title: [Immunohistochemical findings in otosclerotic lesions].
abstract: Despite numerous scientific efforts, the etiology of otosclerosis still remains unknown. Pathogenically, there are several signs of a chronic inflammatory process of the bony otic capsule. In this study, we tried to characterize the components of chronic inflammation by immunohistochemical techniques. Within otosclerotic lesions a mixed cellular infiltrate can be observed, consisting of lymphocytes, macrophages and plasma cells. Macrophages which are capable of presenting antigen in association with major histocompatibility antigens (MHC) class I and class II to CD8(+)-, and CD4(+)-T cells, respectively, were found in otosclerotic lesions based on their expression of the MAC387 antigen. Furthermore, HLA-DR positive cells and complement C3 have been found in resorption lacunae of otosclerotic lesions. Several osteoblasts and chondrocytes in active otosclerotic lesions reveal a strong surface expression of beta-2-microglobulin, indicating an increased MHC class I antigen expression in active otosclerotic lesions. In agreement with recently published data we found that a large fraction of the lymphoid cells are antigen-primed T-cells expressing an alpha/beta T-cell receptor in association with CD3 molecules on their surfaces. CD4+ lymphocytes which functionally represent lymphokine-secreting cells are activated through the specific recognition of antigen, presented in context with MHC class II molecules such as HLA-DR. Therefore, the presence of MHC class II positive cells are crucial for the initiation of a local immune response. Thus, our observation of HLA-DR positive cells in otosclerotic lesions is of particular interest.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Pathologisches Institut, Universität Bern.
authors.forename: H J
authors.initials: HJ
authors.lastname: Altermatt
authors.forename: H A
authors.initials: HA
authors.lastname: Gerber
authors.forename: D
authors.initials: D
authors.lastname: Gaeng
authors.forename: C
authors.initials: C
authors.lastname: Müller
authors.forename: W
authors.initials: W
authors.lastname: Arnold
mesh_terms: D000328:Adult; D000368:Aged; D017252:CD3 Complex / Q000032:analysis; D005260:Female; D015395:Histocompatibility Antigens Class I / Q000032:analysis*; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D006801:Humans; D007111:Immunity, Cellular / Q000276:immunology*; D007124:Immunoenzyme Techniques; D008297:Male; D008875:Middle Aged; D010040:Otosclerosis / Q000276:immunology* / Q000473:pathology; D013199:Stapes / Q000276:immunology / Q000473:pathology; D001613:beta 2-Microglobulin / Q000032:analysis
chemical_list: D017252:CD3 Complex; D015395:Histocompatibility Antigens Class I; D000949:Histocompatibility Antigens Class II; D001613:beta 2-Microglobulin
vernacular_title: Immunohistochemische Befunde in otosklerotischen Läsionen.