Mucosal leishmaniasis unresponsive to glucantime therapy successfully treated with AmBisome

Emulgel-loaded mannosylated thiolated chitosan-coated silver nanoparticles for the treatment of cutaneous leishmaniasis

Topical treatment of cutaneous leishmaniasis holds great promise for decreasing drug associated side effects and improving efficacy. This study was aimed to develop mannosylated thiolated chitosan-coated silver nanoparticles (MTCAg) loaded emulgel for the treatment of cutaneous leishmaniasis. MTC-Ag were synthesized via a chemical reduction method and were loaded into the emulgel. The nanoparticles had a zeta potential of +19.8 mV, an average particle size of 115 nm and a narrow polydispersity index of 0.26. In-vitro release profiles showed controlled release of silver ions from both the MTC-Ag and the emulgel-loaded MTC-Ag nanoparticles after 24 h. An ex-vivo retention study indicated 5 times higher retention of silver by the emulgel-loaded MTC-Ag than by the MTC-Ag nanoparticles. The in-vitro anti-leishmanial assay revealed that MTC-Ag had an excellent inhibitory effect on intracellular amastigotes, leading to ~90 % inhibition at the highest concentration tested. A 4-fold reduction in the IC₅₀ value was found for MTC-Ag compared to blank Ag nanoparticles. Cytotoxicity assay showed 83 % viability of macrophages for MTC-Ag and 30 % for Ag nanoparticles at a concentration of 80 μg/mL, demonstrating the improved biocompatibility of the polymeric nanoparticles. Drug release and retention studies corroborate the great potential of MTC-Ag-loaded emulgel for the treatment of cutaneous leishmaniasis.

Cutaneous Leishmaniasis: A 2022 Updated Narrative Review into Diagnosis and Management Developments

This review is an update of an earlier narrative review published in 2015 on developments in the clinical management of cutaneous leishmaniasis (CL) including diagnosis, treatment, prevention and control measurements. CL is a vector-borne infection caused by the protozoan parasite Leishmania. The vector is the female sandfly. Globally, CL affects 12 million cases and annually 2 million new cases occur. CL is endemic in almost 100 countries and the total risk population is approximately 350 million people. WHO lists CL an emerging and uncontrolled disease and a neglected tropical disease. Local experience-based evidence remains the mainstay for the management of CL. Whereas intralesional therapeutic options are the first treatment option for most CL patients, those with mucocutaneous and disseminated involvement require a systemic therapeutic approach. Moreover, different Leishmania species can vary in their treatment outcomes. Therefore, species determination is critical for optimal CL clinical management. New DNA techniques allow for relatively easy Leishmania species determination, yet they are not easily implemented in resource-limited settings. There is a desperate need for novel, less toxic, and less painful treatment options, especially for children with CL. Yet, the large and well conducted studies required to provide the necessary evidence are lacking. To further control and potentially eliminate CL, we urgently need to improve vector control, and diagnostics, and we require efficient and safe vaccines. Alas, since CL primarily affects poor people, biotechnical companies dedicate little investment into the research programs that could lead to diagnostic, pharmaceutical, and vaccine innovations.

Comparative study on liposomal amphotericin B and other therapies in the treatment of mucosal leishmaniasis: A 15-year retrospective cohort study

Background

Liposomal amphotericin B (L-AMB) has been used for mucosal leishmaniasis (ML), but comparative studies on L-AMB and other drugs used for the treatment of ML have not been conducted. The present study aimed to evaluate the outcome of patients with ML who were treated with L-AMB.

Methods

This is a 15-year retrospective study of Brazilian patients with a confirmed diagnosis of ML. The therapeutic options for the treatment of ML consisted of L-AMB, amphotericin B lipid complex (ABLC), deoxycholate amphotericin B (d-AMB), itraconazole, antimonial pentavalent, or pentamidine. Healing, cure rate and adverse effects (AEs) associated with the drugs used to treat this condition were analyzed.

Results

In 71 patients, a total of 105 treatments were evaluated. The outcome of the treatment with each drug was compared, and results showed that L-AMB was superior to other therapeutic regimens (P = 0.001; odds ratio [OR] = 4.84; 95% confidence interval [CI] = 1.78–13.17). d-AMB had worse AEs than other treatment regimens (P = 0.001, OR = 0.09; 95% CI = 0.09–0.43). Approximately 66% of the patients presented with AEs during ML treatment. Although L-AMB was less nephrotoxic than d-AMB, it was associated with acute kidney injury compared with other drugs (P <0.05).

