Randomized, Double-Blind Clinical Trial of Topical Imiquimod 5% with Parenteral Meglumine Antimoniate in the Treatment of Cutaneous Leishmaniasis in Peru

Immunotherapeutic Strategies as Potential Treatment Options for Cutaneous Leishmaniasis

Cutaneous leishmaniasis (CL), caused by protozoan parasites of the Leishmania genus, is prevalent in tropical and subtropical regions, with important morbidity, particularly in low- to middle-income countries. Current systemic treatments, including pentavalent antimonials and miltefosine, are associated with significant toxicity, reduced efficacy, and are frequently ineffective in cases of severe or chronic CL. Immunotherapies leverage the immune system to combat microbial infection and offer a promising adjunct or alternative approach to the current standard of care for CL. However, the heterogeneous clinical presentation of CL, which is dependent on parasite species and host immunity, may require informed clinical intervention with immunotherapies. This review explores the clinical and immunological characteristics of CL, emphasising the current landscape of immunotherapies in in vivo models and clinical studies. Such immune-based interventions aim to modulate immune responses against Leishmania, with additive therapeutic effects enabling the efficacy of lower drug doses and decreasing the associated toxicity. Understanding the mechanisms that underlie immunotherapy for CL provides critical insights into developing safer and more effective treatments for this neglected tropical disease. Identifying suitable therapeutic candidates and establishing their safety and efficacy are essential steps in this process. However, the feasibility and utility of these treatments in resource-limited settings must also be considered, taking into account factors such as cost of production, temperature stability, and overall patient access.

Imiquimod Reverses Chronic Toxoplasmosis-Associated Behavioral and Neurocognitive Anomalies in a Rat Model

Toxoplasma gondii is the etiologic agent of toxoplasmosis, a highly prevalent parasitosis. Toxoplasma gondii (T. gondii) transits in the brain from acute (AT) to chronic toxoplasmosis (CT), under host immune control. In immunocompromised patients, reactivation of CT is potentially life-threatening. Behavioral and neurological complications have been associated with CT. Furthermore, an effective treatment targeting CT is still lacking. We previously reported the efficacy of imiquimod against CT. Here, we demonstrate the molecular effects of imiquimod or imiquimod followed by the clinically used combination of sulfadiazine and pyrimethamine (SDZ + PYR) on CT-associated behavior in a rat model. Imiquimod decreased the number of cysts in the brains of chronically infected rats due to an induced reactivation of bradyzoites into tachyzoites. Importantly, this decrease was more pronounced in rats treated with imiquimod followed by SDZ + PYR. Rats chronically infected with T. gondii exhibited an anxiety-like behavior. Notably, treatment with imiquimod reversed this behavior aberrancy, with even a more pronounced effect with imiquimod followed by SDZ/PYR. Similarly, rats chronically infected with T. gondii exhibited learning deficits, and imiquimod alone or followed by SDZ/PYR reversed this behavior. Our results enhance our knowledge of the implications of CT on behavioral aberrancies and highlight the potency of imiquimod followed by SDZ + PYR on these CT-associated complications.

Drug repurposing for parasitic protozoan diseases

Protozoan parasites are major hazards to human health, society, and the economy, especially in equatorial regions of the globe. Parasitic diseases, including leishmaniasis, malaria, and others, contribute towards majority of morbidity and mortality. Around 1.1 million people die from these diseases annually. The lack of licensed vaccinations worsens the worldwide impact of these diseases, highlighting the importance of safe and effective medications for their prevention and treatment. However, the appearance of drug resistance in parasites continuously affects the availability of medications. The demand for novel drugs motivates global antiparasitic drug discovery research, necessitating the implementation of many innovative ways to maintain a continuous supply of promising molecules. Drug repurposing has come out as a compelling tool for drug development, offering a cost-effective and efficient alternative to standard de novo approaches. A thorough examination of drug repositioning candidates revealed that certain drugs may not benefit significantly from their original indications. Still, they may exhibit more pronounced effects in other disorders. Furthermore, certain medications can produce a synergistic effect, resulting in enhanced therapeutic effectiveness when given together. In this chapter, we outline the approaches employed in drug repurposing (sometimes referred to as drug repositioning), propose novel strategies to overcome these hurdles and fully exploit the promise of drug repurposing. We highlight a few major human protozoan diseases and a range of exemplary drugs repurposed for various protozoan infections, providing excellent outcomes for each disease.

The scientific journey of a novel adjuvant (AS37) from bench to bedside

A decade ago, we described a new approach to discover next generation adjuvants, identifying small-molecule immune potentiators (SMIPs) as Toll-like receptor (TLR)7 agonists. We also optimally formulated these drugs through adsorption to aluminum salts (alum), allowing them to be evaluated with a range of established and early-stage vaccines. Early proof-of-concept studies showed that a TLR7 agonist (TLR7a)-based SMIP, when adsorbed to alum, could perform as an effective adjuvant for a variety of different antigens, in both small and large animals. Studies in rodents demonstrated that the adjuvant enhanced immunogenicity of a recombinant protein-based vaccine against Staphylococcus aureus, and also showed potential to improve existing vaccines against pertussis or meningococcal infection. Extensive evaluations showed that the adjuvant was effective in non-human primates (NHPs), exploiting a mechanism of action that was consistent across the different animal models. The adjuvant formulation (named AS37) has now been advanced into clinical evaluation. A systems biology-based evaluation of the phase I clinical data with a meningococcal C conjugate vaccine showed that the AS37-adjuvanted formulation had an acceptable safety profile, was potent, and activated the expected immune pathways in humans, which was consistent with observations from the NHP studies. In the intervening decade, several alternative TLR7 agonists have also emerged and advanced into clinical development, such as the alum adsorbed TLR7/8 SMIP present in a widely distributed COVID-19 vaccine. This review summarizes the research and early development of the new adjuvant AS37, with an emphasis on the steps taken to allow its progression into clinical evaluations.

Metabolic Pathways of Leishmania Parasite: Source of Pertinent Drug Targets and Potent Drug Candidates

Leishmaniasis is a tropical disease caused by a protozoan parasite Leishmania that is transmitted via infected female sandflies. At present, leishmaniasis treatment mainly counts on chemotherapy. The currently available drugs against leishmaniasis are costly, toxic, with multiple side effects, and limitations in the administration route. The rapid emergence of drug resistance has severely reduced the potency of anti-leishmanial drugs. As a result, there is a pressing need for the development of novel anti-leishmanial drugs with high potency, low cost, acceptable toxicity, and good pharmacokinetics features. Due to the availability of preclinical data, drug repurposing is a valuable approach for speeding up the development of effective anti-leishmanial through pointing to new drug targets in less time, having low costs and risk. Metabolic pathways of this parasite play a crucial role in the growth and proliferation of Leishmania species during the various stages of their life cycle. Based on available genomics/proteomics information, known pathways-based (sterol biosynthetic pathway, purine salvage pathway, glycolysis, GPI biosynthesis, hypusine, polyamine biosynthesis) Leishmania-specific proteins could be targeted with known drugs that were used in other diseases, resulting in finding new promising anti-leishmanial therapeutics. The present review discusses various metabolic pathways of the Leishmania parasite and some drug candidates targeting these pathways effectively that could be potent drugs against leishmaniasis in the future.

