RESUMO
BACKGROUND: The presence of surface antigen of hepatitis B (HBsAg) virus in serum from recently vaccinated adults has been scarcely investigated. In this work, after the detection by chance of seven HBsAg-positive patients on hemodialysis who reported recent hepatitis B vaccination, a prospective study was undertaken to verify the presence and duration of post-vacunal antigenemia. PATIENTS AND METHODS: Nineteen non-selected patients on hemodialysis were followed for serologic markers of hepatitis B, after receiving a dose of the recombinant vaccine (Engerix B) according to their vaccination schedule. Enzyme-immunoassay techniques were used for the study of serologic markers, and the reactivity of HBsAg was confirmed by means of a neutralization assay with specific anti-HBs antibodies. RESULTS: After the administration of one vaccine dose, 31.5% of patients were HBsAg positive at least once. Antigenemia was identified more frequently 2 to 4 days (83.3%) after immunization. In all cases antigenemia was transient and had cleared after 11 days of vaccination. The follow-up of serologic markers revealed the absence of infection with virus B. Only 16.6% of patients with transient antigenemia responded to vaccination (titer of anti-HBs > or = 10 mIU/ml), while the corresponding percentage in the group of HBsAg-negative patients was 69.2% (p < 0.05). All patients were HCV and HIV negative. CONCLUSIONS: A high frequency of post-vacunal antigenemia is reported in patients on hemodialysis, in absence of virus B infection as well as the possible relationship between the presence of transient antigenemia and the non-responder status.
