Abstract
The host-parasite relationship in the nasopharynx of young children with bacterial colonization and antigen uptake in the mucosa and lymphatic tissue provides an opportunity to investigate infectious/inflammatory processes and responses. IL-1 beta, IL-6 and tumour necrosis factor-alpha (TNF-alpha) were analysed in nasopharyngeal secretions and serum from children with or without recurrent episodes of acute otitis media, from healthy adults and adults with or without recurrent episodes of acute otitis media, from healthy adults and adults with hypogammaglobulinaemia or selective deficiency of IgG3. Nasopharyngeal secretions generally contained substantial amounts of IL-1 beta, IL-6 and TNF-alpha. In contrast, IL-1 beta, IL-6 and TNF-alpha were not detectable in sera on the same occasion. Children were found to have higher levels of IL-1 beta, IL-6 and TNF-alpha than healthy adults and than adults with immunodeficiency. High levels of IL-1 beta were associated with low or undetectable levels of IL-6 and TNF-alpha, whereas the opposite pattern was seen in association with low levels of IL-1 beta. This was especially true for children with recurrent episodes of acute otitis media (RAOM). In children with nasopharyngeal colonization with Haemophilus influenzae, significantly higher levels of IL-1 beta, IL-6 and TNF-alpha (P = 0.0001, respectively) were found compared with non-colonized children. Notably, the RAOM children exhibited significantly lower levels of IL-1 beta, IL-6, and TNF-alpha in nasopharyngeal secretions (P = 0.0001, 0.01 and 0.0001, respectively) than healthy children. These results demonstrate local production of inflammatory cytokines in nasopharynx, related to bacterial colonization, and suggest that children with RAOM are poor nasopharyngeal cytokine producers.