Immunology of tonsils and adenoids: everything the ENT surgeon needs to know.
The lymphoid tissue of Waldeyer's ring, and particularly the nasopharyngeal tonsil (adenoids), appears to be functionally comparable to nasal-associated lymphoid tissue in rodents. Antigen-stimulated lymphoid follicles give rise to: (a) clonal B-cell expansion; (b) B-cell receptor affinity maturation; (c) positive selection of B cells according to receptor affinity for antigen; (d) differentiation to B memory cells and plasma cells; and (e) variable induction of the joining (J)-chain gene. B-cell differentiation is also important to promote downstream isotype switching of the immunoglobulin (Ig) heavy chain constant genes. For tonsillar B cells, this process gives mainly rise to IgG and IgA plasma cells, partially associated with J-chain expression. Because the J chain is a key peptide in the polymer structure of secretory IgA, tonsils and adenoids may provide B cells for mucosal effector sites. Thus, several observations suggest that these lymphoid organs generate polymeric IgA (pIgA)-expressing B cells that migrate to the upper airway mucosa, lacrimal glands and salivary glands. Accordingly, the nasal route of vaccination induces secretory IgA-dependent regional mucosal immunity and will also enhance systemic immunity. Although the pIgA-producing capacity of tonsillar B cells is considerably decreased in children with recurrent tonsillitis, a conservative attitude towards adenotonsillectomy appears immunologically desirable, particularly in the young age group.
Brandtzaeg
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Laboratory for Immunohistochemistry and Immunopathology (LIIPAT), Institute of Pathology, University of Oslo, Rikshospitalet, Oslo N-0027, Norway. per.brandtzaeg@labmed.uio.no
D000233:Adenoidectomy / Q000009:adverse effects; D000234:Adenoids / Q000276:immunology* / Q000378:metabolism; D015703:Antigens, CD / Q000276:immunology; D002450:Cell Communication / Q000502:physiology; D013502:General Surgery; D006801:Humans; D007070:Immunoglobulin A / Q000276:immunology* / Q000378:metabolism; D007074:Immunoglobulin G / Q000276:immunology* / Q000378:metabolism; D007075:Immunoglobulin M / Q000276:immunology* / Q000378:metabolism; D008214:Lymphocytes / Q000276:immunology; D008221:Lymphoid Tissue / Q000276:immunology / Q000378:metabolism; D010036:Otolaryngology; D013506:Otologic Surgical Procedures; D014066:Palatine Tonsil / Q000276:immunology* / Q000378:metabolism; D011361:Professional Competence; D014068:Tonsillectomy / Q000009:adverse effects
D015703:Antigens, CD; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M