Conclusion

L-AMB was more effective than other therapies for the treatment of ML. However, a high incidence of toxicity was associated with its use. Therapeutic choices should be reassessed, and the development of new drugs is necessary for the treatment of ML.

Intraspecies differences in natural susceptibility to amphotericine B of clinical isolates of Leishmania subgenus Viannia

Amphotericin B (AmB) is a recommended medication for the treatment of cutaneous and mucosal leishmaniasis in cases of therapeutic failure with first-line medications; however, little is known about the in vitro susceptibility to AmB of clinical isolates of the subgenus Viannia, which is most prevalent in South America. This work aimed to determine the in vitro susceptibility profiles to AmB of clinical isolates of the species L. (V.) panamensis, L. (V.) guyanensis and L. (V.) braziliensis. In vitro susceptibility to AmB was evaluated for 65 isolates. Macrophages derived from the U937 cell line were infected with promastigotes and exposed to different AmB concentrations. After 96 hours, the number of intracellular amastigotes was quantified by qPCR, and median effective concentration (EC₅₀) was determined using the PROBIT model. The controls included sensitive strains and experimentally derived less sensitive strains generated in vitro, which presented EC₅₀ values up to 7.57-fold higher than the values of the sensitive strains. The isolates were classified into groups according to their in vitro susceptibility profiles using Ward’s hierarchical method. The susceptibility to AmB differed in an intraspecies-specific manner as follows: 28.21% (11/39) of L. (V.) panamensis strains, 50% (3/6) of L. (V.) guyanensis strains and 34.61% (9/26) of L. (V.) braziliensis strains were classified as less sensitive. The latter subset featured three susceptibility groups. We identified Colombian isolates with different AmB susceptibility profiles. In addition, the capacity of species of subgenus Viannia to develop lower susceptibility to AmB was demonstrated in vitro. These new findings should be considered in the pharmacovigilance of AmB in Colombia and South America.

Efficacy and Safety of Liposomal Amphotericin B for the Treatment of Mucosal Leishmaniasis from the New World: A Retrospective Study

The standard treatment of mucosal leishmaniasis (ML) is pentavalent antimonials, agents with serious adverse effects. Alternative agents include amphotericin B deoxycholate and liposomal amphotericin B. We performed a retrospective study including 29 patients treated with liposomal amphotericin B, most of whom had comorbidities, history of previous treatment of ML, and contraindications to the use of antimonial pentavalent or amphotericin B deoxycholate. We observed a cure rate of 93.1%. Kidney failure was the most important side effect, reported in five patients (17.2%). This study showed a good efficacy and safety profile of liposomal amphotericin B in patients with ML and contraindications to the use of other agents.

Cutaneous leishmaniasis: recent developments in diagnosis and management

This review focuses on recent developments in the diagnosis, treatment, management, and strategies for the prevention and control of cutaneous leishmaniasis (CL) caused by both Old and New World Leishmania species. CL is caused by the vector-borne protozoan parasite Leishmania and is transmitted via infected female sandflies. The disease is endemic in more than 98 countries and an estimated 350 million people are at risk. The overall prevalence is 12 million cases and the annual incidence is 2–2.5 million. The World Health Organization considers CL a severely neglected disease and a category 1 emerging and uncontrolled disease. The management of CL differs from region to region and is primarily based on local experience-based evidence. Most CL patients can be treated with topical treatments, but some Leishmania species can cause mucocutaneous involvement requiring a systemic therapeutic approach. Moreover, Leishmania species can vary in their sensitivity to available therapeutic options. This makes species determination critical for the choice of treatment and the clinical outcome of CL. Identification of the infecting parasite used to be laborious, but now the Leishmania species can be identified relatively easy with new DNA techniques that enable a more rational therapy choice. Current treatment guidelines for CL are based on poorly designed and reported trials. There is a lack of evidence for potentially beneficial treatments, a desperate need for large well-conducted studies, and standardization of future trials. Moreover, intensified research programs to improve vector control, diagnostics, and the therapeutic arsenal to contain further incidence and morbidity are needed.

