Methods for determining responsiveness to anti-tumor necrosis factor therapy in the treatment of psoriasis

A method for treating psoriasis in a subject, the method comprising:

• measuring a level of at least one biomarker in a biological sample of uninvolved, non-inflamed skin isolated from a subject with psoriasis prior to treatment with an anti-tumor necrosis factor (anti-TNF) agent, wherein the at least one biomarker is
• (a) ubiquitin specific protease 18 (USP18) and the level of USP18 is increased relative to a control level;
• (b) keratin, type II cytoskeletal 2 epidermal (KRT2) and the level of KRT2 is decreased relative to a control level;
• (c) interleukin 4 receptor (IL4R) and the level of IL4R is increased relative to a control level;
• (d) sex-determining region Y-box transcription factor 5 (SOX5), and the level of SOX5 is decreased relative to a control level;
• or
• (e) interferon induced with helicase C domain 1 (IFIH1), and the level of IFIH1 is increased relative to a control level;
• or
• (f) a combination of biomarkers of any two or more of (a)-(e),
• wherein (i) the increased level of USP18, IL4R, or ILH1 or the decreased level of KRT2 or SOX5, or (ii) the increased level of USP18, IL4R, or ILH1 and/or the decreased level of KRT2 or SOX5 in the combination of any two or more biomarkers in the sample of uninvolved, non-inflamed skin isolated from the subject relative to the control level predicts that the subject will be responsive to treatment with the anti-TNF agent, and
• wherein the control level is the mean level of the biomarker in uninvolved, non-inflamed skin in a population of subjects suffering from psoriasis prior to treatment with the anti-TNF agent;
• and
• administering an effective amount of an anti-TNF agent to the subject predicted to be responsive to treatment.