Evaluating the Efficacy of Combined Intralesional Sodium Stibogluconate Plus Topical Imiquimod on Healing and Risk of Scarring of Cutaneous Leishmaniasis: A Case-Control Study

Background: A combination treatment of cutaneous leishmaniasis (CL) that hastens the healing and reduces the chance of scarring, especially in aesthetically receptive sites, is required.

Objectives: To evaluate if a combination of intralesional sodium stibogluconate (SSG) injection and topical imiquimod 5% cream (IMI) accelerates healing and improves the quality of scars from CL.

Patients and Methods: A prospective, placebo-controlled, randomized clinical trial was conducted at Basrah Teaching Hospital, Basrah, southern Iraq from 2017 to 2019 on a cohort of patients with CL. Eligible patients were injected intralesionally with sodium stibogluconate (SSG) weekly for six weeks and randomized to receive either topical imiquimod 5% cream (IMI group) or topical emollient cream (placebo group). The healing rate and scar quality were assessed at week six.

Results: One hundred twenty-one patients completed the trial (66 [55%] males, mean age SD: 34.1 years). The clinical healing rate was significantly higher in the IMI group than in the placebo group (94% versus 74%, p <0.05). A high rate of scars was noticed in both groups (66.6% in the IMI group and 91.2% in the placebo group). However, superficial non-atrophic scars were more frequent in the IMI group (40% versus 26%), while deep atrophic scars were more evident in the placebo group than in the IMI group (65.2% versus 26.6%, p<0.05).

Conclusions: Combined intralesional SSG plus topical imiquimod was beneficial in accelerating CL healing and improving scar quality, and should be considered when CL is located in aesthetically sensitive areas.

A phase II multicenter randomized study to evaluate the safety and efficacy of combining thermotherapy and a short course of miltefosine for the treatment of uncomplicated cutaneous leishmaniasis in the New World

Background

Systemic pentavalent antimonials, mainly meglumine antimoniate, continue to be the first-choice drugs for treatment of cutaneous leishmaniasis (CL) despite their toxicity, difficulty of administration and high cost. In the search for therapeutic alternatives, combining two treatment interventions has emerged as a potential alternative to either reduce the use of antimonials with the associated toxicities, or to increase efficacy. Here, we report the results of a recently completed trial assessing the efficacy and safety of a combination of thermotherapy (TT) plus a short course of miltefosine (MLT) for the treatment of uncomplicated CL in Colombia and Peru.

Methods

A multicenter, randomized, evaluator-blinded, phase II, controled clinical trial was conducted. Adult volunteers with a parasitologically confirmed diagnosis of uncomplicated CL were randomly allocated to receive either a single session of TT or a combination of TT plus a short course of MLT (3 weeks). Therapeutic response outcomes and safety were assessed.

Results

130 subjects were included in the study, of whom 64 were randomly assigned to the TT arm and 66 to the TT + MLT arm. Cure at 3 months’ follow-up was achieved in 57.8% (n = 37) and 80.3% (n = 53) in the TT and TT + MLT groups, respectively, in the intention to treat analysis. The TT + MLT regimen was better that TT alone (p = 0.0055). The presence of vesicles at the site of heat application was the most common adverse event reported associated with the use of TT; while vomiting (31.8%) and elevation of liver enzymes (28.8%) were the most frequent adverse events reported associated with the use of MLT.

Conclusion

The combination of TT plus a short course of MLT was shown to be significantly better than TT alone for the treatment of uncomplicated CL in the New World.

Trial registration

Registered in clinicaltrials.gov NCT02687971.

Cutaneous leishmaniasis is a disease caused by Leishmania parasites transmitted by sandflies. It is a complex and neglected disease. Generally, it manifests as ulcers, nodules, or other lesions, mainly on the face and extremities. An estimated 0.7–1 million new cases occur annually in around 88 countries in South and Central America, Africa, Europe, the Middle East, and Asia, with the appearance of new outbreaks in different regions of the world.

For more than 70 years, pentavalent antimonials have been the first line treatment, despite their toxicity, varying efficacy and need of administration of painful injections for 20 days or more.

There is limited availability of effective and safe treatment alternatives and the strength of scientific evidence on the efficacy and safety of the different schemes is variable, limiting the control of the disease from a therapeutic approach. Hence the need for effective, safe, low-cost treatment alternatives with non-invasive routes of administration.

This article reports the results of a clinical trial aiming to evaluate a combined therapy with two therapeutic alternatives (miltefosine and thermotherapy) approved for the treatment of cutaneous leishmaniasis, comparing it with thermotherapy alone. In this study, the combined therapy was significantly better than the monotherapy in managing cutaneous leishmaniasis.

Toxoplasmosis: Current and Emerging Parasite Druggable Targets

Toxoplasmosis is a prevalent disease affecting a wide range of hosts including approximately one-third of the human population. It is caused by the sporozoan parasite Toxoplasma gondii (T. gondii), which instigates a range of symptoms, manifesting as acute and chronic forms and varying from ocular to deleterious congenital or neuro-toxoplasmosis. Toxoplasmosis may cause serious health problems in fetuses, newborns, and immunocompromised patients. Recently, associations between toxoplasmosis and various neuropathies and different types of cancer were documented. In the veterinary sector, toxoplasmosis results in recurring abortions, leading to significant economic losses. Treatment of toxoplasmosis remains intricate and encompasses general antiparasitic and antibacterial drugs. The efficacy of these drugs is hindered by intolerance, side effects, and emergence of parasite resistance. Furthermore, all currently used drugs in the clinic target acute toxoplasmosis, with no or little effect on the chronic form. In this review, we will provide a comprehensive overview on the currently used and emergent drugs and their respective parasitic targets to combat toxoplasmosis. We will also abridge the repurposing of certain drugs, their targets, and highlight future druggable targets to enhance the therapeutic efficacy against toxoplasmosis, hence lessening its burden and potentially alleviating the complications of its associated diseases.

Comparative assessment of interventions for treating cutaneous leishmaniasis: A network meta-analysis of randomized clinical trials

INTRODUCTION

Various interventions including laser therapy, heat therapy, and several drugs have been trialed in patients with cutaneous leishmaniasis. Due to the lack of an evidence-based comparison of all these interventions, we carried out the present network meta-analysis.

METHODS

Electronic databases were searched for randomized clinical trials evaluating the efficacy and safety of any interventions in patients with cutaneous leishmaniasis. The proportion of patients with complete cure was the primary outcome. The proportion of lesions cured at the end of treatment, the proportion of lesions with minimal/no response to treatment, and proportion of wounds with minimal/no change were the secondary outcomes. Random-effects modeling was used for generating pooled estimates. Rankogram plot was used for identifying the 'best intervention'. For interventions containing a combination of treatments, backslash (/) has been used for depicting the same.