Cutaneous leishmaniasis in Cuban immigrants to Texas who traveled through the Darién Jungle, Panama

Cutaneous leishmaniasis is rarely seen in the United States. Four Cuban immigrants traveled along the same route at different times from Cuba to Ecuador, then northward, including through the Darién Jungle in Panama. These patients had chronic ulcerative non-healing skin lesions and were given a diagnosis of leishmaniasis.

Species-directed therapy for leishmaniasis in returning travellers: a comprehensive guide

Background

Leishmaniasis is increasingly reported among travellers. Leishmania species vary in sensitivity to available therapies. Fast and reliable molecular techniques have made species-directed treatment feasible. Many treatment trials have been designed poorly, thus developing evidence-based guidelines for species-directed treatment is difficult. Published guidelines on leishmaniasis in travellers do not aim to be comprehensive or do not quantify overall treatment success for available therapies. We aimed at providing comprehensive species-directed treatment guidelines.

Methodology/Principal Findings

English literature was searched using PubMed. Trials and observational studies were included if all cases were parasitologically confirmed, the Leishmania species was known, clear clinical end-points and time points for evaluation of treatment success were defined, duration of follow-up was adequate and loss to follow-up was acceptable. The proportion of successful treatment responses was pooled using mixed effects methods to estimate the efficacy of specific therapies. Final ranking of treatment options was done by an expert panel based on pooled efficacy estimates and practical considerations. 168 studies were included, with 287 treatment arms. Based on Leishmania species, symptoms and geography, 25 clinical categories were defined and therapy options ranked. In 12/25 categories, proposed treatment agreed with highest efficacy data from literature. For 5/25 categories no literature was found, and in 8/25 categories treatment advise differed from literature evidence. For uncomplicated cutaneous leishmaniasis, combination of intralesional antimony with cryotherapy is advised, except for L. guyanensis and L. braziliensis infections, for which systemic treatment is preferred. Treatment of complicated (muco)cutaneous leishmaniasis differs per species. For visceral leishmaniasis, liposomal amphotericin B is treatment of choice.

Conclusions/Significance

Our study highlights current knowledge about species-directed therapy of leishmaniasis in returning travellers and also demonstrates lack of evidence for treatment of several clinical categories. New data can easily be incorporated in the presented overview. Updates will be of use for clinical decision making and for defining further research.

Human leishmaniasis is caused by unicellular parasites that are injected into the skin by sand-flies, small, flying insects. Many different Leishmania species cause various manifestations of disease, both of the skin and internal organs. Leishmaniasis is a curable disease but clear guidelines on the best available treatment are lacking. Leishmania species differ in sensitivity to available drugs. Until recently, identification of the infecting Leishmania parasite was laborious, thus therapy could not precisely be targeted to the infecting species, in contrast to many other infectious diseases. Nowadays, Leishmania parasites can be identified relatively easily with new DNA techniques. We studied efficacy of therapies for diseases due to different Leishmania species, limited to the English literature. Efficacy was summarized and presented in an easy to read format. Because of difficulties with identification of parasite species in earlier studies, quality of evidence was often limited. Our findings are a major help for clinicians to easily find optimal treatment for specific patients. Moreover, our results demonstrate where additional research is needed to further improve treatment of leishmaniasis.

Novel low-cost thermotherapy for cutaneous leishmaniasis in Peru

Thermotherapy is an accepted alternative therapy for new-world cutaneous leishmaniasis, but current heat-delivery modalities are too costly to be made widely available to endemic populations. We adapted a low-cost heat pack named the HECT-CL device that delivers safe, reliable, and renewable conduction heat. 25 patients with cutaneous leishmaniasis completed treatment with the device at an initial temperature of 52°C ± 2°C for 3 minutes to each lesion, repeated daily for 7 days, and were followed up for 6 months by direct observation. The overall definitive clinical cure rate was 60%. Concurrently, 13 patients meeting minimally significant exclusion criteria received identical compassionate use treatment with a cumulative definitive cure rate of 68.4%, 75% for those who had experienced CL relapse after prior antimonial treatment. Therapy was well tolerated. Reversible second-degree burns occurred in two patients and no bacterial super-infections were observed. HECT-CL is a promising treatment and deserves further study to verify its safety and efficacy as adjuvant and mono- therapy.

