B- and T-lymphocyte subpopulations in the adenoids of children with otitis media.

Adenoid hyperplasia is connected with the pathogenesis of otitis media in children, as implicated by the residence of pathogens causing otitis media in adenoids, and by the beneficial effect of adenoidectomy. We have quantitated the proportions of certain T- and B-lymphocyte subsets in the adenoids by three-color flow cytometry. Three groups were studied: 1) children with persistent effusion in the middle ear (pOME), 2) children with recurrent otitis media with no effusion in the middle ear at the time of surgery (rAOM), and 3) children with adenoid hyperplasia without otitis media (AH) presenting either with snoring or upper respiratory tract infections. B lymphocytes comprised on average 64, 66 and 58% of all mononuclear cells in the respective patient groups. The majority of the B lymphocytes were of the follicular mantle zone phenotype expressing surface IgD (on average 69, 67 and 70% of all B lymphocytes in the respective patient groups). Almost one third of the B lymphocytes were of the germinal center cell phenotype, expressing CD38 but negative for surface IgD (on average 29, 30 and 25% in the respective patient groups). CD3+ T lymphocytes comprised 33, 33 and 40%, respectively, of all mononuclear cells, and the average CD4+/CD8+ ratio was 5.2, 4.9 and 5.7, respectively. No statistically significant differences between the patient groups were seen in these T- and B-lymphocyte subpopulations. These results suggest that the relative sizes of the germinal center, follicular mantle and interfollicular compartments of the adenoids do not correlate with the disease status of the middle ear cavity.