Korean J Intern Med.
1997 Jun;12(2):201-207.
Precore codon 28 stop mutation in hepatitis B virus from patients with
hepatocellular carcinoma
- Affiliations
-
- 1National Cancer Institute, National Institutes of Health, Bethesda, Maryland,
USA.
Abstract
OBJECTIVES
Hepatitis B virus (HBV) with a stop mutation at precore codon 28
(TGG-->TAG, tryptophan-->stop) was investigated to clarify if such a mutant
virus might play a role in hepatocarcinogenesis. METHODS: A total of 73 patients
with HBV-related hepatocellular carcinoma were included in this study.
Polymerase chain reaction (PCR) was performed in DNA samples extracted from 73
sera to amplify a HBV-DNA segment involving the precore and proximal core
regions, and sequences of PCR products were analyzed to see the presence of the
mutations at precore codon 28 by a direct sequencing method. RESULTS: HBV-DNA
was detectable in 64 (88%) patients by PCR. The stop mutation at precore codon
28 was identified in 50 of 58 PCR products (86%), in which direct sequencing was
performed. Among patients with this mutant HBV, 21/50 (42%) patients were
co-infected with wild-type HBV. The mutant virus was found in 23/28 (82%)
patients with hepatitis B e antigen (HBeAg) and 27/30 (90%) patients without
HBeAg. The mutant HBV alone was found in 10/28 (36%) patients with HBeAg and
19/30 (63%) without HBeAg. Among those patients on whom laparoscopy was
performed, 22/24 (92%) with the precore codon 28 stop mutant alone had
cirrhosis, compared to 12/19 (63%) co-infected by both the mutant and the
wild-type (p < 0.05). The association of this mutant virus with both the
presence and absence of HBeAg, and its association with cirrhosis when there is
no co-infection with wild-type HBV, suggests an evolving pattern of liver
pathology. CONCLUSION: The high prevalence of a stop mutation at precore codon
28 in these patients with hepatocellular carcinoma suggests that HBV with this
mutation may contribute to the development of hepatocellular carcinoma.