CHANGES OF PLASMA CHEMICAL MEDIATORS AFTER BRONCHIAL PROVOCATION TEST WITH ALLERGEN

Abstract

Twenty-six patients with bronchial asthma underwent bronchial inhalation chall-enge with house dust or aspergillus fumigatus. Venous blood samples were collected before inhalation of allergen and 5 minutes, 3 hours and 8 hours after inhalation. Plasma histamine, leucotriene C₄ (LTC₄) and thromboxane B₂ (TXB₂), a metabolite of thromboxane A₂ (TXA₂), were then measured. These twenty-six patients were divided into three groups: Six had no asthmatic responses (group N) . Eight had immediate asthmatic responses (group I) . Twelve had dual (immediate and late) asthmatic responses (group D) . In the three groups, plasms histamine was unchanged. The plasma LTC₄ rose when immediate asthmatic response appeared in both the I and D groups. The percentage increase of LTC₄ correlated with the percentage fall of peak flow and V₂₅. The plasma TXB₂ increased slightly when immediate asthmatic responses appeared in both the I and D groups, and it also increased slightly in the D group 3 hours after inhalation of allergen. The results suggest that LTC₄ and TXA₂ are important in the appearance of an immediate asthmatic response and that TXA₂ is ivolved in appearance of the late asthmatic response.