title: Immunoelectron microscopy of Schüffner's dots in Plasmodium vivax-infected human erythrocytes.
abstract: Plasmodium vivax induces morphologic alterations in infected host erythrocytes that are visible by light microscopy in Romanovsky-stained blood smears as multiple brick-red dots. These morphologic changes, referred to as Schüffner's dots, are important in the identification of this species of malarial parasite and have been associated by electron microscopy with caveolavesicle complexes along the erythrocyte plasmalemma. We have produced a monoclonal antibody (MAb A 20) that identifies an antigen in Plasmodium vivax-infected erythrocytes that is associated with the caveola-vesicle complexes of the parasitized host cell. This monoclonal antibody reacts with air-dried P vivax-infected erythrocytes to produce a pattern by the indirect immunofluorescence test (IFT) that is evocative of Schüffner's dots. Immunoelectron microscopy of P vivax-infected human erythrocytes using MAb A 20 confirmed the location of this antigen within vesicles of caveola-vesicle complexes. On Western blots MAb A 20 recognized four polypeptides of 54, 64, 72, and 86 kd. MAb A 20 reacted by IFT with 90% of Sri Lankan isolates and with a Brazilian P vivax isolate, which indicates that the epitope identified by this monoclonal is conserved.
authors.affiliation: Department of Parasitology, Faculty of Medicine, University of Colombo, Sri Lanka Institute of Pathology.
authors.forename: P V
authors.initials: PV
authors.lastname: Udagama
authors.forename: C T
authors.initials: CT
authors.lastname: Atkinson
authors.forename: J S
authors.initials: JS
authors.lastname: Peiris
authors.forename: P H
authors.initials: PH
authors.lastname: David
authors.forename: K N
authors.initials: KN
authors.lastname: Mendis
authors.forename: M
authors.initials: M
authors.lastname: Aikawa
mesh_terms: D000818:Animals; D004912:Erythrocytes / Q000469:parasitology / Q000648:ultrastructure*; D005455:Fluorescent Antibody Technique; D006801:Humans; D008288:Malaria / Q000097:blood*; D008854:Microscopy, Electron / Q000379:methods; D010966:Plasmodium vivax / Q000302:isolation & purification