Expression of eotaxin and alpha-2 macroglobulin in nasal lavage in allergic rhinitis

Abstract

Problem: The expression of eotaxin and alpha-2 macroglobulin in nasal lavage from naturally occurring perennial and seasonal allergic rhinitis was investigated. Methods: Subjects with seasonal allergic rhinitis (in-season, n = 16; and out-of-season, n = 13), perennial allergic rhinitis (n = 21), and nonatopic nonrhinitic volunteers (n = 20) were recruited and phenotyped for this study. Nasal lavage fluid was obtained from subjects following the skin prick allergy test. Cytospins were also prepared from the supernatant. For cell count analysis, the “Rapi-Diff” staining method was used. Results: Eotaxin levels were significantly increased in the perennial rhinitis ( P = 0.01) and seasonal (in-season) rhinitis ( P = 0.002) groups compared to nonatopic controls. Eotaxin levels were significantly increased in the perennial ( P = 0.01) and seasonal (in-season) rhinitis groups ( P = 0.008) compared with the out-of-season group. Alpha-2 macroglobulin levels were significantly increased in the seasonal (in-season) rhinitics group compared with non-atopic controls and out-of-season rhinitics ( P = 0.009, P = 0.002 respectively). A significant correlation was observed between the levels of alpha-2 macroglobulin and levels of eotaxin (rs = 0.55, P < 0.001). The percentage of eosinophils was significantly increased in seasonal (in-season) ( P < 0.001) and perennial rhinitis groups ( P = 0.008), compared with nonatopic controls. There was a significant increase in the percentage of eosinophils in the seasonal (in-season) group compared with the out-of-season group ( P = 0.007). A significant correlation was observed between the number of eosinophils and levels of eotaxin (rs = 0.5, P < 0.001) and alpha-2 macroglobulin (rs = 0.41, P = 0.003). Conclusion: We have provided evidence of ongoing eosinophil activation with increased levels of eotaxin in nasal lavage fluid in both naturally occurring seasonal and perennial allergic rhinitis, which we have been able to relate to eosinophil influx into nasal mucosa as well as an increased level of vascular permeability. Significance: The results of this study support the likely role for eotaxin in mediating the mucosal accumulation and activation of eosinophils in allergic rhinitis. Reducing or blocking eotaxin may therefore represent a novel and exciting future therapeutic approach for allergic rhinitis. Support: The Louis Alexander, and Frances and Augustus Newman Foundation Royal College of Surgeons of England Research Fellowships. The Royal Society of Medicine Laryngology and Rhinology Section Equipment Grant Award.