Mucosal leishmaniasis ("espundia" Escomel, 1911)

Treatment of Refractory Mucosal Leishmaniasis Is Associated with Parasite Overexpression of HSP70 and ATPase and Reduced Host Hydrogen Peroxide Production (Brief Report)

BACKGROUND

Mucosal leishmaniasis (ML) is a deforming type of American Tegumentary Leishmaniasis caused by Leishmania (Viannia) braziliensis that frequently does not respond to treatment. Despite its relapsing clinical course, few parasites are usually found in mucosal lesions. Host and parasite factors may be responsible for this paradox in the pathogenesis of the disease, allowing for both a low parasite burden and the inability of the host to clear and eliminate the disease.

METHODS AND RESULTS

In this work, we present a clinical case of relapsing ML that was treated for 25 years without success with SbV, N-methyl glucamine, sodium stibogluconate, amphotericin B deoxycholate, gabromycin, antimonial plus thalidomide, liposomal amphotericin B, Leishvacin (a vaccine made in Brazil) and miltefosine. In a comparative analysis using nanoscale liquid chromatography coupled with tandem mass spectrometry of protein extracts of L. (V.) braziliensis promastigotes isolated from the patient and from the reference strain (MHOM/BR/94/M15176), we observed increases in ATPase and HSP70 protein levels in the parasite. We also observed an impairment in the production of hydrogen peroxide by peripheral mononuclear blood monocytes (PBMCs), as assessed by the horseradish peroxidase-dependent oxidation of phenol red.

CONCLUSIONS

We hypothesise that these parasite molecules may be linked to the impairment of host parasiticidal responses, resulting in Leishmania persistence in ML patients.

Antigenic reactivity of Leishmania (Viannia) lainsoni axenic amastigote proved to be a suitable alternative for optimizing Montenegro skin test

BACKGROUND

Laboratory diagnosis of American cutaneous leishmaniasis (ACL) requires a tool amenable to the epidemiological status of ACL in Brazil. Montenegro skin test (MST), an efficient immunological tool used for laboratory diagnosis of ACL, induces delayed-type hypersensitivity (DTH) response to the promastigote antigens of Leishmania; however, human immune responses against infection are modulated by the amastigote of the parasite. Leishmania (V.) lainsoni induces strong cellular immunity in humans; therefore, the antigenic reactivity of its axenic amastigote (AMA antigen) to MST was evaluated for the laboratory diagnosis of ACL.

METHODS

Among 70 individuals examined, 60 had a laboratory-confirmed diagnosis of ACL; 53 had localized cutaneous leishmaniasis (LCL), and 7 had mucosal leishmaniasis (ML). Patients were treated at the Evandro Chagas Institute's leishmaniasis clinic, Pará State, Brazil. Ten healthy individuals with no history of ACL (control group) were also examined. Leishmania (V.) braziliensis promastigote antigen (PRO) was used to compare the reactivity with that of AMA antigen. Paired Student's t-test, kappa agreement, and Spearman test were used to evaluate the reactivity of AMA and PRO.

RESULTS

The mean reactivity of AMA in ACL patients was 19.4 mm ± 13.3, which was higher (P < 0.001) than that of PRO: 12.1 mm ± 8.1. MST reactivity according to the clinical forms revealed that AMA reactivity in LCL and ML, 18.8 mm ± 13.3 and 24.3 mm ± 13.7, was higher (P < 0.001) than that of PRO, 11.8 mm ± 8.2 and 14.6 mm ± 8.4, respectively.

CONCLUSION

AMA reactivity was higher than that of PRO, indicating that AMA is a promising alternative for optimizing MST in the laboratory diagnosis of ACL.

