title: Nasal neutrophilia and eosinophilia induced by challenge with platelet activating factor.
abstract: BACKGROUND
  It has been demonstrated that in vitro platelet activating factor-acether (1-O-hexadecyl-2-acetyl-sn-glycero-3-phosphorylcholine; PAF) has the capacity to attract eosinophils and neutrophils. We investigated whether the same applies when human nasal airways are stimulated with PAF.
  
  
  METHODS
  Symptom scores and cytologic changes in nasal lavage fluids were evaluated in 10 atopic and 10 nonatopic subjects after nasal challenge with PAF, its precursor and metabolite, 1-O-hexadecyl-sn-glycero-3-phosphorylcholine (lyso-PAF), or saline solution.
  
  
  RESULTS
  Nasal obstruction was reported by all the atopic subjects and seven of the 10 nonatopic subjects after nasal challenge with PAF; other symptoms such as rhinorrhea, itching, and sneezing were generally mild. PAF induced neutrophilia, which appeared after 30 minutes in atopic subjects and after 1 hour in nonatopic subjects, and peaked at 3 hours in both. Less neutrophilia was found 3 hours after stimulation with lyso-PAF in both groups of subjects. PAF also induced eosinophilia, which appeared after 30 minutes in atopic subjects and only after 3 hours in nonatopic subjects. An increase in eosinophil counts was observed 3 hours after lyso-PAF stimulation in atopic but not in nonatopic subjects.
  
  
  CONCLUSIONS
  PAF can attract neutrophils and eosinophils into human nasal airways; however, the recruitment of inflammatory cells is more rapid in atopic than in nonatopic subjects, suggesting a different degree of responsiveness to PAF challenge in the two groups of subjects.
authors.affiliation: Department of Internal Medicine, Infectious Diseases and Immunopathology, University of Milan, Ospedale Policlinico, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Tedeschi
authors.forename: G
authors.initials: G
authors.lastname: Palumbo
authors.forename: N
authors.initials: N
authors.lastname: Milazzo
authors.forename: A
authors.initials: A
authors.lastname: Miadonna
mesh_terms: D000328:Adult; D004802:Eosinophilia / Q000139:chemically induced* / Q000276:immunology / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D017817:Nasal Lavage Fluid / Q000166:cytology; D009297:Nasal Mucosa / Q000187:drug effects* / Q000276:immunology / Q000473:pathology; D015508:Nasal Obstruction / Q000139:chemically induced; D009504:Neutrophils / Q000187:drug effects* / Q000276:immunology / Q000473:pathology; D010972:Platelet Activating Factor / Q000031:analogs & derivatives / Q000494:pharmacology* / Q000502:physiology; D006255:Rhinitis, Allergic, Seasonal / Q000209:etiology / Q000276:immunology / Q000473:pathology
chemical_list: C029271:O-deacetyl platelet activating factor; D010972:Platelet Activating Factor