Presentations 2020: OMFS

375 - Immunohistochemical Expression Patterns of Inflammatory Cells Involved in Chronic Hyperplastic Candidosis

A Williams D Williams H Rogers M Lewis D Farnell A Jones
Presented by: Ailish Williams
Cardiff Dental Hospital

Introduction Chronic hyperplastic candidosis (CHC) is characterised by Candida albicans invasion of the oral mucosa and an associated inflammatory cell infiltrate. Of concern in CHC is its association with malignant transformation. As such, increasing our understanding of both C. albicans virulence and the accompanying host response is important. Methods Tissue sections from archive biopsy tissues were stained with antibodies targeting CD3+ (T lymphocytes), CD4+ (T helper cells), CD8+ (cytotoxic T cells) and CD20+ (B lymphocytes) antigens. Examined tissues included CHC (n=20), squamous papilloma with secondary Candida infection (n=4), lichen planus (n=10) and tonsillar control (n=1). Manual counting of antibody stained cells, captured in digitised images was undertaken, and the relative proportion of stained cells in the entire tissue section, the epithelium and the lamina propria determined. Results In all tissues, the mean proportion of T-cells was significantly higher than that of B-cells. Highest inflammatory cell infiltrate occurred in lichen planus and lowest with squamous papilloma. In the case of CHC, the mean proportion of CD3+ cells was 15.6%, with highest proportions occurring in the lamina propria (32.6%) compared with the epithelium (3.9%). There were considerably fewer B-cells (1.8%) in CHC tissues. In CHC, T-helper cells (9.0%) predominated compared with cytotoxic T-cells (4.4%). This contrasted with lichen planus where there was more equity in the relative proportions of T-helper cells (34%) and cytotoxic T-cells (29%). Conclusion From these results, it can be concluded that the immune response in CHC is different to that of other oral inflammatory lesions and is driven by a T helper cell response. Further work that further distinguishes the T-helper cell subsets is warranted. Differentiation of CD4+ cells into Th17, Th1, Th2 and T-reg subsets will indicate whether C. albicans induces an immune response that is antifungal (Th1 and Th17) or one that could allow persistence of the fungus in the tissue.
Consent Statement: There are no details on individual patients reported within the abstract.

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