Phagocytosis in the nasopharyngeal secretion by cells from the adenoid

The aim of this study was to elucidate whether granulocytes and macrophages in surface secretion on the adenoid emanate from the adenoid and whether these cells participate in the control of the nasopharyngeal bacterial flora. Samples of the adenoid and its surface secretion were obtained during adenoidectomy from 12 children with recurrent acute otitis media, secretory otitis media or enlarged adenoids causing obstruction. Immunochemistry was used to examine the location of granulocytes and macrophages in the adenoid as well as the presence of IgA, IgM, IgG and plasma cells in the secretion. Phagocytosis in the secretion was examined in imprints stained with May Grünwald Giemsa. Acridine Orange and Gram staining were used to demonstrate the presence and location of bacteria in the secretion and mucosa. As a control, surface secretions were obtained from 12 children without any history of recurrent airway problems. Granulocytes and macrophages were observed in the epithelium of the adenoid and some of these cells penetrated the epithelial surface. Positive staining for IgA, IgM and IgG was observed in all secretions. In 10 of 12 children plasma cells were present in the secretion. Bacteria were observed in all imprints. With the exception of I child in each group phagocytosis of bacteria in the surface secretion was demonstrated from imprints in all children. We conclude that granulocytes and macrophages leave the adenoid and enter the surface secretion, where constant phagocytic activity takes place. The spatial relations between mononuclear and polymorphonuclear cells imply a possible cooperation between these cells in the overall control of the nasopharyngeal bacterial flora.