Hepatitis C virus core protein fused to hepatitis B virus core antigen for serological diagnosis of both hepatitis C and hepatitis B infections by ELISA

The sequence encoding the truncated core protein (amino acids 1-98) of hepatitis C virus (HCc) was expressed in E. coli for production of HCc(1-98), or fused with the truncated core antigen (HBcAg) and segments from the preS1 and preS2 regions from hepatitis B virus (HBV) for production of HBcPreS1PreS2HCc(1-98). The HCc(1-98) and HBcPreS1PreS2HCc(1-98) proteins reacted with sera from HCV-infected individuals by immunoblot analyses, while the latter protein also exhibited HBV core antigenicity. They induced antibodies against HBcAg and/or HCV core protein in rabbits and in mice. Moreover, HBcPreS1PreS2HCc(1-98) is more immunogenic than HCc(1-98) in terms of anti-HCc induction. An ELISA that employed recombinant HCV core antigens of either HCc(1-98) or HBcPreS1PreS2HCc(1-98) to detect anti-HCc and/or anti-HBc antibodies was developed. Evaluation of serum samples with different status of HBV and HCV infections suggested that HCc(1-98) might be suitable for the determination of antibodies against HCV core protein, while HBcPreS1PreS2HCc(1-98) might be of value to detect HCV and/or HBV infection in donated blood in HBV low-prevalence countries.

Feasibility and efficacy of routine PCR screening of blood donations for hepatitis C virus, hepatitis B virus, and HIV-1 in a blood-bank setting

BACKGROUND

Despite sensitive antibody-based blood-donor screening, a residual risk of transfusion-transmitted viral infections exists. Only direct monitoring by sensitive nucleic-acid tests would provide data accurately to measure the risk and to assess risk-reduction procedures. We investigated the feasibility and efficacy of routine screening of donors for hepatitis C virus (HCV), hepatitis B virus (HBV), and HIV-1 by PCR.

METHODS

For PCR testing, individual donor plasma samples were pooled (96x100 microL) overnight by two automatic pipetting machines. Viruses were concentrated by centrifugation and nucleic acids were extracted. HCV PCR was done on the Cobas Amplicor system (Hoffmann-La Roche, Mannheim, Germany). HBV and HIV-1 sequences were amplified by single (non-nested) in-house PCRs and detected by agarose-gel electrophoresis. Detection limits were 1000-5000 genome equivalents/mL in the donor blood.

FINDINGS

PCR testing was done in parallel to antibody screening with a maximum throughput of 3000 samples in 7-8 h. Positive samples were identified 1-2 days later. 111 of 373,423 donations (107 of 4500 pools) were PCR and antibody/antigen-confirmed positive. We found one HCV PCR-positive antibody-negative donation with normal alanine aminotransferase and one HCV PCR-positive donation with an elevated alanine aminotransferase (100 IU), which was negative in the AxSYM 2.0 and Matrix 1.0, but positive after control in the Abbott Prism test (Abbott GmbH, Wiesbaden, Germany).

INTERPRETATION

PCR is a suitable and fast blood-donor screening procedure and contributes to a reduction in viral transmission by transfusion of blood components. In our selected donor population, the yield of detected contaminated donations from donors in the time window in which they are highly infectious but do not have any symptoms or detectable antigen and antibody concentrations (diagnostic window), confirms theoretical estimates.

Prognosis of schistosomiasis mansoni patients infected with hepatitis B virus

A clinical study on the evolution of patients with schistosomiasis mansoni has been conducted since 1983 at the outpatient clinic of the Infectious and Parasitic Disease Service in the Clementino Fraga Filho University Hospital in Rio de Janeiro, Brazil, comparing prevalence of positive tests for HBsAg, anti-HBsAg, and anti-HBc among patients infected with Schistosoma mansoni coming from various regions of Brazil and with different clinical forms of the disease. A non-significant predominance of HBsAg, anti-HBsAg, and anti-HBc was detected among patients with the hepatosplenic form of schistosomiasis, who presented a more severe clinical evolution with a higher frequency of hematemesis and/or melena, in addition to the development of macronodular cirrhosis and a worse prognosis as compared to patients with the toxemic form, schistosomiasis-infection and the hepatointestinal form.

