High values of alpha (CXCL10) and beta (CCL2) circulating chemokines in patients with psoriatic arthritis, in presence or absence of autoimmune thyroiditis.

The possible role of circulating alpha and beta chemokines in psoriatic arthritis is not extensively studied. The aim of the study is to evaluate serum levels of CXCL10, CXCL9 (alpha) and CCL2 (beta) chemokines in a large series of psoriatic arthritis patients, with or without autoimmune thyroid (AT) disorders, and to relate chemokines levels to the clinical phenotype of these patients. Serum levels of CXCL10 and CCL2 were measured in 37 patients with psoriatic arthritis without AT (PsA) and 28 with AT (PsA+AT), and in gender- and age-matched (1:1) controls without (control 1) or with AT (control 2). Serum CXCL10 levels were significantly higher in control 2 than in control 1 (p < 0.001) and in PsA than control 1 or 2 (p < 0.0001). PsA+AT patients have CXCL10 higher than controls 1 and 2 (p < 0.0001, for both) and than PsA (p < 0.001). By defining a high CXCL10 level as a value at least 2 SD above the mean value of the control group (>192 pg/ml), 5% of control 1, 19% of control 2, 42% of PsA and 63% of PsA+AT, had high CXCL10 (p < 0.0001; chi(2)). Serum CCL2 levels were similar in controls 1 and 2. PsA or PsA+AT patients have serum CCL2 levels significantly (p < 0.01, for both) higher than controls 1 and 2. Serum CXCL9 was not significantly different in the study groups. In conclusion, our study demonstrates higher serum levels of CXCL10 and CCL2 chemokines in patients with PsA than in controls. Serum CXCL10 (alpha chemokine) levels in psoriatic arthritis patients are significantly higher in presence of AT.