Good clinical response to anti‐psoriatic treatment with adalimumab and methotrexate does not inflict a direct effect on compartmentalization of T‐cell subsets: A pilot study

Abstract

Objectives: The most recently introduced therapeutics for psoriasis are biologicals which can target the T‐cell‐mediated pathology of psoriasis in a direct or indirect manner. The present pilot study focuses on and compares the effect of a conventional systemic agent (methotrexate; MTX) with the effect of a TNF‐binding biological (adalimumab) on psoriasis‐associated T‐cell subsets in peripheral blood (PB) and lesional skin. Insight is provided in the hypothesized compartmentalization of these T‐cell subsets between PB and the cutaneous compartment. Methods: Immunohistochemical stainings of designated T‐cell subsets on psoriatic skin sections were performed and similar subsets were isolated from PB specimens by flow cytometry. These counts were correlated with clinical severity. Results: Results showed that adalimumab had a greater clinical effect than MTX treatment after 12 weeks. In the dermis, only the CD3+ T cells were significantly reduced after 12 weeks of adalimumab therapy, whereas for MTX only CD3+ T cells in the epidermis and CD45RO+ T cells in the dermis reduced significantly. However, PB T‐lymphocyte populations did not show significant shifts in quantification of T‐cell subsets. Conclusion: Therefore, recompartmentalization of psoriasis‐associated T‐cell subsets between PB and lesional skin was not induced in this study as a therapeutic principle. Consequently, recompartmentalization of T‐cell subsets does not seem an obligatory event in order to achieve good clinical response.

• Adalimumab
• methotrexate
• psoriasis
• (re)compartmentalization
• T cell