Recent developments leading toward a paradigm switch in the diagnostic and therapeutic approach to human leishmaniasis

Abstract

Purpose of review: To identify recent papers showing how human and parasite genetics influence leishmaniasis, and how understanding of the immunopathology may be utilized in immunotherapy for these diseases.

Recent findings: Progress has been made in recent years showing the complexity within populations of Leishmania spp. and indicating that different strains lead to diverse clinical pictures and responses to treatment. Thus detection of parasite genetic tags for the precise identification of infecting strains, and for predictive diagnosis of clinical and therapeutic fates seems now possible. Host genetic loci involved in disease outcome have been detected, which may also be explored for better case management. These developments in diagnosis will demand expanding the therapeutic arsenal to take their expected effect. This is starting to be fulfilled by immunotherapies successfully employed to treat cases refractory to standard first line drugs, as the result of a more profound comprehension of the immunopathology of the leishmaniases.

Summary: The knowledge mounting has already helped explain why different patients present different forms of leishmaniasis and respond differently to treatment, and may be on the verge of catalyzing a major change in the already over a century old paradigm of diagnosing and managing these patients.

Figure 1. Immunotherapy is a promising new tool in the arsenal to fight leishmaniasis

(a) Facial lesion of a disseminated leishmaniasis patient after the fourth consecutive course of standard treatment with intravenous Glucantime at 20 mg/kg of body weight for 30 days. (b) The same patient after a single course of Glucantime (20 mg/kg of body weight) as in (a), combined with oral pentoxifylline at 400 mg, three times a day for 30 days.