[Investigation on virus genotype in patients infected with hepatitis B virus in four cities of Guizhou].

OBJECTIVE

To investigate the distribution of hepatitis B virus (HBV) genotype in Guizhou and to study the relationship between the genotype and the progression of liver disease.

METHODS

786 patients with chronic HBV infection, from 4 cities of Guizhou, including 346 asymptomatic carriers (ASC), 313 chronic hepatitis (CH), 77 liver cirrhosis (LC), 50 hepatocellular carcinoma (HCC) were examined. HBV genotype was determined by restriction fragment length polymorphism analysis and the subtypes were determined by direct sequencing of PCR product in 94 patients with HBV B genotype, the relationship between HBV genotype and the progression of liver disease was studied by multifactor analysis such as HBeAg positivity, HBV DNA load and ALT level.

RESULTS

Of the 786 patients, 7 (0.89%), 497 (63.23%), 275 (34.99%), and 7 (0.89%) belonged to genotype A, B, C, D, respectively. There was statistically significant difference in the distribution of genotype B among Kaili (96.04%), Zunyi (78.79%), Duyun (64.52%) and Guiyang (53.14%) (P< 0.01). Genotype C was more prevalent in Guiyang than in other three cities (P < 0.01, or P < 0.05). Out of 94 genotypes B, 93 (98.94%) belonged to subtype Ba, only one was subtype Bj. There were statistically significant difference in the distribution of genotype B and C among various stage of liver disease (P < 0.05 or P < 0.01). Genotype B showed a gradual decrease from ASC, CH, LC to the HCC group while in contrast, genotype C showed a gradual increase in the same order. The ALT levels and the mean age were significantly higher and older in patients with genotype C than those in genotype B (P < 0.01 or 0.05). The HBeAg positivity was significantly lower in genotype C than that in genotype B (P < 0.025).

CONCLUSION

Data showed that there were genotype A, B, C and D existing in Guizhou. Genotype B was the major one but genotype C was more commonly seen. In genotype B, subtype Ba appeared to be predominant. The geographic distribution of genotype B and C were different in some cities of Guizhou. Compared to genotype B, genotype C was associated with the development of more severe liver damage.