Transcripts of chemokine receptor 5 (Ccr5), chemokine ligand 7 (Ccl7) and IFN-gamma-inducible proteins (Ifi47) and GTP-ase 1 were expressed at the highest levels in both antigen-stimulated lymphocytes and pre-inflamed synovium, which suggests a key role of these genes in both lymphocyte maturation and arthritis initiation.
The CCR5 density on T cell surface, which is constant over time for a given individual, but varies drastically from one individual to another, might thus be a factor determining the intensity of joint inflammation in the course of RA.
Our work suggests that the genetic variation at the CCR2/CCR5 genes did not contribute to the risk for Ps, but CCR2 polymorphisms could modulate the risk for arthritis in patients with psoriasis.
The predominance of CCR5-positive mononuclear cells in the synovial effusions of patients with arthritis suggests an important role for CCR5 in the process of joint inflammation, and identifies CCR5 as a possible new target for therapeutic intervention.
CCR5 blockade in animal models of RA results in amelioration of arthritis, suggesting that CCR5 blockade could also modify disease in patients with RA.