title: Unspecific reactivity of IgM directed against the low-molecular-weight antigen of Toxoplasma gondii.
abstract: During routine serological survey, eight patients (5 pregnant women, 3 grafted patients) were positive for Toxoplasma gondii-specific IgM by enzyme-linked immunoassay but negative by a simultaneously performed immunosorbent agglutination assay. No clinical or biological symptoms of toxoplasmosis were observed later, despite the absence of treatment. Only one IgM-reactive band, which corresponded to the low-molecular-weight antigen of Toxoplasma gondii, was observed by Western blotting of these patients' sera. Dot blotting of lipid extracts of Toxoplasma gondii demonstrated that this reactivity was directed against sphingolipids or ceramides. This IgM positivity, which is unrelated to acute toxoplasmosis, raises strong concerns about the possibility of misleading results of this test in the diagnosis of toxoplasmosis in humans.
authors.affiliation: Service de Parasitologie-Mycologie, CHU de Nancy, 54511 Vandoeuvre les Nancy, France. a.dao@chu-nancy.fr
authors.forename: A
authors.initials: A
authors.lastname: Dao
authors.forename: N
authors.initials: N
authors.lastname: Azzouz
authors.forename: C
authors.initials: C
authors.lastname: Eloundou Nga
authors.forename: J F
authors.initials: JF
authors.lastname: Dubremetz
authors.forename: R T
authors.initials: RT
authors.lastname: Schwarz
authors.forename: B
authors.initials: B
authors.lastname: Fortier
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000276:immunology*; D000953:Antigens, Protozoan / Q000276:immunology*; D002522:Chlorocebus aethiops; D005260:Female; D006801:Humans; D007075:Immunoglobulin M / Q000276:immunology*; D011247:Pregnancy; D014122:Toxoplasma / Q000737:chemistry / Q000166:cytology / Q000276:immunology*; D014709:Vero Cells
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D007075:Immunoglobulin M