A Territory-Wide Study on the Seroprevalence of Hepatitis B Virus in the General Population after Universal Hepatitis B Immunization ERA in Hong Kong, China

POSTER PRESENTATIONS were assayed for HBV DNA by real-time PCR. Subsequently, the samples were tested by a sensitive standard PCR employing independent set of primers for all HBV genes and analyzed by direct sequencing Results: In initial sampling (2009), HBV DNA was detected in 21/75 (28%) of children, ranged between 77 and 9240 copies/mL. The mean age (±SD) of studied patients was 3.57 ± 2.75 years. All were positive for anti-HBs. Five (24%) were found to be positive for anti-HBc, and anti-HBc-only positive individual were not observed. Eight isolates (38%) did not contain any mutation. Other 13 infected children (62%) contained at least one mutation in regions known to be involved in functional and/or immune epitope activity. 10 were contained G145R mutations. In the last follow up (2012), of 21 OBI-positive, 17 children were enrolled. The mean (±SD) age was 6.57 ± 2.75 years. All children still were negative for HBsAg. However, all but one (94%) were negative for HBV DNA. The results of the most recent anti-HBs titration showed that 4 (23.5%) and 13 (76.5%), had low (<10 IU/mL) and adequate (>10 IU/mL) levels of anti-HBs, respectively. The only still OBI-positive patient had an HBV DNA level of 50 copy/mL, carried the G145R mutation. Further follow up showed that after 18 months (2013) he was negative for HBV DNA. Conclusions: HBsAg negativity is not sufficient to completely exclude HBV DNA presence. HBV occult infection seems to be relatively frequent in immunized children born to HBsAg-positive mothers. However, the initial HBV DNA positivity early in the life (vertical infection), does not necessarily indicate a prolonged persistence of HBV DNA (occult infection). Adequate levels of anti-HBs after vaccine and HBIg immunoprophylaxis following birth could eventually clear the virus as time goes by. Periodic monitoring of these children at certain time intervals is highly recommended. THU-162 A TERRITORY-WIDE STUDY ON THE SEROPREVALENCE OF HEPATITIS B VIRUS IN THE GENERAL POPULATION AFTER UNIVERSAL HEPATITIS B IMMUNIZATION ERA IN HONG KONG, CHINA S.H.K. Liu1, W.-K. Seto1, D.K.-H. Wong1, J.C.-H. Yuen1, Y.F.F. Lam1, K.S.M. Cheung1, W.P.E. To1, K.L.M. Ko1, L.Y.L. Mak1, C.-L. Lai1, M.-F. Yuen1. 1Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong, Hong Kong, China E-mail: [email protected] Background and Aims: Chronic hepatitis B (CHB) remains a major health burden in the Asia-Pacific region. No population-based study has been carried out to assess the territorial prevalence of CHB after the introduction of universal hepatitis B vaccination program in1988 in Hong Kong. We aimed to document the point prevalence of viral hepatitis B in Hong Kong. Methods: Questionnaires containing demographics, family history of hepatitis infection, previous hepatitis vaccination and risks of hepatitis exposure are collected from general population in different townships over Hong Kong. HBsAg was measured. HBeAg/ anti-HBe, and anti-HDV were tested for HBsAg positive subjects. Anti-HBs and anti-HBc were tested for HBsAg negative subjects. Results: The study aimed to recruit 10,000 subjects. Since study commencement in February 2015, a total of 4803 subjects (M:F 32 vs 68%) were recruited. Mean age were comparable in both gender (male 52.9 ± 14.7 vs female 53.6 ± 14.1). Interim analysis of 4795 subjects showed overall HBsAg positivity of 8.7% and anti-HDV of 0%. Distribution of positive HBsAg, HBeAg and anti-HBe across different age groups were summarized in table 1. Among HBsAg negative subjects, overall positive anti-HBc was 39.6% with increasing proportion of positivity as moving from age group <26 to age group >75 (range 2.3% to 75.6%; p < 0.001) (Table 1). Among subjects with CHB family history, 38.9% were anti-HBc positive which was similar to 39.4% of positive anti-HBc in subjects without CHB family history.

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Conclusions: The overall HBsAg positive rate (8.7%) remained high in our territory. The hepatitis B prevalence rate was modest (4.4%) for subjects who had received hepatitis B vaccine. HBeAg-negative CHB became the dominant population even among the young CHB carriers. About 40% of subjects with negative HBsAg had previous exposure as evidenced by anti-HBc positivity. Family history alone is not reliable enough to identify subjects with potential occult HBV. THU-163 THE ROLE OF CELLULAR IMMUNITY AND CYTOKINES IN THE PATHOGENESIS OF CHRONIC HEPATITIS B IN CHILDREN T. Raba1, T. Kalinski2. 1State University Of Medicine and Pharmacy “N. Testemitanu”; 2Mother and Child Institute, Chisinau, Republic of Moldova E-mail: [email protected] Background and Aims: The purpose of this work was to study the role helper T lymphocytes, cytotoxic T lymphocytes, B lymphocytes and significance of cytokines IL-1-β, INF-γ, TNF-α in the pathogenesis of chronic hepatitis B in children with chronic hepatitis B in Republic of Moldova. Methods: There were examined 55 children aged 3–17 years with chronic viral hepatitis B that cellular immunity were assessed by determining CD3, CD4, CD8 and their immunophenotyping by enzyme immunoassay monoclonal and IFN-γ serum levels of TNF-α IL-1β by ELISA (6 children). The diagnosis was confirmed clinical, epidemiological, biochemical, immunologic modification, including degree of viremia HBV DNA (PCR Real Time ROTOR Gene6000 Corbett Research) and transient elastometry (Fibroscan) and histological activity by liver biopsy needle Menghini (5 children). Statistical analysis was performed with the Student’s test determining average values, standard error of the mean. The cases with p ≤ 0.05 were considered statistically significant. Results: In 82% of cases of children aged between 6 and 15 years were with predominance of males. HBV infection in children was 43.8% in the usual horizontal horses from family members with chronic HBsAg porting average duration of chronic HVB infection was 2.7 + 0.47 years. 69.5% of patients had HVB viremia phase with the presence of HBeAg and DNA VHB. In 52,7% (29) cases it has been found significant in reducing the immunosuppression condition of total T lymphocytes (CD3), helper T lymphocytes (CD4) cytotoxic T lymphocytes (CD8) and B lymphocytes (p < 0.01). 6 children serum

Journal of Hepatology 2016 vol. 64 | S213–S424