CXCL10 (alpha) and CCL2 (beta) chemokines in systemic sclerosis - a longitudinal study

Objectives. To measure serum levels of CXCL10 and CCL2 chemokines in patients with SSc, and relate the findings to clinical phenotype and disease progression. Methods. Serum CXCL10 and CCL2 were assayed in 72 consecutive newly diagnosed SSc patients and in 72 sex- and age-matched controls. In 37 SSc and 37 controls, serum CXCL10 and CCL2 were re-evaluated 5 yrs later. Results. SSc at onset showed significantly higher CXCL10 serum levels than controls (216 +/- 126 vs 92 +/- 53 pg/ml; P < 0.0001), as well as CCL2 (388 +/- 172 vs 318 +/- 120 pg/ml; P=0.01). CXCL10 was significantly increased in SSc with interstitial lung involvement or with kidney involvement (P=0.01 and P=0.02, respectively). A significant decrease of CXCL10 was observed from the baseline after 5 yrs in SSc (137 +/- 112 vs 270 +/- 122 pg/ml, respectively; P < 0.0001), while no significant change was observed for CCL2 (418 +/- 176 vs 405 +/- 164 pg/ml; P=NS); the CCL2/CXCL10 ratio significantly increased at the fifth year (1.7 +/- 0.8 vs 3.5 +/- 2.5; P < 0.0001). No significant variations were observed in controls from the basal to the 5-yr evaluation with regards to CXCL10, CCL2 or CCL2/CXCL10 ratio. Conclusions. Our study demonstrates high serum levels of CXCL10 (Th1) and CCL2 (Th2) chemokines in newly diagnosed SSc. High values of CXCL10 are associated with a more severe clinical phenotype ( lung and kidney involvement). CXCL10 declined during the follow-up, while CCL2 remained unmodified, suggesting that the disease progresses from the early Th1 inflammatory condition to the advanced Th2-like stage.