Antibodies to Toxocara in the sera of visceral larva migrans patients: the significance of raised levels of IgE.

It was possible to detect in the sera of patients, for whom visceral larva migrans had been confirmed histologically, not only antibodies to the excretory–secretory antigens of Toxocara canis by means of fluorescence techniques, but also specific homocytotropic antibody measured by passive cutaneous anaphylactic tests in baboons and monkeys. It was observed that these patients had ten to fifteen times the average normal level of IgE as determined by the radioimmunosorbent test. All cases authenticated histologically gave these results, which suggests that these sort of serological findings can make a contribution towards establishing a diagnosis of visceral larva migrans in man. A schematic representation is given which shows the immunological responses of the host which may result from different nematode allergens and antigens, and the immunopathological mechanisms likely to be involved.