The effect of an ex vivo boosted immune cell therapy on canine atopic dermatitis: an open, uncontrolled pilot study

Background: Canine atopic dermatitis (cAD) is associated with an imbalance between multiple T lymphocytes and cytokines. Ex vivo boosted immune cell (EBIC) therapy is the sequential administration of ex vivo cultured and activated lymphocytes to patients to improve immune function. Objective: This pilot study aimed to assess the safety of EBIC therapy and demonstrate its efficacy as a novel treatment for cAD. Animals: Ten dogs with AD. Methods and materials: The phenotypes of the immune cells before and after ex vivo culture were analysed by flow cytometry. EBICs (1.0–5.0 × 10⁸ cells/animal) were administered to dogs every two weeks, with a total of six injections. The cAD extent and severity index (CADESI)-03 and pruritus scores were calculated to evaluate the efficacy of EBIC therapy for cAD. For safety assessment, regular blood examination was conducted, and any adverse events recorded. The serum levels of interleukin (IL)-4, IL-10, IL-31 and interferon-gamma (IFN-γ) were evaluated. Results: The cells expanded by an average of 57.52-fold and the proportions of CD8⁺ cells and IFN-γ-producing cells significantly increased after ex vivo culture. Sequential EBIC therapy improved CADESI-03, and pruritus scores significantly. After stopping treatment the improvement rates increased for the CADESI score and were maintained for the pruritus score. There were no significant changes in cytokine levels. No significant adverse events were observed. Conclusions and clinical significance: EBIC therapy is a safe and efficient treatment for cAD. This therapy could correct the immunological imbalance in dogs with AD by infusing activated T lymphocytes.