CTACK /CCL27 expression in psoriatic skin and its modification after administration of etanercept.

BACKGROUND: Tumour necrosis factor-alpha upregulates the expression of a cutaneous T cell-attracting chemokine (CTACK/CCL27), that promotes migration of cutaneous lymphocyte-associated antigen-positive lymphocytes into the skin. The role of CTACK/CCL27 in pathogenesis of psoriasis has recently been documented but no data are available at the present time on its modification in psoriatic cutaneous tissue after administration of etanercept. OBJECTIVES: To evaluate modifications of CTACK/CCL27 expression in skin of patients with psoriasis after administration of etanercept and their relation with disease activity. METHODS: Twenty-two patients with moderate to severe psoriasis underwent clinical, histological and immunohistochemical evaluations of disease activity at baseline and at 12 and 24 weeks after starting treatment with etanercept. RESULTS: All selected patients experienced an improvement of Psoriasis Area and Severity Index (PASI) score (P < 0.001) and Dermatology Life Quality Index score (P < 0.001) during the treatment. Skin histological abnormalities showed statistically significant modifications during treatment (P < 0.001). Immunohistochemical expression of CTACK/CCL27 decreased significantly (P < 0.001) and its relation with final PASI score was statistically significant (P < 0.05); the pattern of distribution of CTACK/CCL27 immunoreactivity significantly moved from diffuse and predominantly suprabasal to basal (P < 0.001) and the restoration of basal distribution of CTACK/CCL27 was also significantly related to clinical improvement of cutaneous disease (P < 0.001). CONCLUSIONS: Etanercept induces a clinical and histological improvement of psoriatic disease, promoting a reduction in CTACK/CCL27 cutaneous immunostaining and favouring the restoration of physiological CTACK/CCL27 epidermal expression. Moreover, CTACK/CCL27 reduction in cutaneous expression during administration of etanercept could be considered a favourable prognostic marker.