Immunotherapy as a strategy for treatment of leishmaniasis: a review of the literature

Leishmaniasis occurs as a spectrum of clinical syndromes divided into cutaneous, mucocutaneous and visceral forms. The epidemiology and clinical features are highly variable owing to the interplay of many factors ranging from parasite species and strains, vectors, host genetics and environment. Currently, there is no effective licensed vaccine for use in humans against leishmaniasis. Most traditional and low-cost treatment options, particularly in poor and endemic areas, are toxic with many adverse reactions and they require a long course of administration. The use of more effective, less toxic drugs is limited because total treatment cost is very high (expensive) and there are fears of development of drug resistance. Recent studies indicate that certain strategies aimed at modulating the host immune response (collectively called immunotherapy) could result in prophylactic and/or therapeutic cure of leishmaniasis under both laboratory and field conditions. In this review, we focus on treatment of leishmaniasis with a particular emphasis on immunotherapy/immunochemotherapy as an alternative to conventional drug treatment.