# Plasma Cytokines for the Prediction of the Effectiveness of TNFα Inhibitors Etanercept, Infliximab, and Adalimumab in the Treatment of Psoriasis

## TL;DR

This study explores how baseline plasma cytokine levels, such as IL20, may predict the effectiveness of TNFα inhibitors in treating psoriasis.

## Contribution

The study identifies IL20 and other cytokines as potential biomarkers for predicting treatment response to TNFα inhibitors in psoriasis.

## Key findings

- IL20 levels were 2.61 times higher in patients who responded positively to TNFα inhibitors.
- VEGF, sCD40L, and ICAM1 were identified as important predictors by a random forest model.
- Treatment reduced IL17F, IL31, sCD40L, and VEGF levels in all patients.

## Abstract

Background/Objectives: Psoriasis is a chronic, inflammatory, immuno-mediated cutaneous disease characterized by a prominent TNFα-IL23/IL17 immune axis. In recent years, targeted therapies have become standard practice for managing moderate-to-severe psoriasis and have demonstrated efficacy. At the same time, identifying factors associated with the success or failure of TNFα inhibitor therapy remains one of the most difficult aspects in psoriasis treatment. Methods: A clinical, non-randomized study was conducted to evaluate the impact of TNFα inhibitors on the plasma cytokine profiles in patients with moderate-to-severe psoriasis vulgaris (ICD-10 code L40.0). The patients were treated with either etanercept, adalimumab, or infliximab for 16 weeks. Plasma cytokine profiles were assessed using a BioPlex200 System. Results: By the 16th week of therapy, a positive treatment response (PASI ≥ 75) was observed in 51 patients (63%), while 30 patients (37%) showed no response (PASI ≤ 50). When using etanercept, a positive effect was observed in 11 patients (41%), in 14 patients (52%) using adalimumab, and in 26 patients (96%) using infliximab. Analysis of the baseline cytokine levels revealed no differences between the “positive effect” and “no effect” groups, except for IL20, which was 2.61 times higher in the “positive effect” group compared to the “no effect” group, suggesting its potential predictive role in the effectiveness of therapy with TNFα inhibitors. Treatment led to a decrease in IL17F, IL31, sCD40L, and VEGF for all patients, and in IL20 for the “positive effect” group. The increase in ICAM1 in the “no effect” group suggests the possible retention of active migration and the fixation of T cells in the affected skin in these patients. No significant difference in cytokine levels was observed when categorizing patients into subgroups based on the effectiveness of therapy with etanercept, infliximab, and adalimumab; only a pre- and post-treatment difference in the whole cohort was noted. A random forest model showed the importance of VEGF, sCD40L, and ICAM1. Conclusions: The baseline levels of VEGF, sCD40L, and ICAM1, as well as IL20, could serve as potential predictors of treatment effectiveness using TNFa inhibitors. However, this hypothesis requires confirmation with a larger patient population.