Monitoring toxicity associated with parenteral sodium stibogluconate in the day-case management of returned travellers with New World cutaneous leishmaniasis [corrected]

Treatment of leishmaniasis with chemotherapy and vaccine: a mathematical model

Leishmaniasis, an infectious disease, manifests itself mostly in two forms, cutaneous leishmaniasis (CL) and, a more severe and potentially deadly form, visceral leishmaniasis (VL). The current control strategy for leishmaniasis relies on chemotherapy drugs such as sodium antimony gluconate (SAG) and meglumine antimoniate (MA). However, all these chemotherapy compounds have poor efficacy, and they are associated with toxicity and other adverse effects, as well as drug resistance. While research in vaccine development for leishmaniasis is continuously progressing, no vaccine is currently available. However, some experimental vaccines such as LEISH-F1+MPL-SE (V) have demonstrated some efficacy when used as drugs for CL patients. In this paper we use a mathematical model to address the following question: To what extent vaccine shots can enhance the efficacy of standard chemotherapy treatment of leishmaniasis? Starting with standard MA treatment of leishmaniasis and combining it with three injections of V , we find, by Day 84, that efficacy increased from 29% to 65-91% depending on the amount of the vaccine. With two or just one injection of V , efficacy is still very high, but there is a definite resurgence of the disease by end-time.

Intravenous Liposomal Amphotericin B Efficacy and Safety for Cutaneous and Mucosal Leishmaniasis: A Systematic Review and Meta-analysis

Background

Tegumentary leishmaniasis is often subject to limited funding, underpowered studies, and a paucity of high-quality interventional studies. Intravenous liposomal amphotericin B (L-AmB) has been increasingly used to treat cutaneous and mucosal leishmaniasis (CL and ML, respectively) despite the lack of well-conducted interventional studies. We conducted a systematic review to consolidate the descriptive evidence on the efficacy and safety of L-AmB in treating CL and ML.

Methods

Several online databases and the reference lists of included studies were searched to extract data from 132 studies comprising both case reports and case series. The population, intervention, comparison, outcome, and study design strategy and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were used.

Results

Of 132 studies included, 92 were case reports and 40 were case series. Of the 92 cases, 65 (82.3%) were considered cured after receiving L-AmB as part of their treatment regimen. Twenty-one of the 92 (22.8%) cases reported adverse reactions to L-AmB. A pooled cure rate of 87.0% (95% CI, 79.0%-92.0%) was reported for the 38 case series that reported on treatment efficacy; 40.7% of the cases were associated with an adverse reaction.

Conclusions

Observational data on cure rates using L-AmB suggest efficacy between 80% and 90%, similar to rates reported for other antileishmanial drugs. The highest efficacy rates were observed when a single cycle of L-AmB was administered to patients with mild-moderate CL and ML. The limitations of this study include the heterogeneity observed among the included studies and the increased likelihood of publication bias associated with the inclusion of case reports and case series. This systematic review further illustrates the need for high-quality comparative trials of intravenous L-AmB for the treatment of tegumentary leishmaniasis.

Sterol profiling of Leishmania parasites using a new HPLC-tandem mass spectrometry-based method and antifungal azoles as chemical probes reveals a key intermediate sterol that supports a branched ergosterol biosynthetic pathway

Human leishmaniasis is an infectious disease caused by Leishmania protozoan parasites. Current chemotherapeutic options against the deadly disease have significant limitations. The ergosterol biosynthetic pathway has been identified as a drug target in Leishmania. However, remarkable differences in the efficacy of antifungal azoles that inhibit ergosterol biosynthesis have been reported for the treatment of leishmaniasis. To better understand the sterol biosynthetic pathway in Leishmania and elucidate the mechanism underlying the differential efficacy of antifungal azoles, we developed a new LC-MS/MS method to study sterol profiles in promastigotes of three Leishmania species, including two L. donovani, one L. major and one L. tarentolae strains. A combination of distinct precursor ion masses and LC retention times allowed for specific detection of sixteen intermediate sterols between lanosterol and ergosterol using the newly developed LC-MS/MS method. Although both posaconazole and fluconazole are known inhibitors of fungal lanosterol 14α-demethylase (CYP51), only posaconazole led to a substantial accumulation of lanosterol in azole-treated L. donovani promastigotes. Furthermore, a key intermediate sterol accumulated by 40- and 7-fold when these parasites were treated with posaconazole and fluconazole, respectively, which was determined as 4α,14α-dimethylzymosterol by high resolution mass spectrometry and NMR spectroscopy. The identification of 4α,14α-dimethylzymosterol supports a branched ergosterol biosynthetic pathway in Leishmania, where lanosterol C4- and C14-demethylation reactions occur in parallel rather than sequentially. Our results suggest that selective inhibition of leishmanial CYP51 is insufficient to effectively prevent parasite growth and dual inhibitors of both CYP51 and the unknown sterol C4-demethylase may be required for optimal antiparasitic effect.

