Blood Cytokines in Psoriasis: Association with Clinical Scores of the Disease Severity and Psoriatic Arthritis

Introduction. Dysregulation of the immune system and inflammationis associated with the pathogenesis of psoriasis andmanifestedas significant changes in cytokine profile. This fact can be used to monitor the course of the disease and its treatment. However, the results of these studies are insufficient, sometimes contradictory and require a more in-depth analysis. Aim to identify matches between cytokine profile, clinical scoresof psoriasis severity and the presence of psoriatic arthritis (PsA). Methods. Standardized clinical scores (PASI, BSA, and sPGA) were used to assess the severity of psoriasis. It was defined as moderate if 10 PASI 20 and sPGA was 23, and as severe if PASI 20 and sPGA was 45. Determination of the cytokine levelsin plasma was carried out by the multiplex immunological analysis using xMAP technology. Statistical analysis and visualization of the obtained data was carried out using RStudio for MacOS and the R programming language. Results. The total 113 patients with psoriasis vulgaris of moderate and severe severity were enrolled in the present study. On the basis of PASI score, moderate psoriasis was diagnosed in 55 (48.7%) patients and severe in 58 (51.3%) patients. PsA was diagnosed in 41 (36.3%) patients. Depends on disease severity the differences in the levels of IL-12, IL-20 and IL-22 were revealed. Significant difference in IL-6 level between patients with PsA and without it were shown. We have identified two independent cytokine networks, represented by a cluster of cytokines associated with psoriasis severity scores (IL1TNFIL-17A, IL-22, and IL-20), and a cluster which was not associated with severity (IL-21, IL-23, IL-25, IL-17F, IL-31, IL-33, IL-4, and IL-10). Conclusion. The results of the study for the first time describe the cytokine networks associated with the systemic inflammation in psoriasis; characterize the main effector cytokines determined the severity of the inflammatory response in skin and the development of PsA.