Circulating levels of Th1 and Th2 chemokines in patients with ankylosing spondylitis.

OBJECTIVE

Although chemokines are critical elements for the selective attraction and activation of various leukocyte subsets in the inflammatory process, there are few findings concerning T helper (Th) 1 or Th2 chemokines in ankylosing spondylitis (AS). This study was designed to determine whether serum levels of chemokines that are preferentially chemotactic for Th1 (IFN-gamma-inducible protein-10, IP-10/CXCL10) and Th2 (thymus and activation regulated chemokine, TARC/CCL17) and (macrophage derived chemokine, MDC/CCL22) cells were elevated and whether they correlated with the clinical features in patients with AS.

METHODS

Forty-two patients with axial AS and 25 healthy controls were enrolled into the study. Serum levels of chemokines (IP-10, TARC and MDC) and cytokines (IFN-γ, TNF-α and IL-4) were examined using ELISA. The disease activity was evaluated by Ankylosing Spondylitis Disease Activity Score (ASDAS). Serum levels of IgG, IgA, IgM, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were measured.

RESULTS

Serum chemokine levels of IP-10, TARC and MDC were significantly higher in patients with AS than those in healthy controls. Serum cytokine levels of IFN-γ, TNF-α were also significantly increased, but the levels of IL-4 were not. Furthermore, IP-10 levels in AS patients correlated with ESP, CRP and ASDAS, while the levels of TARC and MDC did not correlate with these clinic indexes. Correlation analysis between the levels of chemokines and cytokines revealed a positive correlation between IP-10 and TNF-α. The levels of both Th1 and Th2 chemokines decreased under blockade of TNF-α.

CONCLUSION

Our results suggest that both a Th1 chemoattractant IP-10 and Th2 chemoattractants, TARC and MDC, cooperatively play a role in the development of AS.