# A Simple Score Scale Composed of Serum Inflammatory Factors Assists in Psoriasis Arthritis Prediction among Patients with Psoriasis Vulgaris

## TL;DR

This study identifies serum inflammatory markers that can help predict which psoriasis patients are at risk of developing psoriatic arthritis.

## Contribution

A novel score scale using CRP, IL-6, and TNF-α is proposed for early prediction of psoriatic arthritis in psoriasis patients.

## Key findings

- CRP, IL-6, and TNF-α levels were significantly higher in patients who progressed to psoriatic arthritis.
- The score scale achieved 59.3% sensitivity and 83.5% specificity for predicting psoriatic arthritis.
- The score scale showed consistent predictive performance across different treatment groups and in an external cohort.

## Abstract

Aim: To compare the levels of serum inflammatory indicators in psoriasis vulgaris patients who progress to PsA and those not, as well as to establish and validate a simple score scale for predicting PsA for psoriasis vulgaris patients. Methods: A cross-sectional study was performed at a university hospital in China to recruit five hundred and seventy-seven patients who had been diagnosed with psoriasis vulgaris for at least 10 years. After evaluation, 86 were enrolled in the PsA group, and the others were selected as the control group. Eight serum inflammatory factors were detected and compared between the two groups. A simple score scale for PsA prediction was established and validated. Results: Serum CRP, IL-6, and TNF-α levels were significantly higher in the PsA group than in the control group. A simple score scale composed of CRP, IL-6, and TNF-α was established. The sensitivity was 59.30% and the specificity was 83.50% for predicting PsA among all psoriasis vulgaris patients when the cut-off value of the total score was set as 1.8 points. The simple score scale presented a predictive value for progressing to PsA among all psoriasis vulgaris patients internally (AUC = 0.788), and the performance was also conformed in psoriasis vulgaris patients receiving topical treatment (AUC = 0.746), systemic treatment (AUC = 0.747) and biological treatment (AUC = 0.808), respectively. The predictive performance of this scale was also validated by an external retrospective cohort (AUC = 0.686). Conclusions: CRP, IL-6, and TNF-α were potential indicators to recognize PsA risk in patients with psoriasis vulgaris. A simple score scale may provide new insights for early prediction of PsA among psoriasis vulgaris patients.