Abstract: | Granulocyte locomotory responses in 5 patients with symptomatic seasonal allergic rhinitis were lower compared with similar responses from 27 normal nonallergic controls. In a subsequent controlled, double-blind crossover study, neither cimetidine (histamine H2-receptor blocker) nor placebo improved these responses. In our in vitro study, histamine did not inhibit granulocyte responses to chemotactic attractant. These results indicate that defective granulocyte response in patients with seasonal allergic rhinitis may be due to factors other than or in addition to histamine. |