Leishmania tropica and Leishmania donovani: solid phase radioimmunoassay using leishmanial excreted factor.
A radioimmunoassay for the quantitative determination of anti-leishmanial excreted factor (EF) antibody in rabbit sera was developed. The assay, using Leishmania tropica and Leishmania donovani promastigotes EF, purified by either extraction with phenol followed by fractionation on a Sephadex G-100 column or by the dissociation of EF antibody complexes, was shown to be sensitive and reproducible. Using monospecific anti-EF antibodies, levels of as low as 0.06-0.12 micrograms/ml of anti-EF IgG could be detected. The specificity of the assay was assessed by inhibition with homologous and heterologous EF. Only minor cross-reactivity with heterologous EF was observed, and as little as 2.5 micrograms/ml of EF could be detected. Sera from kala-azar patients showed only 1.8-3.1 times more anti-EF activity, as compared with uninfected controls. No specificity was observed with sera from kala-azar patients with regard to the type of EF used. Almost the same activity was obtained with both EF from L. tropica and L. donovani. No anti-EF antibodies were detected in sera from patients with cutaneous leishmaniasis.
D000818:Animals; D000906:Antibodies / Q000032:analysis* / Q000302:isolation & purification; D000918:Antibody Specificity; D003429:Cross Reactions; D006801:Humans; D007891:Leishmania / Q000276:immunology* / Q000302:isolation & purification; D007896:Leishmaniasis / Q000276:immunology; D007898:Leishmaniasis, Visceral / Q000276:immunology; D011863:Radioimmunoassay / Q000379:methods*; D051381:Rats
D000906:Antibodies