ABSTRACT
A multi-dot enzyme-linked immunosorbent assay (ELISA) was developed for the rapid and simple differential diagnosis of eosinophilic meningitis due to helminth infections. Ultrafiltered, purified antigens of Parastrongylus (=Angiostrongylus) cantonensis, Gnathostoma spinigerum and Taenia solium metacestodes, the most common parasites that invade the central nervous system and cause eosinophilic pleocytosis, were dotted onto a single nitrocellulose membrane strip. Antigen-coated strips, when blocked with 5% skimmed milk and dried, were stable for at least 6 months at 4 degrees C. With peroxidase conjugated anti-human immunoglobulins and 4-chloro-1-naphthol as a substrate, antibodies in the corresponding patients' sera were clearly detected on the membrane strip as well-defined blue dots. Although cross-reactions between P. cantonensis and G. spinigerum antigens were observed with the use of partially purified antigens, the darkest dot correlated well with the infecting parasites in all cases. This fast, easy and economical multiple dot-blot ELISA method is useful for the differential diagnosis of eosinophilic meningitis caused by parasitic helminths, as semi-purified antigens can be easily obtained by ultrafiltration and used. Further improvements using highly specific parasite antigens may make this multi-immunodot test more suitable for wide-scale use in field studies and diagnostic laboratories.
Subject(s)
Enzyme-Linked Immunosorbent Assay/methods , Eosinophilia/diagnosis , Helminthiasis/complications , Meningitis/diagnosis , Angiostrongylus cantonensis/immunology , Angiostrongylus cantonensis/isolation & purification , Animals , Antibodies, Helminth/immunology , Antibody Specificity/immunology , Antigens, Helminth/immunology , Cross Reactions , Cysticercosis/diagnosis , Cysticercosis/immunology , Diagnosis, Differential , Eosinophilia/immunology , Eosinophilia/parasitology , Gnathostoma/immunology , Gnathostoma/isolation & purification , Helminthiasis/immunology , Humans , Meningitis/immunology , Meningitis/parasitology , Spirurida Infections/diagnosis , Spirurida Infections/immunology , Strongylida Infections/diagnosis , Strongylida Infections/immunology , Taenia solium/immunology , Taenia solium/isolation & purificationABSTRACT
Serological evidence for Toxoplasma gondii infection in Thai pregnant women was investigated. One thousand six hundred and sixty-nine blood specimens were collected from 838 HIV-seropositive and 831 HIV-seronegative pregnant women attending the antenatal-care clinic at Siriraj Hospital, Bangkok, Thailand, during a two-year period. Toxoplasma IgG antibody was detected, using a solid-phase enzyme-linked immunosorbent assay in which the membrane protein p-30 was the predominant antigen. IgG positive sera were subsequently examined for IgM antibody by the capture antibody enzyme immunoassay. The IgG antibody was found in 450 (53.7%) HIV seropositive women and 44 (5.3%) non-HIV infected women, with a statistically significant difference (p < 0.0001). Three of the 450 HIV-seropositive and 2 of the 44 HIV-seronegative sera with IgG antibody were positive for IgM antibody against T. gondii. This result suggested that HIV seropositive pregnant women had a higher risk of Toxoplasma infection with increase exposure to their offspring.