Leishmaniasis chemotherapy--challenges and opportunities

Although there have been significant advances in the treatment of visceral leishmaniasis (VL), there remain challenges to ensure that treatments effective in India are also effective in other regions of the world and to identify treatment for post kala-azar dermal leishmaniasis as well as the opportunity to develop a safe oral short-course treatment. At the same time, there have been few advances for the treatment of simple or complex forms of cutaneous leishmaniasis (CL), other than topical paromomycin formulations. The main challenge for CL is to ensure that this disease is on the research and development agenda, so that new drugs are evaluated or compounds are screened in appropriate models, and that the standardization of quality of clinical trials is guaranteed. Problems also remain in the treatment of HIV/leishmaniasis co-infected patients. We are some way from having the ideal treatments for VL and CL and drug research and development for these diseases must remain focused.

Can we use a lower dose of liposomal amphotericin B for the treatment of mucosal American leishmaniasis?

Liposomal amphotericin B has been used as an alternative treatment of mucosal leishmaniasis, but the optimal dose is not established. We retrospectively reviewed the clinical outcome of eight patients with mucosal leishmaniasis treated with liposomal amphotericin B. The mean total dose was 35 mg/kg (range 24-50 mg/kg), which resulted in the healing of all the lesions in all patients and no recurrences were observed during the follow-up period (mean 25 months; range 7-40 months).

A cluster of cutaneous leishmaniasis associated with human smuggling

Cutaneous leishmaniasis (CL) is rarely seen in the United States, and the social and geographic context of the infection can be a key to its diagnosis and management. Four Somali and one Ethiopian, in U.S. Border Patrol custody, came to the United States by the same human trafficking route: Djibouti to Dubai to Moscow to Havana to Quito; and then by ground by Columbia/Panama to the United States-Mexico border where they were detained. Although traveling at different times, all five patients simultaneously presented to our institution with chronic ulcerative skin lesions at different sites and stages of evolution. Culture of biopsy specimens grew Leishmania panamensis. Soon thereafter, three individuals from East Africa traveling the identical route presented with L. panamensis CL to physicians in Tacoma, WA. We document here the association of a human trafficking route and new world CL. Clinicians and public health officials should be aware of this emerging infectious disease risk.

A pilot study comparing low-dose liposomal amphotericin B with N-methyl glucamine for the treatment of American cutaneous leishmaniasis

BACKGROUND

Cutaneous leishmaniasis is an infectious re-emerging disease that has increased in incidence worldwide. Antimony, a highly toxic drug, remains the first choice therapy to treat it. Liposomal amphotericin B is active against Leishmania and is less toxic than antimony.

OBJECTIVE

To compare low-dose liposomal amphotericin B with N-methyl glucamine for the treatment of American cutaneous leishmaniasis.

PATIENTS/METHODS

In a controlled open-label trial 35 patients with a localized form of American cutaneous leishmaniasis were included. They were allocated to a first group treated with 1.5 mg/kg/day of liposomal amphotericin B for 5 days, or to a second one treated with 20 mgSbV/kg/day of N-methyl glucamine for 20 days.

RESULTS

In the first group, 50% and 81% of patients experienced a clinical cure and clinical improvement respectively. There was a 100% clinical cure in the second group.

CONCLUSION

Liposomal amphotericin B seems to be promising and safe for the treatment of American cutaneous leishmaniasis.

Cutaneous and mucocutaneous leishmaniasis

Leishmaniasis is a cluster of diseases caused by protozoa in the genus Leishmania. There are three basic clinical forms: cutaneous, mucocutaneous, and visceral leishmaniasis. The present review focuses on the diagnosis and treatment of cutaneous and mucocutaneous leishmaniasis. Characteristics of both the human host and the parasite species influence the clinical disease manifestations that range from asymptomatic exposure, to self-healing skin ulcers, to life-threatening widespread destructive ulcerations. Whether through medical treatment or through spontaneous resolution, skin ulcerations generally result in disfiguring scars with significant social and economic impact. Tests to confirm the diagnosis should be performed on patients who have recently visited endemic areas and have skin or mucosal manifestations consistent with leishmaniasis. Treatment depends on the species of Leishmania and the risk of widespread or disfiguring disease. Because of increasing trends in global travel, educating health care providers to recognize and treat leishmaniasis in both endemic and non-endemic countries is imperative.

