Allergen-induced Changes in Nasal Secretory Responsiveness and Eosinophil Granulocytes

Abstract

The release of toxic granule proteins from the eosinophil granulocytes is generally believed to play a crucial part in the development of allergen-induced lesions of the barrier function leading to such clinical features of continuous allergic airway disease as oedema, hypersecretion, changes in responsiveness to specific and non-specific stimuli and, in the case of the lower airways, bronchoconstriction. In the upper airways, a nasal challenge/rechallenge model has proved useful in the study of the allergic inflammatory response in hay fever patients both in experimental settings and during natural pollen exposure. Repeated nasal lavage procedures and challenges with methacholine following an initial challenge with different doses of allergen or placebo were performed in 16 hay fever patients. Following an immediate allergic reaction, a statistically significant increase in the secretory response to methacholine was seen 30 min after challenge with the higher doses of allergen (p less than 0.01) but not after the lowest dose or placebo. An influx of eosinophil granulocytes was seen within 30-60 min of the allergen challenge regardless of the dose (p less than 0.01). The activation of these cells was measured by the increased levels of ECP (eosinophil cationic protein) in the nasal lavage fluid. No relationship was found between individual changes in eosinophils or levels of ECP and changes in the secretory response to methacholine or nasal symptoms. This lends further support to our previous observations that eosinophil granulocytes are not necessarily linked to allergen-induced changes in nasal secretory responsiveness.

Involvement of kinins in hyperresponsiveness induced by platelet activating factor in the human nasal airway

“…The production of kinins by PAF and the kinin‐dependent development of PAF‐induced hyperresponsiveness could result from an action of PAF which is independent of eosinophils. Antigen‐induced hyperresponsiveness can occur without an obvious eosinophilia in both animals (Spina et al ., 1991) and man (Klementsson et al ., 1991). As previously mentioned, intranasal PAF induced an increase in kinins 2 h after administration, at a time when no hyperresponsiveness is detected (Austin & Foreman, 1993).…”

Norm values for eosinophil cationic protein in nasal secretions: influence of specimen collection

“…The histological and cytological evaluation of these cells is widely used to monitor the inflammatory status of the mucosa [1][2][3][4][5]. The histological and cytological evaluation of these cells is widely used to monitor the inflammatory status of the mucosa [1][2][3][4][5].…”

Hyperresponsiveness in the Human Nasal Airway: New Targets for the Treatment of Allergic Airway Disease

“…It is also possible that eosinophil cationic prote ins act on othe r inflammatory c ells to ge nerate the c onditions require d for AHR. 22 While there is e vide nce for a relationship betw e en ECP levels in nasal lavage and nasal AHR, 47 this has not alw ays be en reproduc ed in other studie s, 48,49 so ECP is unlikely to be solely responsible for the induc tion of nas al AHR.…”

“…Studie s c onducted in animal mode ls indic ate that AHR can occ ur w ithout a dete ctable eosinophilia, and vice versa. 156 Data obtaine d from studie s in the human nose similarly imply that AHR doe s not ne cessarily occ ur toge ther w ith e osinophil ac tivatio n, 48,49 w hile antige n can induc e an e osinop hilia w ithout c ausing AHR. 157 There are a range of airw ay inf lammatory c onditio ns w hich feature an eosinophilic infiltration, but no assoc iate d AHR.…”