Prevalence of serum markers of hepatitis B and C virus in blood donors of Nouakchott, Mauritania]

This preliminary survey was intended to collect transversal data to ensure a better understanding of the hepatitis B and C epidemiology in Mauritania. The authors have studied the seroprevalence rate of HBs antigen and HCV antibodies among 349 blood donors. Data of this study showed that anti-HCV antibody was detected in 1.1% and HBs antigen in 20.3% blood donors.     

HBV基因分型与病毒载量及血清标志物关系的探讨

目的探讨HBV基因型与HBV-DNA水平及血清标志物的相关性。方法选择125例乙肝患者血清HBV-DNA复制阳性的标本分别检测HBV病毒基因分型、HBV-DNA、乙肝血清标志物、谷丙转氨酶（ALT）和总胆红素（TBL）。结果 125例HBV-DNA复制阳性标本中HBV基因分型以B型为主占71.2%（89/125）,C型占24.0%（30/125）,BC混合型占2.4%（3/125）,非B非C型占2.4%（3/125）;B基因型患者血清ALT（297.3±193.6）U/L和TBL（105.1±59.7）mol/L水平高于C基因型患者ALT（158.1±107.5）U/L和TBL（53.1±22.7）mol/L,P〈0.01;B基因型患者血清抗-HBe阳性率91.0%（81/89）显著高于C基因型的23.3%（7/30）,P〈0.01;B型HBV-DNA水平（5.87±1.72）log10copies/mL与C型（6.01±1.91）log10copies/mL无差异（P〉0.05）。结论本地区HBV病毒基因型以B型为主,C型次之,B基因型对肝脏损害较C基因型重,并与HBV载量及HBeAg系统具有相关性,B基因型易发生YMDD突变。     

丙型肝炎病毒感染的血清学检测

目的了解丙型肝炎病毒（ＨＣＶ）感染及病毒血症存在情况。方法用酶联免疫吸附试验（ＥＬＩＳＡ）和聚合酶链反应（ＰＣＲ）对不同人群的血清标本做了抗－ＨＣＶ、抗－ＨＣＶＩｇＭ和ＨＣＶＲＮＡ的检测，并对三项指标间的关系进行了对比分析。结果抗－ＨＣＶ在普通成年人、献血员、急性肝炎和肝硬化患者中的检出率分别是３５７％，８５８％，６２５％和４８３８％；与ＨＣＶＲＮＡ的符合率分别是１１４３％，６１１１％，８００％和７３３３％。相同人群抗－ＨＣＶＩｇＭ与ＨＣＶＲＮＡ的符合率分别是７５％，９０９％，８１８１％和１００％。结论抗－ＨＣＶＩｇＭ比抗－ＨＣＶ能更客观地反映ＨＣＶ病毒血症的情况，个别抗－ＨＣＶ阴性血清检测到了抗－ＨＣＶＩｇＭ和ＨＣＶＲＮＡ。     

Occult hepatitis B virus and hepatitis C virus infections

Occult HBV infection is a well-recognised clinical entity characterised by the detection of HBV-DNA in serum and/or in liver in the absence of detectable hepatitis B surface antigen (HBsAg). Occult HBV infection has been described not only in patients who have resolved an acute or chronic HBV infection but also in patients without any serological markers of a past HBV infection. Occult HBV infection in patients with chronic HCV infection may induce more severe liver disease and lower response rate to interferon treatment. The existence of occult HCV infections has been also reported more recently. Occult HCV infection is characterised by the presence of HCV-RNA in liver and peripheral blood mononuclear cells in the absence of detectable serum HCV-RNA. Occult HCV infection may occur under two different clinical situations: in hepatitis C antibody-(anti-HCV) negative and serum HCV-RNA-negative patients with abnormal liver function tests and in anti-HCV-positive patients who have no detectable serum HCV-RNA and who have normal liver enzymes. The clinical relevance of occult HCV infections is still under investigation.     

Hepatitis B virus core-related antigens as markers for monitoring chronic hepatitis B infection

