No abstract available.
Prevalence ; Humans ; Hepatitis B/*diagnosis/epidemiology/immunology

<b>OBJECTIVEb>To see the HBV DNA detection instance in the HBsAg negative people and to study the serological method detection strategy for detecting hepatitis B virus large surface protein (HBLP) to filtrate the occult HBV infection.

<b>METHODSb>The HBsAg negative serum samples were divided into HBsAb negative and positive two species according to the hepatitis B virus markers (HBVM) in daily work excepting the special HBVM modes. Total 2000 stochastic serum samples with 1000 HBsAb negative results and 1000 HBsAb positive results were collected from the copy tubes to detect HBVM with national ELISA reagent kits and put them -20 degrees C frostily. Mixed samples (8 x 30 microl) were analyzed with fluorescence quantitative PCR (FQ-PCR) and filtrated the individual positive samples. The filtrated samples were doubly tested again with American MONOLISA HBsAg ULTRA reagents.

<b>RESULTSb>No HBV DNA positive results were found out from the 1000 HBsAb positive samples and 19 cases HBV DNA positive results were found out from the 1000 HBsAb negative samples. On these 19 samples, the HBsAg results from the American MONOLISA HBsAg ULTRA reagents were all positive and the HBLP results were all positive, too. The 19 HBV DNA quantitative results were divided into 2 cases more than 500 copies/ml, 3 cases between 400-500 copies/ ml, 3 cases between 300-400 copies/ml, 7 cases between 200-300 copies/ml and 4 cases between 100-200 copies/ml.

<b>CONCLUSIONb>The leaked samples tested HBsAg with national reagents are mostly from the HBsAb negative people. HBLP results may be positive on these samples and detecting HBLP marker is propitious to filtrate the occult HBV infection. This study provided a kind of serological reference for actively searching for the detecting strategy in occult HBV infection field.

Antibody Specificity ; Hepatitis B ; diagnosis ; Hepatitis B Antibodies ; immunology ; Hepatitis B Surface Antigens ; immunology ; Hepatitis B virus ; isolation & purification ; Humans ; Laboratories ; Polymerase Chain Reaction

Occult HBV infection is characterized by the absence of serum HBsAg with persistence of low level of intrahepatic HBV DNA. Several suggested mechanisms for the origin of occult HBV infection include strong suppression of viral replication and gene expression, mutation in the regulatory regions of HBV genome, formation of immunoglobulin-bound HBsAg, viral interference, and blockage of HBsAg secretion from infected hepatocytes. Standardized assays are not yet available, and sensitive HBV DNA amplification assay is necessary for the diagnosis of cryptic infection. Detection rate of HBV DNA is highest in IgG anti-HBc positive population. However, neither anti-HBc nor anti-HBs can be detected in a significant proportion of infected persons. Occult HBV infection occurs in a number of clinical settings and is highly prevalent in HCV-infected patients as well as in patients with cryptogenic chronic liver disease including hepatocellular carcinoma.
DNA, Viral/analysis ; Hepatitis B/*diagnosis/*epidemiology/metabolism ; Hepatitis B Antibodies/blood ; Hepatitis B Core Antigens/immunology ; Hepatitis B Surface Antigens/blood ; Humans

The clinical value of an enzyme-linked immunosorbent assay (ELISA) for the detection of anti-HBc IgM was evaluated by testing 202 sera from acute viral hepatitis B (AVHB), hepatitis B (HB), chronic hepatitis (CAH), chronic liver disease (CLD), cirrhosis, primary hepatoma, HBsAg carrier, acute viral hepatitis A (AVHA), hepatitis A (HA), non-A, non-B (NANB) hepatitis and miscellaneous conditions other than hepatic disease, and 19 additional various hepatic disease cases were examined for anti-delta. In clinical situations the accurate diagnosis of HB is not always possible and the differential diagnosis seems to be very important especially in making decisions of treatment and estimation of prognosis. In overall cases the highest positive rate of anti-HBc IgM was found in AVHB as shown as 74.3% (26/35) comparing to other conditions in which the positive rate was extremely low (2.1%). The anti-HBc IgM appeared to be highly specific to AVHB (83.9%) as compared to the other. The positive rate of HBsAg was high in AVHB, CAH and HBsAg carrier (100.0%) followed by CLD, cirrhosis and HB (up to 70.8%). The ALT activities and ALPalb fractions were significantly high in AVHB (p less than 0.005). The correlation between the positivity of anti-HBc IgM and highly abnormal ALT appeared be high. AVHB was confined mostly to 10-20 age group and the male to female ratio was about 6 to 1. Subgroup of AVHB II with positive anti-HBc IgM appeared to have a greater chance being positive for HBsAg and ALPalb. The S/N ratio of anti-HBc IgM was as high as 20 which was unique to AVHB.
Adolescent ; Adult ; Biological Markers ; Child ; Diagnosis, Differential ; Female ; Hepatitis/*diagnosis ; Hepatitis Antibodies/*analysis ; Hepatitis B/diagnosis/immunology ; Hepatitis B Antibodies/analysis ; Hepatitis Delta Virus/*immunology ; Humans ; *Immunoenzyme Techniques ; Immunoglobulin M/immunology ; Isoenzymes/immunology ; Male ; Middle Aged

<b>OBJECTIVEb>This study was designed to explore the incidence rate of occult HBV infection in patients with anti-HBc positive alone and analyze the possible reasons of occult infection.