RESULTS

One-hundred and thirty-one studies were included. Intralesional meglumine, topical paromomycin/gentamicin, topical paromomycin, parenteral sodium stibogluconate, topical honey/intralesional meglumine, topical liposomal amphotericin B, oral zinc sulphate, oral miltefosine, parenteral meglumine, heat therapy, topical liposomal azithromycin, intralesional meglumine/silver dressing, intralesional sodium stibogluconate, parenteral meglumine/intralesional meglumine, oral allopurinol/parenteral meglumine, topical trichloroacetic acid/heat therapy, oral zinc sulphate/oral ketoconazole, topical imiquimod/cryotherapy, intralesional meglumine/cryotherapy, topical herbal extract of Z-HE, parenteral pentamidine, topical trichloroacetic acid/intralesional meglumine, carbon-dioxide laser, topical recombinant granulocyte-macrophage colony-stimulating factor/parenteral meglumine, intralesional dapsone, carbon-dioxide laser/intralesional meglumine, moist wet dressing with sodium hypochlorite, parenteral sodium stibogluconate/intralesional recombinant granulocyte-macrophage colony-stimulating factor, oral dapsone, intralesional sodium stibogluconate/oral ketoconazole, intralesional sodium stibogluconate/parenteral sodium stibogluconate and electrocautery/moist wet dressing with sodium hypochlorite were observed with significantly greater proportion of patients with complete cure compared to placebo/untreated controls. Rankogram analysis revealed that parenteral pentamidine has the highest statistical probability of being the best in the pool.

CONCLUSION

We observed several interventions to be effective for treating cutaneous leishmaniasis. However, greater caution is required in interpreting the results as the estimates are likely to change with the advent of results from future studies.

Mechanisms of Immunopathogenesis in Cutaneous Leishmaniasis And Post Kala-azar Dermal Leishmaniasis (PKDL)

Leishmaniasis is a neglected tropical disease that affects 12 million people worldwide. The disease has high morbidity and mortality rates and is prevalent in over 80 countries, leaving more than 300 million people at risk of infection. Of all of the manifestations of this disease, cutaneous leishmaniasis (CL) is the most common form and it presents as ulcerating skin lesions that can self-heal or become chronic, leading to disfiguring scars. This review focuses on the different pathologies and disease manifestations of CL, as well as their varying degrees of severity. In particular, this review will discuss self-healing localized cutaneous leishmaniasis (LCL), leishmaniasis recidivans (LR), mucocutaneous leishmaniasis (MCL), anergic diffuse cutaneous leishmaniasis (ADCL), disseminated leishmaniasis (DL), and Post Kala-azar Dermal Leishmaniasis (PKDL), which is a cutaneous manifestation observed in some visceral leishmaniasis (VL) patients after successful treatment. The different clinical manifestations of CL are determined by a variety of factors including the species of the parasites and the host's immune response. Specifically, the balance between the pro and anti-inflammatory mediators plays a vital role in the clinical presentation and outcome of the disease. Depending upon the immune response, Leishmania infection can also transition from one form of the disease to another. In this review, different forms of cutaneous Leishmania infections and their immunology are described.

Three decades of clinical trials on immunotherapy for human leishmaniases: a systematic review and meta-analysis

Aim: Current treatments for leishmaniases are not satisfactory, thus alternatives are needed. We searched for clinical trials with immunotherapeutic approaches for patients with leishmaniasis. Materials & methods: Out of 205 articles, 24 clinical trials were selected, and eight submitted to meta-analysis. Results: A reduction in healing time was observed in patients with tegumentary leishmaniasis treated with pentavalent antimony plus granulocyte-macrophage colony-stimulating factor, and therapeutic vaccines. Overall meta-analysis indicated that immunotherapy associated with the standard chemotherapy generated a significantly reduced risk of treatment failure than the pentavalent antimony alone (p = 0.03). Conclusion: Our review confirmed the efficacy of immunotherapies for the treatment of cutaneous and visceral leishmaniasis and highlighted the importance of clinical trials using immunotherapies for leishmaniases.

Host-Directed Therapies for Cutaneous Leishmaniasis

Cutaneous leishmaniasis exhibits a wide spectrum of clinical presentations from self-resolving infections to severe chronic disease. Anti-parasitic drugs are often ineffective in the most severe forms of the disease, and in some cases the magnitude of the disease can result from an uncontrolled inflammatory response rather than unrestrained parasite replication. In these patients, host-directed therapies offer a novel approach to improve clinical outcome. Importantly, there are many anti-inflammatory drugs with known safety and efficacy profiles that are currently used for other inflammatory diseases and are readily available to be used for leishmaniasis. However, since leishmaniasis consists of a wide range of clinical entities, mediated by a diverse group of leishmanial species, host-directed therapies will need to be tailored for specific types of leishmaniasis. There is now substantial evidence that host-directed therapies are likely to be beneficial beyond autoimmune diseases and cancer and thus should be an important component in the armamentarium to modulate the severity of cutaneous leishmaniasis.

An overview of the treatment of cutaneous leishmaniasis

Leishmaniasis is a neglected tropical disease caused by species of Leishmania, with a broad spectrum of clinical manifestations, such as cutaneous, visceral, and mucocutaneous presentations. Many drugs are used for its treatment, and a current effective one is a pentavalent antimonial, especially in developing countries. In this review, we discuss recent proposed therapies as well as their side effects.

Therapeutic advances in the topical treatment of cutaneous leishmaniasis: A review

Cutaneous leishmaniasis has been endemic since decades. Millions of cases are reported worldwide specially in developing and underdeveloped countries. There are 2 major types of cutaneous leishmaniasis based on the causating species found in different regions of the world. These include New and Old World cutaneous leishmaniasis, which are self-healing, but if not treated, these may cause severe scars and many other complications like mucosal involvement. The conventional gold standard treatment for both types is mainly intralesional or parenteral administration of antimonial. Lately, a great deal of research has been done on development of topical treatment based on single agent or combination therapy. This review summarizes the current state of literature regarding therapeutic outcome of topical treatment against cutaneous leishmaniasis caused by different species in different regions.

Efficacy and Tolerability of Miltefosine in the Treatment of Cutaneous Leishmaniasis

BACKGROUND

Cutaneous leishmaniasis (CL) is a neglected tropical disease causing an estimated 1 million new cases annually. While antimonial compounds are the standard of care worldwide, they are associated with significant adverse effects. Miltefosine, an oral medication, is United States (US) Food and Drug Administration approved to treat CL caused by Leishmania braziliensis, Leishmania guyanensis, and Leishmania panamensis. Evidence of efficacy in other species and side-effect profiles in CL has been limited.

METHODS

Twenty-six patients with CL were treated with miltefosine at the US National Institutes of Health. Species included L. braziliensis (n = 7), L. panamensis (n = 5), Leishmania mexicana (n = 1), Leishmania infantum (n = 3), Leishmania aethiopica (n = 4), Leishmania tropica (n = 2), Leishmania major (n = 1), and unspeciated (n = 3). Demographic and clinic characteristics of the participants, response to treatment, and associated adverse events were analyzed.

RESULTS

Treatment with miltefosine resulted in cure in 77 % (20/26) of cases, with cures among all species. Common adverse events included nausea/vomiting (97%) and lack of appetite (54%). Clinical management or dose reduction was required in a third of cases. Gout occurred in 3 individuals with a prior history of gout. Most laboratory abnormalities, including elevated creatinine and aminotransferases, were mild and normalized after treatment.