Pentamidine inhibits proliferation, migration and invasion in endometrial cancer via the PI3K/AKT signaling pathway

BACKGROUND

Pentamidine has been reported to have many pharmacological effects including anti- protozoal, anti-inflammatory, and anti-tumor activities. The aim of this study is to investigate the potential therapeutic role of Pentamidine and molecular mechanisms of Pentamidine on PI3K/AKT signaling pathway underlying the anti-tumor properties in endometrial cancer.

METHODS

Our study was carried out in the central laboratory of Harbin Medical University from 2019 to 2021. Human endometrial cancer cell lines Ishikawa and HEC-1A were treated with Pentamidine. The proliferation ability of cells was investigated by MTS and colony formation assays. The cell cycle distribution was detected by flow cytometry. Cell migration and invasion were analyzed by using the wound healing assay and Transwell assay. Western blotting was performed to measure the levels of AKT, p-AKT, MMP-2, and MMP-9.

RESULTS

Our results revealed that treatment of Pentamidine inhibited proliferation, migration and invasion of Ishikawa and HEC-1A endometrial cancer cells. Mechanistic investigation showed that Pentamidine inhibited PI3K/AKT signaling pathway and also reduced the expression of MMP-2 and MMP-9. In addition, co-treatment with PI3K kinase inhibitor LY294002 and Pentamidine leaded to increased repression of cell viability and the protein expression of p-AKT in Ishikawa cells.

CONCLUSIONS

Pentamidine suppresses PI3K/AKT signaling pathway, and inhibits proliferation, migration and invasion of EC cells. These findings suggested that Pentamidine might be a potential candidate for treating EC through PI3K/AKT pathway.

Antileishmanial Drug Discovery and Development: Time to Reset the Model?

Leishmaniasis is a vector-borne parasitic disease caused by Leishmania species. The disease affects humans and animals, particularly dogs, provoking cutaneous, mucocutaneous, or visceral processes depending on the Leishmania sp. and the host immune response. No vaccine for humans is available, and the control relies mainly on chemotherapy. However, currently used drugs are old, some are toxic, and the safer presentations are largely unaffordable by the most severely affected human populations. Moreover, its efficacy has shortcomings, and it has been challenged by the growing reports of resistance and therapeutic failure. This manuscript presents an overview of the currently used drugs, the prevailing model to develop new antileishmanial drugs and its low efficiency, and the impact of deconstruction of the drug pipeline on the high failure rate of potential drugs. To improve the predictive value of preclinical research in the chemotherapy of leishmaniasis, several proposals are presented to circumvent critical hurdles-namely, lack of common goals of collaborative research, particularly in public-private partnership; fragmented efforts; use of inadequate surrogate models, especially for in vivo trials; shortcomings of target product profile (TPP) guides.

Liposomal amphotericin B treatment of Old World cutaneous and mucosal leishmaniasis: A literature review

Old World cutaneous and mucosal leishmaniasis is a potentially serious disease. Systemic treatment approaches with pentavalent antimonials, liposomal amphotericin B, fluconazole and miltefosine are increasingly used despite the absence of supportive evidence - to date, no prospective clinical trials have been conducted for systemic treatment of these diseases. We performed a literature search to delineate the contemporary evidence for the use of liposomal amphotericin B, and found that although cure rates of 17/20 (85%) were achieved in immune competent patients with Old World cutaneous leishmaniasis and cure rates of 10/13 (77%) for Old World mucosal leishmaniasis due to L. infantum, the available data is highly limited with high variation in total treatment dosages. The presented findings reflect a lack of consensus on the optimal treatment dosage and on the schedule of application.

