Composite recombinant antigens were constructed from diagnostically relevant antigenic regions derived from the hepatitis C virus (HCV) core, NS3, NS4 and NS5 proteins. Antigenic properties of each antigenic region included into these composite antigens were preliminary evaluated by testing recombinant proteins containing the HCV protein fragments of different sizes encoded by overlapping PCR fragments. Immunoreactive recombinant proteins were tested by EIA against a large panel of anti-HCV positive and negative serum specimens to identify the most immunoreactive and specific proteins. Three composite antigens were designed based on this analysis. The fist composite protein was composed of one antigenic region from core, NS3 and NS4. The second protein contained an additional NS4 region, while the third protein contained all immunodominant antigenic regions identified in this study. After EIA analysis for the detection of anti-HCV, each composite protein showed almost identical results compared to combining each of the corresponding individual proteins.
hepatitis C ; antigens ; viruses

The rate of HBsAg carriers among blood donors at at Thua Thien Hue province during 5 years (1997 - 2001) is relative high, with 13.57% on average. At the same time, the incidence of HCV infection is lower than other areas (with mean 0.64%). The rate of HBsAg carrier is higher in rural than in Hue city (14.72% vs. 12.27%). The young adults in precincts have higher HBsAg incidence than in other groups.
Blood Donors ; Hepatitis B Surface Antigens ; Hepatitis C Antibodies

In 1997, the Blood Bank in ViÖt §øc hospital discovered 14 cases of HIV1 positive: 1 case was not enough serum to make further test, 1 was regular donor with HIV positive, Anti HCV negative, HBsAg negative. The incidence of Anti HCV (Hepatitis C) was 12/13 positive (92.3%). The incidence of heroin users was 12/13 (92.3%). The incidence of HBsAg (Hepatitis B) was: 1/13 positive (7.8%).
HIV ; Hepatitis C virus ; Hepatitis B Surface Antigens ; Blood Donors

As part of the immunoserology program of the Korean Association of External Quality Assessment Service, we organized two trials on the external quality assessment of hepatitis viral markers in 2016 and 2017. The hepatitis viral antigens and antibodies program consisted of 10 test items. We delivered two and three types of pooled sera specimens to 965 and 965 institutions for the first and second trials of external proficiency testing in 2016, respectively. The number of participating laboratories was 915 (94.8%) and 913 (95.0%) in the first and second trials in 2016, respectively. We also delivered three kinds of pooled sera specimens to 936 and 1,015 institutions for the first and second trials of external proficiency testing in 2017, respectively. The number of participating laboratories was 920 (98.3%) and 996 (98.1%) in the first and second trials in 2017, respectively. The most commonly tested items were hepatitis B surface antigen, followed by the antibodies to hepatitis B surface antigen, anti-hepatitis C virus, hepatitis B envelope antigen, antibodies to hepatitis B envelope antigen, anti-hepatitis A virus and antibodies to hepatitis B core antigen. The most frequently used methods for detecting viral markers were the chemiluminescence immunoassay and the electrochemiluminescence immunoassay, but they yielded a few-false positive results due to the matrix effect. The immunochromatographic assay yielded false-negative results for anti-hepatitis A virus due to low sensitivity. Continuous improvement in the quality of viral hepatitis testing through participation in the survey seems necessary.
Antibodies ; Antigens, Viral ; Biomarkers* ; Hepatitis A ; Hepatitis B ; Hepatitis B Core Antigens ; Hepatitis B Surface Antigens ; Hepatitis B virus ; Hepatitis C ; Hepatitis* ; Immunoassay ; Immunochromatography ; Korea* ; Laboratory Proficiency Testing ; Luminescence

