Allergenic cross-reactivity of several strains of Trichinella in mice and rats by the passive cutaneous anaphylaxis technique.

The cross-reactivity of antiparasite IgE antibody responses induced by allergenic antigens obtained from Trichinella spiralis and Trichinella pseudospiralis was determined by the passive cutaneous anaphylaxis (PCA) technique in BCF1 mice infected with T. spiralis, Trichinella nelsoni, Trichinella nativa, and T. pseudospiralis and in rats infected with T. spiralis and T. pseudospiralis. Our results demonstrate that when the antigen used for the PCA challenge is derived from muscular L1 larvae of T. spiralis, high IgE antibody titres can be detected from sera of animals infected with T. spiralis, T. nelsoni, or T. nativa, but not with T. pseudospiralis, during the entire life cycle of the parasite. However, when homologous antigens are used in the PCA test, we obtained comparable values of IgE titres in rats and mice infected with both T. spiralis and T. pseudospiralis strains. These results suggest the existence of a high degree of immunologic identity between the allergenic antigens of T. spiralis, T. nelsoni, and T. nativa strains, but not T. pseudospiralis.