Final diagnosis of 86 cases included in differential diagnosis of American tegumentary leishmaniasis in a Brazilian sample: a retrospective cross-sectional study

BACKGROUND

Cutaneous leishmaniasis is distributed worldwide, including Brazil. Its several clinical forms need to be distinguished from other dermatoses. Clinical similarities and lack of a gold standard diagnostic tool make leishmaniasis-like lesions a challenging diagnosis.

OBJECTIVES.

To report the final diagnosis of patients primarily suspected of having American tegumentary leishmaniasis (ATL).

METHODS.

A retrospective cross-sectional study was conducted on the basis of medical records of 437 patients with clinical suspicion of ATL, registered in electronic hospital system between 1980 and 2013. Demographic, clinical, and laboratory data were compiled.

RESULTS.

Analysis of 86 cases (19.7%) registered as ATL in one of the hypothesis revealed a different final diagnosis; 55 (63.9%) and 31 cases (36.1%) had skin and mucosal lesions, respectively. In 58 cases (67.4%), the requested PCR did not identify Leishmania sp. In 28 cases (32.5%), biopsies established the diagnosis and confirmed tumors, mycobacteriosis, and subcutaneous or systemic mycosis. Overall, 27% of the cases had inflammatory etiology, mainly nasal nonspecific inflammatory processes; 27% had infectious etiology, especially paracoccidioidomycosis and leprosy; 20% had neoplastic etiology, mainly basal and squamous cell carcinoma; 15% had miscellaneous etiology, including neuropathic ulcer, traumatic ulcers, idiopathic ulcer; 11% missed the follow-up.

STUDY LIMITATIONS

Some cases had no final diagnosis due to loss of follow-up.

CONCLUSION.

ATL can be confused with several differential diagnoses, especially inflammatory and infectious granulomatous diseases as well as non-melanoma skin cancers. Clinicians working in tropical areas should be aware of the main differential diagnosis of leishmaniasis-like lesions.

Diagnosis and Treatment of Leishmaniasis: Clinical Practice Guidelines by the Infectious Diseases Society of America (IDSA) and the American Society of Tropical Medicine and Hygiene (ASTMH)

It is important to realize that leishmaniasis guidelines cannot always account for individual variation among patients. They are not intended to supplant physician judgment with respect to particular patients or special clinical situations. The IDSA and ASTMH consider adherence to these guidelines to be voluntary, with the ultimate determinations regarding their application to be made by the physician in the light of each patient's individual circumstances.

The Cure Rate after Placebo or No Therapy in American Cutaneous Leishmaniasis: A Systematic Review and Meta-Analysis

INTRODUCTION

There are few drugs with proven efficacy in cutaneous leishmaniasis (CL), and pentavalent antimonial derivatives are still the main first-line therapeutic agents worldwide, despite their recognized high toxicities. Randomized controlled clinical trials assessing the efficacy and safety of new therapeutic modalities are of high priority, and the definition of the design of such trials raises debate about the use of placebo as a comparator. To support the use of placebo as a comparator, two main points need to be addressed: 1--the cure rate without any therapeutic intervention and 2--the damage caused by CL and its impact on patients.

OBJECTIVE

The aim of this study was to systematically assess the spontaneous cure rate for American CL and to broaden the discussion about placebo use in CL trials.

METHODS

The PRISMA guidelines for systematic reviews and the Cochrane manual were followed. The sources used were the PubMed and LILACS databases. Studies were included if they reported cure rates using placebo or no treatment in American CL.

