Study On Relation Between Genotype Of HBV And Chronic Liver Disease In Changchun Of China

Objective: To get some knowledge of the distribution of HBV genotypes in Changchun area and to analyze the relationship between HBV genotypes and the seriousness of the disease,the titer of HBV DNA, the state of HbeAg, serological data, gender and age.Backgroud: It was reported that the full nucleotide sequences of 18 hepatitis B virus (HBV) strains clusterd into four genetic groups (A to D) with more than 8% divergence between the groups by Okamoto in 1988. So far, A-H eight genotypes have been found by this type of criterion.Recently, researches of many scholars show that HBV genotypes have characteristic geographical distribution and may be related to the seriousness and progress of the disease and response to antiviral therapy.Method: 149 patients infected by HBV in Changchun area were analyzed[27 asymptomatic carrier (ASC), 6 acute hepatitis B (AHB), 87 chronic hepatitis B (CHB), 22 liver cirrhosis (LC), 7 hepatocellular carcinoma (HCC)]. we extracted HBV DNA from serum samples, and then amplified HBV S gene by semi-nested polymerase chain reaction (semi-nested PCR). According to the different restriction sites of the restriction enzymes and the restriction fragments of different genotypes, we use five restriction enzymes (HphI, NciI, Alw I, Ear I and NlaIV) to digest the second-round PCR product. Subsequently, the restriction products were electrophoresed on a 3% agarose gel and analyzed. Use x2 and rank-sum test to analyze clinical data.Result: 1. Of the 149 HBV infected cases, 15 were genotype B and 127 were genotype C which was the major genotype in Changchun area, 7 were genotype D. The proportions of genotypes B, C and D were 10.1% (15/149), 85.2% (127/149) and 4.7% (7/149) respectively. No other genotypes, such as A, E, F, G. H were found. The genotypes of asymtomatic carrier included 6 genotype B and 21 genotype C. The numbers of genotype B, C and D were 1, 4, 1 respectively among acute hepatitis B. The numbers of genotype B, C and D were 7, 76, 4 respectively among chronic hepatitis B. The numbers of genotype B, C and D were 1, 20, 1 respectively among liver cirrhosis. The numbers of genotype B, C and D were 0, 6, 1 respectively among hepatocellular carcinoma. By the different clinical degree, the constituent ratio of genotype C in asymptomatic carriers, acute hepatitis B, chronic hepatitis B, liver cirrhosis and hepatocellular carcinoma were 77.8%, 66.7%, 87.4%, 90.9%, 85.7% respectively, on the contrary, the constituent ratio of genotype B were 22.2%, 16.7%, 8.0%, 4.5%, 0% respectively. The propotion of genotype C was higher in liver cirrhosis group than that in other disease groups while the propotion of genotype B was higher in asymtomatic carrier and acute hepatitis B than that in other groups. There was no statistical difference between C and B genotype group in the distribution of different liver diseases (x2=5.2729, P=0.2604>0.05). 3. There was a stastistical difference of average age between C genotype group and B genotype group (T=468, P<0.05). The average age of patients infected by genotype C was higher than that of patients infected by genotype B (37.3±13.8 vs 23.8±7.5, P=0.0001). Patients infected by genotype C were usually more than 35 years old, mostly 41-50 years old. Patients infected by genotype B were usually less than 35 years old, mostly 21-30 years old. There was no clear sign of the distribution of genotype D in liver diseases because the number of patients infected by genotype D was limited. Classifying patients into two groups with the age from 1 year to 35 years and above 35 years old, there was no significant difference comparing the propotion of genotype B with that of genotype in the two groups (x2=10.91P<0.05). 4. Clinically, the incidence, mortality rate and clinic degree of liver diseases of male patients were higher than those of female patients, but there was no stastistical difference in gender between B genotype group and C genotype group (x2=2.3551, P>0.05). The level of ALT, AST, GGT, ALP, TBIL and DBIL in patients infected by genotype C were higher than those in patients infected by genotype B. The level of ALB and CHE in patients infected by genotype C were lower than those in patients infected by genotype B, but there was no statistical difference among them (P>0.05). 5. In replication of virus, The titer of HBV DNA of genotype B and C was 6.76±1.07and 6.86±1.26, the positive rate of HBeAg in patients infected by genotype C was higher than that in patients by genotype B (60.6% vs 60%), but the positive rate of HBeAb in patients by genotype C was lower than that in patients by genotype B (20.5% vs 40%). In conculsion, there was no statistical difference in the titer of HBV DNA, the positive rate of HBeAg and HBeAb among them (P>0.05).Conclusion: 1. The major genotype of HBV in patients of Changchun area was genotype C. 2. There was no significant difference in the seriousness of the disease, the titer of HBV DNA, the state of HBeAg, serological data (ALT, AST, GGT, ALP, TBIL, DBIL, ALB, CHE), gender and age. 3. Genotype was associated with age. The average age of patients infected by genotype C was higher than that of patients infected by genotype B.