Cost-effectiveness study of therapeutic approaches for mucosal leishmaniasis

This study aimed to estimate the cost-effectiveness of four therapeutic approaches available for mucosal leishmaniasis in Brazil: miltefosine, meglumine antimoniate, combined with and without pentoxifylline, and liposomal amphotericin B. The perspective adopted was that of the Brazilian Unified National Health System (SUS). The outcome of interest was "cured patient", which was analyzed using a decision tree model. Estimates of direct costs and effectiveness were obtained from the scientific literature. Meglumine antimoniate alone was the base comparator strategy; liposomal amphotericin B showed an incremental cost-effectiveness ratio (ICER) of USD 7,409.13 per cured patient, and the combination of meglumine antimoniate with pentoxifylline presented an ICER of USD 85.13. Miltefosine was absolutely dominated, with higher cost and similar effectiveness when compared to meglumine antimoniate. Sensitivity analyses, varying the cost by ±25%, did not change the results. However, when the cost of miltefosine was estimated at less than USD 171.23, this strategy was dominant over meglumine antimoniate alone. The results confirm that treatment with liposomal amphotericin B remains the option with the highest ICER among the approaches analyzed. Miltefosine may be cost-effective based on the variation in the acquisition price, which deserves attention because it is the only available oral option. The non-accounting of other aspects prevent the use of these results immediately to support decision-making, but they point out the need to negotiate the prices of drugs available for mucosal leishmaniasis and indicates the need of encouraging technology transfer or other actions aimed at expanding the performance of the Brazilian national industrial complex.

Visceral Leishmaniasis in a Twin Pregnancy: A Case Report and Review of the Literature

Visceral leishmaniasis (VL), often referred to as kala-azar, is quite rare in developed countries during pregnancy. Only few studies have evaluated its impact on perinatal outcome. It is caused primarily by Leishmania donovani or Leishmania infantum and presents with a wide spectrum of clinical manifestations from cutaneous ulcers to multisystem disease. Differential diagnosis is challenging as symptoms and signs are insidious, mimicking other diseases. Misdiagnosis can result in severe adverse perinatal outcomes, even maternal/neonatal death. Early treatment with liposomal amphotericin-B (LAmB) is currently the first choice with adequate effectiveness. We report a rare case of VL in a twin pregnancy with onset at the second trimester, presenting with periodic fever with rigors, right flank pain, and gradual dysregulation of all three cell lines. The positive rK39 enzyme-linked immunosorbent assay test confirmed the diagnosis. Treatment with LAmB resulted in clinical improvement within 48 h and in the delivery of two late-preterm healthy neonates with no symptoms or signs of vertical transmission. The one-year follow-up, of the mother and the neonates, was negative for recurrence. To our knowledge, this is the first reported case of VL in a twin pregnancy, and consequently treatment and perinatal outcome are of great importance.

MicroRNAs regulating macrophages infected with Leishmania L. (V.) Braziliensis isolated from different clinical forms of American tegumentary leishmaniasis

Background

Leishmaniasis is an infectious disease caused by protozoa of the genus Leishmania. There are still no vaccines, and therapeutic options are limited, indicating the constant need to understand the fine mechanisms of its pathophysiology. An approach that has been explored in leishmaniasis is the participation of microRNAs (miRNAs), a class of small non-coding RNAs that act, in most cases, to repress gene expression. miRNAs play a role in the complex and plastic interaction between the host and pathogens, either as part of the host's immune response to neutralize infection or as a molecular strategy employed by the pathogen to modulate host pathways to its own benefit.

Methods

Monocyte-derived macrophages from healthy subjects were infected with isolates of three clinical forms of L. braziliensis: cutaneous (CL), mucosal (ML), and disseminated (DL) leishmaniasis. We compared the expression of miRNAs that take part in the TLR/NFkB pathways. Correlations with parasite load as well as immune parameters were analyzed.

Results

miRNAs -103a-3p, -21-3p, 125a-3p -155-5p, -146a-5p, -132- 5p, and -147a were differentially expressed in the metastatic ML and DL forms, and there was a direct correlation between miRNAs -103a-3p, -21-3p, -155-5p, -146a-5p, -132-5p, and -9-3p and parasite load with ML and DL isolates. We also found a correlation between the expression of miR-21-3p and miR-146a-5p with the antiapoptotic gene BCL2 and the increase of viable cells, whereas miR-147a was indirectly correlated with CXCL-9 levels.

Conclusion

The expression of miRNAs is strongly correlated with the parasite load and the inflammatory response, suggesting the participation of these molecules in the pathogenesis of the different clinical forms of L. braziliensis.

