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

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>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 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

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

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

Autoimmune Diseases ; diagnosis ; immunology ; pathology ; therapy ; Child ; China ; Gastroenterology ; Hepatitis B ; diagnosis ; pathology ; therapy ; Humans ; Infant

BACKGROUND/AIMS: Many patients with positive anti-HBc, but negative HBsAg, are known to harbor occult HBV infection, which may transmit the virus through the graft in liver transplantation. We examined the change of HBV DNA within the liver allograft tissue of the donor with positive anti-HBc, but negative HBsAg, before and after the transplantation and assessed its significance. METHODS: Twenty-eight patients with available posttransplant biopsies that received anti-HBc positive liver allografts between April 2000 and November 2003 were enrolled in the study. Intraoperative wedge biopsy of donor liver and needle biopsy of the recipient around the 12th postoperative day were used. HBV DNA within the liver tissue was identified by polymerase chain reaction technique using paraffin-embedded liver tissue. RESULTS: Among 13 patients that showed positive amplification before transplantation, 10 turned negative and 3 remained positive after transplantation. One patient, who was negative, became positive after transplantation. Three patients had recurrent HBV infection, but none had positive PCR before or after transplantation and recurrence was not associated with PCR results. Donors with low anti-HBs titer were more likely to be PCR positive compared to donors with high anti-HBs serology (P<0.05). CONCLUSIONS: Under adequate prophylactic measures, the presence of HBV DNA within the liver tissue does not affect recurrence and most allografts harboring HBV DNA before transplantation will eventually show viral clearance. However, many anti-HBc positive allografts are infected by HBV at subclinical level so vigilant surveillance is essential.
Middle Aged ; Male ; *Living Donors ; *Liver Transplantation ; Liver/virology ; Humans ; Hepatitis B, Chronic/diagnosis/immunology/virology ; Hepatitis B virus/*genetics ; Hepatitis B Core Antigens/*immunology ; Hepatitis B Antibodies/*analysis ; Female ; DNA, Viral/*analysis ; Adult

BACKGROUND: The aim of this study was to report the first experience of using tests of antibody to hepatitis B core antigen (anti-HBc) and antibody to hepatitis B surface antigen (anti-HBs) for the selection of blood donors in a tertiary hospital blood center in Korea. METHODS: From January 2005 to December 2007, the data of all eligible donors according to the Korean Blood Regulation Law were analyzed. Anti-HBc testing was performed in all donors, but anti-HBs was tested only in anti-HBc seropositive donors. Anti-HBs negative but anti-HBc positive donors were regarded as ineligible for blood donation. Cost for donor testing was calculated based on Korean health insurance payment schedule from 2005 to 2007. RESULTS: The seroprevalence of anti-HBc in blood donors was 23.2% (162/699) and increased with increasing age. The proportion of ineligible donors for blood collection was 2.7% (19/699) of total donors and 11.6% (19/162) of anti-HBc seropositive donors. The cost of testing for anti-HBc and anti-HBs was estimated to be about 40% of the total screening cost. CONCLUSIONS: Although additional donor screening tests for anti-HBc and anti-HBs requires increased cost and relatively small number of donors are additionally excluded by these tests, they are considered to be helpful for the safety of blood products, because our blood center has characteristics with small number of donors and relatively high percentage of donors in the age group of thirties and older.
Adolescent ; Adult ; Age Factors ; Blood Banks ; *Blood Donors ; Hepatitis B/diagnosis/economics ; Hepatitis B Antibodies/*blood ; Hepatitis B Core Antigens/*immunology ; Hepatitis B Surface Antigens/*immunology ; Humans ; Korea ; Laboratories, Hospital ; Middle Aged ; Seroepidemiologic Studies ; Serologic Tests/economics