Polymorphonuclear Leukocyte Function during Otitis Media

Abstract

Polymorphonuclear leukocyte (PMN) function was evaluated in children with serous (SOM) and mucoid otitis media (MOM) and in an experimental model of acute purulent otitis media due to Streptococcus pneumoniae using chinchillas. Twenty-three of 100 children with SOM or MOM had depressed peripheral blood PMN chemotactic, bactericidal or chemiluminescence activity. Depressed PMN chemotactic acitvity was observed in 17(18%) of 97 children. Children whose middle ear effusions cultured Hemophilus influenzae were more than twice as likely to have depressed PMN chemotactic activity as children whose effusions were sterile. Depressed PMN bactericidal activity was observed in seven (23%) of 30 children, and depressed PMN chemiluminescence activity was found in three (16%) of 19 children. Combined chemotactic and bactericidal dysfunction was observed in four (13%) of 30 children. All seven of the chinchillas with pneumococcal otitis media showed significantly depressed PMN chemotactic activity during the first week after inoculation, while only two of ten uninfected control chinchillas showed the same degree of chemotactic depression ( P = .002). The association of H. influenzae and S. pneumoniae with depressed PMN function suggested that bacterial components of these microbes might have functional similarities. Both bacteria are surrounded by capsular polysaccharides which are known to persist in mammalian tissues for an extended period. It is possible that these or other components of H. influenzae and S. pneumoniae, or even host factors generated during middle ear infection and inflammation, impair the PMN response to middle ear infection resulting in delayed bacterial killing and persistent middle ear effusion.