Etanercept and efalizumab are effective and safe treatments of psoriasis, even in a high-need population. Etanercept was able to sustain the clinical improvement throughout 24 weeks, whereas efalizumab was not in 47% of subjects.

In several studies peripheral blood T-cells have been quantiWed, yet few data are available on lymphocyte subsets in moderate-to-severe psoriasis (in terms of extent and activity of lesions) versus mild psoriasis. The objective is to compare lymphocyte subsets in peripheral blood of patients with moderate-to-severe disease (PASI-score ¸12) to patients with mild disease (PASI-score <12) and to healthy subjects. By means of Xow cytometry method, lymphocytes in peripheral blood of 27 patients with psoriasis and 10 healthy controls were characterized. The absolute number of total lymphocytes was markedly decreased in patients with moderate-to-severe psoriasis as compared to patients with mild disease and normal subjects. Cellcounts of all analysed subsets were found to be increased in more severe psoriasis, except for CD8+CD45RO+ cells. The under-representation of CD8+CD45RO+ cells is compatible with the dynamics of acquired immunity, which requires a time log after the relapse of the lesions to diVerentiate from CD45RA+ naive cells.

Although alefacept showed some results in treating nail pathology in psoriasis, a more extensive study is required, covering both more patients and a more extensive time period. Furthermore, it would also be clinically relevant to compare the effects of alefacept on nail psoriasis with other biologicals.

Treatment with efalizumab establishes successful recompartmentalization of T-cell subsets with modest clinical efficacy after 12 weeks, whereas in etanercept-treated patients, a significant clinical response is no guarantee for significant changes in T-cell subsets in the different compartments. Reductions in T-cell subsets cannot be used as predictive markers for the clinical response to therapy. Interference with the studied T-cell populations in its own right seems not to be responsible for the clinical efficacy of efalizumab and etanercept.

Dimethylfumarate is an effective therapy for moderate-to-severe plaque psoriasis. The drug may act by reducing lesional T-cell subsets and normalizing epidermal hyperproliferation and keratinization, but does not reduce NKT cells.