Pathological significance of sex hormones (testosterone and estrogen) associated with pro-inflammatory cytokines (IL-12, IL-17A, and IL-23) in patients with psoriasis and psoriatic arthritis

Abstract

Introduction

Psoriasis (PsO) and psoriatic arthritis (PsA) are immune-mediated inflammatory disorders, in which pro-inflammatory cytokines play a pathogenic role. In addition, sex hormones have been shown to influence the systemic inflammation associated with psoriatic disease.

Objective

Therefore, combined assessment of pro-inflammatory cytokines and sex hormones may shed more light on the pathological inflammatory response associated with PsO and PsA.

Materials and methods

In this case–control study, serum concentrations of three pro-inflammatory interleukins (IL-12, IL-17A, and IL-23) and two sex hormones (testosterone and estrogen) were explored in 88 patients with psoriatic disease (44 PsO and 44 PsA) and 88 controls using enzyme-linked immunosorbent assay kits.

Results

IL-12, IL-17A, and IL-23 concentrations were significantly greater in PsO and PsA patients than in controls. In addition, IL-12 was significantly higher in PsO than in PsA, while IL-17A was significantly elevated in PsA compared to PsO. IL-23 showed no significant difference between PsO and PsA. Testosterone concentrations were significantly elevated in PsA patients compared to PsO patients or controls, whereas there was no significant difference between PsO patients and controls. Estrogen concentrations were significantly lower in PsO and PsA patients compared to controls. Correlation analysis revealed that IL-12 was positively correlated with IL-17A in PsO, while in PsA it was positively correlated with IL-23. IL-17A and IL-23 were positively correlated with testosterone in PsO, while in PsA, IL-17A and IL-23 were negatively correlated with estrogen and testosterone, respectively.

Conclusions

IL-12, IL-17A, and IL-23 were up-regulated in the serum of PsO and PsA patients. However, IL-12 was more bound to PsO, IL-17A was more bound to PsA, while IL-23 levels were similar in PsO and PsA. Up-regulated testosterone levels were only linked to PsA and not PsO. PsO and PsA shared down-regulated levels of estrogen. Testosterone and estrogen were differentially associated with IL-12, IL-17A, and IL-23 in PsO and PsA.