A New Arthritis Therapy with Oxidative Burst Inducers

BACKGROUND: Despite recent successes with biological agents as therapy for autoimmune inflammatory diseases such as rheumatoid arthritis (RA), many patients fail to respond adequately to these treatments, making a continued search for new therapies extremely important. Recently, the prevailing hypothesis that reactive oxygen species (ROS) promote inflammation was challenged when polymorphisms in Ncf1, that decrease oxidative burst, were shown to increase disease severity in mouse and rat arthritis models. Based on these findings we developed a new therapy for arthritis using oxidative burst-inducing substances. METHODS AND FINDINGS: Treatment of rats with phytol (3,7,11,15-tetramethyl-2-hexadecene-1-ol) increased oxidative burst in vivo and thereby corrected the effect of the genetic polymorphism in arthritis-prone Ncf1 (DA) rats. Importantly, phytol treatment also decreased the autoimmune response and ameliorated both the acute and chronic phases of arthritis. When compared to standard therapies for RA, anti-tumour necrosis factor-α and methotrexate, phytol showed equally good or better therapeutic properties. Finally, phytol mediated its effect within hours of administration and involved modulation of T cell activation, as injection prevented adoptive transfer of disease with arthritogenic T cells. CONCLUSIONS: Treatment of arthritis with ROS-promoting substances such as phytol targets a newly discovered pathway leading to autoimmune inflammatory disease and introduces a novel class of therapeutics for treatment of RA and possibly other chronic inflammatory diseases

Interferon regulatory factor 5 gene variants rs2004640 and rs4728142 are associated with carotid intima media thickness but not with cardiovascular events in rheumatoid arthritis

OBJECTIVES: Rheumatoid arthritis (RA) is associated with cardiovascular (CV) morbidity and mortality. Interferon regulatory factor 5 (IRF5) gene polymorphisms rs2004640 and rs4728142 have been associated with autoimmune diseases, but also with atherosclerosis. Differences in IRF5 gene expression can lead to the production of different interferons and might play a role in the atherogenic process in RA. METHODS: We investigated the effects of IRF5 gene variants rs2004640 and rs4728142 on clinical parameters related to atherosclerosis, such as cIMT (in subgroup n=101), and new CV events (in whole cohort n=353). RESULTS: For rs2004640, cIMT values at baseline were highest within the group of patients carrying the GG-genotype, followed by GT- and TT- genotypes, which was statistically significant. Over time patients with the TT-genotype had the highest increase in cIMT. For rs4728142 cIMT values were also the highest for patients with the GG-genotype at baseline, but the difference between the groups was not statistically significant. Over time the highest increase in cIMT was in the patients with the AA-genotype. Both rs2004640 and rs4728142 were not associated with new CV events during follow-up. CONCLUSIONS: IRF5 alleles are associated with changes in cIMT, but not with new CV events in RA. Although these findings implicate a role of the IRF5 transcription pathway in atherosclerosis, IRF5 single nucleotide polymorphisms do not appear to increase the risk of future CV events