ABSTRACTA prospective clinical cohort study was established to investigate the humoral immune response in middle ear fluids (MEF) and serum against bacterial surface proteins in children suffering from recurrent acute otitis media (rAOM) and chronic otitis media with effusion (COME), using Luminex xMAP technology. The association between the humoral immune response and the presence ofMoraxella catarrhalisandStreptococcus pneumoniaein the nasopharynx and middle ear was also studied. The levels of antigen-specific IgG, IgA, and IgM showed extensive interindividual variation. No significant differences in anti-M. catarrhalisand anti-S. pneumoniaeserum and MEF median fluorescence intensity (MFI) values (anti-M. catarrhalisand antipneumococcal IgG levels) were observed between the rAOM or COME groups for all antigens tested. No significant differences were observed forM. catarrhalisandS. pneumoniaecolonization and serum IgG levels against theMoraxellaand pneumococcal antigens. Similar to the antibody response in serum, no significant differences in IgG, IgA, and IgM levels in MEF were observed for allM. catarrhalisandS. pneumoniaeantigens between OMM. catarrhalis-orS. pneumoniae-positive and OMM. catarrhalis-orS. pneumonia-negative children suffering from either rAOM or COME. Finally, results indicated a strong correlation between antigen-specific serum and MEF IgG levels. We observed no significantin vivoexpressed anti-M. catarrhalisor anti-S. pneumoniaehumoral immune responses using a range of putative vaccine candidate proteins. Other factors, such as Eustachian tube dysfunction, viral load, and genetic and environmental factors, may play a more important role in the pathogenesis of OM and in particular in the development of rAOM or COME.
Temporal development of the humoral immune response to surface antigens of Moraxella catarrhalis in young infants
