Anti-IgE-induced histamine release from basophils was examined in 46 asthmatic subjects using a whole blood method. Basophils from subjects less than 30 years old released more histamine than those from subjects aged 41 to 50. The age at onset of the disease also affected the reactivity of basophils to anti-IgE: basophils showed a high response in subjects whose age at onset was between 0 and 10 years, and low response in the subjects whose age at onset was between 41 and 50 years. There was a correlation between histamine release and serum IgE levels. However, individual dose-response curves of histamine release varied greatly in whom serum IgE levels were low.</p
