Relationship between etanercept and thyroid function in patients with psoriasis vulgaris

Background and aim Psoriasis vulgaris, a chronic inflammatory skin disease, requires a long term medication, in order to avoid relapsing episodes. TNF-alpha, one of the targeted molecule in psoriasis therapy, seems to be also involved in thyroid disorders etiopathogenesis. The aim of this study was to evaluate the relationship between anti TNF-alpha therapy and thyroid parameters: serum level of triiodothyronine (T3), free thyroxine (FT4), thyroid-stimulating hormone (TSH) and antithyroidperoxidase antibody (AbTPO) in psoriasis treated population. Methods The study was performed on 44 patients with psoriasis vulgaris (20 patients under antiTNF-alpha treatment (etanercept), 24 patients with no previous systemic therapy). Serum concentrations of hormones, AbAntiTPO and TNF-alpha were measured and a thyroid ultrasonographic evaluation was performed for each patient. Results The mean serum level of FT4 was significantly higher in patients with no systemic treatment (p<0.05). The patients treated with etanercept had a significantly higher level of TNF-alpha (p<0.05). No significant difference was observed for the other evaluated parameters. Also, we found a significant negative correlation between TNF-alpha and TSH levels (r=-0.366, p=0.015). Conclusions We only found that the mean level of FT4 was significantly higher in patients with no systemic treatment. Also, a negative strong correlation was seen between serum level of TSH and TNF-alpha. Based on our data, comparison with other anti TNF-alpha therapies might be of interest in future studies.