RESULTS

Thirteen studies of a total of 352 patients were ultimately included in this review. The summarized global cure rates for all Leishmania species according to the intention-to-treat analyses performed at approximately three ("initial cure") and nine ("definitive cure") months after "no treatment" or placebo use were 26% (CI95%: 16 to 40%) and 26% (CI95%:16 to 38%), respectively. Notably, a significantly lower cure rate was observed for L. braziliensis infection (6.4%, CI95%:0.2 to 20%) than for L. mexicana infection (44%, CI95%:19 to 72%), p = 0.002. Of note, relapse occurred in 20% of patients with initial healing (CI95%:9.2 to 38.9%).

CONCLUSION

These results clearly demonstrate a low spontaneous cure rate following no-treatment or placebo use, confirming that this strategy for the control group in CL studies expose patients to greater morbidity, especially for CL caused by L. braziliensis. Therefore, from this point, the crucial question to consider regarding placebo use is the seriousness of the suffering caused by this disease.

Immucillins ImmA and ImmH Are Effective and Non-toxic in the Treatment of Experimental Visceral Leishmaniasis

BACKGROUND

Immucillins ImmA (IA), ImmH (IH) and SerMe-ImmH (SMIH) are synthetic deazapurine nucleoside analogues that inhibit Leishmania (L.) infantum chagasi and Leishmania (L.) amazonensis multiplication in vitro without macrophage toxicity. Immucillins are compared to the Glucantime standard drug in the chemotherapy of Leishmania (L.) infantum chagasi infection in mice and hamsters. These agents are tested for toxicity and immune system response.

METHODOLOGY/PRINCIPAL FINDINGS

BALB/c mice were infected with 107 amastigotes, treated with IA, IH, SMIH or Glucantime (2.5mg/kg/day) and monitored for clinical variables, parasite load, antibody levels and splenocyte IFN-γ, TNF-α, and IL-10 expression. Cytokines and CD4+, CD8+ and CD19+ lymphocyte frequencies were assessed in uninfected controls and in response to immucillins. Urea, creatinine, GOT and GPT levels were monitored in sera. Anti-Leishmania-specific IgG1 antibodies (anti-NH36) increased in untreated animals. IgG2a response, high levels of IFN-γ, TNF-α and lower levels of IL-10 were detected in mice treated with the immucillins and Glucantime. Immucillins permitted normal weight gain, prevented hepato-splenomegaly and cleared the parasite infection (85-89%) without renal and hepatic toxicity. Immucillins promoted 35% lower secretion of IFN-γ in uninfected controls than in infected mice. IA and IH increased the CD4+ T and CD19+ B cell frequencies. SMIH increased only the proportion of CD-19 B cells. IA and IH also cured infected hamsters with lower toxicity than Glucantime.

CONCLUSIONS/SIGNIFICANCE

Immucillins IA, IH and SMIH were effective in treating leishmaniasis in mice. In hamsters, IA and IH were also effective. The highest therapeutic efficacy was obtained with IA, possibly due to its induction of a TH1 immune response. Low immucillin doses were required and showed no toxicity. Our results disclose the potential use of IA and IH in the therapy of visceral leishmaniasis.

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.

Complementary exams in the diagnosis of American tegumentary leishmaniasis

The diagnosis of American Tegumentary Leishmaniasis is a difficult but essential task when considering the high toxicity profile of the drugs available. Since the discovery of its etiologic agent, numerous diagnostic tests have been developed. None of the tests available today can be considered as the gold standard, since they do not add enough accuracy for the disease detection. Good epidemiological and clinical knowledge of the disease are fundamental precepts of the dermatology practice and precede the rational use of existing diagnostic tests. In this article we aim, through extensive literature review, to recall fundamental concepts of any diagnostic test. Subsequently, based on this information, we will weave important comments about the characteristics of existing diagnostic tests, including immunological tests such as Montenegro's skin test, serology and detection of parasites by direct examination, culture or histopathology. Finally we will discuss the new technologies and options for the diagnosis of Cutaneous Leishmaniasis. The molecular biology technique is considered a promising tool, promoting the rapid identification of the species involved. We also aim to educate dermatologists about a disease with high morbidity and assist in its difficult recognition.

