Serum Levels of Certain Cc and Cxc Chemokines in Birch Pollen Allergic Individuals out of the Pollen Season

Chemokines play a key role in the regulation of cell trafficking during immune responses. In pollen-allergic individuals, the roles of chemokines have been predominantly studied during active allergic reactions. However, little is known about chemokine levels and their effect on immune responses out of the pollen season when atopic individuals do not show clinical symptoms of allergy. Therefore, the aim of the present study was to investigate the serum levels of CCL11/Eotaxin, CCL17/TARC, CCL22/MDC, CXCL1/GRO , CXCL9/MIG, CXCL10/IP-10, and CXCL11/I-TAC out of the pollen season and to determine whether there are differences between birch pollen-allergic and non-allergic individuals. We observed significantly increased concentrations of CCL11/Eotaxin (p<0.01), CCL17/TARC (p<0.01), CCL22/MDC (p<0.01), CXCL9/MIG (p<0.05) and CXCL10/IP-10 (p<0.05) in the sera of birch pollen-allergic patients compared to healthy individuals. In contrast, the serum levels of CXCL1/GRO were lower (p<0.05) in the allergic group compared to the non-allergic subjects. Furthermore, IFN-γ and IL-17 levels were significantly elevated (p<0.05) in the sera of birch-pollen allergic individuals. These results suggest persistent Th17 activity in birch pollen-allergic individuals. The detected differences implicate a role of these chemokines in subclinical allergic responses, which could provide the basis for development of new therapies and strategies for disease monitoring.