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

BACKGROUND: Hepatitis B virus (HBV) infection is one of the worldwide public health problem affecting about 300 million people. The envelope protein of HBV consists of three components known as preS1, preS2, and S antigen. According to the recent study, anti-HBs Ab showed effective neutralization ability against HBV from chronic hepatitis B and liver transplant patients, suggesting the possible development of therapeutic antibody. METHODS: Spleen cells immunized with S antigen of HBV were fused with myeloma cell line to obtain HBsAg specific monoclonal antibodies. High affinity antibodies against HBsAg (adr, ad and ay type) were selected by competitive ELISA method. Nucleotide sequence of the variable regions of monoclonal antibodies was analyzed by RT-PCR followed by conventional sequencing method. RESULTS: We produced 14 murine monoclonal antibodies which recognize S antigen of HBV. Two of them, A9-11 and C6-9 showed the highest affinity. The sequence analysis of A9-11 revealed that variable regions of the heavy chain and light chains are members of mouse heavy chain I (B) and light chain lambda 1, respectively. Likewise, the sequence analysis of C6-9 revealed that variable regions of the heavy chain and light chains are members of mouse heavy chain II (B) and light chain kappa 1, respectively. Neutralization assay showed that A9-11 and C6-9 effectively neutralize the HBV infection. CONCLUSION: These results suggest that A9-11 and C6-9 mouse monoclonal antibodies can be used for the development of therapeutic antibody for HBV infection.
Animals ; Antibodies ; Antibodies, Monoclonal* ; Base Sequence ; Cell Line ; Enzyme-Linked Immunosorbent Assay ; Hepatitis B Surface Antigens ; Hepatitis B virus* ; Hepatitis B* ; Hepatitis B, Chronic ; Hepatitis* ; Humans ; Liver ; Mice ; Public Health ; Sequence Analysis ; Spleen

<b>BACKGROUNDb>To establish a new assay for detecting the quantity of HBV DNA with PCR and enzyme-linked immunosorbent assay(ELISA).

<b>METHODSb>The products of PCR using primers pre-labeled with biotin were hybridized with the capture probes that were immobilized on the microtiter strips and then bond with Sav-Ap. The quantity of DNA was detected by measuring the yellow color at 405 nm wave length.

<b>RESULTSb>Totally 125 sera from patients with hepatitis B were tested for HBV DNA by this method,the sera were also tested for HBV immunological markers by solid phase radio immuno-assay (SPRIA). The HBV positive rate with PCR-ELISA was 64.9% (24/37) in samples which were positive for HBsAg, HBeAg and HBcAb; and 34.2% (13/38) in sera which were positive for HBsAg, HBeAb and HBcAb; in sera positive for HBsAg and HBcAb or only HBcAb, the positive rate was 6.7% (1/15) and 5.9% (2/34) respectively.

<b>CONCLUSIONSb>The PCR ELISA assay is simple and suitable for clinical laboratory in quantitative determination of HBV DNA.

DNA Probes ; DNA, Viral ; analysis ; biosynthesis ; genetics ; Enzyme-Linked Immunosorbent Assay ; Hepatitis B ; virology ; Hepatitis B Antibodies ; blood ; Hepatitis B Surface Antigens ; blood ; Hepatitis B e Antigens ; blood ; Hepatitis B virus ; genetics ; isolation & purification ; Humans ; Polymerase Chain Reaction ; Sensitivity and Specificity

<b>OBJECTIVEb>To observe the HBV serum markers and HBV DNA expressions of the neonates born to the HBsAg-positive mothers.

<b>METHODSb>By detecting serum immunity markers of hepatitis B virus (5 items) and serum HBV DNA of 283 neonates (a pair of twins) born to 282 HBsAg-positive mothers.

<b>RESULTSb>12 patterns emerge from the study of the hepatitis B serum markers of 283 neonates. Topping the list is the combination of HBeAg and anti-HBc positive accounting for 48.41% (137/283), followed by the combination of anti-HBe and anti-HBc positive accounting for 22.26% (62/283). The third highest combination is that of HBsAg, HBeAg and anti-HBc positive accounting for 12.37% (35/283). There are five combinations accounting for 16.61% (47/283), each with HBsAg-positive. No case is found of the five items all negative or only HBsAb positive. Five cases are detected of serum HBV DNA > or = 1 x 103 IU/ml accounting for 1.77%.

<b>CONCLUSIONSb>Neonates born to HBsAg-positive mothers display complex patterns of serum hepatitis B markers, the dominant pattern being the combination of HBeAg and anti-HBc positive. Cases of serum HBV DNA > or = 1 x 10(3) IU/ml are rare.

Biomarkers ; blood ; DNA, Viral ; analysis ; Female ; Hepatitis B ; transmission ; Hepatitis B Antibodies ; blood ; Hepatitis B Core Antigens ; blood ; Hepatitis B Surface Antigens ; blood ; Hepatitis B e Antigens ; blood ; Humans ; Infant, Newborn ; Infectious Disease Transmission, Vertical ; Male

<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>OBJECTIVEb>To investigate the prevalence of occult HBV infection in the normal population in Xiamen.