LeishMan recommendations for treatment of cutaneous and mucosal leishmaniasis in travelers, 2014

BACKGROUND

Treatment of cutaneous leishmaniasis (CL) and mucosal leishmaniasis (ML) in travelers is still controversial. Over the last decade, national and international consortia have published recommendations for treating CL in travelers. These guidelines harmonize many issues, but there are some discrepancies.

METHODS

Leishmania parasites causing CL can now be genotyped by polymerase chain reaction techniques for detecting Leishmania DNA. Therefore, treatment recommendations can now be species based rather than based on geographical exposure. To review the evidence on which the recommendations were based, "LeishMan" (Leishmaniasis Management), a group of experts from 13 institutions in eight European countries, performed a PubMed MEDLINE) literature search and considered unpublished evidence and the experts' own personal experiences. The Oxford evidence grading system was used to evaluate the information.

RESULTS AND CONCLUSION

In this article, the authors provide practical treatment recommendations for imported CL and ML in Europe, drawn up from the review by the European experts.

Hepatotoxicity of pentavalent antimonial drug: possible role of residual Sb(III) and protective effect of ascorbic acid

Pentavalent antimonial drugs such as meglumine antimoniate (Glucantime [Glu; Sanofi-Aventis, São Paulo, Brazil]) produce severe side effects, including cardiotoxicity and hepatotoxicity, during the treatment of leishmaniasis. We evaluated the role of residual Sb(III) in the hepatotoxicity of meglumine antimoniate, as well as the protective effect of the antioxidant ascorbic acid (AA) during antimonial chemotherapy in a murine model of visceral leishmaniasis. BALB/c mice infected with Leishmania infantum were treated intraperitoneally at 80 mg of Sb/kg/day with commercial meglumine antimoniate (Glu) or a synthetic meglumine antimoniate with lower Sb(III) level (MA), in association or not with AA (15 mg/kg/day), for a 20-day period. Control groups received saline or saline plus AA. Livers were evaluated for hepatocytes histological alterations, peroxidase activity, and apoptosis. Increased proportions of swollen and apoptotic hepatocytes were observed in animals treated with Glu compared to animals treated with saline or MA. The peroxidase activity was also enhanced in the liver of animals that received Glu. Cotreatment with AA reduced the extent of histological changes, the apoptotic index, and the peroxidase activity to levels corresponding to the control group. Moreover, the association with AA did not affect the hepatic uptake of Sb and the ability of Glu to reduce the liver and spleen parasite loads in infected mice. In conclusion, our data supports the use of pentavalent antimonials with low residue of Sb(III) and the association of pentavalent antimonials with AA, as effective strategies to reduce side effects in antimonial therapy.

Cutaneous leishmaniasis in Switzerland: first experience with species-specific treatment

BACKGROUND

Different species of the genus Leishmania can cause cutaneous (CL) and mucosal leishmaniasis (ML). PCR-based tests allow a rapid diagnosis and determination of the species, thereby enabling species-oriented treatment. Such treatment procedures have not been evaluated to date.

METHODS

Patients presenting with CL and ML between 1999 and 2011 were analysed retrospectively. PCR technology was used to diagnose the disease and identify the protozoan to the species level.

RESULTS

A total of 61 cases were reviewed, including 58 patients with CL and three patients with ML. Treatment was effective in most patients. Treatment failure was reported in six patients with L. panamensis (one fluconazole, one ketoconazole), L. infantum (one excision, one fluconazole), L. tropica (one paromomycin/methylbenzethonium), L. braziliensis (1 paromomycin/methylbenzethonium). In 11 (18 %) patients treatment had to be interrupted due to adverse events, and in eight patients (13 %) a second treatment had to be applied. Treatment with meglumine antimoniate had to be interrupted in six patients, with QTc prolongation the reason for the interruption in three patients.

CONCLUSIONS

Species-related, targeted treatment resulted in good responses in CL and ML lesions. Treatment recommendations for L. panamensis were changed from ketoconazole to miltefosine because of new evidence of treatment failures. Meglumine antimoniate should be restricted to species with poor response to alternative medications and should be used with caution in patients older than 60 years because of its toxicity. Treatment in immunosuppressed patients was successful, but relapses were observed when the immune system could not be restored. This is the first report on L. aethiopica from Egypt.