A prospective study of transfusion-transmitted virus transmission by blood transfusion

Recently, a new single-stranded DNA virus (TT virus, TTV) has been isolated and related to post-transfusion hepatitis. The aim of this study was to investigate the prevalence of TTV in blood donors and blood recipients, and the incidence of TTV transmission by blood transfusion. TTV DNA and serum markers of hepatitis B virus (HBV) and hepatitis C virus (HCV), were examined in 130 blood recipients, and the presence of TTV was studied in their 340 corresponding blood donors. The prevalence of TTV infection was 10.6% (36/340) in donors and 8.5% (11/130) in blood recipients, before transfusion. Eighteen subjects (15.1%) were found to be TTV positive, after transfusion, in the 119 blood recipients without TTV before transfusion; at least one of the corresponding donors was TTV positive. There were 46 subjects with post-transfusion hepatitis virus infection, 45 with HCV infection (including seven co-infected with TTV) and two with HBV infection (including one co-infected with HCV and one co-infected with TTV). The recipient with TTV and HBV co-infection and three of the seven patients with TTV and HCV infection had alanine aminotransferase (ALT) levels higher than 90 Ul-1, but only two of the 10 isolated TTV infections had a mild ALT elevation. These results show that prevalence of TTV was high in blood donors and hospitalized patients, and isolated TTV infection is not related to significant ALT elevation.

Viral markers in a blood donor population

BACKGROUND

The viral safety of blood depends on donor selection and screening of the blood for viruses.

OBJECTIVE

To determine the frequency of human immunodeficiency viruses 1 and 2, hepatitis B virus and hepatitis C virus in a population of donors.

DESIGN

Retrospective study including all blood donations at a hospital-based transfusion unit between January 1995 and August 1998.

RESULTS

A significant declining trend in the frequency of the human immunodeficiency virus from 4.5% in 1995 to 3.0% in 1998 was noted. Hepatitis B virus (HBV) decreased from 4.2% in 1995 to 3.9% in 1998, while hepatitis C (HCV) increased from 1.5% in 1996 to 1.8% in 1998. The changes for both HBV and HCV were not statistically significant.

CONCLUSION

The safety of blood and blood products with respect to HIV, HBV and HCV is very high. It is important to educate donors regarding transfusion transmitted infections. It is recommended that HCV screening be implemented as a standard test for all donations.

Quantitative detection of hepatitis B virus DNA in two international reference plasma preparations. Eurohep Pathobiology Group

Quantitative detection of hepatitis B virus (HBV) in serum or plasma is of significance for monitoring of therapy and establishment of the prognosis of the disease, as well as for infectivity assessment and quality control of the diagnosis. Unfortunately, various commercially available test kits for HBV DNA yielded conflicting quantitative results, with differences of up to a factor of 120. The Eurohep Pathobiology Group has established two reference samples of plasma from HBV carriers and determined as accurately as possible the number of HBV DNA molecules in these samples. Plasma donations from two single highly viremic carriers of HBV genotype A (HBV surface antigen subtype adw2) and genotype D (ayw2/3), respectively, were collected, and coded dilutions of these samples were analyzed by members of the Eurohep Pathobiology Group. Quantitative results from the seven laboratories reporting consistent results were initially divergent. Limiting dilution and nested PCR assays suffered from incomplete DNA extraction. Hybridization assays used inaccurately quantitated cloned DNA as a reference. Two hybridization assays could not be calibrated directly with cloned HBV DNA, because virion-derived DNA reacted much less efficiently. After identification and elimination of these problems, limiting-dilution assays from three laboratories and hybridization assays from two producers generated consistent and concordant results: 2.7 x 10(9) HBV DNA molecules/ml (range, 2.1 x 10(9) to 3.4 x 10(9) HBV DNA molecules/ml) in the plasma from the carrier of genotype A and 2.6 x 10(9) HBV DNA molecules/ml (range, 2.1 x 10(9) to 3.0 x 10(9) HBV DNA molecules/ml in the plasma from the carrier of genotype D. The two Eurohep reference plasma samples have already been used for the standardization of test kits and in quality control trials, and the plasma from the carrier of genotype A will probably be the basis of a World Health Organization reference sample.

