Does IL-31 Have a Proinflammatory Role in PsA?

In close association with the Th17 cytokine profile, interleukin-31 (IL-31) appears to have a proinflammatory role in psoriatic arthritis (PsA), according to results of a new study.

This determination comes after the researchers found not only increased serum levels of IL-31in patients with PsA, but also a positive correlation of IL-31 with the Th17 cytokine profile and a high retinoic acid-related orphan receptor C (RORC) gene expression.

For their cross-sectional study, the researchers analyzed the cytokine serum levels and RORC mRNA expression in 50 participants with PsA and in 30 age- and gender-matched controls.

According to the researchers, the two groups demonstrated significant differences in IL-31 levels. While participants with PsA had an IL-31 level of 77.23 pg/mL, participants who acted as controls had an IL-31 level of 64.4 pg/mL.

There were also significant differences in Th17 cytokine profile serum levels between the two groups. Compared with the controls, participants with PsA had higher levels of IL-17A, IL-17F, IL-17E, and IL-21. The difference in IL-23 levels was not significant. 

The researchers determined that there was a positive correlation between IL-31 and Th17 cytokine profile serum levels.

Furthermore, the PsA group had a 6.85-fold increase in RORC gene expression compared with the control group. However, there was no association between the serum levels of cytokines and RORC gene expression. 

—Colleen Murphy

Reference:

Bautista-Herrera LA, De la Cruz-Mosso U, Román-Fernández IV, et al. A potential inflammatory role of IL-31 in psoriatic arthritis: a correlation with Th17 cytokine profile. Int J Immunopathol Pharmacol. 2020; 34:2058738420907186. doi:10.1177/2058738420907186.