RESUMEN
Background:Patients on chronic hemodialysis have a lower immune response to vaccination against hepatitis B virus (HBV) than the general population. Aim: To identify factors that may interfere with immunization against hepatitis B virus (HBV) in Brazilian hemodialysis patients and analyze the evolution of the level of antibodies. Patients and Methods: A retrospective longitudinal study, using records of patients on hemodialysis in the years 2000-2008. Non-responder patients, defined as a level of anti-HBs less than 10 IU/mL, were identified. The effect of social and demographic factors, clinical and laboratory data on the lack of response was evaluated. Logistic regression analysis was used to assess the independent effect of each factor. The difference between initial and final anti-HBs levels (24 months), was also analyzed. Results: Fifty seven percent of patients responded adequately to vaccination. After adjustment with other variables, the only factor associated with immune response was serum ferritin. Responding patients of less than 40 years of age did not have a significant decrease in antibody titers over time. The initial anti-HBs title, influenced the final title. Fifty percent of non-responders achieved serum levels of protection after revaccination. Conclusions: The study showed that ferritin may be a marker of reduced immune response. Patients aged less than 40 years were the only ones who maintained over time their initial anti-HBs levels.