Elevated serum IL-6 levels predict treatment interruption in patients with moderate to severe psoriasis: a 6-year real-world cohort study

Background: Real-world, primary data on the treatment of psoriasis are scarce, especially concerning the role of soluble biomarkers as outcome predictors. Objective: The authors evaluated the utility of Th1/Th17 serum cytokines along with clinical characteristics as predictors of drug survival in the treatment of psoriasis. Methods: The authors consecutively included participants with moderate to severe psoriasis who were followed up for 6 years. Baseline interferon-a, tumor necrosis factor-a, and inter-leukin (IL)-2, IL-4, IL-6, IL-10, and IL-17A were measured using a cytometric bead array; clinical data were assessed. The authors calculated hazard ratios (HRs) for drug survival using a Cox proportional hazards model. Results: The authors included 262 patients, most of whom used systemic immunosuppressants or biologics. In the multivariate model, poor quality of life measured by the Dermatology Life Quality Index (HR = 1.04; 95% CI 1.01-1.07; p = 0.012) and elevated baseline IL-6 (HR = 1.99; 95% CI 1.29-3.08; p = 0.002) were associated with treatment interruption. Study limitations: The main limitation of any cohort study is the presence of confounders that Conclusions: Poor quality of life and elevated baseline serum IL-6 level predicted treatment interruption in patients with moderate to severe psoriasis. Although IL-6 is not the most important mediator of the inflammatory pathway in the skin environment, it is an interesting (c) 2023 Sociedade Brasileira de Dermatologia. Published by Elsevier Espan similar to a, S.L.U. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).