Hepatitis B virus genotypes and clinical manifestation among hepatitis B carriers in Thailand.
BACKGROUND
Hepatitis B virus (HBV) genotypes have distinct geographic distributions. The aim of the present study was to evaluate the distribution of HBV genotypes and their clinical relevance in Thailand.


METHODS
Hepatitis B virus genotypes among 107 hepatitis B carriers residing in Thailand were evaluated using serologic and genetic methods. They were clinically classified into asymptomatic carriers with normal serum alanine transaminase (ALT) levels and patients with chronic liver disease, such as those with chronic hepatitis (CH), liver cirrhosis (LC) and hepatocellular carcinoma (HCC).


RESULTS
Hepatitis B virus genotype distribution among the 107 patients was 25.2% for genotype B, 72.0% for genotype C and 2.8% for genotype D. The serum ALT levels, HBV-DNA and hepatitis B e antigen positivity were significantly higher in carriers infected with genotype C HBV than in those infected with genotype B (P < 0.05). The proportion of genotype B HBV was higher in asymptomatic carriers than in patients with CH and those who developed liver disease, such as LC and HCC (45.5, 16.9 and 25.0%, respectively; P < 0.05). In contrast, the proportion of genotype C HBV was higher in patients who developed liver disease and CH than in asymptomatic carriers (68.7, 83.0 and 50.0%, respectively; P < 0.05). Phylogenetic analysis based on entire genome sequences revealed three HBV isolates, which were classified into a subgroup of genotype C in isolates from South-East Asian countries.


CONCLUSIONS
Genotypes B and C are the predominant types among hepatitis B carriers residing in Thailand and those genotypes influence the clinical manifestation in carriers with chronic hepatitis B infection.
Sugauchi
Fuminaka
F
Second Department of Internal Medicine and Department of Laboratory Medicine, Nagoya City University Medical School, Kawasumi, Mizuho, Nagoya 467-8601, Japan.
Chutaputti
Anuchit
A
Orito
Etsuro
E
Kato
Hideaki
H
Suzuki
Seiji
S
Ueda
Ryuzo
R
Mizokami
Masashi
M
D000328:Adult; D006528:Carcinoma, Hepatocellular / Q000821:virology; D002353:Carrier State; D004279:DNA, Viral / Q000235:genetics; D005260:Female; D005838:Genotype; D006511:Hepatitis B Antigens / Q000097:blood; D006515:Hepatitis B virus / Q000235:genetics* / Q000276:immunology; D019694:Hepatitis B, Chronic / Q000150:complications / Q000821:virology*; D006801:Humans; D008103:Liver Cirrhosis / Q000821:virology; D008113:Liver Neoplasms / Q000821:virology; D008297:Male; D008875:Middle Aged; D013785:Thailand
D004279:DNA, Viral; D006511:Hepatitis B Antigens