient group was found. A lack of significant associations was also observed between positivity for HBV-DNA and CD4 count, viral load and previous lamivudine treatment in these HIV-positive patients.

The influence of occult infection with hepatitis B virus on liver histology and response to interferon treatment in chronic hepatitis C patients

Occult hepatitis B virus (HBV) infections have been identified in patients with chronic hepatitis C virus (HCV) infection, although the clinical relevance of occult HBV infection remains controversial. We searched for serum HBV DNA in 106 HBsAg negative/anti-HBc positive patients with chronic HCV infection and in 150 blood donors HBsAg negative/anti-HBc positive/anti-HCV negative (control group) by nested-PCR. HCV genotyping was done in 98 patients and percutaneous needle liver biopsies were performed in 59 patients. Fifty-two patients were treated for HCV infection with interferon alone (n=4) or combined with ribavirin (n=48) during one year. At the end and 24 weeks after stopping therapy, they were tested for HCV-RNA to evaluate the sustained virological response (SVR). Among the 106 HCV-positive patients, 15 (14 percent) were HBV-DNA positive and among the 150 HCV-negative blood donors, 6 (4 percent) were HBV-DNA positive. Liver biopsy gave a diagnosis of liver cirrhosis in 2/10 (20 percent) of the HBV-DNA positive patients and in 6/49 (12 percent) of the HBV-DNA negative patients. The degree of liver fibrosis and portal inflammation was similar in HCV-infected patients HBV-DNA, irrespective of HBV-DNA status. SVR was obtained in 37.5 percent of the HBV-DNA positive patients and in 20.5 percent of the HBV-DNA negative patients; this difference was not significant. In conclusion, these data suggested that occult HBV infection, which occurs at a relatively high frequency among Brazilian HCV-infected patients, was not associated with more severe grades of inflammation, liver fibrosis or cirrhosis development and did not affect the SVR rates when the patients were treated with interferon or with interferon plus ribavirin.

The influence of occult infection with hepatitis B virus on liver histology and response to interferon treatment in chronic hepatitis C patients.

Occult hepatitis B virus (HBV) infections have been identified in patients with chronic hepatitis C virus (HCV) infection, although the clinical relevance of occult HBV infection remains controversial. We searched for serum HBV DNA in 106 HBsAg negative/anti-HBc positive patients with chronic HCV infection and in 150 blood donors HBsAg negative/anti-HBc positive/anti-HCV negative (control group) by nested-PCR. HCV genotyping was done in 98 patients and percutaneous needle liver biopsies were performed in 59 patients. Fifty-two patients were treated for HCV infection with interferon alone (n=4) or combined with ribavirin (n=48) during one year. At the end and 24 weeks after stopping therapy, they were tested for HCV-RNA to evaluate the sustained virological response (SVR). Among the 106 HCV-positive patients, 15 (14%) were HBV-DNA positive and among the 150 HCV-negative blood donors, 6 (4%) were HBV-DNA positive. Liver biopsy gave a diagnosis of liver cirrhosis in 2/10 (20%) of the HBV-DNA positive patients and in 6/49 (12%) of the HBV-DNA negative patients. The degree of liver fibrosis and portal inflammation was similar in HCV-infected patients HBV-DNA, irrespective of HBV-DNA status. SVR was obtained in 37.5% of the HBV-DNA positive patients and in 20.5% of the HBV-DNA negative patients; this difference was not significant. In conclusion, these data suggested that occult HBV infection, which occurs at a relatively high frequency among Brazilian HCV-infected patients, was not associated with more severe grades of inflammation, liver fibrosis or cirrhosis development and did not affect the SVR rates when the patients were treated with interferon or with interferon plus ribavirin.

Hepatitis B virus DNA in sera of blood donors and of patients infected with hepatitis C virus and human immunodeficiency virus.

With the use of PCR, we searched for hepatitis B virus (HBV) DNA in serum samples from 415 HBsAg-negative, anti-HBc-positive patients: 150 were blood donors, 106 had only hepatitis C virus (HCV) infection, and 159 had human immunodeficiency virus (HIV) infection (of which 88 were HCV positive and 71 were HCV negative). HBV DNA was detected in 4% of blood donors, 3.4% of HIV- and HCV-positive patients, and 24% of HCV-positive patients.

Prevalence of HIV and Treponema pallidum infections in pregnant women in Campinas and their association with socio-demographic factors

The anonymous seroprevalence of HIV and syphilis was studied by collecting umbilical cord blood samples from 5,815 women who gave birth in Campinas'hospitals throughout a six-month period. ELISA and Western blot were used for HIV, and VDRL and TPHA for Treponema pallidum screening. While maintaining the anonymity of the women, information was recorded on the hospital of origin, divided into university (public) and private hospitals, as well as on the form of payment (social security, private insurance or direct payment), age, marital status, education, employment and place of residence. Seroprevalence was 0.42 percent for HIV and 1.16 percent for syphilis. There was a significant correlation between a positive reaction to the two infections (p=0.02). After univariate and logistic regression analysis, only university hospitals were shown to be associated with seropositivity for HIV, whereas the same variable and an older age were associated with syphilis. All positive reactions were found either in public hospitals or among social security patients treated at private institutions. The conclusion was that HIV infection is becoming almost as prevalent as syphilis among this population, and affects primarily the lower socio-economic strata. This suggests that routine, voluntary HIV serology should be considered and discussed with patients during prenatal or delivery care whenever a population shows a seroprevalence close to or greater than 1 percent.

Hepatites pós-transfusionais na cidade de Campinas, SP, Brasil. II. Presença dos anticorpos anti-HBc e anti-HCV em candidatos a doadores de sangue e ocorrência de hepatites pós-transfusionais pelo vírus C nos receptores de sangue ou derivados / Post-transfusional hepatitis in the city of Campinas, SP, Brazil. II. Presence of anti-HBc and anti-HCV antibodies in blood donor candidates and occurrence of post-transfusional hepatitis C in recipients of blood or derivates

We have analysed anti-HBc and anti-HCV antibodies in serum samples from 799 donors which had their blood or derivates transfused to 111 recipients. Anti-HBc and anti-HCV were reactive in respectively 9 and 2.1 of the donors tested. We have observed that among the 111 recipients, 44 had received at least one positive anti-HBc unit and 67 had been transfused only with negative anti-HBc, units. The risk of developing hepatitis C virus was 4.5 times higher for the recipients who received at least one positive anti-HBc unit. If the test for anti-HBc had been made for the blood donors in the serological screening, about 56 of the HCV cases in the recipients could have been avoided. The population of recipients who received at least one reacting unit of anti-HCV, presented a risk 29 times higher of developing this hepatitis, as compared to the transfused recipients with all anti-HCV negative units. Testing blood from donors for anti-HCV would avoid 79 of the post-transfusional HCV cases. Brazilian candidates to blood donors seem to be carriers either simultaneously or sequentially to hepatitis virus B and C, since 44.4 of the positive anti-HCV were also positive for anti-HBc. Testing for anti-HBc and anti-HCV in blood screening must be indicated in order to prevent post-transfusional hepatitis transmission in our community.