Mucosal leishmaniasis . Current scenario and prospects for treatment

Leishmaniasis causes significant morbidity and mortality and thus constitutes a serious public health problem. Even though it has long been endemic in developing countries, in recent years the economic globalization and the increased volume of international travel have extended its prevalence in developed countries. In addition, native populations may be exposed to the infection through blood transfusion and the use of blood products produced from infected asymptomatic individuals. Mucosal leishmaniasis (ML) is a chronic form of this infection, which attacks the mucosa. In most cases this form of leishmaniasis results from the metastatic spread of Leishmania (Viannia) braziliensis from cutaneous lesions. It is a healthcare issue because of its wide demographic distribution, its association with significant morbidity levels, and because of the pressing concern that tourists who travel to endemic areas might present the disease even years later. The treatment currently available for ML is based on drugs such as pentavalent antimony-containing compounds, amphotericin B deoxycholate and pentamidine and often guarantees a satisfactory clinical response. Nevertheless, it also frequently provokes serious side effects. This review offers a critical analysis of the drugs now available for the treatment of ML as also of the future prospects for the treatment of the disease.

Cutaneous leishmaniasis

Cutaneous leishmaniasis is endemic in the tropics and neotropics. It is often referred to as a group of diseases because of the varied spectrum of clinical manifestations, which range from small cutaneous nodules to gross mucosal tissue destruction. Cutaneous leishmaniasis can be caused by several Leishmania spp and is transmitted to human beings and animals by sandflies. Despite its increasing worldwide incidence, but because it is rarely fatal, cutaneous leishmaniasis has become one of the so-called neglected diseases, with little interest by financial donors, public-health authorities, and professionals to implement activities to research, prevent, or control the disease. In endemic countries, diagnosis is often made clinically and, if possible, by microscopic examination of lesion biopsy smears to visually confirm leishmania parasites as the cause. The use of more sophisticated diagnostic techniques that allow for species identification is usually restricted to research or clinical settings in non-endemic countries. The mainstays of cutaneous leishmaniasis treatment are pentavalent antimonials, with new oral and topical treatment alternatives only becoming available within the past few years; a vaccine currently does not exist. Disease prevention and control are difficult because of the complexity of cutaneous leishmaniasis epizoology, and the few options available for effective vector control.

Tratamento da Leishmaniose Tegumentar Americana

A leishmaniose tegumentar americana é doença infecciosa da pele e mucosa, cujo agente etiológico é um protozoário do gênero Leishmania. Seu tratamento é desafio porque as drogas disponíveis apresentam elevada toxicidade, e nenhuma delas é bastante eficaz. A recidiva, a falha terapêutica em pacientes imunodeprimidos e a resistência ao tratamento são fatores que motivam a busca de uma droga ideal.

Leishmaniose mucosa fatal em criança

A leishmaniose tegumentar americana, doença endêmica e crescente no Brasil, pode manifestar-se por úlceras na pele e lesões nas mucosas nasal, oral e faringiana. O antimônio pentavalente é a droga de primeira escolha no tratamento, com resposta menos favorável nas formas mucosas. Destaca-se a dificuldade para diagnosticar e tratar um caso de leishmaniose mucosa em criança de cinco anos que teve exames parasitológicos, imunológicos e reação em cadeia da polimerase negativos. Somente após várias repetições o esfregaço foi positivo. A paciente apresentou infecção bacteriana secundária persistente das lesões e falta de resposta a drogas específicas e antibióticos, evoluindo para septicemia e óbito.

New world cutaneous leishmaniasis in travellers

As travel to Latin America has become increasingly common, cutaneous leishmaniasis is increasingly seen among returning travellers--eg, the number of observed cases has doubled in the Netherlands and tripled in the UK in the past decade. A surprisingly high proportion of cases were acquired in rural or jungle areas of the Amazon basin in Bolivia. The clinical manifestations range from ulcerative skin lesions (cutaneous leishmaniasis) to a destructive mucosal inflammation (mucocutaneous leishmaniasis), the latter usually being a complication of infection with Leishmania (Viannia) braziliensis. PCR is now the diagnostic method of choice, since it has a high sensitivity and gives a species-specific diagnosis, allowing species-specific treatment. Treatment of cutaneous leishmaniasis aims to prevent mucosal invasion, to accelerate the healing of the skin lesion(s), and to avoid disfiguring scars. Pentavalent antimonials drugs are still the drug of choice for many patients. However, a high rate of adverse events, length of treatment, and relapses in up to 25% of cases highlight the limitations of these drugs. Although only used in a small number of patients thus far, liposomal amphotericin B shows promising results. Further studies are needed to find efficacious and better-tolerated drugs for new world leishmaniasis.

