Adenoid as a source of lymphocytes in the surface secretions of nasopharynx

Abstract

The significance and protective efficacy of surface secretions on mucosal membranes in the upper airways are well recognized. The aim of our study was to reveal the role of the adenoids as a source of cellular components in the mucosal secretion. The adenoid removed because of its hypertrophy and the samples of surface secretions taken by "imprint method" described by Ebenfelt et al. from the group of 38 children were examined by flow cytometry. The lymphocyte subsets with following antigens: CD3, CD4, CD8, CD19, CD23, CD16+56, CD45RA, CD45RO, HLA-DR were analyzed. Two groups were studied: (1) AH, children with adenoid hyperplasia without otitis media; (2) OME, children with adenoid hyperplasia and persistent otitis media with effusion. Age-related changes in percentages of lymphocyte subpopulations were analyzed. The percentage of lymphocyte subsets in adenoid and secretion were similar, however, in the surface secretion there was higher proportion of lymphocytes B and NK and lower of T. There was no correlation between percentages of lymphocyte in adenoid and surface secretion except for lymphocytes Th with memory phenotype and lymphocytes B with marker CD23(+). In adenoid the percentage of T and Th lymphocytes increased with age and the percentage of B lymphocytes decreased. In the secretion age-related changes were less pronounced and only the percentage of lymphocytes B CD23(+) showed positive correlation with age. In cases of otitis media with effusion there was higher proportion of lymphocytes B (CD19(+) and CD19(+)CD23(+)) and lower of lymphocytes Ts and Th with naive phenotype in the secretion. In adenoid however, the cases of OME revealed lower percentage of lymphocytes B and higher of lymphocytes Ts. Similar proportions of lymphocyte subpopulations in surface secretion and in adenoid imply that adenoid is the source of those cells. However, lack of correlation between the percentages of lymphocytes in secretion and in adenoid suggest that the process of lymphocyte migration has active and selective character.