[A clinical study on hepatitis B virus genotype].

OBJECTIVE

To study the hepatitis B virus (HBV) genotype and its relation to clinical degree and responsiveness to antiviral therapy on hepatitis in order to guide the clinical therapy.

METHODS

We amplified HBV S gene by polymerase chain reaction (PCR), using the second-round PCR product, which was digested by restriction fragment length polymorphism (RFLP). This genotype method was designed under the analysis of the restriction fragment length polymorphism and using the restriction enzymes that identified the genotype-specific sequences. Five restriction enzymes, Hph I , Nci I , Alw I, Ear I and NlaIV, were identified in genotype-specific RFLP from the S gene region. Representative sequences from the S genome region of each HBV genotype were aligned to show the restriction sites by the five restriction enzymes. The amplified S gene nucleotide sequences were sequenced by dideoxy-chain-termination method and the corresponding amino acid sequence was deduced using DNASIS software. Later, they were genotyped by comparing to representative S gene sequences obtained from GenBank. This confirmed the results of RFLP HBV genotyping methods, coincident with that of S gene sequence.

RESULTS

Genotypes A, B, C, D were classified in 216 patients with HBV and DNA positive. The results showed that: 1 case (0.46%) of genotype A, 19 cases genotype B (8.8% ), 175 genotype C (81.02%) and 21 genotype D (9.72%). A total of 86 patients in the hospital were divided into either genotype C cases (69) or non-genotype C cases (17).

CONCLUSION

Genotype C was the major genotype in Changchun. Among HBV patients, type C was 80.95%, followed by genotypes B and D. Both hepatocellular carcinoma and liver cirrhosis showed relations with genotype C.