Photo-inactivated allergens I. Preparation, physicochemical and biological properties

A method is described for the preparation of inactive atopic allergens by irradiation with ultraviolet light. From an analysis of the absorption and fluorescence emission spectra, and with the aid of synthetic model compounds, it is concluded that the allergenic determinant of lysine-sugar conjugation is extremely sensitive to ultraviolet light. Considerable reduction of allergenicity in vitro (diminished capacity to inactivate human complement in fluid phase) and in vivo (impressive reduction of skin-reactivity in atopic patients and, by passive transfer, in monkeys) was demonstrated. Only slight modification of the antigenic characteristics was detected.