High prevalence of infection with hepatitis B and C viruses in patients with hepatocellular carcinoma in Japan

BACKGROUND/AIMS

Hepatitis B and C viruses are closely associated with hepatocellular carcinoma. We studied the prevalence of infection with either virus in patients with this cancer by examination of sera and tumor tissue.

METHODOLOGY

Serum samples obtained before treatment from 330 patients with hepatocellular carcinoma were assayed for antibodies against hepatitis C virus and against hepatitis B surface and core antigen. Tumor tissues from 65 patients were examined for hepatitis B virus RNA.

RESULTS

Of the 330 patients, 87 had anti-hepatitis C alone; 161 had anti-hepatitis C and anti-hepatitis B (core); 13 had anti-hepatitis C and anti-hepatitis B (surface); 39 had anti-hepatitis B (surface) alone; and, 19 had anti-hepatitis B (core) alone. Eleven patients had none of these. Hepatitis B virus genes were detected in tumor tissue in all 13 patients with anti-surface antibody, in 21 of 30 patients with anti-core antibody, and in 9 of 22 patients without hepatitis B antibodies. Viral genes were detected in tumor tissue in 5 of 11 patients with neither B nor C virus markers in their sera; viral markers were found in either serum or tumor tissue in 324 of 330 patients (98.2%).

CONCLUSIONS

The prevalence of hepatitis B or C virus infection in patients with hepatocellular carcinoma in Japan is extremely high. The prevalence of co-infection with both viruses is also high.

Should we routinely check for hepatitis B and C in patients with lichen planus or cutaneous vasculitis?

The study aimed to determine the prevalence of HBs-Ag and anti-HCV antibodies in a group of 43 patients with lichen planus and 19 patients with cutaneous vasculitis versus 30 controls. The results showed that 12 (27.9%) patients with lichen planus were positive for HBs-Ag, 9 (20.9%) were positive for anti-HCV antibodies and 3 (7%) were positive for both. In cutaneous vasculitis patients, 3 (15.8%) were HBs-Ag-positive, 7 (36.8%) were anti-HCV-positive and 3 (15.8%) were positive for both. In the control group, 8 (26.7%) were HBs-Ag positive, 3 (10%) were anti-HCV-positive and 1 (3.3%) was positive for both. These values were not statistically significant.

Decrease in the prevalence of hepatitis B and a low prevalence of hepatitis C virus infections in the general population of the Seychelles

A serological survey of hepatitis B virus (HBV) and hepatitis C virus (HCV) infections was carried out on a random sex- and age-stratified sample of 1006 individuals aged 25-64 years in the Seychelles islands. Anti-HBc and anti-HCV antibodies were detected using commercially available enzyme-linked immunosorbent assays (ELISA), followed by a Western blot assay in the case of a positive result for anti-HCV. The age-adjusted seroprevalence of anti-HBc antibodies was 8.0% (95% CI: 6.5-9.9%) and the percentage prevalence among males/females increased from 7.0/3.1 to 19.1/13.4 in the age groups 25-34 to 55-64 years, respectively. Two men and three women were positive for anti-HCV antibodies, with an age-adjusted seroprevalence of 0.34% (95% CI: 0.1-0.8%). Two out of these five subjects who were positive for anti-HCV also had anti-HBc antibodies. The seroprevalence of anti-HBc was significantly higher in unskilled workers, persons with low education, and heavy drinkers. The age-specific seroprevalence of anti-HBc in this population-based survey, which was conducted in 1994, was approximately three times lower than in a previous patient-based survey carried out in 1979. Although there are methodological differences between the two surveys, it is likely that the substantial decrease in anti-HBc prevalence during the last 15 years may be due to significant socioeconomic development and the systematic screening of blood donors since 1981. Because hepatitis C virus infections are serious and the cost of treatment is high, the fact that the prevalence of anti-HCV antibodies is at present low should not be an argument for not screening blood donors for anti-HCV and eliminating those who are positive.

Characterization and selectivity of catalytic antibodies from human serum with RNase activity

IgG purified from sera of several patients with systemic lupus erythematosus and hepatitis B are shown to present RNA hydrolyzing activities that are different from the weak RNase A-type activities found in the sera of healthy donors. Further investigation brings evidence for two intrinsic activities, one observed in low salt conditions and another specifically stimulated by Mg2+ions and distinguishable from human sera RNases. Cleavage of RNA substrates by the latter activity is not sequence-specific but sensitive to both subtle conformational and/or drastic folding changes, as evidenced by comparative analysis of couples of structurally well-studied RNA substrates. These include yeast tRNAAsp and its in vitro transcript and human mitochondrial tRNALys-derived in vitro transcripts. The discovery of catalytic antibodies with RNase activities is a first step towards creation of a new generation of tools for the investigation of RNA structure.

