ELEVATED SERUM IL-6 LEVELS PREDICT TREATMENT DISCONTINUATION IN
PATIENTS WITH MODERATE TO SEVERE PSORIASIS: A REAL-LIFE COHORT STUDY FOR 6 YEARS.
psoriasis; immunology; immunosuppression; autoimmune disease; biomarkers.
Real-world, primary data on the treatment of psoriasis are scarce,
especially concerning the role of soluble biomarkers as outcome predictors. Objective:
We evaluated the utility of Th1/Th17 serum cytokines along with clinical characteristics
as predictors of drug survival in the treatment of psoriasis. Methods: We consecutively
included participants with moderate to severe psoriasis who were followed up for 6
years. Baseline interferon-gama (IFN-γ), tumor necrosis factor-alpha and interleukin
(IL)-2, IL-4, IL-6, IL-10 and IL-17A were measured using a cytometric bead array
(CBA); clinical data were assessed. We calculated hazard ratios (HRs) for drug survival
using a Cox proportional hazards model. Results: We 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. 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 candidate biomarker
for predicting psoriasis treatment response.