Hepatitis B virus genotyping by enzyme-linked immunosorbent assay in Taiwan

Restriction fragment length polymorphism (RFLP) and enzyme-linked immunosorbent assay (ELISA) with monoclonal antibodies (mAbs) were used in this study to detect genotypes of HBV, and the efficiency and precision of ELISA using the mAbs for HBV genotype detection were also estimated. The ELISA with mAbs method was used for the detection of HBV genotype in a Taiwanese population. The HBV genotypes of 100 chronic hepatitis B patients were determined by ELISA and were then compared with those obtained using RFLP. Genotype B was found to be the most prevalent in this study (63% by RFLP; 62% by ELISA) followed by genotype C (31% by RFLP; 35% by ELISA). There was no significant difference between the results obtained by RFLP and ELISA (P = 0.75). The ELISA overall genotypeable rate, the correct genotyping rate from genotypeable specimens, and the concordance of the HBV genotyping assay was 96.00, 94.79, and 91.00%; for the ELISA HBV genotyping assay for genotype B specimens was 96.77, 100.00, and 96.77%; and for genotype C specimens was 97.14, 91.18, and 88.57%, respectively. The mean HBV DNA level was higher in the specimens that could be genotyped by both RFLP and ELISA samples (6.24 +/- A 1.77 vs. 2.34 +/- A 0.90, log IU/ml), and a significant difference in terms of HBV DNA level of more than 2 x 10(3) IU/ml was identified between the genotyped RFLP samples (P < 0.001). ELISA is a practical and a useful method for HBV genotyping in a clinical setting in Taiwan, in particular for patients with lower levels of HBV DNA.