The multitransfused beta-thalassemic child: a model for the study of IgE response.

Positive skin tests to common inhalant allergens and the frequency of respiratory atopic diseases were determined in a population of multitransfused beta-thalassemic patients and in their parents and siblings. Positive skin test responses and respiratory atopic diseases were significantly less frequent in patients than in their relatives and in controls. Negative patients differed from positive patients as to the age at first transfusion, since the former had started transfusion earlier than the latter. It is speculated that in beta-thalassemic patients, allergen-specific IgG acquired early in life through transfusions suppresses the synthesis of allergen-specific IgE.