Subsets of tonsillar lymphocytes and activated cells in each subset analysed by three-color flow cytometry

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.

Flow cytometric quantification of lymphocyte subpopulations and immunoglobulin-containing cells in adenoid tissue in relation to secretory otitis media and age

This study was designed to identify differences in the immunological reactions in adenoid tissue between children suffering from chronic secretory otitis media (SOM) and control children without ear disease. Cell populations were identified using monoclonal antibodies and flow cytofluorometry to facilitate quantitative comparisons. A modification of the FOG method was developed to quantify lymphocytes with intracellular IgG and IgA. Immunological screening was done in the first part of the study. No significant differences were found between the groups regarding cells positive for CD3, CD4, CD8, CD20 or CD25. A significantly higher number of PCA-1 positive cells (presumably plasma cells) were found in the SOM group. The second part of the study concentrated specifically on cells containing IgG or IgA. No statistically significant differences in number of positive cells were found between the groups. When we related the percentage of positive cells to age, a statistically significant decrease with age for IgA-positive cells was found in the SOM group but not in the control group. This result supports the hypothesis that SOM is associated with an immunological reaction that influences immunoglobulin production in adenoid tissue.

Adenoid tissue lymphocyte subpopulations--evaluation of a quantitative analysis with flow cytometry

Secretory otitis media (SOM) is a common childhood disease without a completely clarified etiology. A chronic inflammatory condition in the nasopharynx, presumably caused by an increased bacterial load, is one factor of probable etiological importance. In the present study a flow cytometric method for analysis of adenoid lymphoid cell populations was developed to facilitate quantitative comparisons between children with SOM and children without ear disease. Adenoids removed from 18 children due to adenoid hyperplasia and obstructive symptoms were studied. Results of the flow cytometric analysis correlated well with the findings from immunohistological studies of five of the adenoids. PCA-1 and CD25 were found to be good markers of increased cellular activity after non-specific stimulation in cell culture. It is concluded that the flow cytometric method is suitable for further quantitative analysis of adenoid tissue.

Influence of IL-6 on proliferation and differentiation of tonsillar lymphocytes and detection of IL-6 producing cells in tonsil

When tonsillar B cells were cultured in the presence of exogenous interleukin-6 (IL-6), a small portion of them differentiated into plasma cells which seemed to have IL-6 receptors on their surfaces. The number of plasma cells tended to be greater in the tonsils of children than in the tonsils of adults. When tonsillar cells collected by Ficoll-Conray's method were cultured in medium containing IL-6, T cells differentiated and the number of activated T cells increased. Of the four subsets of T cells, this effect of IL-6 was strongest on cytotoxic T cells. IL-6-mediated proliferation and activation of cytotoxic T cells tended to be greater in the tonsils of children than in those of adults. IL-6 is produced in some tonsillar macrophages. The number of macrophages producing IL-6 was very different in different subjects. However, the number of macrophages producing IL-6 in tonsils of children tended to be greater than the number in tonsils of adults.