<b>METHODSb>Sera of 183 patients carrying anti-HBc alone(A < or = 0.1) were collected and real-time PCR was used to select samples with HBV DNA positive. HBV pre-S/S amplification products were obtained by PCR, and clonal sequencing were then used for these samples with HBV DNA positive.

<b>RESULTSb>DNA quantitative results of three samples were greater than 10(3) copies/ml in 183 samples, with a fraction of 1.6%. Pre-S/S sequencing results of two samples from these three samples were obtained. Point mutations within "a" determinant with Q129R/P mutations and co-existence of the mutant type and wild type were found in the two samples.

<b>CONCLUSIONSb>Occult HBV infection existed in samples with anti-HBc alone. Factors contributing to the loss of HBsAg detection by immunoassays include S gene mutations and low levels of circulating antigen which are below the assay limit of detection. Occult HBV infection not only can lead to a false clinical diagnosis, but also can result in hematological pollution due to such occult infection of blood donors.

Base Sequence ; Blood Donors ; DNA, Viral ; analysis ; Genotype ; Hepatitis B ; diagnosis ; immunology ; Hepatitis B Antibodies ; Hepatitis B Core Antigens ; isolation & purification ; Hepatitis B Surface Antigens ; genetics ; Hepatitis B virus ; genetics ; immunology ; Humans ; Polymerase Chain Reaction ; Protein Precursors ; genetics

<b>INTRODUCTIONb>Dried blood spot (DBS) collection is an appealing alternative to whole blood or plasma sampling, as it has technical and economic advantages over the latter.

<b>MATERIALS AND METHODSb>A prospective cross-sectional study was conducted at a Malaysian tertiary referral hospital from November 2009 to March 2010. One hundred and fifty paired specimens of DBS and plasma were analysed by the standard assays for HIV Ag/Ab, HBsAg, anti-HBS and anti-HCV, separately (total 600 paired specimens). DBS sample titres were then compared to the results of plasma testing, which was used as the gold standard.

<b>RESULTSb>For the HIV Ag/Ab assay with a cut-off point of 0.35 Relative Light Units (RLUs), the sensitivity and specificity were both 100%. For the HBsAg assay, the sensitivity was 96.5% and the specificity was 97.8%, with a cut-off point of 1.72 RLUs. Sensitivity for the anti-HBs test was 74.2% and the specificity was 86.9%, using a cut-off point of 0.635 RLUs. For the anti-HCV assay, the sensitivity was 97.3% and the specificity was 100%, with a cut-off point of 0.10 RLUs.

<b>CONCLUSIONb>DBS is an ideal choice to be used as a screening tool for the detection of HIV, Hepatitis B and Hepatitis C virus infections. However, different cut-off values need to be used for the validation of test positivity in DBS samples because the small amount of blood in the DBS specimens leads to lower assay titres.

Cross-Sectional Studies ; Dried Blood Spot Testing ; HIV Antibodies ; blood ; immunology ; HIV Antigens ; blood ; immunology ; HIV Infections ; diagnosis ; Hepacivirus ; isolation & purification ; Hepatitis B ; diagnosis ; Hepatitis B Antibodies ; blood ; immunology ; Hepatitis B Surface Antigens ; blood ; immunology ; Hepatitis C ; diagnosis ; Hepatitis C Antibodies ; blood ; immunology ; Hepatitis C Antigens ; blood ; immunology ; Humans ; Malaysia ; Plasma ; virology ; Prospective Studies ; Referral and Consultation ; Sensitivity and Specificity ; Specimen Handling

<b>OBJECTIVEb>To investigate the distribution of hepatitis delta virus (HDV) marker among hepatitis B virus (HBV) infected patients and to reveal its clinical significance.

<b>METHODb>To collect the clinical data and sera samples of HBV infected patients and to detect HDAg, Anti-HDV as well as HBV infection markers by means of enzyme-linked immunosorbnent assay. These data combined with clinical diagnostic results and biochemical index were then analyzed.

<b>RESULTb>462 samples of HBV infected patients were collected including 210 HBV carriers without symptom, 175 chronic HBV infections, 35 acute HBV infections and 42 liver fibrosis. The HDV infection rate was 4.8% overall. The highest infection rate of 9.5% was found in the group of liver fibrosis whereas the lower rate of 6.9% was found in HBV chronic carriers. HDV infection rate was 7.8% among the population of 40-60 years old, obviously higher than any other age groups.

