Reduced false positive reactions in the Dot-enzyme-linked immunosorbent assay for human visceral leishmaniasis.
Specificity of the Dot-enzyme-linked immunosorbent assay (Dot-ELISA) for visceral leishmaniasis was significantly improved through the use of enzyme-conjugated antisera specific for IgG heavy chains. Of sera from Kenyans with visceral leishmaniasis, 97% (29/30) were positive using horseradish peroxidase (HRP)-conjugated anti-IgG (heavy and light chain specific) which detected bound IgG and IgM. False positive reactions occurred in 80% of sera from both trypanosomiasis-infected patients (8/10) and apparently healthy Africans (24/30). HRP-conjugated anti-IgG (heavy chain specific), which detected only bound IgG, significantly reduced false positive reactions among trypanosomiasis-infected (2/10, P less than 0.02) and healthy Africans (6/30, P less than 0.001), without reducing test sensitivity in leishmaniasis patients. No false positives occurred when either HRP-conjugated antiserum was used to assay sera from 30 North Americans. Application of enzyme-conjugated antisera specific for IgG improves the serodiagnostic value of the Dot-ELISA for individual patient evaluation and epidemiologic investigations.
D000293:Adolescent; D000918:Antibody Specificity; D004797:Enzyme-Linked Immunosorbent Assay; D005189:False Positive Reactions; D006801:Humans; D007124:Immunoenzyme Techniques; D007074:Immunoglobulin G / Q000032:analysis; D007143:Immunoglobulin Heavy Chains; D007075:Immunoglobulin M / Q000032:analysis; D007898:Leishmaniasis, Visceral / Q000175:diagnosis / Q000276:immunology*; D014353:Trypanosomiasis, African / Q000276:immunology
D007074:Immunoglobulin G; D007143:Immunoglobulin Heavy Chains; D007075:Immunoglobulin M