IMMUNE-RESPONSES OF ADENOIDAL LYMPHOCYTES SPECIFIC TO HAEMOPHILUS-INFLUENZAE IN THE NASOPHARYNX

Objectives: Investigate immune responses of adenoidal lymphocytes agai nst outer-membrane protein P6 purified from nontypeable Haemophilus in fluenzae (EH). Clarify the role of adenoids in regulating the coloniza tion of III in the nasopharynx. Study Design: Microbiological and immu nological examinations of adenoids obtained hom 21 children, 15 boys a nd five girls, hom 1 to 13 years of age (median, 5 y), suffering from adenoidal hypertrophy complicated by otitis media with effusion (OME). Methods: The incidence of HI in adenoids was compared with the number of PG specific immunoglobulin (Ig) A-secreting cells in adenoids, det ermined by enzyme-linked immunoassay. Results: Quantitative culture as say showed significant correlation between the numbers of RT in adenoi ds and those in nasopharyngeal secretions (NS). In children aged 5 yea rs and younger the numbers of PG-specific IgA-secreting cells in adeno ids were significantly correlated with IgA antibody titers in NS (r = 0.68, P < .05). The numbers of PG specific IgG- and IgA-secreting cell s were lower in children aged 6 years and older than in children aged 5 years and younger. Furthermore, the number of PG-specific IgA-secret ing cells was significantly increased in HI-negative subjects when com pared with HI-positive subjects (P <.05). Conclusions: Adenoids play a n important role as an effector site of the mucosal immune system in t he upper respiratory tract. IgA immune responses in adenoids are respo nsible for the clearance of HT from the nasopharynx.