[Immunohistological investigation of squamous metaplasia and expression of cytokeratin subclasses in laryngeal epithelia].

The expression of cytokeratin (CK) subclasses was immunohistologically investigated in normal laryngeal epithelia by the ABC technique using monospecific monoclonal antibodies. There are two types of epithelium in the larynx; squamous epithelium of the glottis and ciliated epithelium mainly of the supraglottis. A difference in expression pattern was observed between these two epithelia only in 3 CKs, specifically CK-8, CK-13 and CK-19. In the glottis, CK-8 was negative in all layers, CK-13 was positive in the suprabasal and superficial layers, and CK-19 was strongly positive in the basal layer, but apparently reduced in suprabasal layers and completely negative in the superficial layers. In the supraglottis, on the contrary, CK-8 was positive except in the basal layer, CK-13 was negative in all layers, and CK-19 was positive in all layers. When ciliated epithelia were reduced to squamous metaplasia, the epithelial cells were morphologically similar to the squamous cells, and the CK expression also showed the same pattern. In proximity to this squamous metaplasia, however, there were lesions whose cell type morphologically still resembled that of the ciliated epithelium, but whose pattern of CK expression had already been reduced to that of the squamous cell.