Drug Discovery for Cutaneous Leishmaniasis: A Review of Developments in the Past 15 Years

Leishmaniasis is a group of vector-borne, parasitic diseases caused by over 20 species of the protozoan Leishmania spp. The three major disease classifications, cutaneous, visceral, and mucocutaneous, have a range of clinical manifestations from self-healing skin lesions to hepatosplenomegaly and mucosal membrane damage to fatality. As a neglected tropical disease, leishmaniasis represents a major international health challenge, with nearly 350 million people living at risk of infection a year. The current chemotherapeutics used to treat leishmaniasis have harsh side effects, prolonged and costly treatment regimens, as well as emerging drug resistance, and are predominantly used for the treatment of visceral leishmaniasis. There is an undeniable need for the identification and development of novel chemotherapeutics targeting cutaneous leishmaniasis (CL), largely ignored by concerted drug development efforts. CL is mostly non-lethal and the most common presentation of this disease, with nearly 1 million new cases reported annually. Recognizing this unaddressed need, substantial yet fragmented progress in early drug discovery efforts for CL has occurred in the past 15 years and was outlined in this review. However, further work needs to be carried out to advance early discovery candidates towards the clinic. Importantly, there is a paucity of investment in the translation and development of therapies for CL, limiting the emergence of viable solutions to deal with this serious and complex international health problem.

Factors associated with mucosal involvement in tegumentary leishmaniasis: a nation-based study using surveillance data from Brazil

This study aimed to assess the factors associated with mucosal leishmaniasis (ML) within the scope of tegumentary leishmaniasis (TL) cases reported in Brazil. Surveillance data were assessed, and comparisons were made between ML and cutaneous leishmaniasis (CL) cases. Additionally, ML incidence rates for municipalities were depicted through a geographic information system. From 2007 to 2017, 235,489 TL cases were reported, of which 235,232 were classified as follows: 14,204 (6%) were ML cases and 221,028 (94%) were CL cases. Multivariate analysis showed that the proportion of ML cases reached 16.8% among individuals >75 years (adjusted OR = 2.77; 95% CI = 2.41-3.19; p < 0.001), and ML was also more frequent among males (aOR = 1.28; 95% CI = 1.20-1.38; p < 0.001), HIV-positive patients (aOR = 2.15; 95% CI = 1.80-2.56; p < 0.001), patients residing in urban areas (aOR = 1.52; 95% CI = 1.43-1.62; p < 0.001), and imported cases (with respect to county) when compared to autochthonous cases (aOR = 1.84; 95% CI = 1.71-1.98; p < 0.001). A lower proportion of positive results in direct parasitological examinations was observed in ML cases (32.6% vs. 60.8%; p < 0.001). The leishmanin skin test results were more often positive in ML cases (41.7% vs. 25.9%; p < 0.001). In ML, compatible changes in histopathology were more frequent (14.6% vs. 3.9%; p < 0.001). A greater proportion of ML cases were treated with amphotericin B (6.9% vs. 0.9%; p < 0.001). The case-fatality rate was higher in ML (0.6% vs. 0.1%; p < 0.001). A higher incidence of ML was observed in a geographical band extending across the Amazon region from the southern Para State to the Acre State. ML exhibited varying frequencies within specific populations. The definition of predictable factors predisposing Leishmania-infected subjects to develop ML is important for defining strategies to mitigate the mucosal damage caused by leishmaniasis.

Clinical and immunological spectra of human cutaneous leishmaniasis in North Africa and French Guiana

Cutaneous leishmaniasis (CL) caused by infection with the parasite Leishmania exhibits a large spectrum of clinical manifestations ranging from single healing to severe chronic lesions with the manifestation of resistance or not to treatment. Depending on the specie and multiple environmental parameters, the evolution of lesions is determined by a complex interaction between parasite factors and the early immune responses triggered, including innate and adaptive mechanisms. Moreover, lesion resolution requires parasite control as well as modulation of the pathologic local inflammation responses and the initiation of wound healing responses. Here, we have summarized recent advances in understanding the in situ immune response to cutaneous leishmaniasis: i) in North Africa caused by Leishmania (L.) major, L. tropica, and L. infantum, which caused in most cases localized autoresolutives forms, and ii) in French Guiana resulting from L. guyanensis and L. braziliensis, two of the most prevalent strains that may induce potentially mucosal forms of the disease. This review will allow a better understanding of local immune parameters, including cellular and cytokines release in the lesion, that controls infection and/or protect against the pathogenesis in new world compared to old world CL.

