Value of fluid phase complement consumption as a means of 'in vitro' allergen standardization

Atopic allergens can readily be shown to inactivate hemolytic complement in human serum. This property has been explored as a means of in vitro allergen quantitation and standardization. The purification of house dust allergen, guided by skin tests and complement inactivation, demonstrates that the in vitro technique is clinically relevant. Since human sera differ in their sensitivity to complement inactivation by allergens, it is desirable to prepare a purified house dust allergen as a standard. By referring to this standard, other house dust extracts may then be standardized by using any given serum sample of human origin, provided that such extracts have undergone some degree of purification. Kinetic studies demonstrate that other allergens of the house dust group may be standardized in similar fashion; it was noted that the ratio of the complement inactivating powers of these respective allergens remains constant whatever the serum used. The method is not suited for the quantitation of pollen allergens.