title: Secretory immunoglobulin A antibodies to the galactose-inhibitable adherence protein in the saliva of patients with amebic liver disease.
abstract: Monoclonal antibodies directed against the 260-kD galactose-inhibitable adherence protein (GIAP) of Entamoeba histolytica inhibit binding of amebic trophozoites to purified colonic mucins, suggesting that anti-GIAP secretory immunoglobulin A (sIgA) may have a role in host defense in invasive amebiasis. We determined by enzyme-linked immunosorbent assay (ELISA) whether a salivary anti-GIAP sIgA response was present in patients from the Republic of South Africa with invasive E. histolytica infection. In 13 patients with amebic liver abscess (ALA), salivary anti-GIAP sIgA was significantly higher (mean +/- SD optical density [OD] = 0.448 +/- 0.258) than that determined for seven South African adult patients hospitalized with nonamebic illness (0.084 +/- 0.072; P = 0.002), seven healthy South African Adults (0.194 +/- 0.119: P = 0.025), and seven healthy adults from Charlottesville, Virginia (0.036 +/- 0.023; P = 0.004). Of the patients with ALA, nine had acute disease, and four had been cured of amebiasis 2-8 months previously. There was no significant difference between these two groups in the anti-GIAP sIgA levels. All ALA patients had a high titer serum anti-amebic antibody response, and there was no direct correlation between the level of anti-GIAP salivary IgA and anti-GIAP serum antibodies (R = 0.187). These findings demonstrate that the E. histolytica GIAP is a mucosal antigen in naturally occurring invasive E. histolytica infection.
authors.affiliation: Department of Medicine, University of Virginia, Charlottesville.
authors.forename: B L
authors.initials: BL
authors.lastname: Kelsall
authors.forename: T G
authors.initials: TG
authors.lastname: Jackson
authors.forename: V
authors.initials: V
authors.lastname: Gathiram
authors.forename: S B
authors.initials: SB
authors.lastname: Salig
authors.forename: M
authors.initials: M
authors.lastname: Vaithilingum
authors.forename: R D
authors.initials: RD
authors.lastname: Pearson
authors.forename: J I
authors.initials: JI
authors.lastname: Ravdin
mesh_terms: D000328:Adult; D000818:Animals; D000953:Antigens, Protozoan / Q000276:immunology; D002448:Cell Adhesion; D002648:Child; D004748:Entamoeba histolytica / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D005779:Immunodiffusion; D007071:Immunoglobulin A, Secretory / Q000032:analysis*; D007074:Immunoglobulin G / Q000097:blood; D008101:Liver Abscess, Amebic / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D015800:Protozoan Proteins / Q000276:immunology*; D012463:Saliva / Q000276:immunology*; D012680:Sensitivity and Specificity; D013019:South Africa
chemical_list: D000953:Antigens, Protozoan; D007071:Immunoglobulin A, Secretory; D007074:Immunoglobulin G; D015800:Protozoan Proteins