Real-World Efficacy and Systemic Immune Modulation Upon Tralokinumab Treatment in Atopic Dermatitis

Tralokinumab, an interleukin-13 (IL-13) monoclonal antibody, has shown clinical efficacy in randomized trials for moderate-to-severe atopic dermatitis (AD). This study aims to evaluate clinical and immunological outcome upon tralokinumab treatment in a real-world cohort of patients with moderate-to-severe AD.

We recruited 81 AD patients receiving tralokinumab, performing clinical assessments (oScorad, IGA, BSA, DLQI, pruritus-VAS) at baseline and months 3, 6, 9, and 12. For immunophenotyping (n = 25), PBMCs were collected at baseline and months 6/12. Peripheral T-cell subsets, CLA, OX40, TFH, and cytokines (IL-4, IL-13, IL-17A, IL-10, IFNγ) were analyzed via multiparametric flow cytometry. Serum total/specific IgEs were measured by ImmunoCap and eosinophils by differential blood counts.

Tralokinumab treatment induced a continued clinical response: at 12 months, oScorad and BSA decreased by 60.8% and 78.8%. CLA⁺CD4⁺ and CD8⁺ T cells declined by 63.0% and 25.8%, and OX40⁺ CD4⁺/CD8⁺ T cells by 62.4% and 44.0%. CD4⁺ effector memory T cells increased 4.6-fold, while TEMRA cells decreased 34.0%. CD4⁺ T cells expressing IL-13, IL-4, and IL-17A declined by 70.8%, 72.8%, and 69.3%, while IFNγ⁺ and IL-10⁺ CD4⁺ T cells increased by 62.0%. Total IgE decreased by 9.7%, while eosinophil counts remained stable.

In real-world practice, tralokinumab achieves robust clinical benefit and a rebalanced systemic immune pattern. Selective IL-13 blockade reshapes T-cell function, shifting the immune balance from Th2/Th17 dominance toward Th1/regulatory profiles, suggesting immunomodulatory effects consistent with disease modification. Future studies are needed to determine the long-term stability of these immunological changes following treatment prolongation or interruption.