Serum Levels of IL-17 and IL-22 Are Reduced by Etanercept, but not by Acitretin, in Patients with Psoriasis: a Randomized-Controlled Trial

There are no controlled trials comparing etanercept and acitretin efficacy and therapeutic mechanisms in psoriasis. In the present study, 30 patients were given etanercept 50 mg twice weekly and 30 patients acitretin 0.4 mg/kg per day, both for 12 weeks. Before and after treatment, psoriasis area and severity index was calculated, and serum levels of interleukin (IL)-17, IL-22, and IL-23 were investigated. After treatment, psoriasis area and severity index was significantly lower for both groups. However, etanercept-treated patients showed lower psoriasis area and severity index than acitretin-treated ones. Psoriasis patients showed higher IL-17 and IL-22 levels than controls, while no IL-23 was found in any serum. Furthermore, a correlation between IL-17 levels and psoriasis severity was found. Only etanercept was able to reduce IL-17 and IL-22 levels. Our findings suggest that etanercept is more effective than acitretin in the treatment of psoriasis and that it is able to affect Th17 system.