title: Diagnosis of invasive amebiasis by enzyme-linked immunosorbent assay of saliva to detect amebic lectin antigen and anti-lectin immunoglobulin G antibodies.
abstract: Saliva from subjects with amebic liver abscess (ALA), acute amebic colitis, asymptomatic infection with Entamoeba histolytica or Entamoeba dispar, and uninfected controls was tested by enzyme-linked immunosorbent assay (ELISA) for the presence of E. histolytica galactose-inhibitable lectin antigen and salivary immunoglobulin (IgG) antibodies to a recombinant cysteine-rich lectin-derived protein (LC3). Salivary lectin antigen was found in 65.8% of subjects with acute colitis, compared to 22.2% of those convalescent from ALA, 10.0% with asymptomatic E. histolytica infection, 9.8% with E. dispar infection, and 2.6% of controls (subjects from the United States and study patients with nonamebic diarrhea) (P < 0.001 for each compared to values for subjects with colitis). Salivary anti-LC3 IgG antibodies were found in 92% of ALA patients regardless of duration of illness and in 83.3% of colitis patients who were symptomatic for at least 7 days (P < 0.001 compared to other study groups). Serum anti-LC3 IgG antibodies were detected in 56.3% of subjects with acute colitis, 100% of subjects with ALA or prolonged colitis, 45% of subjects with asymptomatic E. histolytica infection, 32.3% of subjects with E. dispar infection, and 23.4% of diarrhea controls. In comparison to ELISA for serum anti-LC3 IgG antibodies, the salivary lectin antigen assay is a more sensitive and specific test for acute amebic colitis. Detection of salivary anti-LC3 IgG antibodies by ELISA is an effective means for the diagnosis of ALA and prolonged cases of amebic colitis.
authors.affiliation: El-Hussein University Hospital, Cairo, Egypt.
authors.forename: M D
authors.initials: MD
authors.lastname: Abd-Alla
authors.forename: T F
authors.initials: TF
authors.lastname: Jackson
authors.forename: S
authors.initials: S
authors.lastname: Reddy
authors.forename: J I
authors.initials: JI
authors.lastname: Ravdin
mesh_terms: D000913:Antibodies, Protozoan / Q000302:isolation & purification; D000953:Antigens, Protozoan / Q000302:isolation & purification; D002353:Carrier State; D003937:Diagnosis, Differential; D004404:Dysentery, Amebic / Q000175:diagnosis; D004749:Entamoebiasis / Q000175:diagnosis*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D006801:Humans; D007074:Immunoglobulin G / Q000302:isolation & purification; D037102:Lectins / Q000276:immunology*; D008101:Liver Abscess, Amebic / Q000175:diagnosis; D008562:Membrane Glycoproteins / Q000276:immunology*; D011237:Predictive Value of Tests; D015800:Protozoan Proteins / Q000276:immunology*; D012463:Saliva / Q000276:immunology*; D012680:Sensitivity and Specificity
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D007074:Immunoglobulin G; D037102:Lectins; D008562:Membrane Glycoproteins; D015800:Protozoan Proteins; C052452:galactose inhibitable adherence protein, Entamoeba histolytica