Evolution of primary and compensatory lamivudine resistance mutations in chronic hepatitis B virus-infected patients during long-term lamivudine treatment, assessed by a line probe assay.

With the availability of more potent nucleotide/nucleoside analogues, the early detection of drug-resistant mutants of hepatitis B virus (HBV) is important for the strategic treatment of chronic hepatitis B. We studied 336 serum samples from 80 patients chronically infected with HBV who were receiving lamivudine treatment for the presence of lamivudine resistance mutations at codons 80, 173, 180, and 204 of the HBV polymerase. The sequencing data were compared with the results generated with the INNO-LiPA HBV DR (drug resistance) v2 strip, a line probe assay (LiPA) covering wild-type and mutant motifs, for resistance mutations to lamivudine and adefovir dipivoxil. This method provided at least the same information as sequencing for 99.1% of all codons analyzed. On the basis of the LiPA results, 20 of 80 patients developed a lamivudine resistance mutation after 1 year. In all 20 patients, the mutation occurred in the YMDD motif at reverse transcriptase position 204 (rt204; M204V/I) either with or without the compensatory mutation at position rt180 (L180M). A compensatory mutation at position rt80 (L80V/I) was detected in half of these patients. After 36 months, a compensatory mutation was seen at position rt173 (V173L) in 3/15 patients. Time-to-event survival analysis indicated a 2.8 times greater chance for LiPA to detect a given mutation than sequencing at any moment in time (hazard ratio, 2.8, 95% confidence interval, 1.79, 4.41; P < 0.0001). These results demonstrate that a highly sensitive and specific assay such as the INNO-LiPA HBV DR v2 can precociously detect and monitor the emergence of primary and compensatory lamivudine resistance mutations in patients chronically infected with HBV and is more sensitive than sequencing.

Precore and core promoter mutations at the time of HBeAg seroclearance in Chinese patients with chronic hepatitis B.

OBJECTIVE: To determine the prevalence of precore and core promoter (CP) mutations before, at and after HBeAg seroclearance in Chinese patients. METHODS: Precore and CP mutations were determined in 93 patients with chronic hepatitis B 12-24 months before, at and 12 months after the time of HBeAg seroclearance. RESULTS: No significant changes were found in the prevalence of precore or CP mutations before, at and after HBeAg seroclearance. Seven patients (7.8%) had HBeAg seroreversion within 1 year of HBeAg seroclearance. There was no significant difference in the prevalence of precore and CP mutations between patients with and without HBeAg seroreversion. 68.3% and 48.7% of patients harbored the same precore and CP genotypes throughout. 32.0% patients with precore mutations and 8.9% patients with CP mutations before HBeAg seroclearance had reversion to wild type within 1 year of HBeAg seroclearance. Patients with genotype C patients had a higher prevalence of CP mutations before HBeAg seroclearance compared with patients with genotype B (82.4% vs. 44%, P=0.001). CONCLUSIONS: Precore and CP mutations existed in a substantial proportion of Chinese patients before HBeAg seroclearance. The replication of precore and, to a lesser extent, CP mutants could be suppressed around the time of HBeAg seroclearance.

Determinants for the occurrence of acute exacerbation of hepatitis B virus infection in Chinese patients after HBeAg seroclearance.

This study was performed to determine the factors for predicting the occurrence of acute exacerbation of hepatitis B virus infection in HBeAg-negative patients. Two hundred and sixteen patients with known times of HBeAg seroclearance were recruited. Liver biochemistry and virologic markers were monitored. Precore and core promoter mutations were determined by a line probe assay. The median age at HBeAg seroclearance was 34.5 years. The median follow-up duration was 26.4 months. Fifty-six (27.9%) patients had acute exacerbations. By Cox regression analysis, male gender, older age, and core promoter mutations at the time of HBeAg seroclearance were independently associated with the occurrence of acute exacerbation after HBeAg seroclearance (P = 0.025, 0.018, and 0.001, respectively). Fourteen (7.0%) patients had HBeAg seroreversion within a median follow-up period of 11.6 months after HBeAg seroclearance. By Cox regression analysis, older age at HBeAg seroclearance was independently associated with the chance of HBeAg seroreversion (P = 0.01). We concluded that male patients with core promoter mutations and delayed HBeAg seroclearance had a higher cumulative chance of acute exacerbation in the HBeAg-negative phase. Patients with delayed HBeAg seroclearance had a higher frequency of HBeAg seroreversion.

