Serum interleukin-17 levels are related to clinical severity in allergic rhinitis

Background:T helper (Th)-17 cells are a subset of T helper lymphocytes thatexert regulatory activities. Recently, it has been reported that serum interleukin(IL)-17 levels are high in the most severe cases of birch allergy studied outsidethe pollen season.Objective:The aim of this study was to investigate a possible relationshipbetween serum IL-17 levels and clinical parameters in patients with allergicrhinitis studied during the pollen season.Methods:In all, 56 patients with persistent pollen-induced allergic rhinitis wereevaluated during the pollen season. Serum IL-17 levels were evaluated byenzyme-linked immunosorbent assay. Symptoms were assessed by visual ana-logue scale, drug use was monitored and peripheral eosinophils were counted.Results:Serum IL-17 levels were significantly related to clinical symptoms, druguse and peripheral eosinophil counts (P= 0.0001 for all).Conclusion:This study provides evidence that serum IL-17 level assessmentmight be considered to classify allergy severity.