الفهرس 
Hepatitis B Virus InfectionOnly 14 pages are availabe for public view
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Abstract
here are more than 2 billion individuals with serological evidence of HBV infection worldwide. Of these 400 million are chronic carriers and 500,000 to 1.2 million die annually from cirrhosis and HCC. HBV infection has serious consequences such as chronic hepatitis, cirrhosis and HCC that ultimately cause death of infected persons.
Chronic HBV carriers are the main source of HBV infection in the population. Thus, the detection of HBV infection in pregnant women and blood donors is required to prevent spread of the infection.
Many studies have confirmed that the pathogenesis of HBV is largely due to the host immune system particularly the cellular immune response.
Hepatitis B surface antigen (HBsAg) is a major envelope protein of HBV. It can serve as an epitope and provide the host with immunity.
HBsAg is one of the first serum markers to appear during the course of HBV infection and can be detected 2 to 8 weeks before biochemical evidence of liver dysfunction and the onset of jaundice. HBsAg is cleared within a few months in self-limiting illness. If HBsAg persists for more than 6 months, spontaneous clearance is very improbable and the infected individual is considered a chronic HBV carrier.
Among the many commercially licensed HBsAg assays available, ELISAS are currently the most frequently used. These assays use either monoclonal or polyclonal anti-HBs antibodies bound to a solid phase and a second labeled anti-HBs to detect the captured antigen. Despite the high-level performance of screening assays, transfusion-associated HBV infection is still reported.
To reduce the residual risk of transfusion-associated hepatitis B, the sensitivity of HBsAg screening assays is continuously improved.
Recently, antiviral agents such as lamivudine and interferon-α (IFN-α) have been used as standard therapies for the treatment of chronic hepatitis B. Also new drugs have been or are being developed to treat refractory mutant viral infections.
Quantitative measures of HBsAg level in serum are important for monitoring response to anti-viral treatment during the management of patients with a chronic HBV infection.
This study is a comparative study, comparing the results of the quantitative assay of HBsAg by ARCHITECHT (Abbott diagnostics) with those of a commercial qualitative ELISA or cobas e411 (Roche Diagnostics) in a trial to establish a relationship between both measurements, aiming at replacing the expensive ARCHITECHT, not-always-available measuring technique, with (qualitative ELISA or cobas e411) available one, for the follow up of chronic HBV treated patients.
The study was conducted on 123 blood samples obtained from patients attending immunology laboratory in Ain Shams University Hospital. Eighty one of the patients (65.9%) were HBsAg positive, 42 (34.1%) were borderline by ELISA.
On Cobas e411,83 (67.5%) patients were reactive for HBsAg on Cobas e411 machine;40(32.5%)were non reactive, while none of our study patients had borderline results.There was a positive significant correlation between HBsAg by both Cobas e411 and Elisa.
The positive samples were then run on quantitative Architect and there was a positive significant correlation between HBsAg results by Architect and both Cobas e411 and Elisa.
HBV DNA by PCR was positive in 35(59.3%) patients and below detection limit in 24(40.7%) patients. HBsAg OD results by ELISA showed a statistically significant positive correlation with ALT (p=0.002), and HBV DNA levels (p=0.032). Similarly, HBsAg Cobas e411 results had a statistically significant positive correlation with AST (p=0.017), ALT (p=0.001) and HBV DNA (p=0.028), while HBsAg Architect results correlated significantly positively with only HBV DNA (p=0.000).
In conclusion,comparing the results of the quantitative assay by Architect with those of the commercial qualitative ELISA test and Cobas e411 we can replace the expensive not-always available measuring technique (Architect) with (qualitative ELISA, or Cobas e411) available test, for the follow up of chronic HBV treated patients. Reliability (high sensitivity and specificity) attained at high cut-off levels for both.