Epidemiological study of hepatitis B virus genotypes, core promoter and precore mutations of chronic hepatitis B infection in Hong Kong.

BACKGROUND/AIMS: We conducted a population study to document the prevalence of hepatitis B virus (HBV) genotypes in Hong Kong. METHODS: HBV genotypes, core promoter (CP) and precore mutations were determined in 776 asymptomatic patients. RESULTS: 92.6% patients had single genotype [B (32.5%), C (62.5%)]. 99.1% of genotype B was subtype Ba. Patients with age <50 years had a lower prevalence of genotype B than patients with age >51 years (32.5% vs. 41%, respectively, P=0.028). Compared to patients with genotype C, patients with genotype B had a higher cumulative rate (P=0.018) and younger age (40.1 vs. 34.2 years, respectively, P=0.018) of HBeAg seroconversion. There were no differences in the HBV DNA levels between patients with genotypes B and C, and with wild-type and mutants of CP and precore regions. By multivariate analysis, patients with genotype C and with CP mutations had higher alanine aminotransferase (ALT) levels. CONCLUSIONS: B and C were the two most common HBV genotypes in Hong Kong. The former had a higher chance of earlier HBeAg seroconversion and lower ALT levels. The prevalence of genotype B was lower in patients with age <50, probably related to influx of immigrants from China since 1949.

Prognostic factors in severe exacerbation of chronic hepatitis B.

Forty-seven patients with severe hepatitis B exacerbation were compared with patients who had mild exacerbation (n=96) or no exacerbation (n=96). Seventeen patients (36.2%) died or underwent liver transplantation. Preexisting cirrhosis and a prothrombin time (PT) of >30 s were associated with adverse outcome in 60.9% and 87.5% of patients, respectively. The rate of adverse outcome increased to 92.3% when albumin levels of < or =35 g/L and bilirubin levels of >200 microM were present. Other factors associated with adverse outcomes included peak bilirubin level, peak PT, time to reach peak PT, and the presence of encephalopathy and/or ascites. There was no difference in the frequency of precore mutations in patients with severe or mild exacerbation or without exacerbation. A significantly lower prevalence of core promoter mutants was found in patients with severe exacerbation (50%), compared with those who had mild exacerbation (81.3%; P=.004). Patients with severe exacerbation of hepatitis B with poor prognostic factors should be considered for early liver transplantation.

Relationship between the development of precore and core promoter mutations and hepatitis B e antigen seroconversion in patients with chronic hepatitis B virus.

Chinese patients with chronic hepatitis B virus (332 with and 44 without cirrhosis-related complications) were studied. Fifty percent of patients <30 years old had precore mutations. The prevalence of precore mutations among hepatitis B e antigen (HBeAg)-positive patients, although lower than that among anti-HBe-positive patients (P=.031), was already high (44.2%). Median HBV DNA level in anti-HBe-positive patients was 1.5 x 10(6)-1.55 x 10(6) copies/mL, irrespective of the presence or absence of precore mutations. There was no difference in the prevalence of precore mutations between patients with and without complications (P, not significant). However the prevalence of core promoter mutations was higher among patients with complications than among those without complications (90.5% vs. 69.3%, respectively; P=.003). In conclusion, precore mutations occurred in a large proportion of Chinese patients with chronic hepatitis B virus before HBeAg seroconversion. The development of complications was not related to precore mutations but was probably due to the persistence of significant viremia after HBeAg seroconversion.