ABSTRACT
Objective To evaluate the multiplex nucleic acid testing (NAT) assays for HBV,HCV and HIV in detecting HBV DNA in plasma samples. Methods 534 plasma samples collected form several areas were detected with Abbott Architect i2000 HBsAg, ani-HBs, HBeAg, anti-HBe, anti-HBc and anti-HBc IgM diagnostic kits. HBV DNA levels of those samples were detected with Roche COBAS AmpliPrep/ COBAS TaqMan HBV Test. Two kinds of multiplex NAT assays for HBV, HCV and HIV were used to test HBV DNA of those 534 samples. Results of serology-markers and quantitative HBV DNA levels with results of NAT were compared. Results HBV DNA was positive in all 81 HBsAg, HBeAg and anti-HBc positive samples,detected by both of NAT assays. HBV DNA was positive in 11 and 19 of 200 HBsAg negative samples when detected with the two kinds of NAT assays separately. Compared with the quantitative results detected by Roche COBAS AmpliPrep/COBAS TaqMan HBV Test, the HBV DNA positive rates were 96.9% and 94.3% in 193 samples of HBV DNA levels over 500 IU/ml while 40.2% and 45.3% in 117 samples of HBV DNA levels below 500 IU/ml while 99.3% and 96.0% in 151 samples of DNA negative HBV. Conclusion There are some occult low level HBV DNA carriers with HBsAg negative results in China. NAT assays for HBV, HCV and HIV may be useful to improve the transfusion safety.
ABSTRACT
<p><b>OBJECTIVE</b>To evaluate anti-HEV diagnostic kits by experimental infecting rhesus monkeys with HEV.</p><p><b>METHODS</b>Eight rhesus monkeys were infected with genotype 1 and 4 HEV separately. The alanine aminotransferase (ALT) level of all monkeys were detected before and after the process of infection. HEV RNA in stool specimens was tested by reverse transcriptase-polymerase chain reaction (RT-PCR) assay. Anti-HEV IgG in serum was detected by GL-IgG and WT-IgG.</p><p><b>RESULTS</b>HEV RNA presented in the stool of all the 8 monkeys after infection. The ALT level of 1 monkey infected with genotype 1 HEV and 2 monkeys infected with genotype 4 HEV appeared abnormally after infection. Tested by GL-IgG, 2 of the 4 monkeys infected with genotype 1 HEV and 1 of 4 monkeys infected with genotype 4 HEV seroconverted to anti-HEV IgG. However, when tested by WT-IgG, all the infected monkeys seroconverted to anti-HEV IgG. The anti-HEV IgG tested by WT-IgG was positive during the whole observation period,and the anti-HEV IgG measured by GL-IgG only remained 12 weeks after infection. Detected by GL-IgG and WT-IgG, seropositive conversion of the anti-HEV IgG happened almost at the same time.</p><p><b>CONCLUSION</b>Both GL-IgG and WT-IgG could detect the anti-HEV IgG of experimentally infected rhesus monkeys but the WT-IgG had a higher sensitivity for detection of anti-HEV IgG than</p>
Subject(s)
Animals , Alanine Transaminase , Blood , Disease Models, Animal , Genotype , Hepatitis E , Allergy and Immunology , Virology , Hepatitis E virus , Genetics , Allergy and Immunology , Immunoglobulin G , Allergy and Immunology , Macaca mulatta , Reverse Transcriptase Polymerase Chain ReactionABSTRACT
<p><b>OBJECTIVE</b>To establish the national quantity standard of hepatitis B surface antigen according to the world health organization' s standard material and prepare the national liner reference panel for hepatitis B surface antigen.</p><p><b>METHODS</b>Sera from hepatitis B patients and health blood donors in different areas were collected and detected by domastic HBsAg kits, anti-HBs kits, HBeAg kits, anti-HBe kits, anti-HBc kits and anti-HCV, and then confirmed by the kits produced by Abbott, which was approved by WHO. One serum with high concentration of HBsAg was calibrated with the standard sample of WHO. And then it was diluted by 1.5 fold as the liner HBsAg reference panel.</p><p><b>RESULTS</b>The HBsAg concentration of one serum was 1226 IU/ml calibrated by 21 independent standardization measurements with 7 kinds of kits. The coefficient of variation of each calibration were less then 15%. A panel contained 8 serial dilutions was established as the national liner HBsAg reference panel. The permitted range of every dilution was stipulated and the stability of the panel was detected by accelerated test.</p><p><b>CONCLUSIONS</b>The national quantity standard of hepatitis B surface antigen was established and the national quantitative reference panel for HBsAg which contains eight liner serum was developed.</p>
Subject(s)
Humans , China , Hepatitis B , Virology , Hepatitis B Surface Antigens , Blood , Immunoenzyme Techniques , Methods , Reference Standards , Reagent Kits, Diagnostic , Reference Standards , Reference StandardsABSTRACT
HCV RNA positive serum was first selected by RT-PCR test kit from several anti-HCV positive sera obtained from Xi'an.HCV RNA extrac ted from the elected sera was converted to cDNA by reverse transcription with ra ndom primer.Half-nested PCR was performed.The amplified product was 852 bp.The purified PCR product was digested by restriction endonucleases and then ligated to epressio vector pET-22b\++.Its nucleotide sequence was determined by dideoxy chain termination method.A comparison of the sequence with several isolates rep orted previously showed that the sequence belonged to HCV type Ⅱ.