Serum samples from 123 males and 123 females collected by age in 1996 were analyzed for antibodies against surface antigen of Hepatitis B virus and C22-3, C200 antigens of Hepatitis C virus. Sera from the children under the age of 10 showed 30% seropositivity to the surface antigen of Hepatitis B virus, 33.3% in 10~19 year group, 20% in 20~29 year group, 17.6% in 30~39 year group, 3.3% in 40~49 year group, 5.9% in 50~59 year group, 8,3% in 60~69 year group, 2.9% in 70~79 year group, but antibody could not found in 80~86 year group. 12 out of 123 male sera were positive, 19 out of 123 female sera were positive and overall rate of positivity of antibody against surface antigen of Hepatitis B virus was 12.6%. Serum samples from peoples under the age of 30 had not antibody against C22-3, C200 antigens of Hepatitis C virus. The positivity rate was 2.9% in 30~39 year group. 5 out of 30 sera from 40~49 year age group were positive, and 3 positive sera showed extremely high titer (1:524,288) but the titers of two remaining sera were 1:32, 1:8,192 respectively. 5.9% was positive in 50~59 year group, 8.3% in 60~69 year group, 11.8% in 70~79 year group but all negative in 80~86 yea. group. 6 out of 123 male sera were positive (4.9%), 9 out of 123 female sera were positive (7.3%). Overall .ate of positivity of antibody against C22-3, C200 antigen of Hepatitis C virus was 6.1%. None out of 246 sera had both antibodies against Hepatitis B virus and Hepatitis C virus.
Antibodies* ; Antigens, Surface ; Child ; Female ; Hepacivirus* ; Hepatitis B virus* ; Hepatitis B* ; Hepatitis C* ; Hepatitis* ; Humans* ; Male

To investigate the association between hepatocellular carcinoma(HCC) and infection of hepatitis B virus(HBV) and hepatitis C virus(HCV) in an HBV endemic area , a case-control study of 254 patients with HCC and of 1,270 age and sex matched health control subjects was done. Among the 254 HCC patients 166(65.4%) were positive for hepatitis B surface antigen(HBsAg), 49(19.3%) were positive for HCV antibody(anti-HCV Ab). The crude odd ratio of patients with HBsAg was 36.1(95% CI :22.4-58.2) and with anti-HCV Ab was 9.0(95% CI :5.5-14.6). In an analysis, which HBsAg(-), HBcAb(-), anti-HCV Ab(-) group was chosen as referent group, odd ratio of HBsAg(+) group was 14.4(95% CI: 7.2-28.9) and of anti- HCV Ab(+) was 10.7(95% CI: 2.9-40.0). Odd ratio of anti-HCV Ab(+), HBsAg(+) group and anti-HCV Ab(+), HBsAg(-), HBcAb(+) group for HCC were elevated to 27.3(95% CI : 9.0-82.9) , 15.9(95% CI:7.1-35.8) respectly. The odd ratio of anti-HCV Ab(-), HBsAg(-), HBcAb(+) group was 2.4(95% CI : 1.1-5.0). These result suggested that HBV and HCV were associated with HCC. In HBV endemic area patients with HBcAb alone should be considered risk group for HCC.
Carcinoma, Hepatocellular* ; Case-Control Studies* ; Hepacivirus* ; Hepatitis B Surface Antigens ; Hepatitis B* ; Hepatitis C* ; Hepatitis* ; Humans

OBJECTIVE: To evaluate the clinical significance of serum hepatitis C virus (HCV) core antigen detected by enzyme linked immunosorbent assay (ELISA). METHODS: The serum HCV core antigen, which was taken from 149 patients with chronic hepatitis C, 20 patients of chronic hepatitis B and 20 health volunteers, was detected by ELISA. Meanwhile, the serum HCV RNA was detected by RT-PCR, and anti-HCV was detected by ELISA. RESULTS: The qualitative HCV core antigen in the serum, which was take from 20 patients of chronic hepatitis B and 20 health volunteers, was negative.The positive percentage of HCV core antigen was 49.66% in the 149 sera of patients with chronic hepatitis C. The coincidence of detective results of HCV RNA and HCV core antigen was 54.36%, without significant difference (P>0.05). The positive percentage of HCV RNA and HCV core antigen in the 149 anti-HCV antibody positive sera samples were 55.03% (82/149) and 49.66% (74/149), respectively, and there was no significant difference (P>0.05). CONCLUSION The qualitative HCV core antigen detected by ELISA has a high specificity. The positive percentage of HCV core antigen in the serum of patients with chronic hepatitis C is 49.66%. HCV core antigen is related to HCV RNA. HCV core antigen may be a useful serum marker which could show HCV viraemia like HCV RNA.
Hepatitis C Antigens ; blood ; Hepatitis C, Chronic ; blood ; Humans ; RNA, Viral ; blood ; Viral Core Proteins ; blood

