Serum levels of a Th1 chemoattractant IP-10 and Th2 chemoattractants, TARC and MDC, are elevated in patients with systemic sclerosis.

BACKGROUND

Although abnormalities of various chemokines are detected in systemic sclerosis (SSc), there are few findings concerning Th1 or Th2 chemoattractants.

OBJECTIVE

To determine whether serum levels of chemokines preferentially chemotactic for Th1 cells (IP-10 and MIG) and predominantly chemotactic for Th2 cells (TARC and MDC) are elevated and whether they correlate with clinical features in patients with SSc.

METHODS

Serum samples from patients with diffuse cutaneous SSc (dSSc; n = 34), limited cutaneous SSc (lSSc; n = 30), dermatomyositis (DM; n = 15), systemic lupus erythematosus (SLE; n = 22), and normal controls (n = 30) were examined by sandwich ELISA.

RESULTS

Serum TARC levels were significantly elevated in dSSc patients (P < 0.0002) and lSSc patients (P < 0.0001) compared with normal controls. Similarly, serum MDC levels were significantly increased in patients with dSSc (P < 0.02) or lSSc (P < 0.05) relative to normal controls. In addition, serum IP-10 was detected significantly more frequently in patients with dSSc (44%), lSSc (30%), or DM (53%) than normal controls (0%) and patients with SLE (0%). Furthermore, elevated TARC levels correlated with the presence of pitting scars and anti-topoisomerase I antibody, increased titers of anti-topoisomerase I and antinuclear antibody, and decreased glomerular filtration rate. Increased MDC levels were associated with pitting scars and younger ages at onset.

CONCLUSION

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