Assessment of immunological profile in ankylosing spondylitis patients following a clinical trial with guluronic acid (G2013), as a new NSAID with immunomodulatory properties.

The present research aims to study the effects of guluronic acid (G2013) on gene expression levels of the T-bet, GATA3, RORγt, AHR, and FOXP3 transcription factors and on gene expression of their related cytokines following oral administration of this drug in ankylosing spondylitis (AS) patients. In this trial (clinical trial identifier: IRCT2016091813739N4), 14 AS patients and 12 age- and sex-matched healthy individuals were enrolled. The level of transcription factors' gene expression and expression of their related cytokines were measured by quantitative real-time PCR, before and 3 months after G2013 therapy. Our data indicated that the gene expression levels of the T-bet and IFN-γ were not significantly reduced during 12 weeks of treatment with G2013 (p > 0.05). The findings showed that the gene expression levels of the GATA3 and IL-4 increased significantly during 12 weeks of treatment with G2013 (p < 0.05). In addition, gene expression levels of the RORγt, IL-17, AHR, and IL-22 decreased significantly during the 12-week treatment with G2013 (p < 0.05). Moreover, the gene expression level of the FOXP3 increased significantly during 12 weeks of treatment with G2013, but the gene expression level of IL-10 did not increase significantly (p < 0.05, p > 0.05, respectively). The present study showed that oral intake of G2013 was able to modify the severity of articular and inflammatory symptoms of AS through reducing the gene expression levels of the RORγt, IL-17, AHR, and IL-22 and increasing the gene expression levels of the GATA3, IL-4, and FOXP3.