Low prevalence of hepatitis B markers among Mexican female sex workers

OBJECTIVES

To estimate the prevalence and associated risk factors of hepatitis B virus (HBV) serological markers in female sex workers (FSW) in Mexico City.

METHODS

The study population consisted of 1498 FSW who attended a detection centre for human immunodeficiency virus (HIV) in Mexico City, between January and October 1992. Study participants responded to a standardised questionnaire and provided a blood sample for serology of syphilis, HIV, and HBV.

RESULTS

A total of 0.2% (95% CI 0.1-0.3) of the population were hepatitis B surface antigen (HBsAg) carriers. The general prevalence of antibodies to hepatitis B core antigen (anti-HBc) was 6.3% (95% CI 5.5-7.1). This marker of previous exposition to HBV, was independently associated by logistic regression multivariate analysis with age, working in the street, and history of blood transfusion (BT) before 1987 (OR 4.8, 95% CI 2.1-11.3). Syphilis prevalence was 7.6% (95% CI 6.2-8.9) and HIV prevalence was 0.1% (95% CI 0-0.3).

CONCLUSIONS

The prevalence of HBV infection in this group of Mexican FSW is lower than previously reported in other countries. In addition, the frequency of HBsAg carriers is similar to that in the general Mexican population. The absence of two major risk factors for HBV transmission in this group of FSW--that is, injecting drug use and anal intercourse, could help to explain this finding. However, the positive association between anti-HBc and history of blood transfusion demonstrated here, highlights the need to reinforce strict control of blood supplies in Mexico.

Seroprevalence of hepatitis B and C and HIV in Malawian pregnant women

OBJECTIVES

to describe the seroprevalence of hepatitis B (HBV) and C (HCV) infection in HIV-positive and HIV-negative pregnant women from rural Malawi.

METHODS

descriptive study using serum samples collected between 1993-1995 in the Shire valley in rural Malawi. Fifty HIV-positive and 100 HIV-negative samples were selected randomly from 153 HIV-positive and 443 HIV-negative women delivering in the hospital.

RESULTS

evidence of HBV and HCV infection was found in 71.7 and 16.5% of women, respectively. Chronic carriage of HBV (HBsAg positive) is high (13%) and in agreement with prevalences reported from highly endemic areas. Exposure to HBV and HCV probably occurred well before adulthood as the prevalence of anti-HBc antibody was high in young mothers <20 years of age (22/27; 81%).

CONCLUSION

HBV and HCV infections are highly endemic in rural Malawi. There was no statistical evidence to suggest that HIV positivity was associated with an increased prevalence of HBV or HCV markers. Infection with HBV or HCV was not statistically associated.

[Hepatitis B virus replication status and its response to surgery for tumor in hepatocellular carcinoma patients with positive markers of HBV]

OBJECTIVE

To investigate the status of hepatitis B virus (HBV) activity in patients with hepatocellular carcinoma (HCC) and its response to surgical interventions for tumor in HBV positive HCC patients.

METHOD

We analyzed HBV marker results and detected HBV DNA in sera of 97 HCC patients (pre-operation 66 cases, post-operation 31 cases) with polymerase chain reaction (PCR) assay. We also investigated the HBV DNA titer in sera before and one week after operation in 20 HCC patients with positive HBV markers by quantitative polymerase chain reaction (Q-PCR).

RESULT

HBV DNA positive rate in sera was 40.9% and 64.52% in the two subgroup respectively (P < 0.05). HBV DNA titer in sera increased after operation (P < 0.01).

CONCLUSION

The infection rate of HBV in Chinese HCC patients is very high. The replication of hepatitis B virus is strong in partial HBV marker positive HCC patients and surgical interventions may promote the virus replication.

