Complement, IgE- and IgG4-antibodies in the diagnosis of atopic diseases.

Haemolytic complement (C) in human sera is readily consumed by most of the common inhalant allergens. The reactivity of C among individual sera differs considerably and is a characteristic parameter for the condition of atopy. The phenomenon is not mediated by specific IgE or IgG4 antibodies. Whereas in groups of patilues (by RAST) are negative in about 50 percent of the cases, this is not so with regard to C-reactivity. In somes cases, especially in allergy to guinea pigs, correlation with the clinical history is better with IgG4 than with IgE antibodies. In other allergies, there is a close correlation between Ige and IgG4 antibodoes.