Viral nucleotide changes in asymptomatic hepatitis B carriers undergoing interferon treatment

BACKGROUND

Interferon might induce mutation in regions of hepatitis B virus DNA that encode for immunologic target of cytotoxic T lymphocytes.

AIM

To investigate the short-term effect of steroid priming and interferon therapy on hepatitis B virus, we followed the nucleotide changes in the precore and core region of hepatitis B virus DNA in seven healthy asymptomatic carriers who underwent steroid priming followed by recombinant alpha interferon for 3 months.

METHODS

Hepatitis B virus DNA from serial sera of the patients were polymerase chain reaction-amplified, and the precore and core region directly sequenced and analysed.

RESULTS

Analysis revealed no serial changes in the hepatitis B virus nucleotide sequence in any of the patients.

CONCLUSIONS

Steroid priming and short-term treatment with interferon in healthy asymptomatic patients does not select for hepatitis B virus with mutations in the precore and core region.

Serological profiles of hepatitis B carrier patients in Singapore with special reference to the frequency and significance of concurrent presence of HBsAg and anti-HBs

Hepatitis B serological markers were investigated in 1,132 consecutive Singaporean HBV carriers. Hepatitis B surface antigen (HBsAg) and hepatitis B surface antibody (anti-HBs) were found concurrently in 234 carriers (234/1132 or 21%). Serum anti-HBs levels were more than 10 mIU/mL in 80 of these carriers (80/234 or 34%). There were no difference in HBeAg positive status, as well as HBV-DNA positive status in concurrent HBsAg/anti-HBs carriers compared to carriers without anti-HBs. Our results suggested that concurrent HBsAg and anti-HBs is a common serologic pattern in Singaporean HBV carriers.

Hepatitis C virus genotypes in Singapore and Indonesia

5' untranslated and partial core (C) region sequence of hepatitis C virus (HCV) in 21 Singaporean and 15 Indonesian isolates were amplified by reverse-transcription polymerase chain reaction and sequenced with the use of conserved primer sequences deduced from HCV genomes identified in other geographical regions. The HCV genotypes are predominantly that of Simmonds type 1 and less of type 2 and 3 with the latter genotype currently not detected in Indonesia. The 5' untranslated sequences are related to HCV-1. DK-7 (Denmark), US-11 (United States of America), HCV-J4, SA-10 (South Africa), T-3 (Taiwan), HCV-J6, HCV-J8, Eb-1 and Eb-8. When compared with the prototype HCV-1, insertions are found within the 5' untranslated region of Singaporean isolates and not in the Indonesians. There are Singaporean and Indonesian isolates that have sequences within the 5' untranslated region that differ slightly from each other. Microheterogeneity is observed in the core region of two Singaporeans and one Indonesian isolate. Finally, not all HCV isolates can be amplified with the conserved core sequence primers when compared with the ease with which these isolates can be amplified with 5' untranslated region conserved primers.