049 Investigating the immunomodulatory mechanism of dithranol in alopecia areata through blood-based in vitro studies

This study investigates the immunomodulatory effects of dithranol in alopecia areata by examining its impact on immune cell function using in vitro assays with peripheral blood mononuclear cells (PBMCs) from alopecia patients and healthy donors. The optimal non-cytotoxic concentration of dithranol was found to be 0.02 µg/ml. Plasma cytokine profiling indicated elevated levels of IFN-γ, IL-6, IL-17, and TNF-α in alopecia patients. Dithranol treatment resulted in a marked reduction of TNF-α and IL-6 secretion from monocytes and decreased production of IFN-γ and TNF-α from T cells. Additionally, dithranol suppressed TNF-α expression and proliferation in Th1-polarised CD4+ T cells, suggesting it attenuates pro-inflammatory cytokine activity. These findings provide insight into dithranol's clinical benefits, with ongoing research to validate these results in ex vivo skin models.