Transient HBs antigenemia in patients on hemodialysis

Background. The presence of surface antigen of hepatitis B (HBsAg) virus in serum from recently vaccinated adults has been scarcely investigated. In t his work, after the detection by chance of seven HBsAg-positive patients on hemodialysis who reported recent hepatitis B vaccination, a prospective st udy was undertaken to verify the presence and duration of post-vacunal anti genemia. Patients and methods. Nineteen non-selected patients on hemodialysis were f ollowed for serologic markers of hepatitis B, after receiving a dose of the recombinant vaccine (Engerix B) according to their vaccination schedule. E nzyme-immunoassay techniques were used for the study of serologic markers, and the reactivity of HBsAg was confirmed by means of a neutralization assa y with specific anti-HBs antibodies. Results. After the administration of one vaccine dose, 31.5% of patients we re HBsAg positive at least once. Antigenemia was identified more frequently 2 to 4 days (83.3%) after inmunization. In all cases antigenemia was trans ient and had cleared after 11 days of vaccination. The follow-up of serolog ic markers revealed the absence of infection with virus B. Only 16.6% of pa tients with transient antigenemia responded to vaccination (titer of anti-H Bs greater than or equal to 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 pa tients on hemodialysis, in absence of virus B infection as well as the poss ible relationship between the presence of transient antigenemia and the non -responder status.