Complement consumption and IgE binding by house dust allergen in the serum of atopic patients.

The reactivity of complement (C) with housedust allergen has been investigated in separate groups of sera from atopic patients with seasonal hay fever, bronchial asthma, atopic dermatitis, animal dander allergy or asthmatic bronchitis as compared to controls. Complement consumption was more pronounced on average in the allergy groups, with the exception of atopic dermatitis. Total IgE levels were elevated in all groups, especially in atopic dermatitis. There was no correlation between C-sensitivity and IgE data (RAST and RIST). The mean levels of C1-inhibitor, 1-antitrypsin and 2-marcroglobulin in the atopic group were found normal. A significant correlation was found between the extent of C-consumption by house dust allergen and the level of C4 in sera. It is concluded that both C and IgE differ from normal in atopic patients, but that neither one is suited for the routine diagnosis of atopy in individual serum samples.