Application of immunofluorescence to detection of antibody in Leishmania infections.

Indirect immunofluorescence was used for determination of antibody in human cases of cutaneous leishmaniasis, mice infected with Leishmania tropica and guinea pigs infected with L. enriettii. Results indicated that antibody in mice is detectable 23 days after infection with L. tropica. The antibody titre correlates well with the extent of infection. In guinea pigs infected with L. enriettii, antibody appears much faster and is detectable 12 days after infection. Here also the antibody titre increased during the course of infection until about 76 days at which time the leishmanial lesion was at its height. Guinea pigs having metastatic lesions consistently showed a high titre of antibody. In several cases of human cutaneous leishmaniasis antibody was detectable at the titre of not more than 1/128. In five cases of suspected systemic leishmaniasis antibody titre was much greater than in cutaneous leishmanial infection. Upon characterization of anti-leishmanial serum of guinea pig with DEAE-cellulose chromatography and analysis of the fractions by immunoelectrophoresis, it was found that the antibody activity detected by the indirect immunofluorescence resided in the gamma2 portion of guinea pig globulin.