A sensitive chemiluminescence enzyme immunoassay has been developed for hepatitis B virus (HBV) core-related antigen (HBcrAg) detection. We aimed to investigate the usefulness of HBcrAg measurement for monitoring chronic hepatitis B disease. HBcrAg levels were measured by a chemiluminescence enzyme immunoassay in 54 untreated patients and 39 patients treated with either entecavir or lamivudine. The HBcrAg concentration correlated positively with the levels of serum HBV DNA (r = 0.820), intrahepatic total HBV DNA (r = 0.700), and covalently closed circular DNA (cccDNA) (r = 0.664; for all, P values were <0.001). A higher HBcrAg concentration was associated with a greater proportion of hepatitis B core antigen immunostaining. Although the differences were not statistically significant, patients with higher Knodell necroinflammation and fibrosis scores tended to have higher serum HBcrAg concentration levels. In the treated patients, the logarithmic reduction in HBcrAg at week 48 correlated positively with the logarithmic reduction of serum HBV DNA, intrahepatic total HBV DNA, and cccDNA. Of the 31 patients with undetectable serum HBV DNA (<300 copies/ml) at the end of treatment, 20 (65%) still had detectable HBcrAg. A greater reduction in posttreatment HBcrAg concentration was associated with histological improvement and a decrease in hepatitis B core antigen immunostaining. HBcrAg concentrations of <40,000 kU/ml at baseline and <200 kU/ml at week 24 were associated with a higher chance of having undetectable HBV DNA at week 48. In conclusion, serum HBcrAg levels correlated with HBV virological markers and reflected the chronic hepatitis B disease activity in the liver.     

Evaluation of hepatitis C virus kits.

Hepatitis C virus (HCV) antibodies were detected in 85.9% of the samples by commercial enzyme immunoassay (EIA) kits. Most EIA-positive samples were reactive (80%) by the RIBA HCV test (Ortho Diagnostics). Samples with optical density values greater than or equal to 2.0 were mostly reactive (87%) by RIBA HCV test, in contrast to those with values less than or equal to 1.0 (6.6%). Samples which were indeterminate by the RIBA HCV test were positive (88.4%) by HCV neutralization EIA (Abbott Laboratories), along with 29.4% of samples which were nonreactive by the RIBA HCV test.     

Use of highly sensitive methods of detecting hepatitis B virus markers for studying epidemic foci of hepatitis B

Passive hemagglutination test (PHA) was found to detect HBsAg in the population living outside the hepatitis B virus foci 1.5-fold as frequently as counter immunoelectroosmophoresis technique, and anti-HBs by enzyme immunoassay 14-fold as frequently. As compared with normal population, the contacts in foci had 4-fold higher levels of HBsAg carrier state and twice as high rates of detection of anti-HBs. The total index of HBV infection in foci was 27.7%. The above materials considerably extend the concepts of HBV epidemiology. The regularity of the results obtained indicate the specificity and high sensitivity of PHA and EIA tests and suggests that they be used on a wider scale.     

Comparison of hepatitis C virus markers in patients with NANB hepatitis.

10 different HCV-specific assays and RT-PCR of the 5' untranslated region of HCV RNA were used to analyze sixty-four patients with chronic NANB liver disease. Po, CP-9 and C22 antigens are located in the putative core; C33c in the putative NS3; C100-3 in the putative NS3/4; KCL in the putative NS4/5 and C825 is located in the putative NS5. GOR protein is not part of the HCV genome, but antibodies to it appear to be present in response to a hepatitis C infection. Positive rates were 91% for Po, 89% for CP-9, 94% for C22, 97% for C33c, 88% for C100-3 (Ortho, EIA), 86% for C100-3 (Abbott, EIA), 84% for C100-3 (Ohtsuka, RIA), 88% for KCL, 59% for C825, 58% for GOR, and 83% for RT-PCR. There were 8 cases which were negative by all anti-C100 tests. 7 of these cases were positive by other anti-HCV markers and/or PCR suggesting the need for improved blood screening assays. There is a variation in the relative reactivity for different markers with different samples. Of the tests employed, anti C33c shows the highest positivity rate.     

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. J. Med. Virol. 57:104–110, 1999. © 1999 Wiley-Liss, Inc.     

MICA and recovery from hepatitis C virus and hepatitis B virus infections

The polymorphic MHC class I chain-related A (MICA) gene encodes a ligand that has different binding affinities for the NKG2D activating receptor of CD8+ T cells and natural killer (NK) cells. We hypothesized that MICA heterogeneity would affect recovery from hepatitis C virus (HCV) and hepatitis B virus (HBV) infections. To test the hypothesis, we initially typed known MICA polymorphisms for 228 persons who cleared HCV infection and 442 persons with persistent hepatitis C matched on other factors affecting viral persistence. Although MICA(*)015 was detected more than two-fold more often in persons with viral clearance (odds ratio 0.36, 95% confidence interval=0.19, 0.80), it occurred in fewer than 5% of the study population. In a similar analysis of 442 persons with chronic hepatitis B and 768 matched controls who recovered, MICA(*)015 was detected in 2.0% of persons with chronic hepatitis B and only 0.9% of controls. No significant associations were detected with other MICA polymorphisms. While further investigation may reveal a structural basis of the MICA(*)015 associations, these data provide little support for the hypothesis that differential distribution of MICA alleles substantially affects recovery from HCV and HBV infections.     

