Combination of topical liposomal amphotericin B and Glucantime in comparison with glucantime alone for the treatment of anthroponotic cutaneous leishmaniasis (ACL) caused by Leishmania tropica: study protocol for a randomized, controlled trial.

BACKGROUND AND OBJECTIVES: Cutaneous leishmaniasis (CL) treatment is a challenging issue, although numerous modalities have been introduced as candidate treatment for CL yet only antimonial agents are commonly used to treat CL, a different form of amphotericin B is used to treat visceral form of leishmaniasis but the efficacy against CL is not high. There are a few reliable clinical trials on CL, the main reason is the nature of the disease which required a well design protocol to evaluate the efficacy of any candidate treatment against CL. In this study, a protocol was developed and used to evaluate a topical formulation of a nano-liposomal form of amphotericin B in addition to glucantime to treat CL caused by L. tropica. MATERIALS AND METHODS: This study is a phase 3, randomized, double-blind, placebo-controlled trial to evaluate the efficacy and safety of topical nano-liposomal amphotericin B (SinaAmpholeish 0.4%) in combination with intralesional injections of meglumine antimoniate in the treatment of ACL caused by L. tropica. Overall, 130 patients, aged 12-60 years, with a diagnosis of ACL caused by L. tropica are recruited and treated according to the protocol. RESULTS: A total of 130 patients with CL lesion will be recruited and doubleblind randomly treated with received intralesional injections of Glucantime weekly or Glucantime plus SinaAmpholeish for 4 weeks. CONCLUSION: The results of this study showed that the protocol works well and the treatment was tolerated by both groups of patients.

Evolution of antigen-specific immune responses in cutaneous leishmaniasis patients.

AIMS: Despite immunization appearing to be the most appropriate strategy for long-term control of the vector-borne leishmaniases, no sustainable vaccine is currently available against any form of leishmaniasis. We therefore evaluated, in the context of vaccine antigen candidates, antigen-specific immune response at various stages of cutaneous leishmaniasis (CL). METHODS AND RESULTS: Peripheral blood mononuclear cells (PBMC) isolated from healthy volunteers and CL patients (caused by either Leishmania major or L tropica) were incubated with crude Leishmania proteins (soluble Leishmania antigen; SLA), single recombinant proteins (TSA, LeIF, LmSTI1) or chimeric fusion proteins (LEISH-F2 and LEISH-F3). The concentrations of immune modulatory cytokines were then determined. While we did not detect appreciable antigen-specific IL-5 secretion, SLA induced secretion of interleukin (IL)-10 in cultures from early active lesion CL patients and even from healthy individuals. Conversely, interferon (IFN)-γ responses to SLA and recombinant proteins followed a similar pattern, developing only in the late active CL lesion phase. Once established, antigen-specific IFN-γ responses persisted in cured CL patients. CONCLUSION: Together, our results provide further insight into the development of immune responses during CL and further validate the selection of LEISH-F2 and LEISH-F3 as vaccine antigen candidates.

Development of a topical liposomal formulation of Amphotericin B for the treatment of cutaneous leishmaniasis.

BACKGROUND: Currently, there is no topical treatment available for any form of cutaneous leishmaniasis (CL) in most of the endemic areas. The aim of the current study was to develop a topical nano-liposomal Amphotericin B (AmB) for the treatment of CL. METHODOLOGY/PRINCIPAL FINDINGS: Liposomes containing 0.1, 0.2 and 0.4% AmB (Lip-AmB) were formulated and characterized for the size, entrapment efficiency, long term stability, and skin penetration properties using Franz diffusion cells. Liposomes diameters were around 100 nm with no change during more than 20 months' storage either at 4 °C or at room temperature. Franz diffusion cells studies showed that almost 4% of the applied formulations penetrated across the skin and the highest skin retention (73.92%) observed with Lip-AmB 0.4%. The median effective doses (ED50), the doses of AmB required to kill 50% of L. major amastigotes were 0.151, 0.151, and 0.0856 (µg/mL) in Lip-AmB 0.1, 0.2, 0.4%, respectively. Lip-AmB 0.4% caused 80% reduction in fluorescence intensity of GFP+ L. tropica infected macrophages at 5 µg/mL of AmB concentration. Topical Lip-AmB was applied twice a day for 4 weeks to the skin of BALB/c mice to treat lesions caused by L. major. Results showed the superiority of Lip-AmB 0.4% compared to Lip-AmB 0.2 and 0.1%. The parasite was completely cleared from the skin site of infection and spleens at week 8 and 12 post-infection in mice treated with Lip-AmB 0.4%. The results suggest that topical Lip-AmB 0.4% may be a useful tool in the treatment of CL and merits further investigation.

Comparison of cytokine profile of IFN-γ, IL-5 and IL-10 in cutaneous leishmaniasis using PBMC vs. whole blood.

BACKGROUND AND OBJECTIVES: The surrogate marker (s) of cure and protection in intracellular pathogens is not yet well defined. The aim of this study was to compare the cytokine profile using whole blood cells (WBC) vs. peripheral blood mononuclear cells (PBMC) in healthy and cutaneous leishmaniasis (CL) volunteers. MATERIALS AND METHODS: In this study, WBC and PBMC of the volunteers with history of CL (HCL), Active lesion (ACL) and healthy volunteers were collected. The WBC and PBMC were cultured and stimulated with either PHA or soluble Leishmania antigens (SLA), after 72 hours, the supernatants were collected and the levels of IFN-γ, IL-5 and IL-10 were titrated using ELISA method. RESULTS: The mean ± SD of cytokines using WBC and PBMC in cutaneous leishmaniasis volunteers stimulated with phytohemagglutin (PHA) or SLA are as follow, PHA, IFN-γ=2295±995 vs. 2339±1115, IL-10=853±309 vs. 1330±966, and IL-5=299±136 vs. 352+156, SLA, IFN-γ, 931±824 vs. 825±532, IL-10, 233±78 vs. 408±381, and IL-5, 185±59 vs. 217±76, respectively. There was no significant difference between the IFN-γ, IL-5 and IL-10 levels using WBC vs. PBMC. There was a strong correlation between the cytokine profiles using WBC and PBMC in cutaneous leishmaniasis volunteers. CONCLUSION: There was no significant difference between IFN-γ, IL-10, IL-5 levels in whole blood and PBMC of volunteers with active lesion or history of CL. Whole-blood culture which is easier, cheaper and more convenient could be used instead of PBMC to evaluate the cytokine profile in field conditions.