An Investigation of the Allergens of Ascaris lumbricoides Using a Radioallergosorbent Test (Rast) and Sera of Naturally Infected Humans: Comparison With an Allergen for Mice Identified by a Passive Cutaneous Anaphylaxis Test

Abstract

The identification of those components of Ascaris lumbricoides (var. suum) body fluid (ABF) which are IgE-inducing antigens (allergens) was found to depend on the type of assay used. By use of the radioallergosorbent test and sera from humans naturally infected with A. lumbricoides, it was found that ABF contains a range of allergens with a variety of isoelectric points and molecular weights. Some cross-reactions were demonstrated between the allergens of A. lumbricoides and Toxocara canis. On the other hand, when a passive cutaneous anaphylaxis assay was used with sera from mice sensitized by nasal inhalation of ABF plus Bordetella pertussis vaccine, it was found that only one relatively pure fraction of ABF was involved. This consisted of some of the largest protein molecules in ABF: it had a molecular weight of approximately 360000 (subunits 140000 and 220000), an isoelectric region of 8·0-8·4, and was clearly very different from the allergens isolated from ABF by other workers.