CONCLUSIONS

Our data suggest that miltefosine has good but imperfect efficacy to a wide variety of Leishmania species. While side effects were common and mostly mild to moderate, some resulted in discontinuation of therapy. Due to oral administration, broad efficacy, and manageable toxicities, miltefosine is a viable alternative treatment option for CL, though cost and lack of local availability may limit its widespread use.

Evidence supporting the enhanced efficacy of pentavalent antimonials with adjuvant therapy for cutaneous leishmaniasis: a systematic review and meta-analysis

Cutaneous leishmaniasis (CL) is one of the major neglected disease worldwide. Although many drugs have been used, the pentavalent antimonials (PA) remain as the first-line choice despite their toxicity and limited efficacy. The combination of two drugs has risen as a potential alternative to increase the cure rate while lowering the side-effects caused by pentavalent antimonials (PA). The objective of this study was to critically review and appraise the potential synergism of the adjuvant therapies of PA with other drugs/interventions previously used in the literature. We carried out a search of literature from PubMed, MEDLINE, Embase, Cochrane and clinicaltrials.gov. Articles that described a two-arm or three-arm design in which one of the arms consisted in a combination of a drug/intervention with intralesional or systemic PA were selected. The primary outcome was proportion of complete clearance of the lesions defined as complete re-epithelization and/or negative direct smear. Our literature search identified 554 references. Thirty-one records with a total sample size of 2668 participants met the eligibility criteria. The studies investigated the association of PA with the following: cryotherapy (five studies), allopurinol, imiquimod, pentoxifylline (four studies each), trichloroacetic acid 50% (three studies) and other additional interventions (eleven studies). Overall, the combined therapy of PA with a supplementary intervention was superior to PA monotherapy (RR: 1.23 95% CI: 1.11-1.35, I2  = 64%). In association with PA, the comparator-specific stratified analysis showed that cryotherapy (RR: 1.50 95% CI: 1.25-1.81, I2  = 57%) and allopurinol (RR: 1.70 95% CI: 1.37-2.12, I2  = 28%) were superior to PA in monotherapy. On the contrary, the combined therapy with imiquimod (RR: 1.08 95% CI: 0.88-1.32, I2  = 40%) and pentoxifylline (RR: 1.14 95% CI: 0.94-1.40, I2  = 41%) revealed a non-significant result. The application of TCA along with PA did not show significant differences in the clearance rate, although it was close to it (RR: 1.31 95% CI: 0.99-1.73, I2  = 84%). The present work represents an attempt to find new and reliable treatment modalities to enhance the efficacy based on the adjuvant therapy of pre-existing drugs/interventions with PA. According to our results, the combination of allopurinol-PA is the most effective adjuvant therapy. The application of cryotherapy and TCA stand as useful and encouraging supplementary interventions. The combination of imiquimod-PA and pentoxifylline adds no additional benefit. The results of this work may be helpful in devising and modifying the current guidelines for CL which face major remaining evidence gaps. Triple therapies consisting in cryotherapy-PA-TCA or allopurinol-PA-cryotherapy or allopurinol-PA-TCA can represent promising treatments yet to be confirmed in future trials.

Interventions for American cutaneous and mucocutaneous leishmaniasis

BACKGROUND

On the American continent, cutaneous and mucocutaneous leishmaniasis (CL and MCL) are diseases associated with infection by several species of Leishmania parasites. Pentavalent antimonials remain the first-choice treatment. There are alternative interventions, but reviewing their effectiveness and safety is important as availability is limited. This is an update of a Cochrane Review first published in 2009.

OBJECTIVES

To assess the effects of interventions for all immuno-competent people who have American cutaneous and mucocutaneous leishmaniasis (ACML).

SEARCH METHODS

We updated our database searches of the Cochrane Skin Group Specialised Register, CENTRAL, MEDLINE, Embase, LILACS and CINAHL to August 2019. We searched five trials registers.

SELECTION CRITERIA

Randomised controlled trials (RCTs) assessing either single or combination treatments for ACML in immuno-competent people, diagnosed by clinical presentation and Leishmania infection confirmed by smear, culture, histology, or polymerase chain reaction on a biopsy specimen. The comparators were either no treatment, placebo only, or another active compound.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Our key outcomes were the percentage of participants 'cured' at least three months after the end of treatment, adverse effects, and recurrence. We used GRADE to assess evidence certainty for each outcome.

MAIN RESULTS

We included 75 studies (37 were new), totalling 6533 randomised participants with ATL. The studies were mainly conducted in Central and South America at regional hospitals, local healthcare clinics, and research centres. More male participants were included (mean age: roughly 28.9 years (SD: 7.0)). The most common confirmed species were L. braziliensis, L. panamensis, and L. mexicana. The most assessed interventions and comparators were non-antimonial systemics (particularly oral miltefosine) and antimonials (particularly meglumine antimoniate (MA), which was also a common intervention), respectively. Three studies included moderate-to-severe cases of mucosal leishmaniasis but none included cases with diffuse cutaneous or disseminated CL, considered the severe cutaneous form. Lesions were mainly ulcerative and located in the extremities and limbs. The follow-up (FU) period ranged from 28 days to 7 years. All studies had high or unclear risk of bias in at least one domain (especially performance bias). None of the studies reported the degree of functional or aesthetic impairment, scarring, or quality of life. Compared to placebo, at one-year FU, intramuscular (IM) MA given for 20 days to treat L. braziliensis and L. panamensis infections in ACML may increase the likelihood of complete cure (risk ratio (RR) 4.23, 95% confidence interval (CI) 0.84 to 21.38; 2 RCTs, 157 participants; moderate-certainty evidence), but may also make little to no difference, since the 95% CI includes the possibility of both increased and reduced healing (cure rates), and IMMA probably increases severe adverse effects such as myalgias and arthralgias (RR 1.51, 95% CI 1.17 to 1.96; 1 RCT, 134 participants; moderate-certainty evidence). IMMA may make little to no difference to the recurrence risk, but the 95% CI includes the possibility of both increased and reduced risk (RR 1.79, 95% CI 0.17 to 19.26; 1 RCT, 127 participants; low-certainty evidence). Compared to placebo, at six-month FU, oral miltefosine given for 28 days to treat L. mexicana, L. panamensis and L. braziliensis infections in American cutaneous leishmaniasis (ACL) probably improves the likelihood of complete cure (RR 2.25, 95% CI 1.42 to 3.38), and probably increases nausea rates (RR 3.96, 95% CI 1.49 to 10.48) and vomiting (RR 6.92, 95% CI 2.68 to 17.86) (moderate-certainty evidence). Oral miltefosine may make little to no difference to the recurrence risk (RR 2.97, 95% CI 0.37 to 23.89; low-certainty evidence), but the 95% CI includes the possibility of both increased and reduced risk (all based on 1 RCT, 133 participants). Compared to IMMA, at 6 to 12 months FU, oral miltefosine given for 28 days to treat L. braziliensis, L. panamensis, L. guyanensis and L. amazonensis infections in ACML may make little to no difference to the likelihood of complete cure (RR 1.05, 95% CI 0.90 to 1.23; 7 RCTs, 676 participants; low-certainty evidence). Based on moderate-certainty evidence (3 RCTs, 464 participants), miltefosine probably increases nausea rates (RR 2.45, 95% CI 1.72 to 3.49) and vomiting (RR 4.76, 95% CI 1.82 to 12.46) compared to IMMA. Recurrence risk was not reported. For the rest of the key comparisons, recurrence risk was not reported, and risk of adverse events could not be estimated. Compared to IMMA, at 6 to 12 months FU, oral azithromycin given for 20 to 28 days to treat L. braziliensis infections in ACML probably reduces the likelihood of complete cure (RR 0.51, 95% CI 0.34 to 0.76; 2 RCTs, 93 participants; moderate-certainty evidence). Compared to intravenous MA (IVMA) and placebo, at 12 month FU, adding topical imiquimod to IVMA, given for 20 days to treat L. braziliensis, L. guyanensis and L. peruviana infections in ACL probably makes little to no difference to the likelihood of complete cure (RR 1.30, 95% CI 0.95 to 1.80; 1 RCT, 80 participants; moderate-certainty evidence). Compared to MA, at 6 months FU, one session of local thermotherapy to treat L. panamensis and L. braziliensis infections in ACL reduces the likelihood of complete cure (RR 0.80, 95% CI 0.68 to 0.95; 1 RCT, 292 participants; high-certainty evidence). Compared to IMMA and placebo, at 26 weeks FU, adding oral pentoxifylline to IMMA to treat CL (species not stated) probably makes little to no difference to the likelihood of complete cure (RR 0.86, 95% CI 0.63 to 1.18; 1 RCT, 70 participants; moderate-certainty evidence).