Evaluation of two simplified methods for genotyping hepatitis C virus

A number of different approaches have been used for genotyping hepatitis C virus (HCV). Two simplified methods were evaluated, both of which used polymerase chain reaction (PCR) to amplify products from the 5′ non-coding region of HCV: non-isotopic restriction fragment length polymorphism (RFLP) analysis and type-specific PCR. Sixty-four viraemic patients suffering from chronic HCV infection were studied using these two techniques; 25/64 samples were further tested with a commercial serotyping ELISA based on synthetic NS4 antigen (Murex, U.K.). The results of the three typing methods were generally in agreement with each other. When only the predominant genotype identified by each method was analysed, the 3 methods had 100% agreement. RFLP did not detect any mixed infections and it was unsuccessful in 16/64 (25%) samples. Both type-specific PCR and serotyping ELISA detected mixed infections. However, serotyping ELISA did not give typeable results in 7/25 (28%) samples, whereas type-specific PCR gave typeable results in all 64 samples. Type-specific PCR detected more mixed infections than serotyping ELISA. Direct sequencing of four PCR products with indeterminate RFLP confirmed changes in restriction enzyme recognition sites. The sequences also confirmed the validity of the predominant genotype in cases of apparent mixed reactions. It is possible that some of these cases were artefacts as a result of quasispecies. J. Med. Virol. 52:35–41, 1997. © 1997 Wiley-Liss, Inc.     

Evaluation of the invader assay for genotyping hepatitis C virus

The Invader 1.0 assay (Invader HCV Genotyping Assay, version 1.0; Third Wave Technologies, Inc., Madison, WI) has been developed for the rapid differentiation of hepatitis C virus (HCV) genotypes 1 to 6 based on sequence variation within the HCV 5' noncoding (NC) region. In the present study, we evaluated the compatibility of Invader 1.0 with the COBAS MONITOR (COBAS AMPLICOR HCV MONITOR Test, version 2.0; Roche Molecular Systems, Inc., Branchburg, NJ), COBAS AMPLICOR (COBAS AMPLICOR Hepatitis C Virus Test, version 2.0; Roche Molecular Systems, Inc.), and COBAS TaqMan (COBAS TaqMan HCV Test; Roche Molecular Systems, Inc.) assays. The minimum HCV RNA titers required for successful HCV genotyping (>/=90% success rate) were 1,000 IU/ml for COBAS MONITOR, 100 IU/ml for COBAS AMPLICOR, and 10 IU/ml for COBAS TaqMan. Invader 1.0 results obtained from unpurified COBAS TaqMan amplification products of 111 retrospectively selected clinical serum specimens (genotypes 1 to 6, with virus titers ranging from 15.1 to 2.1 x 10(7) IU/ml) showed 98% concordance with results obtained from the TRUGENE HCV 5' NC Genotyping Kit (Bayer HealthCare LLC, Tarrytown, NY), used in conjunction with COBAS AMPLICOR. Although the assay is sensitive, accurate, and easy to perform, additional optimization of the Invader 1.0 interpretive software (Invader Data Analysis Worksheet) may be necessary to reduce potential misidentification of HCV genotypes in low-titer specimens. In summary, Invader 1.0 is compatible with a variety of commercially available PCR-based HCV 5' NC region amplification assays and is suitable for routine HCV genotyping in clinical laboratories.     

Distribution of hepatitis B virus in the liver of chronic hepatitis C patients with occult hepatitis B virus infection

Although occult hepatitis B virus (HBV) infection (HBV-DNA in serum in the absence of hepatitis B surface antigen [HBsAg]) is common in chronic hepatitis C, its characteristics are not well known. In this work, the presence of HBV-DNA (by polymerase chain reaction; PCR) and its distribution (by in situ hybridization) in liver biopsies and peripheral blood mononuclear cells (PBMCs) from 32 patients with chronic hepatitis C and occult HBV infection and in 20 HBsAg chronic carriers were determined. The results showed that serum HBV-DNA levels were statistically lower (P = 0.001) in patients with occult HBV infection than in HBsAg chronic carriers. The HBV infection pattern in liver cells was identical between patients with occult HBV infection and those with chronic hepatitis B. However, the mean percentage of HBV-infected hepatocytes was significantly lower (P = 0.001) in patients with occult HBV infection (5 +/- 4.44%) than in HBsAg chronic carriers (17.99 +/- 11.58%). All patients with chronic hepatitis B have HBV-DNA in their PBMCs while this occurred in 50% of the cases with occult HBV infection. In conclusion, patients with occult HBV infection have a low number of HBV-infected hepatocytes and this fact could explain the lack of HBsAg detection and low viremia levels found in these cases.     

Profiles of GBV-C/hepatitis G virus markers in patients coinfected with hepatitis C virus.