In vitro anti-Leishmania activity of new isomeric cobalt(II)complexes and in silico insights: Mitochondria impairment and apoptosis-like cell death of the parasite

The synthesis, physico-chemical characterization and in vitro antiproliferative activity against the promastigote form of Leishmania amazonensis of two new cobalt(II) coordination compounds (i.e. [Co(HL1)Cl₂]0.4,2H₂O (1) and [Co(HL2)(Cl)(CH₃OH)](ClO₄).2H₂O (2)) are reported, where HL1 = 4-{3-[bis(pyridin-2-ylmethyl)amino]-2-hydroxypropoxy}-2H-chromen-2-one and HL2 = 7-{3-[bis(pyridin-2-ylmethyl)amino]-2-hydroxypropoxy}-2H-chromen-2-one. X-ray diffraction studies were performed for complex (2) and the structure of complex (1) was built through Density Functional Theory (DFT) calculations. Complex (1) presented no cytotoxicity to LLC-MK2, but complex (2) was toxic. IC₅₀ against promastigotes of L. amazonensis for complex (1) were 4.90 (24 h), 3.50 (48 h) and 3. 80 μmol L^-1 (72 h), and for complex (2) were 2.09, 4.20 and 2.80 μmol L^-1, respectively. Due to the high toxicity presented by complex (2) against LLC-MK2 host cells, mechanistic studies, to shed light on the probable mode of leishmanicidal activity, were carried out only for the non-cytotoxic complex. Complex (1) was able to elevate mitochondrial membrane potential of the parasites after treatment. Transmission electron microscopy revealed typical apoptotic condensation of chromatin, altered kinetoplast and mitochondria structures, suggesting that apoptosis-like cell death of the protozoa is probably mediated by an apoptotic mechanism associated with mitochondrial dysfunction (intrinsic pathway). Molecular docking studies with complex (1) upon protein tyrosine phosphatase (LmPRL-1) suggests a plausible positive complex anchoring mainly by hydrophobic and hydrogen bond forces close to the enzyme's catalytic site. These promising results for complex 1 will prompt future investigations against amastigote form of L. amazonensis.

Assessment of Immune and Clinical Response in Patients with Mucosal Leishmaniasis Treated with Pentavalent Antimony and Pentoxifylline

Mucosal leishmaniasis (ML) is a severe form of tegumentary leishmaniasis associated with a persistent inflammatory response. High levels of TNF, IFN-γ, CXCL9 and CXCL10 are found in ML patients, and the association of pentoxifylline with antimony is more effective in decreasing the healing time in ML patients when compared to antimony alone. The present study aimed to investigate the existence of a correlation between cytokine and chemokine production and ML severity and evaluate the potential value of cytokine and chemokine production as marker of therapeutic response in ML patients. This prospective study included 86 subjects in an area of endemic Leishmania braziliensis transmission. Patients diagnosed with ML were classified into clinical stages ranging from I to V according to disease severity. TNF, IFN-γ, CXCL9 and CXCL10 levels were quantified in the supernatant of the mononuclear cell cultures by ELISA before and after treatment with antimony alone or antimony plus pentoxifylline. The median TNF level in the group with mild disease (Stages I-II) was 1064 pg/mL (142-3738 pg/mL), while, in the group with moderate or severe disease (Stages III-V), it was 1941 pg/mL (529-5294 pg/mL) (p = 0.008). A direct correlation was observed between ML clinical severity and levels of TNF production (r = 0.44, p = 0.007). Patients who were treated with antimony and pentoxifylline healed significantly faster than those treated with antimony alone (52 vs. 77 days, hazard ratio = 0.60; 95% confidence interval = 0.38-0.95, p = 0.013). Therapeutic failure was higher in the group that received antimony alone (25% vs. 7%; p = 0.041). There was a significant decrease in CXCL9 after therapy of ML in both groups (p = 0.013; p = 0.043). TNF levels are associated with the severity of mucosal diseases, and pentoxifylline associated with antimony should be the recommended therapy for ML in countries where liposomal amphotericin B is not available.