Hepatitis B and blood safety

The safety of blood and blood products is a global issue. Blood transfusion is an important part of modern medicine, but it is also an efficient route of transmission for a number of infectious agents. Although many countries screen all blood donations for a number of infectious agents, a significant proportion of the world's blood supply is either unscreened or poorly screened, with the resultant risk to recipients of transfusion transmitted infections (TTI). Hepatitis B virus (HBV) is of concern because it is transmitted parenterally, many HBV infections are asymptomatic (and infected individuals may thus unwittingly present as blood donors) and the virus is stable in blood and blood products over long periods. The transmission of HBV is minimized by the screening of donors prior to donation, exclusion of high-risk donors, followed by the in-vitro screening of donations for HBsAg (+anti-HBc in some countries) prior to transfusion. However, even in countries with good quality, active screening programmes, there is still a small residual risk of transmission of HBV from undetected donors with early acute infection, resolving infection, silent infection or infection with atypical virus serology. Unfortunately, as with so many infectious agents, the prevalence of HBV is most often higher in those countries with poorly developed healthcare systems and limited resources. In these countries, the safety of the blood supply is compromised frequently, either because of lack of resources with which to purchase screening assays, or because of acute blood shortages and insufficient time to screen blood prior to transfusion. In such situations it is important to encourage and actively support the introduction of appropriate screening programmes which can be based upon simple assay formats, such as agglutination, rather than the favoured but more complex enzyme immunoassays which are more expensive, require specific equipment and support, and take longer to perform. Such approaches will help reduce greatly the transfusion transmission of HBV.

Prognostic value of progressive decrease in serum cholesterol in predicting survival in Child-Pugh C viral cirrhosis

BACKGROUND

The identification of cirrhotic patients with low life expectancy is an open clinical problem. Hypocholesterolemia is frequently found in severe chronic hepatic insufficiency because the liver is the most active site of cholesterol metabolism, but poor information is available on its precise prognostic value. We evaluated the prognostic role of hypocholesterolemia in patients with advanced liver cirrhosis.

METHODS

Serial serum cholesterol concentrations of 34 patients with virus-induced cirrhosis, from the first appearance of Child-Pugh class C to death, were considered. To compare survival functions, we established three base-line cholesterol cut-off points (150, 125, and 100 mg/dl) and stratified patients into groups A and B, with base-line cholesterol levels lower and higher than each cut-off value, respectively.

RESULTS

Cholesterolemia decreased progressively in all patients. At the 100 mg/dl cut-off point all group-A patients died within 17 months, whereas 75% of group-B patients were alive at 24 months (P < 0.0001). Moreover, cholesterolemia was significantly correlated with cholinesterase, indirect bilirubin, and total bilirubin at entry time and immediately before death. No correlation was observed between cholesterol and these variables when stratified for the Child-Pugh score.

CONCLUSIONS

Base-line serum cholesterol levels lower than 100 mg/dl identify a subgroup of Child-C cirrhotic patients with high mortality risk within a 2-year follow-up. The prognostic importance of cholesterolemia may also be deduced by the significant correlation with other well-established indicators of survival.

[Accidental exposure to blood and the risk of transmission of virus infections for various occupational groups in Amsterdam, 1986-1996]

Since 1986 the number of parenteral exposures to potentially infectious blood reported to the Amsterdam Public Health Service increases every year. The number of needlestick accidents increased significantly from 64 in 1986 to 166 in 1996 whereas the number of other exposures decreased from 59 to 44 in these years. The increase was mainly seen in nonhospital based (para)medics. A possible explanation of this increase is greater awareness of the potential infection risk with HIV, hepatitis B or C virus leading to a tendency to report more readily. This assumption is in contradiction with results of studies in hospital-based personnel where a decrease is observed as a result of educational programmes. Other explanations are a higher frequency of use of sharp instruments and (or) an increase in the workload. Out of a total of 1886 needlestick accidents in 1986-1996 one woman became HIV positive; she was deliberately infected by her ex-partner who injected her with blood of an AIDS patient, and one person contracted an hepatitis C virus infection: a policeman wounded by a needle used by a drug addict.

