Immunohistochemical Expression Patterns of Inflammatory Cells Involved in Chronic Hyperplastic Candidosis

The profile of the inflammatory cell infiltrate in chronic hyperplastic candidosis (CHC) was determined in oral mucosal biopsies by immunohistochemistry. One tonsillar tissue section was included as an immunohistochemistry control, whilst squamous papilloma (n = 4) with secondary Candida infection was used as Candida controls. Oral lichen planus tissues (n = 10) provided negative controls for Candida presence, as well as positive controls for inflammation. Immunohistochemistry employed antibodies specific for CD3⁺ (T lymphocytes), CD4⁺ (T helper cells), CD8⁺ (cytotoxic T cells), and CD20⁺ (B lymphocytes). Manual counting of stained cells from digitised images determined the proportion of each cell type relative to the total number of cells, and these were assessed in the mucosa, the epithelium, and the lamina propria. The mean proportion of CD3⁺ cells was significantly higher than CD20⁺ cells in all tissue types. For CHC, the mean proportion of CD3⁺ cells in entire tissues was 15.6%, with the highest proportion in the lamina propria (32.6%) compared with the epithelium (3.9%). CD20⁺ cells were in much lower proportions (1.8%) in CHC, with the highest proportion (3.6%) in the lamina propria. T lymphocytes were predominately CD4⁺ cells (9.0%) compared with CD8⁺ cells (4.4%). CD4⁺ cells were most prevalent in the lamina propria (23.1%) compared with the epithelium (mean = 3.2%). From these results, it was concluded that the immune response invoked by Candida in CHC is primarily driven by the T helper cells.