Monoclonal antibodies that distinguish between New World species of Leishmania

Abstract

The New World Leishmania species¹ Leishmania braziliensis, which causes mucocutaneous leishmaniasis, can be distinguished from Leishmania mexicana, which causes cutaneous leishmaniasis, by the buoyant density of nuclear and kinetoplast DNA², electrophoretic mobility of different isoenzymes^3–6, by differing characteristic growth patterns in the sandfly and hamster and in vitro^7,8, and by size in electron microscopy^9,10. However, there is no available method for rapid and accurate diagnosis of fresh isolates of New World leishmaniasis species. Furthermore, immunological cross-reaction of Leishmania with Trypanosoma cruzi, which is co-endemic with the former, has posed a serious problem in the use of serodiagnostic tests for leishmaniasis^11–13. The ability to distinguish at primary isolation between the species causing cutaneous and mucocutaneous leishmaniasis would make it possible to concentrate on treating those patients likely to suffer serious disfiguring disease. To develop such a specific diagnostic test, we have produced monoclonal antibodies¹⁴ specific for either the L. mexicana or L. braziliensis species. One of these monoclonal antibodies is specific for a subgroup of L. braziliensis; none is cross-reactive with T. cruzi (Y strain) epimastigotes. These monoclonal antibodies should be useful in the taxonomic identification of different species of New World leishmaniae as well as for the direct diagnosis of leishmaniasis.