Evaluation of hepatitis B virus genotyping EIA kit

: Clinical significance of Hepatitis B virus(HBV) genotyping is increasingly recognized. The aim of this study was to evaluate reproducibility, accuracy, and sensitivity of an enzyme immunoassay (EIA) based HBV genotyping kit, which designed to discriminate between genotypes to A, B, C, or D by detecting genotype-specific epitopes in PreS2 region. Using the four genotypes panels, the EIA demonstrated complete inter and intra-assay genotyping reproducibility. Serum specimens had stable results after 8 days at 4 degrees C, or 10 cycles of freezing-thawing. In 91 samples that have been genotyped by DNA sequencing, 87(95.6%) were in complete accordance with EIA genotyping. Of examined 344 HBsAg-positive serum specimens, genotypes A, B, C and D were determined in 26 (7.6%), 62 (18.0%), 228 (66.3%), and 9 (2.6%) cases, respectively. Of 19 (5.5%) specimens unclassified by the EIA, 13 were found to have low titer of HBsAg concentration (< 3 IU/ml), and the other 5 had amino acid mutations or deletions within targeted PreS2 epitopes. The EIA allowed genotyping even in HBV DNA negative samples (96.2%). In conclusion, HBV genotype EIA is reliable, sensitive and easy assay for HBV genotyping. The assay would be useful for clinical use.