Occult hepatitis B virus (HBV) infection is defined as the presence of HBV DNA in the liver (with or without detectable HBV DNA in serum) for individuals testing HBV surface antigen negative. Until recently, the clinical implication of occult HBV infection was unclear. Several studies suggest a high prevalence of occult HBV infection among patients with chronic liver disease. Occult HBV infection is a complex entity comprising many conditions and situations that may be widely different from the biological point of view and clinical consequences. Data regarding natural course and therapy in chronic hepatitis C patients with occult HBV are limited and based on small case numbers. These considerations imply the need for a critical re-evaluation of this field to define better strategies to diagnose and treat this infection.
Antigens, Surface ; DNA ; Hepatitis ; Hepatitis B ; Hepatitis B virus ; Hepatitis C, Chronic ; Hepatitis, Chronic ; Humans ; Liver ; Liver Diseases ; Prevalence

BACKGROUND: The Elecsys hepatitis B surface antigen (HBsAg) II quantitative assay is a newly introduced electrochemiluminescence immunoassay incorporating an initial 1:400 onboard dilution and a simple algorithm to determine HBsAg levels in serum. We evaluated the performance of the Elecsys HBsAg II assay and determined the impact of its initial onboard dilution on laboratory efficiency. METHODS: HBsAg levels were determined using both Roche Elecsys and Abbott Architect HBsAg assays. Linearity and precision of the Elecsys HBsAg II assay and its correlation with the Architect HBsAg assay were evaluated. In particular, precision was verified at Samsung Medical Center, Severance Hospital, Seoul St. Mary's Hospital in Seoul, using the same pooled serum controls. The efficiency of the dilution algorithm for both methods was verified using data from 1,848 clinical samples. RESULTS: The Elecsys HBsAg II assay showed a good linearity from 0.1 to 48,000.0 IU/mL and a good correlation (r=0.9998) between expected and measured values. Precision analyses performed at Samsung Medical Center, Severance Hospital, Seoul St. Mary's Hospital showed excellent performance with coefficients of variation between 1.28% and 6.82%. The values of the Elecsys HBsAg II and Architect HBsAg assays were well correlated (n=506, r=0.987, P<0.001) and also reliably determined in hepatitis C virus- and hepatitis B virus-co-infected patient sera (n=27). In terms of efficiency, 64.0% of samples provided a final HBsAg result on the first run without the need for further dilution, when using the 1:400 onboard pre-dilution protocol of the Elecsys HBsAg II assay. CONCLUSIONS: Given the excellent precision and correlation with the Architect assay, the Elecsys HBsAg II assay showed a potential advantage for laboratory efficiency by significantly reducing the need for retesting samples with high HBsAg levels.
Hepatitis B ; Hepatitis B Surface Antigens* ; Hepatitis B virus ; Hepatitis B, Chronic ; Hepatitis C ; Humans ; Immunoassay ; Seoul

To evaluate the clinical feasibility of the antibody titer against a chimeric polypeptide (named Core 518), in which a domain of Core and NS3 of hepatitis C virus (HCV) was fused, ELISA was performed in a total of 76 serum samples. Each serum was serially diluted using two-fold dilution method with distilled water into 10 concentrations. They were all positive for second generation anti-HCV assay (HCV EIA II; Abbott Laboratories). Genotyping RT-PCR, quantitative competitive RT-PCR, and RIBA (Lucky Confirm; LG Biotech) were also assayed. Anti-Core 518 antibody was detected in x 12800 or higher dilutions of sera from 35 of 43 chronic hepatitis C (81.4%) and nine of 16 hepatocellular carcinoma sera (56.3%), one of four cirrhosis (25%), 0 of four acute hepatitis C, and one of nine healthy isolated anti-HCV-positive subjects (p=0.0000). The anti-Core 518 antibody titers were well correlated with the presence of HCV RNA in serum (p=0.002). The anti-Core 518 antibody titers decreased significantly in nine of ten responders to IFN-alpha treatment. Monitoring anti-Core 518 titers may be helpful not only for differentiating the status of HCV infection among patients with various type C viral liver diseases, but also for predicting responses to IFN-alpha treatment.
Adult ; Aged ; Female ; Genotype ; Hepatitis C/immunology* ; Hepatitis C/drug therapy* ; Hepatitis C/diagnosis ; Hepatitis C/blood ; Hepatitis C Antibodies/immunology* ; Hepatitis C Antibodies/blood ; Hepatitis C Antigens/immunology* ; Hepatitis C-Like Viruses/immunology* ; Hepatitis C-Like Viruses/genetics ; Human ; Immunoblotting ; Interferon Alfa-2a/therapeutic use* ; Male ; Middle Age ; RNA, Viral/blood ; Recombinant Fusion Proteins/immunology ; Viral Core Proteins/immunology* ; Viral Nonstructural Proteins/immunology*