Il-8 is a chemokine which causes chemotaxis of neutrophils, eosinophils and lymphocytes in vitro, however its role as a chemoatractant in allergic inflammation is unclear. The aim of this study was to investigate the in vitro Il-8 induced chemotaxis of eosinophils and the effect of nasal lavage of Il-8 solution on the influx of eosinophils.

Twelve patients (5 women and 7 men) suffering from seasonal allergic rhinitis with average age 30,1 ± 2,67 years were included into the study. Eosinophils from peripheral blood were isolated using the CD16 MicroBeads (MACS, Miltenyi Biotec®) and chemotaxis to Il-8, FMLP, RANTES, Il-5 and C5a were determined. Patients were challenged with Il-8 solution and diluent for Il-8 during the pollen season. The nasal lavage fluids were collected before, during Il-8 or placebo challenge and 30 minutes, 2 hours and 3 hours after the challenge. The number of eosinophils in the lavages was determined.

The optimal concentration of Il-8 for eosinophils chemotaxis was 10–9M, the chemotactic index was 2,03 ± 0,6. The chemotactic index for FMLP (10–7M), RANTES (10–8M), Il-5 (10–7M) and C5a (10–8M) was: 3,24 ± 0,83; 3,51 ± 0,7; 4,02 ± 0,68 and 2,5 ± 0,77, respectively. After the challenge with Il-8 of nasal mucosa we observed a peak of eosinophil influx at 3 hours after challenge reaching the number of 3050 ± 760 cell/ml, but the number of eosinophils after the Il-8 challenge in comparison with diluent was not significantly higher (p>0,05).

Il-8, which is a chemoatractant for eosinophils in vitro, does not provoke a significant influx of eosinophils into the allergen primed nasal mucosa.