Novel CRISPR-based detection of Leishmania species

Tegumentary leishmaniasis, a disease caused by protozoan parasites of the genus Leishmania, is a major public health problem in many regions of Latin America. Its diagnosis is difficult given other conditions resembling leishmaniasis lesions and co-occurring in the same endemic areas. A combination of parasitological and molecular methods leads to accurate diagnosis, with the latter being traditionally performed in centralized reference and research laboratories as they require specialized infrastructure and operators. Clustered regularly interspaced short palindromic repeats/CRISPR-associated protein (CRISPR/Cas) systems have recently driven innovative tools for nucleic acid detection that combine high specificity, sensitivity and speed and are readily adaptable for point-of-care testing. Here, we harnessed the CRISPR-Cas12a system for molecular detection of Leishmania spp., emphasizing medically relevant parasite species circulating in Peru and other endemic areas in Latin America, with Leishmania (Viannia) braziliensis being the main etiologic agent of cutaneous and mucosal leishmaniasis. We developed two assays targeting multi-copy targets commonly used in the molecular diagnosis of leishmaniasis: the 18S ribosomal RNA gene (18S rDNA), highly conserved across Leishmania species, and a region of kinetoplast DNA (kDNA) minicircles conserved in the L. (Viannia) subgenus. Our CRISPR-based assays were capable of detecting down to 5 × 10-2 (kDNA) or 5 × 100 (18S rDNA) parasite genome equivalents/reaction with PCR preamplification. The 18S PCR/CRISPR assay achieved pan-Leishmania detection, whereas the kDNA PCR/CRISPR assay was specific for L. (Viannia) detection. No cross-reaction was observed with Trypanosoma cruzi strain Y or human DNA. We evaluated the performance of the assays using 49 clinical samples compared to a kDNA real-time PCR assay as the reference test. The kDNA PCR/CRISPR assay performed equally well as the reference test, with positive and negative percent agreement of 100%. The 18S PCR/CRISPR assay had high positive and negative percent agreement of 82.1% and 100%, respectively. The findings support the potential applicability of the newly developed CRISPR-based molecular tools for first-line diagnosis of Leishmania infections at the genus and L. (Viannia) subgenus levels.

Development of an immunogen containing CD4+/CD8+ T-cell epitopes for the prophylaxis of tegumentary leishmaniasis

Abstract

Tegumentary leishmaniasis (TL) is a disease of high severity and incidence in Brazil, and Leishmania braziliensis is its main etiological agent. The inefficiency of control measures, such as high toxicity and costs of current treatments and the lack of effective immunoprophylactic strategies, makes the development of vaccines indispensable and imminent. In this light, the present work developed a gene encoding multiple T-cell (CD4⁺/CD8⁺) epitope, derived from conserved proteins found in Leishmania species and associated with TL, to generate a chimeric protein (rMEP/TL) and compose a vaccine formulation. For this, six T-cell epitopes were selected by immunoinformatics approaches from proteins present in the amastigote stage and associated with host-parasite interactions. The following formulations were then tested in an L. braziliensis murine infection model: rMEP/TL in saline or associated with MPLA-PHAD^®. Our data revealed that, after immunization (three doses; 14-day intervals) and subsequent challenging, rMEP/TL and rMEP/TL + MPLA-vaccinated mice showed an increased production of key immunological biomarkers of protection, such as IgG_2a, IgG_2a/IgG₁, NO, CD4⁺, and CD8⁺ T-cells with IFN-γ and TNF-α production, associated with a reduction in CD4⁺IL-10⁺ and CD8⁺IL-10⁺ T-cells. Vaccines also induced the development of central (CD44^highCD62L^high) and effector (CD44^highCD62L^low) memory of CD4⁺ and CD8⁺ T-cells. These findings, associated with the observation of lower rates of parasite burdens in the vaccinated groups, when compared to the control groups, suggest that immunization with rMEP/TL and, preferably, associated with an adjuvant, may be considered an effective tool to prevent TL.

