RESIDUAL HEPATITIS B INFECTION (RBI)~剩余型乙肝

aloha

-Abstract 822 Karen Doucette, Manna Zhang, Kim Hawkins, Kelly D Kaita, Gerald Y Minuk, University of Manitoba, Winnipeg, MB, Canada Residual Hepatitis B Infection (RBI) can be defined as persistent, low level HBV viremia in the setting of serologic evidence of resolved HBV infection. The prevalence, demographic and laboratory features of RBI have yet to be determined. In the few studies reported to date, prevalence of 5-15% were described but these studies involved relatively small numbers of referred subjects or blood donors and therefore, can not be extrapolated to the general population. The principle objective of the present study was to document the prevalence of RBI in a large, community-based population. Stored sera were available from 720 participants in a seroepidemiologic survey of viral hepatitis in a Northern Canadian Inuit settlement (population 850). Of the 720 samples, 107 (15%) had serologic evidence of resolved HBV infection (HBsAg; negative, Anti-HBs; positive and Anti-HBc; positive). All 107 underwent further testing for HBV-DNA by real time PCR with fluorescein-labeled hybridization probes (sensitivity: 100 copies/ml). Demographic and laboratory findings in HBV-DNA positive individuals (RBI group) were then compared to those that tested negative for HBV-DNA (resolved HBV group) and the 25 HBsAg positive individuals residing in the same community (HBsAg positive group). The results of this study showed that HBV-DNA was present in 39 of the 107 (36%) samples with serologic evidence of resolved HBV infection (RBl group). The mean age of the group was 44.6 ?2.2 years (range: 19 to 72 years) and 46 % were male. Serum ALT levels were normal in all cases. The mean HBV-DNA level was 3.8 x 104 copies/mL (range: 1.1 X 104 to 1.3 X 105 copies/mL). The age and gender distribution of the resolved HBV group (HBV-DNA negative) were similar (39.1 ?1.9 years, range: 12 to 79 years and 45% male). ALT testing was also normal in this group. Finally, in the HBsAg positive group, the mean age was 45.7 ?4.1 years, (range 19 to 85 years) and 74% were male. The higher percent of males was significant when compared to both the RBI and resolved HBV groups (p<0.05 respectively). ALT levels were elevated in 2/25 (8%). Nineteen samples were available from this group for further analysis. In these, the mean HBV-DNA level was 1.1 x 107 copies/mL (range; 1.6 x 106 to 2.5 x 107 copies/ml, p< 0.00001 versus RBI group). To determine whether the serologic profile and lower levels of viremia in the RBI group resulted from mutations known to influence HBV serology and replicative activity respectively, S-escape, pre-core stop codon and basal core promoter (BCP) mutation analyses were performed by real time PCR. The prevalence of these mutations was similar to that observed in the HBsAg positive group (S escape; 0% versus 5.3%, pre-core; 2.6% versus 10.5% and BCP 18% versus 5.3%, p>0.05 respectively). The authors of this study conclude that persistent, low-level HBV viremia (RBI) was present in approximately 40% of a community-based population with serologic evidence of resolved HBV infection. There were no age, gender or ALT differences in these individuals compared to those with serologic and virologic evidence of resolved HBV infections. However, both groups had fewer males than did the group who remained HBsAg positive. Although HBV-DNA levels were lower, the prevalence of S-escape, pre-core and basal core promoter mutants were similar in individuals with RBI compared to those who remained HBsAg positive. (hepatitis-b-mail)