PERIPHERAL NEUTROPHILS AFTER ALLERGIC ASTHMATIC REACTIONS

The response of peripheral neutrophils was studied in 16 patients with allergic asthma after challenge with birch/grass pollen allergen, in order to identify inflammatory markers associated with only the early asthmatic reaction and those associated with both early and late asthm atic reactions. The allergen challenge proceeded until the patients ha d an early asthmatic reaction with 100% increase in specific airway re sistance. Bronchoconstriction after allergen challenge was monitored h ourly over 9 h and finally after 18 h, by measurement of the forced ex piratory volume in 1 s. Seven patients had a late reaction, defined as a decrease in forced expiratory volume in 1 s of more than 15%. Blood samples were taken before and 18 h after challenge. After allergen ch allenge (18 h) the blood concentration of neutrophils in patients with a late asthmatic reaction was 1.4 times higher than before challenge and there was a tendency for increased Fc gamma receptor-mediated chem iluminescence. Lewis X-antigen (CD 15), which is associated with endot helial adhesion and extravasation, significantly decreased at the same time. Neutrophils were incubated with the tetrapeptide arginine-glyci ne-aspartate-serine before and 18 h after allergen challenge. Both pat ient groups showed an increased Fc gamma receptor-mediated chemilumine scence and a decreased Fc gamma receptor membrane expression following allergen challenge, suggesting a preactivation. In conclusion, patien ts with a dual asthmatic reaction show a sustained primed inflammatory response and primed neutrophils compared with patients with only an e arly reaction when measured after the decline of clinical symptoms pro voked by allergen challenge.