Immunohistochemical analysis of CD71, CD98 and CD99 activation antigens in human palatine and nasopharyngeal tonsils

OBJECTIVE: Tonsils (palatine and nasopharyngeal) are immunologically active tissues. Due to their anatomical location, they are considered to be the initial defense barrier against the antigens entering into the respiratory and gastrointestinal tract. Tonsils act against these antigens by producing and activating the lymphocytes, which are responsible for the immune response. In order to get information regarding the distribution of cell surface antigens on the epithelial, stromal and lymphoid cells of these organs, we performed immunohistochemical staining by using antibodies against CD99, CD71 and CD98 activation antigens.

METHODS: Tissue samples of 20 patients undergoing tonsillectomy and adenoidectomy who presented with recurrent tonsillitis and adenoid hypertrophy in the Otorhinolaryngology Department, Hacettepe University Medical Faculty Hospital, Ankara, Turkey in 2001, were obtained as partial tissue samples apart from pathological examination. Tissues were immunostained by the indirect immunoperoxidase method.

RESULTS: Strong CD71 reactivity in macrophages was observed as an indicator of the active role of the macrophages in immunoresponse in the chronic inflammation reaction. The CD98 reactivity on the proliferative basal layer of epithelium was a usual finding, as its detection in epithelial neoplasms and proliferative states is well known. We did not observe any reactivity of CD98 in nasopharyngeal tonsil epithelium and lymphoid cells of either nasopharyngeal or palatine tonsils. The CD99 reactivity was observed in the T-cell dependent area.

CONCLUSION: We determined some topographic difference in the expression of some activation antigens in the epithelial, stromal and lymphoid components of the palatine and nasopharyngeal tonsils. Further detailed studies directed to determine the role of these antigens in tonsils would help to understand the role of these molecules in inflammatory events.