Clinical Studies Using Radioallergosorbent Test (RAST) : Correlation between the End Point of Scratch Test and Isotope Count of RAST, Clinical Significance of RAST, and Neutralization between House Dust and Mite Antigens

Abstract

Thirteen inhalants (mite, house dust, silk, 6 pollens, 3 molds and dog and cat danders) and 6 foods (egg york, egg white, shrimp, oyster, crab, mackerel) were chosen and paper disc method was employed to study the correlation between the scratch test and RAST. High correlation was found between the end point of scratch test and the isotope counts of RAST in mite, house dust, silk and grasses, but was not so high in molds, ragweed and cedar. Positive RAST correlated well with positive allergic history in animal danders and foods. When the end point of scratch test was more than 1:10000, RAST was invariably positive. Whereas RAST was negative in all cases, in which scratch test was negative. No correlation was noted between house dust and book lice, cockroach or Aspergillus in RAST. From the cross neutralization of IgE antibodies between house dust and mite, it was further confirmed that the major allergenic component of house dust is mite.