Key points

• Rational design approaches for vaccine development.

• Central and effector memory of CD4+ and CD8+ T-cells.

• Vaccine comprised of rMEP/TL plus MPLA as an effective tool to prevent TL.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00253-022-12033-7.

Leishmania and its relationships with bacteria

Leishmaniasis is a zoonotic and neglected disease, which represents an important public health problem worldwide. Different species of Leishmania are associated with different manifestations, and a practical problem that can worsen the condition of hosts infected with Leishmania is the secondary infection caused by bacteria. This review aims to examine the importance and prevalence of bacteria co-infection during leishmaniasis and the nature of this ecological relationship. In the cases discussed in this review, the facilitation phenomenon, defined as any interaction where the action of one organism has a beneficial effect on an organism of another species, was considered in the Leishmania-bacteria interaction, as well as the effects on one another and their consequences for the host.

Tongue Nodule as Primary Manifestation of American Cutaneous Leishmaniasis in an Immunocompetent Patient

Leishmaniasis is a parasitic disease considered an endemic public health problem in developing countries, where it is a reportable disease. Isolated oral manifestation is rare, and its clinical manifestations are variable. In this paper we describe an unusual case of an immunocompetent patient, 57-year-old man with a painless reddish submucosal nodule located on the tongue dorsum. Microscopical analysis showed chronic inflammatory infiltrate with macrophages containing leishmania in cytoplasmic vacuoles. PCR assays confirmed the diagnosis and patient was treated with meglumine antimoniate for 30 days. Absence of the parasite was confirmed by PCR. Thirteen years after treatment, a scar fibrosis persisted on the tongue dorsum. The case reported reveals that leishmaniasis should be considered in the diagnosis of tongue nodules in immunocompetent patients.

Efficacy and safety of pentamidine isethionate for tegumentary and visceral human leishmaniasis: a systematic review

RATIONALE FOR REVIEW

We performed a systematic review of the literature to investigate the efficacy and safety of pentamidine isethionate for the treatment of human tegumentary and visceral leishmaniasis.

KEY FINDINGS

A total of 616 papers were evaluated, and 88 studies reporting data on 3108 cases of leishmaniasis (2082 patients with tegumentary leishmaniasis and 1026 with visceral leishmaniasis) were finally included. The majority of available studies were on New World cutaneous leishmaniasis and visceral leishmaniasis caused by Leishmania donovani. At the same time, few data are available for Old World cutaneous leishmaniasis, mucosal leishmaniasis, and visceral leishmaniasis caused by L. infantum. Pooled cure rate for tegumentary leishmaniasis was 78.8% (CI 95%, 76.9-80.6%) and 92.7% (CI 95%, 88.3-97.1%) according to controlled randomized trial and observational studies and case report and case series respectively. Pooled cure rate for visceral leishmaniasis was 84.8% (CI 95%, 82.6-87.1%) and 90.7% (CI 95%, 84.1-97.3%) according to controlled randomized trial and observational studies and case report and case series, respectively. Comparable cure rate was observed in recurrent and refractory cases of visceral leishmaniasis. Concerning the safety profile, among about 2000 treated subjects with some available information, the most relevant side effects were six cases of arrhythmia (including four cases of fatal ventricular fibrillation), 20 cases of irreversible diabetes, 26 cases of muscular aseptic abscess following intramuscular administration.

CONCLUSIONS/RECOMMENDATIONS

Pentamidine isethionate is associated with a similar cure rate of the first-line anti-leishmanial drugs. Severe and irreversible adverse effect appear to be rare. The drug may still have a role in the treatment of any form of human leishmaniasis when the first-line option has failed or in patients who cannot tolerate other drugs also in the setting of travel medicine. In difficult cases, the drug can also be considered as a component of a combination treatment regimen.

