UNILATERAL NASAL ALLERGEN CHALLENGE LEADS TO BILATERAL RELEASE OF PROSTAGLANDIN D-2

Background Multiple mediators including prostaglandin D-2 and leukotri ene B-4 have been shown to increase in nasal secretions during the ear ly response to nasal challenge with antigen. Objective Our objective w as to investigate the time course of prostanoid and leukotriene B-4 re lease into nasal secretions on both the ipsilateral and contralateral side after a unilateral nasal allergen challenge. Methods We performed a controlled, randomized trial. Six volunteers were challenged unilat erally with antigen or diluent in a randomized order and discs were us ed to collect nasal secretions from both nostrils at 2 min intervals f or 20 min after the challenge. Prostanoids and leukotriene B-4 (LTB(4) ) in recovered nasal secretions were measured by combined capillary ga s chromatography-negative ion chemical ionization mass spectrometry (G C/MS). Results Nasal allergen challenge resulted in a significant and immediate increase in symptoms and sneezing. PGD(2) was significantly elevated above diluent values (0.6+/-0.6 pg) 30 s after removal of the allergen disc (P<0.05), reached its peak (423.2+/-182.4 pg) at 2 min and then slowly decreased. PGD(2) also increased on the contralateral side after unilateral allergen challenge, reaching peak values about s ix times lower than on the ipsilateral side (70.8+/-21.7 pg at 6 min). Levels of 9a, 11b-PGF(2) after antigen provocation became significant ly higher than after diluent (0+/-0 pg) on the ipsilateral side at 2 m in (17.2+/-5.9 pg), and reached peak levels at 4 min (25.1+/-8.0 pg). LTB(4) also increased significantly on the side of challenge. For the other prostanoids measured (PGF(2), PGF(2 alpha), TxB(2), 6kPGF(1 alph a)), no significant changes in either ipsilateral or contralateral sec retions were observed after allergen challenge. Conclusions Our study described the kinetics of PGD(2) and LTB(4) release as well as the con tralateral release of PGD(2).