<b>METHODSb>4 437 registered permanent residents, aged 1-59 years old, were selected in Xiamen using stratified random sampling method from September to October in 2006. Serum samples were obtained, the basic characteristics, inoculation of HBV vaccine, and liver disease were surveyed. The serum samples were tested five HBV seroimmunological markers. The HBsAg-negative specimens were subjected to HBV-DNA detection by nested PCR targeting for multiple gene segments. The amplified products were sequenced and the sequence was used for determination of HBV genotype and mutation analysis of amino acids located in HBsAg "a" epitope. Subjects with serum detectable HBV-DNA and negative result of HBsAg were considered as occult HBV infection.

<b>RESULTSb>Among the 4 437 subjects, 482 individuals were observed HBsAg positive and 3 944 were observed negative. Of the 3 955 HBsAg- negative specimens, 27 occult HBV infections were determined with the positive rate of 0.68% (27/3 955). There were 16 samples with genotype B and 11 with genotype C. 3 types of amino acid (AA) mutation (M133T, T140I, G145R) that influence "a" epitope conformation were observed in 9 subjects with occult HBV infection. S region was successfully sequenced in 312 of the 482 HBsAg positive samples. In subjects with occult HBV infection, the infection rate of genotype C HBV (40.74%, 11/27), inoculation rate of HBV vaccine (62.96%, 17/27), positive rate of HBsAb (51.85%, 14/27), and mutation rate of critical amino acid of "a" epitope (33.33%, 9/27) were higher than HBsAg positive individuals (22.76% (71/312), 13.78% (43/312),0.32% (1/312),0.99% (31/312), respectively), and all the difference were significant (χ(2) = 4.29, 41.26, 156.00, 13.07, respectively, and P value = 0.038, <0.001, <0.001, <0.001, respectively). While the average age in subjects with occult HBV infection (18.3 ± 16.2) were lower than that in HBsAg positive infection (34.4 ± 11.6), and the difference was significant (t = 6.67, P < 0.001). The reactive rate of HBeAb (11.11%, 3/27) and HBcAb (62.96%, 17/27) in subjects with occult HBV infection were lower than that in HBsAg positive infection (74.36% (232/312), 98.40% (307/312)), and the difference were significant (χ(2) = 46.74, 73.78, respectively, and P value <0.001, <0.001, respectively).

<b>CONCLUSIONb>In normal population in Xiamen, the infection rate of genotype C, the positive rate of HBsAb, the HBV vaccination rate, and the key AA mutation rate in "a" epitope are significantly higher in occult HBV infection than in HBsAg positive infection, and the age, the positive rate of HBeAb and HBcAb are significantly lower.

Adolescent ; Adult ; Child ; Child, Preschool ; DNA Mutational Analysis ; Genotype ; Hepatitis B ; diagnosis ; Hepatitis B Antibodies ; Hepatitis B Surface Antigens ; Hepatitis B Vaccines ; Hepatitis B virus ; Humans ; Infant ; Middle Aged ; Mutation ; Prevalence ; Vaccination

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

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

Adolescent ; Adult ; Child ; Child, Preschool ; DNA, Viral ; analysis ; Female ; Fluoroimmunoassay ; methods ; Hepatitis B Antibodies ; analysis ; Hepatitis B Surface Antigens ; analysis ; Hepatitis B e Antigens ; analysis ; Humans ; Male ; Middle Aged

Serum HBsAg and anti-HBs were measured by radioimmunoassay in 384 patients with renal disease, admitted from January 1979 to December 1981 and in 167 controls. Among 384 cases of renal disease, 41 cases (10.7%) were positive for HBsAg, while only 8 out of 167 (4.8%) of the controls were positive, a difference which was barely significant (P < 0.05). However in 159 biopsy-proven renal disease patients, 28 (17.6%) were positive for HRsAg, a difference which was highly significant when it was compared to the total control group (P < 0.005). Seven of thirty-six (19.4%) cases with mesangio-proliferative glomerulonephritis and 9 of 10 (90.0%) cases with membranous nephro-pathy were positive for HBsAg; when these were compared to the total control group the differences were highly significant (P < 0.01 and P < 0.0001 respective1y). Serum HBsAg was also positive in the other renal diseases and anti-HBs was detected in some of the renal diseases but they were statistically not significant when compared with the non-renal controls. Glomerular deposits of hepatitis B surface antigen were identified in 5 of 8 biopsies in membranous nephropathy. The HBsAg and anti-HBs prevalence rate in the family members of the patients with renal diseases were 34.1% and 29.3% respectively.
Adolescent ; Biopsy ; Child ; Child, Preschool ; Female ; Hepatitis B Antibodies/analysis* ; Hepatitis B Surface Antigens/analysis* ; Human ; Kidney/pathology ; Kidney Diseases/diagnosis* ; Male