IN-VIVO EVALUATION OF IMMUNE-RESPONSES IN LEISHMANIASIS - THE USE OF CROSS-SPECIES LEISHMANIN PREPARATIONS FOR SKIN TESTING

Skin test reactivity to two commercial preparations of Leishmania majo r leishmanin was evaluated in leishmaniasis patents from Ethiopia (L. aethiopica) and Nicaragua (probably L. braziliensis complex). The purp ose of using different preparations of L. major was to evaluate whethe r L. major skin test antigens could generally be used to detect leishm aniasis due to L. aethiopica and L. braziliensis. One preparation was superior in identifying the majority (83-90%) of confirmed cases of lo cal cutaneous leishmaniasis (LCL) from Ethiopia. In vitro responses to promastigotes of Leishmania spp. correlated well with leishmanin posi tivity to this preparation. The skin test antigen, which performed les s well (showing a positive result in only 50% of the LCL patents), sho wed promise when used to test active and cured cases of leishmaniasis in Nicaragua (positive result in 92% of the active and cured patents). Cross-reacting Leishmania spp. may be considered for use in the prepa ration of standardized leishmanin antigen; however, differences in the commercial preparation or the diluent in which the parasites are prep ared may affect antigenicity and thus its efficacy in detecting differ ent forms of leishmaniasis in different geographic areas.