GBV-C/Hepatitis G virus (GBV-C/HGV) is a newly discovered viral agent, found widely among healthy blood donors and among individuals at risk of parenterally transmitted infections. GBV-C/HGV is found frequently in coinfection with HCV. A population of 109 HCV positive patients was examined for the presence of GBV-C/HGV RNA and antibodies to E2. Of the 109 patients, 23 (21%) had serum GBV-C/HGV RNA in serum, 39 (36%) had only antibodies to E2 and 8 (7%) were positive for both markers, with an overall prevalence of 64%. Different serologic and virological patterns were observed in GBV-C/HGV exposed patients according to their infection status. Active infection was characterized by positive RT/PCR signal with primers for both the 5'UTR and NS5 genomic regions, viremia levels above 10(4) copies/mL by real time quantitative RT/PCR and absence of detectable anti-E2. In the transition phase between active infection and recovery, GBV-C/HGV RNA was only detectable by RT/PCR using primers from the 5' untranslated region and viremia levels were below 10(4) copies/ml by quantitative PCR, with or without simultaneous presence of anti-E2 antibodies. Resolved infection was characterized by absence of detectable viremia and, in most patients, by the presence of anti-E2.     

Hepatitis B surface antigen confirmatory testing for diagnosis of hepatitis B virus infection in Taiwan

This study aimed to examine the application of hepatitis B surface antigen (HBsAg) confirmatory testing when diagnosing hepatitis B infection among young persons in Taiwan with a low prevalence rate of hepatitis B infection. HBsAg status, the presence of antibodies against HBsAg (anti-HBs), and the presence of antibodies against hepatitis B core antigen (anti-HBc) were compared among 403 graduate students (mean age 22.8 ± 0.7 years) and 1,745 undergraduate students (18.6 ± 1.0 years) from one university, and 367 adult subjects (41.1 ± 15.8 years) in 2008. Any HBsAg-positive subjects were tested with an HBsAg confirmatory test. Chi-square tests for trend and predictive values of positivity (PVP) when using HBsAg-positive only for determining confirmed cases of hepatitis B infection were compared across the three cohorts. The prevalence of HBsAg positivity among subjects decreased from 16.3% in the adults to 5.2% in the graduate students and then to 2.8% for the undergraduate students (P = 0.0007). The PVP of HBsAg testing when determining cases of hepatitis B decreased from 0.97 for the adults to 0.81 for the graduate students and then to 0.56 for the undergraduate students (P < 0.0001). Thus, a significant decrease in the true-positive rate of HBsAg among the students born after the introduction of hepatitis B vaccination was observed only when HBsAg testing was applied. Additional neutralization tests may therefore become mandatory for persons with a positive HBsAg test result who were born after the commencement of the universal neonatal hepatitis B vaccination program in Taiwan.     

Clinical pathology due to hepatitis B virus]

All information accumulated during last 10 years allows the view on the alterations produced by hepatitis B virus as ubiquitous. Extrahepatic pathology in hepatitis B is associated with the immunocomplex and immunocellular mechanisms but more frequently with their combination. Wide spread of hepatitis B virus infection and high level of morbidity, persistence of the virus in the organism necessitate further study of clinical pathology associated with this virus.     

Standardized hepatitis C virus RNA panels for nucleic acid testing assays.

BACKGROUND: Methods for the quantification of hepatitis C virus (HCV) RNA are useful in the clinical management of infected patients. However, the introduction of assays based upon various nucleic acid testing (NAT) technologies, each utilizing a different set of standards, creates the potential for misinterpretation of patient results. OBJECTIVE: In order to address the need for worldwide standardization of these assays, a HCV RNA quantification panel (NAP HCV-RNA) calibrated against the World Health Organization (WHO) First International Standard for HCV RNA was prepared. The eight-member HCV RNA quantification panel was evaluated utilizing a variety of commercially available and in-house NAT technologies. STUDY DESIGN: NAP HCV-RNA panels were tested and analyzed using the methods and data reduction protocols specific to each NAT technology employed in this study (bDNA, TMA and two PCR methods). Proprietary units of measure from each assay were compared to WHO International Units (IU) for each panel member (0, 50, 500, 5000, 50000, 200000, 500000 and 2000000 IU/ml). RESULTS: Evaluation of the NAP HCV-RNA in a variety of NAT procedures demonstrated linearity across the range of target concentrations detected in each assay and R(2) values ranged from 0.9929 to 0.9995 across the four technologies. As expected, the correspondence of assay specific proprietary units to IU differed depending upon the technology utilized. CONCLUSIONS: NAP HCV-RNA provides a consistent, standardized method for comparing results across laboratories and technologies and is useful in ensuring the quality of NAT testing for HCV RNA, independent of the methodology used.