Entamoeba histolytica: fecal antigen capture immunoassay for the diagnosis of enteric amebiasis by a monoclonal antibody.
Amebiasis continues to be of epidemiological importance in underdeveloped countries. Clinical diagnosis and epidemiological setting in a region are based on the fecal microscopic identification of cysts or trophozoites. This procedure requires well trained personnel, is laborious, of low sensitivity and frequently yields false-positives results. The present study was designed to develop an immunoenzymatic fecal 96 kDa antigen capture test (COPROELISA-Eh) more sensitive and specific than microscopic diagnosis of amebiasis. Triplicates of 177 stool samples processed by the formol-ether concentration method, were defined as positive or negative by three experienced microscopic observers. Another aliquot was submitted to the antigen capture test by a monoclonal antibody against a specific membrane antigen of pathogenic strains of Entamoeba histolytica. Optical densities were interpreted as positive when they exceeded the mean value of negative samples plus two standard deviations. COPROELISA-Eh showed a 94.4% sensitivity, 98.3% specificity, 96.2% positive predictive value and 97.6% negative predictive value for the detection of E. histolytica in feces. COPROELISA-Eh is more sensitive and specific than microscopic examination, does not require specially trained personnel and allows the simultaneous processing of a large number of samples.
Urdaneta
H
H
Institute of Clinical Immunology, Los Andes University, Venezuela. uhaydee@ing.ula.ve
Rangel
A
A
Martins
M S
MS
Muñoz
J F
JF
Hernández
M
M
D000704:Analysis of Variance; D000818:Animals; D000911:Antibodies, Monoclonal / Q000032:analysis; D000953:Antigens, Protozoan / Q000032:analysis; D016009:Chi-Square Distribution; D004748:Entamoeba histolytica / Q000276:immunology* / Q000302:isolation & purification / Q000472:pathogenicity; D004749:Entamoebiasis / Q000175:diagnosis*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005243:Feces / Q000469:parasitology; D006801:Humans; D007124:Immunoenzyme Techniques; D051379:Mice; D008807:Mice, Inbred BALB C; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D014774:Virulence
D000911:Antibodies, Monoclonal; D000953:Antigens, Protozoan