Detection of circulating antigen by monoclonal antibodies for immunodiagnosis of angiostrongyliasis.

Two monoclonal antibodies, which recognize the epitope on an antigen with a molecular weight of 204 kD from the fifth-stage worm of Angiostrongylus cantonensis, were previously prepared and used to detect circulating antigens in patients with eosinophilic meningitis or meningoencephalitis and in mice experimentally infected with this parasite by a double-antibody, sandwich enzyme-linked immunosorbent assay (ELISA). The levels of this circulating antigen in experimentally infected mice were significantly higher three weeks after infection. The ELISA values in the detection of circulating antigens in cerebrospinal fluid (CSF) from patients were markedly higher than those in serum. Immunodiagnosis of patients with angiostrongyliasis by this technique proved to be highly specific for circulating antigens in serum and CSF specimens; however, the sensitivity in CSF was significantly higher than in serum.