Incidence of hepatitis B virus infection in the United States, 1976-1994: estimates from the National Health and Nutrition Examination Surveys

Precise estimates of the incidence of hepatitis B virus (HBV) infection are required to assess the impact of immunization and other prevention strategies in the United States. Race- and age-specific prevalence data obtained from the second and third National Health and Nutrition Examination Surveys (NHANES II, 1976-1980, and NHANES III, 1988-1994) were used to estimate the annual incidence of HBV infection by catalytic modeling. During the period covered by NHANES II, an estimated 323,462 persons were infected annually, and 334,863 were infected annually during the period covered by NHANES III. No statistically significant declines in prevalence of HBV infection occurred between the two surveys, a period during which hepatitis B vaccination targeted only limited numbers of high-risk adults.

[The use of recombinant alfa-2 interferon in treating patients with acute and chronic viral hepatitis B]

Efficiency was assessed of antiviral therapy with recombinant alfa-2 interferon in 90 patients with acute viral hepatitis B and 18 patients with chronic active hepatitis (ChAH). Intramuscular administration of interferon 1,000,000 to 3,000,000 units, during the first days of the illness over 10 to 14 days significantly reduced the duration of HBs-antigenemia and accelerated the regression of clinical and biochemical symptoms of the disease. These positive changes coincided with augmentation in the peripheral blood of T-suppressors and active T-cells. Antiviral therapy in 18 ChAH patients was given at a course dose of at least 100,000 units of interferon combined with prednisolone. The criteria for the above therapy efficiency included lowering of titres and/or disappearance from serum of HBe and DNA HBv, HBe--anti-HBe seroconversion, normalization of A1AT activity. Of the 17 patients, 12 (70.6%) demonstrated a positive effect of antiviral therapy, 10 subject presenting with a positive response to therapy had their A1AT activity completely normalized.

Mini-pool screening by nucleic acid testing for hepatitis B virus, hepatitis C virus, and HIV: preliminary results

BACKGROUND

The purpose of this study was to evaluate the feasibility of nucleic acid testing (NAT) of mini-pools as a blood donation screening test.

STUDY DESIGN AND METHODS

The stepwise implementation of NAT of mini-pools began in January 1997. Since March 1997, all blood donations collected by the German Red Cross Blood Transfusion Service of Baden-Württemberg were tested for hepatitis B virus (HBV), hepatitis C virus (HCV), and HIV nucleic acids. An extra barcoded serum sample is collected from each blood donor for NAT-based screening, which is performed only on hepatitis B surface antigen-, anti-HCV-, anti-HIV-, and anti-Treponema pallidum-seronegative donations. Samples are pooled to a maximum of 96. Positive results are resolved through intersecting subpools (a chessboard design). NAT-based screening does not include a virus concentration step before nucleic acid extraction.

RESULTS

By the end of October 1997, 331, 783 donations in 3,779 pools had been screened. As yet, no viremic but seronegative blood donor has been found for the three markers.

CONCLUSION

It is feasible to incorporate NAT-based screening of mini-pools into the routine virus diagnostics of a large blood transfusion service. It remains to be determined whether screening blood donations by NAT will indeed increase the safety of blood supply.

[Cases of a combination of acute viral hepatitis B and obstructive jaundice]

Cases are described of a concomitant course of acute viral hepatitis B and obstructive jaundice. Particular features are considered of the associated versus singular course of the two conditions. Clinical, biochemical, and ultrasonic data are presented together with criteria for diagnosis. Recommendations are given on diagnosis and treatment of this category of patients.

Hepatitis B virus infection profile in central Brazilian hemodialysis population

Hepatitis B has proved to be a major health hazard in hemodialysis patients. In order to investigate the hepatitis B virus (HBV) infection profile in the hemodialysis population of Goiânia city--Central Brazil, all dialysis patients (N = 282) were studied. The prevalence of any HBV marker (HBsAg, anti-HBs, and anti-HBc) was 56.7% (95% CI: 51.1-62.7), ranging from 33.3% to 77.7% depending on dialysis unit. HBV-DNA was detected in 67.6% and 88.2% of the HBsAg-positive serum samples, in 91.3% and 100% of the HBsAg/HBeAg-positive samples, and in 18.2% and 63.6% of the HBsAg/anti-HBe-reactive sera by hybridization and PCR, respectively. The length of time on hemodialysis was significantly associated with HBV seropositivity. Only 10% of the patients reported received hepatitis B vaccination. The findings of a high HBV infection prevalence in this population and the increased risk for HBV infection on long-term hemodialysis suggest the environmental transmission, emphasizing the urgent need to evaluate strategies of control and prevention followed in these units.