Investigation of the plasma levels of CCL-17 and CCL-25 and their receptor gene expression in rheumatoid arthritis patients

Rheumatoid arthritis (RA) is an autoimmune inflammatory disease of unknown etiology.  The chemokines and their related receptors have a pivotal role in migration and homing of leukocyte involved in the pathogenesis of RA. The goal of this study was to measure the plasma levels of CCL-17 and CCL-25 and their receptors gene (CCR4 and CCR9) expression in rheumatoid arthritis patients. 30 untreated newly diagnosed and 30 under treatment RA patients with disease modifying anti-rheumatic drugs (DMARDs) as well as 30 healthy subjects participated in this study. We assessed the gene expression of CCR4 and CCR9 by the real-time PCR method, and measured plasma levels of CCL25 and CCL17 by enzyme-linked immunosorbent assay (ELISA). Comparison between control group and newly diagnosed rheumatoid arthritis patients showed significantly lower expression of CCR4 and CCR9 (P=0.047, P=0.049 respectively) in the latter group. In addition, the plasma level of CCL-25 was significantly lower in both newly diagnosed and under treatment RA patients compared to that in the healthy subjects (P=0.017, P=0.030 respectively). The altered expression of chemokines and their related receptors, especially those involved in the leukocyte migration to the mucosa of the gastrointestinal tract may be associated with the pathogenesis of RA.