Abstract
Background: Novel therapies against psoriasis are emerging. Alefacept is such a treatment. It selectively targets the memory effector population of T cells and thereby diminishes the psoriatic plaques. In some cases, however, the use of alefacept as a monotherapy is not sufficient. Objective: In the present study we investigate the safety and efficacy of adding topical steroids to alefacept treatment during the initial 4 weeks. Methods: Peripheral blood was obtained from all patients and the presence of specific T‐cell subsets was assessed by flow cytometry. Fourteen patients were included and treated with 15 mg alefacept intramuscularly for a period of 12 weeks. Each of them was randomized to use either betamethasone‐dipropionate cream or a vehicle cream during the first 4 weeks of the alefacept course. Results: Additional topical corticosteroid treatment during the first 4 weeks of alefacept treatment does not have a beneficial effect on the clinical efficacy. Marked changes were seen in the absolute cell counts of various of the analysed T‐cell subsets in peripheral blood after 12 weeks of alefacept, either with or without additional local steroid application. The CD45RO+, CD8+CD45RO+, CD8+CD161+, CD4+CD25+, CD4+CLA+ and CD8+CLA+ populations showed a statistically significant decrease immediately after the treatment period. Further analysis revealed that the addition of local steroid therapy to alefacept results in marked decreases of all T‐cell subsets analysed in this study, in contrast to the addition of the vehiculum only. Conclusion: Alefacept selectively targets the CD45RO+ lymphocyte population, as well as some other subpopulations of lymphocytes. This effect is independent of the use of additional topical therapy during the first 4 weeks. The extent of the decrease, on the contrary, is dependent on the use of corticosteroids.