Detection of Alternaria allergens by crossed radioimmunoelectrophoresis.

Allergens involved in sensitivity to Alternaria have not been well defined. We used crossed radioimmunoelectrophoresis (CRIE) to study antigens in a crude A. alternata extract, which were capable of binding IgE in human serum. Sera from 35 patients sensitive to Alternaria, 10 not sensitive to Alternaria, and five normal controls were examined. CRIE with hyperimmune rabbit sera demonstrated 22 antigens in the Alternaria extract. After exposure of CRIE gels sequentially with patient serum and 125I-labeled anti-human IgE, autoradiography demonstrated that three of the antigens bound IgE in sera of Alternaria-sensitive subjects. Our results suggest that multiple allergens are involved in A. alternata sensitivity.