Avaliação de anticorpos bactericidas contra Neisseria meningitidis sorogrupos B e C em indivíduos saudáveis

Abstract

Neisseria meningitidis is one of the leading causes of bactericidal meningitis and septicemia worldwide, particularly in children less than four years old. However, infection is usually asymptomatic in 10 35% in population, a phenomenon known as carriage. Bactericidal antibodies (SBA) are correlated to protection to meningococcal disease (DM), so that the presence of these antibodies are frequently evaluated after vaccination. The aim of this study was evaluate the serologic profile of a group of blood donors of Rio de Janeiro. We evaluated the presence of SBA against serogroup B (MenB) and C (MenC) meningococci and mutants strains of MenB that do not express PorA or Opa, outer membrane proteins. The specificity of IgG in serum with positive titlers of bactericidal antibodies was evaluated by western blot. The blood donors participants in this study was mainly men, no smokers, with age range 18 to 56 years old. About 26% and 25% of individuals had titlers of antibodies > 4, respectively, to MenB e MenC. Smokers showed higher titlers of bactericidal antibodies against MenC than MenB. Group of blood donors range 36 to 56 years old had higher titlers than the group range 18 to 30 years old, however, without statistic significance. The proteins PorA, but not Opa, was a important target of bactericidal antibodies. However, the western blot do not demonstrate correlation between the PorA recognition and SBA. Together, this results suggest that there is a high protection in adult population of Rio de Janeiro against DM and PorA represents a important target to protectors antibodies.