Studies of immediate hypersensitivity in a patient with Acanthocheilonema perstans filarial infection.

A 25-year-old white female returned from West Africa with a two-year history of epidosic swelling, pruritus, and pain in a wrist, associated with peripheral eosinophilia. Serologic and immediate skin tests with Dirofilaria immitis antigen were positive, and blood smears transiently showed microfilariae of Acanthocheilonema perstans after the patient had been treated with diethylcarbamazine. Before treatment, both the serum concentration of IgE and the eosinophil content of arylsulfatase, an enzyme that selectively inactivates slow-reacting substance of anaphylaxis, were elevated; the patient's peripheral leukocytes released histamine and eosinophil chemotactic factor of anaphylaxis when challenged with D. immitis antigen. After one course of diethylcarbamazine, the clinical manifestations and abnormal in vitro immunologic results resolved. Host response to A. perstans infection appears to involve both IgE-mediated hypersensitivity and alterations in an eosinophil enzyme.