Quantitative estimation of leishmanial antibody titers by enzyme-linked immunosorbent assay.
The response to immunization against Leishmania braziliensis in rabbits was followed by measurement of antibody by enzyme-linked immunosorbent assay (ELISA), passive hemagglutination, complement fixation, and countercurrent immunoelectrophoresis. Passive hemagglutination and complement-fixation titers were interpreted according to standard methods, whereas ELISA exact titers were derived by the equation Y = a-b log X, which describes the straight line that results when absorbances are plotted against test serum dilutions. Peak titer was measured at 32 +/- 1 days after initial injection, irrespective of the assay method. After seven days, the reciprocal antibody titer was 1,130 by ELISA, 0 by passive hemagglutination, and 8 by complement fixation. Precipitin bands were shown by countercurrent immunoelectrophoresis only at peak titer. With sera from hamsters experimentally infected with Leishmania, 94% showed leishmanial antibody by ELISA, compared with 92% by complement fixation and 65% by passive hemagglutination. When 31 samples of sera from human patients with cutaneous leishmaniasis were tested only by ELISA, 23 were positive for leishmanial antibodies.
D000818:Animals; D000906:Antibodies / Q000032:analysis*; D003168:Complement Fixation Tests; D003378:Counterimmunoelectrophoresis; D006224:Cricetinae; D004797:Enzyme-Linked Immunosorbent Assay; D006386:Hemagglutination Tests; D006801:Humans; D007124:Immunoenzyme Techniques; D007891:Leishmania / Q000276:immunology*; D007896:Leishmaniasis / Q000175:diagnosis / Q000276:immunology*
D000906:Antibodies