IMMUNOLOGICAL CROSS-REACTIVITY AMONG VARIOUS STRAINS OF SARCOPTES-SCABIEI

Varieties of Sarcoptes scabiei from different hosts are highly host sp ecific but they are morphologically indistinguishable. The purpose of this study was to investigate the immunologic cross-reactivity among s everal varieties of scabies mites using serum from a human scabies pat ient and from several other species of infested hosts. Homologous and heterologous crossed-immunoelectrophoretic (CIE) analysis of extracts prepared from var. canis (dog) and var. suis (pig) mites yielded very similar antigen profiles. Serum from a human patient infested with var . hominis had circulating IgE that bound to antigens present in extrac ts prepared from each animal mite variety. Antigen homology was furthe r confirmed by fused peaks on tandem CIE. Additionally, sodium dodecyl sulfate polyacrylamide gel electrophoresis/immunoblot analysis showed that the 2 extracts contained proteins that bound antibody in serum f rom a var. suis-infested pig, a var. canis-infested dog, var. canis-in fested rabbits, and a var. hominis-infested human. The results of this study clearly indicate that different varieties of scabies mites, tho ugh host specific, introduce some immunologically cross-reactive molec ules into the host. However, each serum from the 4 scabies-infested ho sts also contained antibody that was specific for proteins in extract from only 1 variety of mite. These data indicated that each variety of scabies introduced some unique molecules into the host, each strain p roduced some similar molecules, or both, but different hosts responded immunologically to different sets of these.