Staining patterns of oral lesions of discoid lupus erythematosus by monoclonal anti-keratin antibodies.

The immunofluorescent staining patterns of oral lesions of discoid lupus erythematosus were examined by use of monoclonal antibodies AE1, AE2 and AE3. AE1 and AE2 showed suprabasal staining, whereas AE3 stained all cell layers of the epithelium. This pattern is consistent with that of other benign hyperkeratinized lesions of the oral mucosa. Occasionally, however, the most basally positioned epithelial cells stained positive with AE1. The morphology of these cells was similar to stratum spinosum cells. Colloid bodies in the epithelium as well as in the connective tissue stained positive with AE1 and AE3, demonstrating their epithelial origin. Few bodies in the connective tissue staining positive with IgM were negative for keratin. These structures may be Russell bodies or may be derived from the basement membrane zone.