Seasonal variation in interleukin 4 in patients with hayfever

This study was performed to investigate the value of interleukin 4 as a mar ker of activity in mild atopic disease. We compared IL-4 levels to eosinoph il cationic protein (ECP), a suggested inflammatory marker in allergic dise ase, in patients with hayfever. Patients with hayfever were assessed during January and then in late June at the height of the grass pollen season, an d their levels of serum ECP and IL-4 compared. Serum ECP was determined by radio-immunoassay and serum IL-4 by a high-sensitivity enzyme-linked immuno sorbent assay. ECP was found to increase significantly in patients with hay fever during the grass pollen season (P<0.01), Conversely, serum levels of IL-4 were found to decrease significantly over the same period when compare d with winter values, ECP and IL-4 were not seen to correlate significantly with each other. The fall in serum IL-4 seen during the grass pollen seaso n in the hayfever patients may reflect allergen driven upregulation of memb rane IL-4 receptor expression or sequestration of cytokine producing cells to inflammatory sites. These findings suggest that serum IL-4 is a poor ind icator of inflammatory status in allergic disease. (C) 2000 Academic Press.