A novel immunoassay for PreS1 and/or core-related antigens for detection of HBsAg variants.

A novel immunoassay that detects simultaneously hepatitis B virus (HBV) PreS1 and/or core-related antigens was developed and evaluated for its potential for detecting hepatitis B surface antigen (HBsAg) variants. The detection limits of the assay was 102.9±0.5copies/mL (mean±SD) for HBsAg-positive sera with different genotypes, and 103.5±1.2copies/mL for HBsAg variants sera. The specificity of the assay was 99.9% (95% CI: 99.7–99.9%, 4551 healthy individuals). The sensitivities were 93.9% (95% CI: 92.8–94.9%), 59.3% (95% CI: 38.7–77.6%) and 80% (95% CI: 44.4–97.5%) in three independent groups which include: 2065 hepatitis patients, 27 patients with occult hepatitis B and 10 HBsAg variants, respectively. In addition, a novel premature stop code mutation at position 112 of HBsAg was observed in two patients with chronic hepatitis B with different genotypes.