AUTHORS' CONCLUSIONS

Evidence certainty was mostly moderate or low, due to methodological shortcomings, which precluded conclusive results. Overall, both IMMA and oral miltefosine probably result in an increase in cure rates, and nausea and vomiting are probably more common with miltefosine than with IMMA. Future trials should investigate interventions for mucosal leishmaniasis and evaluate recurrence rates of cutaneous leishmaniasis and its progression to mucosal disease.

Leishmaniasis immunopathology-impact on design and use of vaccines, diagnostics and drugs

Leishmaniasis is a disease complex caused by 20 species of protozoan parasites belonging to the genus Leishmania. In humans, it has two main clinical forms, visceral leishmaniasis (VL) and cutaneous or tegumentary leishmaniasis (CL), as well as several other cutaneous manifestations in a minority of cases. In the mammalian host Leishmania parasites infect different populations of macrophages where they multiply and survive in the phagolysosomal compartment. The progression of both VL and CL depends on the maintenance of a parasite-specific immunosuppressive state based around this host macrophage infection. The complexity and variation of immune responses and immunopathology in humans and the different host interactions of the different Leishmania species has an impact upon the effectiveness of vaccines, diagnostics and drugs.

Imiquimod-loaded nanoarchaeosomes as a promising immunotherapy against Trypanosoma cruzi infection

The purpose of this study was to evaluate the efficacy of imiquimod-containing nanovesicles prepared with lipids extracted from the hyperhalophile archaebacterium Halorubrum tebenquichense (nanoARC-IMQ) to induce protection against Trypanosoma cruzi infection. The therapeutic efficacy of archaeolipid nanovesicles was assessed in an experimental murine model of acute infection with T. cruzi. The administration of nanoARQ-IMQ prevented mortality as compared to infected untreated animals, reduced parasitemia levels and diminished myocardial and musculoskeletal lesions in mice infected with a lethal strain of T. cruzi. Our findings suggest that the immunotherapy with nanoARC-IMQ has potential to limit the progression of Chagas disease.

Exploiting knowledge on pharmacodynamics-pharmacokinetics for accelerated anti-leishmanial drug discovery/development

Introduction: Being on the top list of neglected tropical diseases, leishmaniasis has been marked for elimination by 2020. In the light of small armamentarium of drugs and their associated drawbacks, the understanding of pharmacodynamics and/or pharmacokinetics becomes a priority to achieve and sustain disease elimination. Areas covered: The authors have looked into pharmacological aspects of existing and emerging drugs for treatment of leishmaniasis. An in-depth understanding of pharmacodynamics and pharmacokinetics (PKPD) provides a rationale for drug designing and optimizing the treatment strategies. It forms a key to prevent drug resistance and avoid drug-associated adverse effects. The authors have compiled the researches on the PKPD of different anti-leishmanial formulations that have the potential for improved and/or effective disease intervention. Expert opinion: Understanding the pharmacological aspects of drugs forms the basis for the clinical application of novel drugs. Tailoring drug dosage and individualized treatment can avoid the adverse events and bridge gap between the in vitro models and their clinical application. An integrated approach, with pragmatic use of technological advances can improve phenotypic screening and physiochemical properties of novel drugs. Concomitantly, this can serve to improve clinical efficacies, reduce the incidence of relapse and accelerate the drug discovery/development process for leishmaniasis elimination.

Therapeutic response and safety of the topical, sequential use of antiseptic, keratolytic, and pentamidine creams (3-PACK) on Leishmania (Viannia) braziliensis-infected mice

BACKGROUND

Topical treatment of New World cutaneous leishmaniasis can be affected by bacterial coinfection, hyperkeratosis, and transdermal drug delivery.

OBJECTIVE

The aim of this work was to evaluate the therapeutic response and safety of the topical, sequential use of antiseptic, keratolytic, and pentamidine isethionate (PMD) creams (3-PACK kit) on CL-infected BALB/c mice.

METHODS

A 0.5% chlorhexidine solution (CGH), 10% salicylic acid (SA), and 3% or 6% PMD were used as antiseptic, keratolytic, and antileishmanial drugs, respectively. During the first seven days, antiseptic, followed by 10% SA gel and PMD cream, were applied topically. Subsequently, treatment was performed only with the antiseptic and PMD creams. Skin irritation, reduction of lesion size (mm²), and parasitic load were observed until 30 days of treatment were completed.

FINDINGS

The 3-PACK treatment using 6% PMD induced a complete lesion reduction in 3/6 mice and a partial reduction in 1/6 mice, with no parasites observed. In contrast, CGH and SA alone, along with the vehicle, were not effective (p < 0.05). Moderate to severe erythema was observed at the application site.

MAIN CONCLUSION

The topical 3-PACK using 6% PMD was 67% effective in the treatment of CL by Leishmania (Viannia) braziliensis. Currently, work is ongoing to improve PMD isethionate formulation and to determine a dose-response.

How to master the host immune system? Leishmania parasites have the solutions!

