Langerhans cells in candidal leukoplakia

Using histochemical and immunohistochemical methods, we examined specimens of candidal leukoplakia from the oral mucosa of 5 smokers to determine the morphological relationships between Candida and Langerhans cells (LC) in tissue sections. LC were fairly evenly distributed in control sections, but had a patchy distribution in lesions. Fewer LC were found in lesions than in control tissue, but the difference was not statistically significant. Candidal antigens were not detected on LC by the methods used, but we found ATPase-positive LC among, or at least near, intraepithelial candidal hyphae. However, sections double-reacted with anti-Candida and T6 antibodies to label candidal antigens and LC, respectively, showed a clear zone of epithelium between the T6-positive LC and the candidal hyphae. The difference in distribution of ATPase-positive and T6-positive LC may indicate locations of 2 subtypes of LC, or a change in T6 antigen expression by the LC closest to the candidal hyphae.