<b>CONCLUSIONb>HDV infection was significantly higher in the chronic HBV patients and liver fibrosis patients. Because HDV infection was highly associated with the progress of liver disease, we suggest the screen of HDV markers among hepatitis patients and discriminate whether the patient was co-infected with HDV.

Adolescent ; Adult ; Aged ; Biomarkers ; blood ; Child ; Coinfection ; blood ; diagnosis ; immunology ; virology ; Female ; Hepatitis Antibodies ; immunology ; Hepatitis B ; blood ; diagnosis ; immunology ; virology ; Hepatitis B Antigens ; blood ; Hepatitis B virus ; immunology ; isolation & purification ; physiology ; Hepatitis D ; blood ; diagnosis ; immunology ; virology ; Hepatitis Delta Virus ; immunology ; isolation & purification ; Humans ; Male ; Middle Aged ; Young Adult

Occult HBV infection (OBI) is defined as presence of HBV DNA in the liver tissue in patients with serologically undetectable HBsAg. There are differences in virologic and serological profiles of OBI. Majority of OBI are positive for anti-HBs and/or anti-HBc and minor portion are negative for all HBV markers. However, there are no HBV mutations in the surface and its regulatory regions. HBV infection persists by the presence of covalently closed circular DNA (cccDNA) within the infected hepatocytes, which serves as a reservoir for future infection. OBI increases the risk of HBV transmission through transfusion, hemodialysis, and organ transplantation. Therefore effective measures should be employed to screen OBI. Antiviral therapy is needed in HBsAg-negative transplant patients who are anti-HBc positive to prevent the recurrence of HBV infection. Since HBV replication is strongly suppressed by immune surveillance system in OBI patients, immunosuppression results in massive HBV replication. This leads to acute hepatitis and sometimes mortality when immune surveillance is recovered after stopping immunosuppressive drugs/anticancer chemotherapy. Therefore, narrow surveillance is required to recognize the viral reactivation and start antiviral agents during immunosuppressive therapy/anticancer chemotherapy in patients with OBI.
Blood Transfusion ; DNA, Viral/analysis ; Hepatitis B/*diagnosis/transmission ; Hepatitis B Core Antigens/immunology ; Hepatitis B virus/genetics/*physiology ; Humans ; Liver Transplantation ; Renal Dialysis ; Virus Activation

BACKGROUNDS/AIMS: Occult HBV infection is characterized by the presence of HBV infection with undetectable HBsAg. This study was carried out to find out the frequency of HBV infection in HBsAg- negative patients. METHODS: Fifty-six HBsAg-negative patients including 17 anti-HCV positive patients were evaluated. Patients were grouped according to their serological status; group A (anti-HBc+, anti-HBs-, n=16), B (anti-HBc+, anti-HBs+, n=26), and C (anti-HBc-, anti-HBs+/-, n=14). DNA was extracted from frozen liver biopsy specimen, and HBV DNA level was measured with real-time PCR. RESULTS: Overall frequency of detectable intrahepatic HBV DNA was 34% (19/56). The frequency was 56% (9/16) in group A, 31% (8/26) in group B and 14% (2/14) in group C (P=0.01). Intrahepatic HBV DNA levels were as follows; 2,010 +/- 6,660 copies/mg in group A, 6,180 +/- 29,530 copies/mg in group B and 350 +/- 1,220 copies/mg in group C. The frequency of occult HBV infection was not increased in anti-HCV positive patients. CONCLUSIONS: Intrahepatic HBV DNA is frequently detected in anti-HBc positive, HBsAg-negative patients, although the concentration is low.
Middle Aged ; Male ; Liver/*virology ; Humans ; Hepatitis B virus/*genetics/isolation & purification ; Hepatitis B Surface Antigens/*analysis ; Hepatitis B/*diagnosis/immunology/virology ; Female ; DNA, Viral/*analysis ; Aged ; Adult

<b>OBJECTIVEb>To identify human single chain Fv antibody (ScFv) against hepatitis B viral surface antigen.

<b>METHODSb>The recombinant phages were panned by HBsAg which was coated in a microtiter plate, after five rounds of biopanning, 56 phage clones were identified specific to HBsAg. The specificity of ScFv was evaluated by ELISA and immunohistochemistry, respectively.

<b>RESULTSb>The data of HB sAg-ScFv DNA digestion and DNA sequencing showed that the ScFv gene is composed of 750 bp. ELISA and immunohistochemistry demonstrated that the human single chain Fv antibody against hepatitis B surface antigen has a specific combination character with hepatitis B surface antigen of different sources and paraffin-embedded patients tissue specimens, it did not react with normal liver tissue and HCV.

<b>CONCLUSIONSb>The application of HBsAg specific ScFv in immunohistochemistry was successfully achieved.

Bacteriophages ; metabolism ; Enzyme-Linked Immunosorbent Assay ; Hepatitis B Antibodies ; Hepatitis B Surface Antigens ; immunology ; Hepatitis B, Chronic ; diagnosis ; Humans ; Peptide Library