Lyso-PAF-acether and
PAF-acether (formerly
platelet-activating factor) were detected in nasal secretions from patients with
hay fever who underwent local
antigen challenge.
Lyso-PAF release was observed in 12 of 13 patients, with a maximum (p less than 0.001) 5 min after stimulation and a progressive decrease during the first hour. PAF was detected in the 5-min postchallenge nasal washings from two of 13 subjects. After HPLC, this mediator was found in four of seven postchallenge nasal washings submitted to this procedure, with a peak 5 min and 10 min after provocation.
Histamine analysis revealed a significant (p less than 0.001) but time-limited (5 min) release in nasal secretion. The pattern of immunoreactive
leukotriene C4 showed a maximal peak (p less than 0.01) 5 min after
allergen provocation, with raised levels for 20 min. Nasal stimulation with nebulized
saline solution or grass pollens in healthy subjects and in patients suffering from
allergic rhinitis caused by Dermatophagoides pteronyssinus was followed by no local mediator release. These data indicate that, in addition to
histamine and
peptide-
leukotrienes,
lyso-PAF and PAF are released in nasal secretions after local
antigen stimulation in patients with
hay fever, with a preponderance of
lyso-PAF response. On the basis of these results, it is conceivable that these
ether-phospholipids may be involved in allergic
inflammation of human nasal airways.