Profiles of Entamoeba histolytica-specific immunoglobulins in human sera.
OBJECTIVE
To determine the profiles of anti-Entamoeba histolytica (E. histolytica) IgA, IgG, and IgM in sera of diarrheic and non-diarrheic individuals and partially characterize target antigens.


METHODS
Serum samples from thirty diarrheic and thirty non-diarrheic individuals were subjected to IgA, IgG, and IgM profiling through enzyme-linked immunosorbent assay (ELISA), flow cytometry, and immunoblot.


RESULTS
ELISA titer results showed that both diarrheic and non-diarrheic individuals possess high levels of E. histolytica-specific IgG compared to IgA and IgM. Flow cytometry data showed that diarrheic serum samples had higher mean reaction percentages against E. histolytica cells compared to non-diarrheic samples. Immunoreactive E. histolytica proteins with molecular weights ranging between 7 kDa and 292 kDa were recognized by diarrheic serum IgG, and 170 kDa and 250 kDa by non-diarrheic serum IgG.


CONCLUSIONS
Our findings suggest that serum anti-E. histolytica IgG, compared with serum anti-E. histolytica IgA and IgM responses, was generally high in both diarrheic and non-diarrheic sera, indicating a past exposure to the organism both in symptomatic patients as well as in asymptomatic carriers, respectively. In addition, serum IgG from diarrheic and non-diarrheic patients were able to detect immunogenic E. histolytica proteins.
Institute of Biology, College of Science, University of the Philippines, Diliman, Quezon City, Philippines. wlrivera@science.upd.edu.ph
Windell L
WL
Rivera
Herbert J
HJ
Santos
Vanissa A
VA
Ong
Lara Jessica G
LJ
Murao
D000328:Adult; D000913:Antibodies, Protozoan / Q000097:blood*; D003967:Diarrhea / Q000276:immunology*; D004748:Entamoeba histolytica / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D015151:Immunoblotting; D007070:Immunoglobulin A / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D007136:Immunoglobulins / Q000097:blood*; D008297:Male
D000913:Antibodies, Protozoan; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007136:Immunoglobulins