Infection by protozoan parasites of the genus Leishmania results in the development of leishmaniasis, an increasingly prevalent group of diseases affecting over 12 million people worldwide. Leishmaniasis can have very different outcomes ranging from cutaneous lesions, mucosal lesions to visceralization depending on the species of the infecting parasite and on the immune response developed by the host. As an obligate intracellular parasite, residing within macrophages, Leishmania evolved in strict contact with the host immune system, developing different mechanisms to evade or modulate the immune response. Various types of immune responses are observed during different Leishmania spp. infections, resulting in parasite clearance but also contributing to the pathogenesis, thus increasing the complexity of the course of the disease. Interestingly, depending on the type of leishmaniasis developed, opposite treatment strategies, which either boost or inhibit the inflammatory response, have shown efficacy. In this review, we summarize the contribution of different immune cell types to the development of the anti-leishmanial immune response and the parasite strategies to evade and modulate host immunity. Further, we discuss the involvement of co-infecting pathogens in the determination of the outcome of leishmaniasis and on the effectiveness of treatment and the implication of the immune response for treatment and vaccine development.

Pentavalent Antimonials Combined with Other Therapeutic Alternatives for the Treatment of Cutaneous and Mucocutaneous Leishmaniasis: A Systematic Review

The first choice drugs for the treatment of cutaneous and mucocutaneous leishmaniasis are pentavalent antimonials, sodium stibogluconate, or meglumine antimoniate. However, the treatment with these drugs is expensive, can cause serious adverse effects, and is not always effective. The combination of two drugs by different routes or the combination of an alternative therapy with systemic therapy can increase the efficacy and decrease the collateral effects caused by the reference drugs. In this systematic review we investigated publications that described a combination of nonconventional treatment for cutaneous and mucocutaneous with pentavalent antimonials. A literature review was performed in the databases Web of Knowledge and PubMed in the period from 01st of December 2004 to 01st of June 2017, according to Prisma statement. Only clinical trials involving the treatment for cutaneous or mucocutaneous leishmaniasis, in English, and with available abstract were added. Other types of publications, such as reviews, case reports, comments to the editor, letters, interviews, guidelines, and errata, were excluded. Sixteen articles were selected and the pentavalent antimonials were administered in combination with pentoxifylline, granulocyte macrophage colony-stimulating factor, imiquimod, intralesional sodium stibogluconate, ketoconazole, silver-containing polyester dressing, lyophilized LEISH-F1 protein, cryotherapy, topical honey, and omeprazole. In general, the combined therapy resulted in high rates of clinical cure and when relapse or recurrence was reported, it was higher in the groups treated with pentavalent antimonials alone. The majority of the articles included in this review showed that cure rate ranged from 70 to 100% in patients treated with the combinations. Serious adverse effects were not observed in patients treated with drugs combination. The combination of other drugs or treatment modalities with pentavalent antimonials has proved to be effective for cutaneous and mucocutaneous leishmaniasis and for most seemed to be safe. However, new randomized, controlled, and multicentric clinical trials with more robust samples should be performed, especially the combination with immunomodulators.

Accuracy of qPCR for quantifying Leishmania kDNA in different skin layers of patients with American tegumentary leishmaniasis

OBJECTIVES

Superficial swab sampling of American tegumentary leishmaniasis (ATL) lesions shows higher amounts of Leishmania than those from biopsy. Subcutaneous involvement is also important in ATL, but parasite quantification according to lesion depth has not been evaluated. We aim to present the best depth at which sampling should be performed for molecular exams of ATL.

METHODS

Patients with a clinical presentation compatible with ATL were allocated to ATL and control groups. Qualitative and quantitative qPCR assays were performed using SYBR Green and primers amplifying the kDNA minicircle of Leishmania spp. in different skin layers, including the epidermis, the superior dermis, the inferior dermis, and the hypodermis.

RESULTS

Fifty-nine patients were included in this study, including 40 who had been diagnosed with ATL and 19 controls. The number of parasites was greater in samples of the epidermis and superior dermis (159.1 × 10⁶, range 4.0-781.7, and 75.4 × 10⁶, range 8.0-244.5, mean Leishmania parasite equivalents per μg of tissue DNA, respectively) than those in samples of the inferior dermis and hypodermis (54.6, range 8.0-256.6, and 16.8 × 10⁶, range 8.0-24.1, mean Leishmania parasite equivalents per μg of tissue DNA, respectively). The best diagnostic accuracy was achieved in the superior dermis (77.9%) and was significantly greater than that in the hypodermis (63.3%; p 0.039).

CONCLUSIONS

We conclude that superficial sampling can retrieve a greater quantity of parasites. Future studies of the role of transepidermal elimination as a mechanism of host defence in ATL must be performed as there is a considerable quantity of Leishmania kDNA in the epidermis.

Eligibility criteria and outcome measures adopted in clinical trials of treatments of cutaneous leishmaniasis: systematic literature review covering the period 1991-2015

OBJECTIVE

To document the sources of heterogeneity in outcomes and shortcomings in trial designs reported by previous systematic reviews.

METHODS

Systematic review of clinical trials of CL treatments published since 1991, to assess and compare eligibility criteria and outcome measures in trials (any type of treatment) of CL (any form) reported before and after the publication of the CONSORT statement.

RESULTS

We identified 106 eligible trials published between 1991 and 2015, 74% after the 2001 CONSORT statement; 58% (n = 63) were on Old-World CL and 37% (n = 40) in New-World CL; overall, 11 531 patients enrolled in 243 treatment groups on 30 different treatments. Both requirements and definitions for eligibility and outcome criteria varied. Compliance with CONSORT requirements increased for studies published after the 2010 update. As for entry criteria, 94% of studies had a requirement for sex (74% of those enrolling also women excluded those who were pregnant or lactating), 69% for age (variable age ranges), 99% parasitological confirmation, 43% prior duration of illness (14% excluded cases with previous episodes), 46% defined the number, 28% the size and 13% the type of lesions (27% with restrictions as to their anatomical location). Follow-up ranged 1-24 months, with 14% and 91% of studies, respectively, having defined initial and final cure.

CONCLUSIONS

This review documents changes in reporting before and after the publication of the CONSORT statement. Lack of standardisation, compounded with the small number of trials relative to the magnitude of the disease in its multiple forms, and with the range of treatments tested explains why evidence to inform treatment guidelines is generally weak for CL. Adopting standardised methodologies will improve the quality and consistency of clinical trials, and ultimately yield better treatments for CL.

Repurposing as a strategy for the discovery of new anti-leishmanials: the-state-of-the-art

Leishmaniasis is a vector-borne neglected tropical disease caused by protozoan parasites of the genus Leishmania for which there is a paucity of effective viable non-toxic drugs. There are 1·3 million new cases each year causing considerable socio-economic hardship, best measured in 2·4 million disability adjusted life years, with greatest impact on the poorest communities, which means that desperately needed new antileishmanial treatments have to be both affordable and accessible. Established medicines with cheaper and faster development times may hold the cure for this neglected tropical disease. This concept of using old drugs for new diseases may not be novel but, with the ambitious target of controlling or eradicating tropical diseases by 2020, this strategy is still an important one. In this review, we will explore the current state-of-the-art of drug repurposing strategies in the search for new treatments for leishmaniasis.

