title: Prostaglandin D2 measurement in nasal secretions is not a reliable marker for mast cell activation in atopic patients.
abstract: BACKGROUND
  Prostaglandin D2 (PGD2) is a very important mast cell product during the early-phase nasal allergic reaction. However, the quantification of PGD2 in nasal secretions has not yet been well established.
  
  
  OBJECTIVE
  Quantitative determination of PGD2 in nasal secretions of atopic patients (n = 17) after nasal allergen challenge (NAC) and in non-allergic healthy volunteers (n = 10).
  
  
  METHODS
  The nasal microsuction sampling technique was used to obtain the nasal secretions with an exactly known and minimally diluted volume. A sensitive and specific enzyme immunoassay was chosen to measure the more stable 11-methoxime derivative of PGD2, which was obtained after extraction in acetone/ethanol and conversion using methoxamine-HCl. The concentrations of PGD2 in nasal secretions obtained from 10 non-allergic healthy volunteers were used as reference values.
  
  
  RESULTS
  There was no significant difference in the concentrations of PGD2 between men (median: 569 pg/mL) and women (median: 407 pg/mL), nor between the baseline concentrations from atopic patients (median: 410 pg/mL) and non-allergic controls (median: 477 pg/mL). In the atopic patient group, PGD2 did not significantly increase during the entire sampling period after NAC. The absence of PGD2 response contrasted with the nasal symptoms manifested by sneezing, increased nasal airway resistance, and the significant increases of the concentrations of histamine, tryptase, and leukotriene C4 (LTC4) 5 min after NAC.
  
  
  CONCLUSIONS
  This observation suggests that the measurement of PGD2 alone in the nasal secretions does not give reliable information on mast cell activation during a nasal allergic reaction.
authors.affiliation: Department of Otorhinolaryngology, Free University of Brussels, Belgium.
authors.forename: D Y
authors.initials: DY
authors.lastname: Wang
authors.forename: J
authors.initials: J
authors.lastname: Smitz
authors.forename: P
authors.initials: P
authors.lastname: Clement
mesh_terms: D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000032:analysis; D015550:Cell Degranulation / Q000276:immunology*; D005260:Female; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000276:immunology* / Q000378:metabolism*; D008297:Male; D008407:Mast Cells / Q000276:immunology / Q000378:metabolism*; D008875:Middle Aged; D009297:Nasal Mucosa / Q000276:immunology / Q000378:metabolism*; D015230:Prostaglandin D2 / Q000032:analysis* / Q000276:immunology
chemical_list: D015415:Biomarkers; D015230:Prostaglandin D2