RT Journal Article SR Electronic T1 Late-breaking abstract: Interleukin 17 expression and peripheral blood neutrophils chemotaxis in patients with allergic rhinitis and asthma challenged with D. pteronyssinus JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP 3409 VO 38 IS Suppl 55 A1 Leva Bajoriuniene A1 Kestutis Malakauskas A1 Simona Lavinskiene A1 Edita Gasiuniene A1 Jolanta Jeroch A1 Astra Vitkauskiene A1 Raimundas Sakalauskas YR 2011 UL http://erj.ersjournals.com/content/38/Suppl_55/3409.abstract AB Background: Increasing evidence suggests that interleukin (IL)-17 is important in neutrophil migration and function. A mouse-model study showed that allergen inhalation enhanced IL-17 expression and recruitment of neutrophils into inflammed airways. But the role of IL-17 in patients with allergic airway diseases is unknown.Aim: To investigate influence of bronchial allergen challenge (BAC) with D. pteronyssinus (DP) on IL-17 expression and peripheral blood (PB) neutrophils chemotaxis in patients with allergic rhinitis (AR) and asthma (AA).Methods: 8 AR, 4 AA patients and 6 healthy individuals (HI) were investigated. All patients had positive skin prick tests to DP and underwent BAC with standardized extracts of DP. Serum IL-17 concentration was analyzed by ELISA. Neutrophils were isolated from PB and chemotaxis was investigated using different concentrations of IL-17 measured by FACSCalibur cytometer 24 h before, 7 h and 24 h after BAC.Results: Serum IL-17 levels and PB neutrophils chemotaxis were significantly higher in AR and AA compared to the HI before and after BAC (figure). Serum IL-17 levels significantly correlated with the PB neutrophils chemotaxis (r=0.67, p=0.043).Conclusion: IL-17 levels and PB neutrophil chemotaxis were increased in allergic patients challenged with DP. IL-17 is significant regulating neutrophil chemotaxis in patients with AR and AA.