American cutaneous leishmaniasis in infancy and childhood

Infant and young child skin diseases are among the most common features of morbidity throughout the tropics. Because the skin is directly exposed to the environment, it is considerably affected by climatic and local conditions such as vectors and microorganisms, as in the case of leishmaniasis. In America the observed magnitude of cutaneous leishmaniasis in children has led to the study of increased risk of exposure of this group due to the possibility of peri- and intradomiciliary transmission. The present review pretends to make a concrete approach all through the broad and main figures of this parasitic disease, including the clinical, physiopathological, epidemiological, diagnostic, and therapeutic aspects, in order to be used as a practical source of reference for pediatricians leading with tropical cutaneous pathology in the region.

Imiquimod in dermatology: an overview

Imiquimod is an immune response modifier commercially available as a 3.75 and 5% cream. Topical imiquimod stimulates the innate and adaptive immune responses and induces cytokine production. This allows its use for the treatment of a wide variety of benign and malignant skin conditions due to its potential antiviral, antitumor, and immunoregulatory effects. Currently, topical imiquimod is US Food and Drug Administration (FDA)-approved for the treatment of anogenital warts, actinic keratosis, and superficial basal cell carcinomas. However, it has also shown a beneficial effect in the treatment of many other skin disorders. In this review, we describe existing evidence on the mechanism of action of topical imiquimod, its FDA-approved indications, off-label uses, and side effects.

Safety and efficacy of current alternatives in the topical treatment of cutaneous leishmaniasis: a systematic review

Studies of topical treatments for leishmaniasis were systematically reviewed, to evaluate the therapeutic efficacy, safety and any adverse effects of these treatments. The papers identified in the databases PubMed and Web of Knowledge involved eight studies with a total of 1744 patients. The majority of trials was from Iran (4/8), covered a period of 8 years (2003–2011), and included patients 4–85 years of age. The most frequent Leishmania species in the studies were L. tropica (4/8) and L. major (2/8). The treatments administered were thermotherapy, paromomycin and combinations, CO2 laser, 5-aminolevulinic acid hydrochloride (10%) plus visible red light (633 nm) and cryotherapy. Six articles reported cure rates over 80·0%. Six studies reported on failure rates, three of them reporting rates lower than 10%. Four studies did not report relapses or recurrences, while the other studies reported low rates (1·8–6·3%). The most common adverse effects of the topical treatments were redness/erythema, pain, pruritus burning, oedema, vesicles and hyper- or hypopigmentation. The results provide strong evidence that the treatments topical evaluated showed high cure rates, safety and effectiveness, with low side-effects, relapse and recurrence rates, except for cryotherapy, which showed a moderate cure rate.

Topical Treatment Modalities for Old World Cutaneous Leishmaniasis: A Review

Diagnosis and therapy of cutaneous leishmaniasis (CL) can be difficult due to the variability of the clinical pictures and resistance to therapy. There is no vaccine currently available for CL. The aim of the present review is to describe different topical treatment modalities for old world CL. The mainstays of treatment for old world CL are pentavalent antimony compounds which are administered parenterally or intralesionally. New topical treatment alternatives have been available within the past few years. Amongst several treatments used topically, physical therapies including cryotherapy, heat therapy and CO2 laser are promising for the treatment of old world CL. Along with that, other randomized placebo controlled trials should be designed to find new effective therapeutic regimens.

Cutaneous leishmaniasis in travellers: a focus on epidemiology and treatment in 2015

Imported cutaneous leishmaniasis (CL) is a growing problem with increasing global travel to endemic areas. Returned travellers seeking care encounter significant barriers to treatment, including diagnostic delays and difficult access to anti-leishmanial drugs. Treatment recommendations in non-endemic settings are a moving target, reflecting recent developments in Leishmania diagnostics and therapeutics. Accumulating experience with molecular-based species identification has enabled species-directed therapy. Clinicians are reevaluating more toxic traditional regimens in light of newly approved therapeutic agents and emerging data on local cutaneous treatments. Referral centers are implementing treatment decision algorithms designed to maximize efficacy while minimizing adverse events. Although management strategies continue to evolve, treatment of CL in non-endemic settings remains controversial. Persistent reliance on expert opinion reflects lack of research focused on travellers and limited randomized controlled trial evidence. We herein review the current epidemiology of cutaneous leishmaniasis in travellers and species-specific evidence for available therapies.

Therapeutic options for old world cutaneous leishmaniasis and new world cutaneous and mucocutaneous leishmaniasis

Estimated worldwide incidence of tegumentary leishmaniasis (cutaneous leishmaniasis [CL] and mucocutaneous leishmaniasis [MCL]) is over 1.5 million cases per year in 82 countries, with 90 % of cases occurring in Afghanistan, Brazil, Iran, Peru, Saudi Arabia and Syria. Current treatments of CL are poorly justified and have sub-optimal effectiveness. Treatment can be based on topical or systemic regimens. These different options must be based on Leishmania species, geographic regions, and clinical presentations. In certain cases of Old World CL (OWCL), lesions can spontaneously heal without any need for therapeutic intervention. Local therapies (thermotherapy, cryotherapy, paromomycin ointment, local infiltration with antimonials) are good options with less systemic toxicity, reserving systemic treatments (azole drugs, miltefosine, antimonials, amphotericin B formulations) mainly for complex cases. The majority of New World CL (NWCL) types require systemic treatment (mainly with pentavalent antimonials), either to speed the healing or to prevent dissemination to oral-nasal mucosa as MCL (NWMCL). These types of lesions are potentially serious and always require systemic-based regimens, mainly antimonials and pentamidine; however, the associated immunotherapy is promising. This paper is an exhaustive review of the published literature on the treatment of OWCL, NWCL and NWMCL, and provides treatment recommendations stratified according to their level of evidence regarding the species of Leishmania implicated and the geographical location of the infection.

Topical resiquimod protects against visceral infection with Leishmania infantum chagasi in mice

New prevention and treatment strategies are needed for visceral leishmaniasis, particularly ones that can be deployed simply and inexpensively in areas where leishmaniasis is endemic. Synthetic molecules that activate Toll-like receptor 7 and 8 (TLR7/8) pathways have previously been demonstrated to enhance protection against cutaneous leishmaniasis. We initially sought to determine whether the TLR7/8-activating molecule resiquimod might serve as an effective vaccine adjuvant targeting visceral leishmaniasis caused by infection with Leishmania infantum chagasi. Resiquimod was topically applied to the skin of mice either prior to or after systemic infection with L. infantum chagasi, and parasite burdens were assessed. Surprisingly, topical resiquimod application alone, in the absence of vaccination, conferred robust resistance to mice against future intravenous challenge with virulent L. infantum chagasi. This protection against L. infantum chagasi infection persisted as long as 8 weeks after the final topical resiquimod treatment. In addition, in mice with existing infections, therapeutic treatment with topical resiquimod led to significantly lower visceral parasite loads. Resiquimod increased trafficking of leukocytes, including B cells, CD4(+) and CD8(+) T cells, dendritic cells, macrophages, and granulocytes, in livers and spleens, which are the key target organs of visceralizing infection. We conclude that topical resiquimod leads to systemic immune modulation and confers durable protection against visceralizing L. infantum chagasi infection, in both prophylactic and therapeutic settings. These studies support continued studies of TLR-modulating agents to determine mechanisms of protection and also provide a rationale for translational development of a critically needed, novel class of topical, preventative, and therapeutic agents for these lethal infections.

