Serum eotaxin levels in patients with chronic spontaneous urticaria

Eotaxin is a potent agonist for CC chemokine receptor 3 that can attract eosinophils at sites of inflammation. Given the potential role of eosinophils in chronic spontaneous urticaria (CU), we measured serum eotaxin levels together with C-reactive protein in 100 CU patients who were characterized according to autologous serum skin test (ASST) and disease severity. Serum eotaxin concentration was significantly higher in CU patients (median 140.1 pg/ml, range 33.7-718.7 pg/ml) than in 45 healthy controls (median 108.9 pg/ml, range 45.5-409.4 pg/ml) (p = 0.032) Serum eotaxin concentration was not significantly different in ASST-positive and ASST-negative patients as well as in patients with different urticaria activity scores. However, eotaxin levels tended to be higher in patients with intense symptoms. In the 7 patients observed during CU exacerbation and during remission, eotaxin serum levels tended to decrease during remission, although statistical significance was not reached (median concentration decreased from 170.0 pg/ml to 123.8 pg/ml). CRP levels were not significantly different in CU patients and healthy subjects, although there was a trend towards higher levels in the former population. Furthermore, in the 7 patients observed during CU exacerbation and during remission, CRP levels decreased significantly during remission (median concentration dropped from 4.1 microg/ml to 0.7 microg/ml, p = 0.015). No significant correlation was found between eotaxin and CRP serum levels. These findings indicate that serum eotaxin levels are increased in CU patients, although they do not reflect strictly disease activity. A role for eotaxin in eosinophil attraction and activation in CU can be envisaged.