After years of exploration, Creative Diagnostics has obtained highly purified HBsAg and mutants using yeast expression system through the established Hepatitis B Virus Surface Antigen Mutants manufacture platform.
Some HBsAg mutants are associated with immune escape, HBsAg detection failure, HCC development, and other major biological or clinical events.
Clinical Significance of HBsAg Mutants
HBsAg mutants associated with immune escape
The "a" determinant region exposed to the outer surface of virus renders its immunogenicity. The antibody produced after HBV vaccination and the antibody used for the diagnostic assays of detecting serum HBsAg are both targeted at this region. Mutants with single amino acid mutation may appear on loops of the "a" determinant and may lead to immune escape, which means the mutants could evade the immune response of patients to maximize their ability of being transmitted to a fresh host or to proceed to grow.
HBsAg mutants are the reason of failed HBsAg detection
Commonly used commercial assays cannot detect serum HBsAg in patients since the HBsAg mutants replace the HBsAg. HBsAg reactivity can be barely detected in the presence of the aa substitution mutants, such as G145R, T131I, K141E and so on.
HBsAg mutants associated with HCC development
Chances of patients with hepatocellular carcinoma (HCC) carrying HBsAg mutant are higher than those without. Over the past decade, growing evidence indicates the positive correlation between HBsAg mutants with mutations in pre-S1or pre-S2 regions and the development of HCC. Research has shown that among the HBsAg-positive patients, the prevalence of HBsAg W4P/R mutants was higher in patients with cirrhosis or HCC than in those with less severe liver illness.
In conclusion, some HBsAg-negative subjects may be infected with HBV because of the presence of HBsAg mutant with amino acid substitutes, which cannot be detected by the commercially available assays. Clinicians and healthcare staff working in laboratories and blood banks should take this possibility into account. Mutants with region or point mutations may imply a higher chance of developing HCC.
Detection Methods for HBsAg and Mutants
The current commonly used detection methods for HBsAg and HBsAb are listed here.
Hepatitis B Virus Antigens and Antibodies The hepatitis B virus is a small DNA virus with features similar to retroviruses, which is a prototype virus of the Hepadnaviridae family. HBV causes acute and chronic hepatitis in humans. The hepatitis B virus consists of an outer lipid envelope and an icosahedral nucleocapsid core composed of protein... Learn more
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