Exploring the role of medicinal plant-based immunomodulators for effective therapy of leishmaniasis

Leishmaniasis is a pestilent affliction that importunately needs better therapeutics necessitated by the absence of effective vaccine, emergence as HIV co-infection, and the dread of debilitating chemotherapy. The Leishmania parasites incapacitate host macrophages by preventing the formation of phagolysosomes, impeding antigen presentation to T cells, leading to suppression of cell-mediated immunity. An ideal approach to cure leishmaniasis includes administration of antileishmanial compounds that can concomitantly establish an effective Th1 response via restoration of requisite signaling between macrophages and T cells, for subsequent activation of macrophages to eliminate intracellular amastigotes. Plants have provided an opulent treasure of biomolecules that have fueled the discovery of antileishmanial drugs. Modulation of immune functions using medicinal plants and their products has emerged as an effective therapeutic strategy. Herein, we review the plant extracts and natural products that have resulted in therapeutic polarization of host immunity to cure leishmaniasis. These immunostimulatory phytochemicals as source of potential antileishmanials may provide new strategies to combat leishmaniasis, alone or as adjunct modality.

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.

Topical application of imiquimod as a treatment for chromoblastomycosis

Chromoblastomycosis is a subcutaneous mycosis that remains a therapeutic challenge, with no standard treatment and high rates of relapse. On the basis of our recent discoveries in mouse models, we tested the efficacy of topical applications of imiquimod to treat patients afflicted with this chronic fungal infection. We report results of treatment for the first 4 recipients of topical imiquimod, all of whom displayed a marked improvement of their lesions, both with and without concurrent oral antifungal therapy.

Leishmaniasis: clinical syndromes and treatment

Leishmaniasis is a global term for cutaneous and visceral anthroponotic and zoonotic diseases caused by the vector-borne parasites of the genus Leishmania. These diseases afflict at least 2 million people each year with more than 350 million at risk in 98 countries worldwide. These are diseases mostly of the impoverished making prevention, diagnosis and treatment difficult. Therapy of leishmaniasis ranges from local treatment of cutaneous lesions to systemic, often toxic, therapy for disseminated cutaneous, mucocutaneous and deadly visceral disease. This review is a summary of the clinical syndromes caused by Leishmania and treatment regimens currently used for various forms of leishmaniasis.

Liposomal resiquimod for the treatment of Leishmania donovani infection

OBJECTIVES

The imidazoquinoline family of drugs are Toll-like receptor 7/8 agonists that have previously been used in the treatment of cutaneous leishmaniasis. Because of the hydrophobic nature of imidazoquinolines, they are traditionally not administered systemically for the treatment of visceral leishmaniasis. We formulated liposomal resiquimod, an imidazoquinoline, for the systemic treatment of visceral leishmaniasis.

METHODS

By using lipid film hydration with extrusion, we encapsulated resiquimod in liposomes. These liposomes were then injected intravenously to treat BALB/c mice infected with Leishmania donovani.

RESULTS

Treatment with liposomal resiquimod significantly decreased the parasite load in the liver, spleen and bone marrow. In addition, resiquimod treatment increased interferon-γ and interleukin-10 production in an antigen recall assay. Resiquimod was shown to be non-toxic in histology and in vitro culture experiments.

CONCLUSIONS

FDA-approved resiquimod, in a liposomal formulation, displays promising results in treating visceral leishmaniasis.

A 3D assessment tool for accurate volume measurement for monitoring the evolution of cutaneous leishmaniasis wounds

Clinical assessment and outcome metrics are serious weaknesses identified on the systematic reviews of cutaneous Leishmaniasis wounds. Methods with high accuracy and low-variability are required to standarize study outcomes in clinical trials. This work presents a precise, complete and noncontact 3D assessment tool for monitoring the evolution of cutaneous Leishmaniasis (CL) wounds based on a 3D laser scanner and computer vision algorithms. A 3D mesh of the wound is obtained by a commercial 3D laser scanner. Then, a semi-automatic segmentation using active contours is performed to separate the ulcer from the healthy skin. Finally, metrics of volume, area, perimeter and depth are obtained from the mesh. Traditional manual 3D and 3D measurements are obtained as a gold standard. Experiments applied to phantoms and real CL wounds suggest that the proposed 3D assessment tool provides higher accuracy (error &#60;2%) and precision rates (error &#60;4%) than conventional manual methods (precision error &#60; 35%). This 3D assessment tool provides high accuracy metrics which deserve more formal prospective study.

Old World cutaneous leishmaniasis: diagnosis and treatment

Cutaneous leishmaniasis is a major world health problem. Diagnosis is suspected on evocative clinical presentation in patients living in or coming from endemic areas. Several methods have been used. The smear is a simple investigation used in endemic regions. The culture enables to identify the specimen. PCR has a high sensitivity. Montenegro's reaction is used in the epidemiological study. Pentavalent antimony derivatives remain the mainstay of systemic treatment. Their efficiency is well established. Their toxicity should be researched. Other treatments can be utilized, such as miltefosine. Local therapy is used in uncomplicated lesions. Injections of the pentavalent antimony derivate, cryotherapy and paromomycin ointmentsis are important options and should be used more frequently in Old World leishmaniasis.

Interventions for American cutaneous and mucocutaneous leishmaniasis: a systematic review update

Introduction

Leishmaniasis is an important public health problem in the Americas. A Cochrane review published in 2009 analyzed 38 randomized controlled trials (RCT). We conducted a systematic review to evaluate the effects of therapeutic interventions for American cutaneous and mucocutaneous leishmaniasis.

Methods

All studies were extracted from PubMed, Embase, Lilacs (2009 to July, 2012 respectively), the Cochrane Central Register of Controlled Trials (6-2012) and references of identified publications. RCTs’ risk of bias was assessed.

Results

We identified 1865 references of interest; we finally included 10 new RCTs. The risk of bias scored low or unclear for most domains. Miltefosine was not significantly different from meglumine antimoniate in the complete cure rate at 6 months (4 RCT; 584 participants; ITT; RR: 1.12; 95%CI: 0.85 to 1.47; I2 78%). However a significant difference in the rate of complete cure favoring miltefosine at 6 months was found in L. panamensis and L. guyanensis (2 RCTs, 206 participants; ITT; RR: 1.22; 95%CI: 1.02 to 1.46; I2 0%). One RCT found that meglumine antimoniate was superior to pentamidine in the rate of complete cure for L. braziliensis (80 participants, ITT; RR: 2.21; 95%CI: 1.41 to 3.49), while another RCT assessing L. guyanensis did not find any significant difference. Although meta-analysis of three studies found a significant difference in the rate of complete cure at 3 months favoring imiquimod versus placebo (134 participants; ITT; RR: 1.45; 95%CI: 1.12 to 1.88; I2 0%), no significant differences were found at 6 and 12 months. Thermotherapy and nitric oxide were not superior to meglumine antimoniate.

Conclusion

Therapeutic interventions for American cutaneous and mucocutaneous leishmaniasis are varied and should be decided according to the context. Since mucosal disease is the more neglected form of leishmaniasis a multicentric trial should be urgently considered.