Clinical and Virological Differences between Hepatitis B Virus Genotypes B and C: A Case-Control Study
Pisit Tangkijvanich MD*, Varocha Mahachai MD**, Piyawat Komolmit MD, PhD**, Juthatip Fongsarun MD***, Apiradee Theamboonlers MSc****, Yong Poovorawan MD****
Affiliation : * Department of Biochemistry, Faculty of Medicine,Chulalongkorn University ** Department of Medicine, Faculty of Medicine,Chulalongkorn University *** The National Blood Center, Thai Red Cross **** Department of Pediatrics, Faculty of Medicine,Chulalongkorn University
Objective : The pathogenic significance of hepatitis B virus (HBV) genotypes is undefined. The aim of this study was to
elucidate the differences in clinical and virological features between HBV genotypes B and C by conducting a case-control
study in Thai patients who were chronically infected with the virus.
Patients and Method : HBV genotyping was assessed by polymerase chain reaction (PCR) and restriction fragment length
polymorphism (RFLP) method in stored sera of 470 patients with chronic hepatitis B. Among these, 65 patients with HBV
genotype B were enrolled and matched individually to those with HBV genotype C according to sex, age, and distribution
of liver disease which included asymptomatic carrier, chronic hepatitis, cirrhosis and hepatocellular carcinoma.
Results : Serum alanine aminotransferase (ALT) was significantly higher in patients with genotype C than those with
genotype B. Hepatitis B e antigen (HBeAg) was significantly more frequent in genotype C than genotype B patients (50.8 and
30.8%, respectively, p=0.03), but the levels of HBV DNA were comparable between them. Among patients who were
positive for HBeAg, the mean age of genotype C patients tended to be older than genotype B patients.
Conclusion : The present study demonstrated that patients with HBV genotype C had a significantly higher rate of HBeAg,
experienced delayed HBeAg seroconversion and exhibited more severe liver disease compared to those with genotype B.
Keywords : Hepatitis B, Genotype, HBeAg