Estudo comparativo da eficácia de isotionato de pentamidina administrada em três doses durante uma semana e de N-metil-glucamina 20mgSbV/kg/dia durante 20 dias para o tratamento da forma cutânea da leishmaniose tegumentar americana

Setenta e nove pacientes com leishmaniose tegumentar americana, forma cutânea, foram divididos em dois grupos: o grupo experimental (I), formado por 38 pessoas que receberam isotionato de pentamidina, 4mg/kg/dia, três aplicações, IM, durante uma semana, e o grupo controle (II), formado por 41 doentes tratados com N-metilglucamina, 20mgSbV/kg/dia por 20 dias, EV. Foram identificados, por técnica de anticorpos monoclonais, 21 isolados com predominância de Leishmania (Viannia) braziliensis. Encontrou-se cura clínica em 71,05% do grupo experimental e 73,17% do grupo controle (p=0,47). Alterações de ECG foram mais freqüentes utilizando antimonial pentavalente, com significância (p<0,05). O tratamento com a pentamidina mostrou eficácia semelhante quando comparado ao antimonial e apresenta vantagens como duração reduzida de tratamento e baixa toxicidade cardiológica.

Promising therapeutic targets for antileishmanial drugs

Current treatments for the parasitic disease leishmaniasis are unsatisfactory due to their route of administration, toxicity and expense. Resistance is also developing to first-line antimonial drugs. Fortunately, a handful of antileishmanial agents, such as the orally available compound miltefosine, are currently in clinical trials. In addition, several promising drug targets and lead molecules are being studied with the goal of developing new antileishmanial agents. Drug candidates have been identified through the continued investigation of parasite sterol metabolism and parasite proteases. New antileishmanial molecules have also been discovered through the study of novel targets and pathways, such as the bisphosphonate inhibitors of isoprenoid biosynthesis. This review presents a synopsis of the drug targets and lead compounds that have been investigated over the last few years against leishmaniasis, gives a perspective on the chemotherapeutic potential of each and discusses some of the obstacles to antileishmanial drug development.

Mucosal leishmaniasis ("espundia") responsive to low dose of N-methyl glucamine (Glucantime) in Rio de Janeiro, Brazil

Response to treatment with antimonial drugs varies considerably depending on the parasite strain involved, immune status of the patient and clinical form of the disease. Therapeutic regimens with this first line drug have been frequently modified both, in dose and duration of therapy. A regimen of 20 mg/kg/day of pentavalent antimony (Sb5+) during four weeks without an upper limit on the daily dose is currently recommended for mucosal disease ("espundia"). Side-effects with this dose are more marked in elderly patients, more commonly affected by this form of leishmaniasis. According to our experience, leishmaniasis in Rio de Janeiro responds well to antimony and, in cutaneous disease, high cure rates are obtained with 5 mg/kg/day of Sb5+ during 30 to 45-days. In this study a high rate of cure (91.4%) employing this dose was achieved in 36 patients with mild disease in this same geographic region. Side-effects were reduced and no antimony refractoriness was noted with subsequent use of larger dose in patients that failed to respond to initial schedule.

Practical guide for the treatment of leishmaniasis

This article summarises the clinical features of visceral, cutaneous and mucocutaneous leishmaniasis, and leishmaniasis in HIV-coinfected patients. The characteristics and clinical use of pentavalent antimonials and the traditional drugs used in all forms of leishmaniasis are described. There have been important developments in therapy, such as aminosidine (paromomycin) conventional amphotericin B and lipid-associated amphotericin B. In most cases of leishmaniasis there is a range of treatment options which is determined by the geographical and clinical features. This review is intended to assist the clinician in choosing treatment and in using unfamiliar drugs with safety and efficacy.