Allergen dependent production of histamine releasing actor by alveolar macrophages.

Human Basophil Degranulation Test (HBDT) has been employed for the research of Histamine Releasing Factor (HRF) from macrophages in asthma. Macrophages have been obtained from broncho-alveolar lavages, incubated with specific allergens and the products of this stimulation added to HBDT preparations. The production of an active HRF has been observed only in macrophages from atopic patients. The effect of this HRF seems to be IgE dependent, the degranulation of human basophils being in general significant only for basophils of atopic patients.