Development of a chimeric protein based on a proteomic approach for the serological diagnosis of human tegumentary leishmaniasis

Leishmania braziliensis is responsible for most cases of human tegumentary leishmaniasis (HTL) and has caused a wide range of clinical manifestations, including cutaneous (CL) and mucosal leishmaniasis (ML). The diagnosis is based on criteria that consider epidemiological data, clinical findings, and laboratory tests and is hard to establish. For laboratory tests, none of the assays available can be considered gold standards for disease detection. In addition, the Montenegro skin test, essential to supporting infectologists in the clinical management of the disease, is no longer available in Brazil. Thus, the aim of this study was to develop new targets to be used in diagnostic tests for HTL. In the first step, we carried out two-dimensional gel electrophoresis, followed by mass spectrometry, combined with heat map analysis and immunoproteomics approach, and disclosed eight proteins expressed in the amastigote stage specifically recognized by serum from CL and ML patients. A chimeric protein was designed based on the combination of thirteen linear B-cell epitopes, identified by immunoinformatics analysis, from L. braziliensis proteins. Our results showed that the strategy used in this work was successful in developing an antigen to be used in immunological assays (100.0% sensitivity and specificity) in the detection of HTL cases and in comparison with results obtained from an ELISA using soluble L. braziliensis antigen (SLb-Antigen) and immunofluorescence assay (Bio-Manguinhos/FIOCRUZ). The present technology opens the door for its use in field exams by means of an immunochromatographic test, which will be even more helpful in regions without laboratory structures.Key points• Rational strategy to develop antigens.• Integration between immunoproteomic and immunoinformatics analysis.• Chimeric protein shows high performance in HTL diagnosis.

Oral Tolerance Induced by Heat Shock Protein 65-Producing Lactococcus lactis Mitigates Inflammation in Leishmania braziliensis Infection

Cutaneous leishmaniasis caused by L. braziliensis induces a pronounced Th1 inflammatory response characterized by IFN-γ production. Even in the absence of parasites, lesions result from a severe inflammatory response in which inflammatory cytokines play an important role. Different approaches have been used to evaluate the therapeutic potential of orally administrated heat shock proteins (Hsp). These proteins are evolutionarily preserved from bacteria to humans, highly expressed under inflammatory conditions and described as immunodominant antigens. Tolerance induced by the oral administration of Hsp65 is capable of suppressing inflammation and inducing differentiation in regulatory cells, and has been successfully demonstrated in several experimental models of autoimmune and inflammatory diseases. We initially administered recombinant Lactococcus lactis (L. lactis) prior to infection as a proof of concept, in order to verify its immunomodulatory potential in the inflammatory response arising from L. braziliensis. Using this experimental approach, we demonstrated that the oral administration of a recombinant L. lactis strain, which produces and secretes Hsp65 from Mycobacterium leprae directly into the gut, mitigated the effects of inflammation caused by L. braziliensis infection in association or not with PAM 3CSK4 (N-α-Palmitoyl-S-[2,3-bis(palmitoyloxy)-(2RS)-propyl]-L-cysteine, a TLR2 agonist). This was evidenced by the production of anti-inflammatory cytokines and the expansion of regulatory T cells in the draining lymph nodes of BALB/c mice. Our in vitro experimental results suggest that IL-10, TLR-2 and LAP are important immunomodulators in L. braziliensis infection. In addition, recombinant L. lactis administered 4 weeks after infection was observed to decrease lesion size, as well as the number of parasites, and produced a higher IL-10 production and decrease IFN-γ secretion. Together, these results indicate that Hsp65-producing L. lactis can be considered as an alternative candidate for treatment in both autoimmune diseases, as well as in chronic infections that cause inflammatory disease.

A Review of Leishmaniasis: Current Knowledge and Future Directions

Purpose of Review

The goal of this review is to summarize the current knowledge of the epidemiology, clinical manifestations, diagnosis, and treatment of cutaneous, mucosal, and visceral leishmaniasis. We will describe the most recent findings and suggest areas of further research in the leishmaniasis field.

Recent Findings

This article reviews newer leishmaniasis tests (including rapid diagnostic tests using rK39 antibodies), vaccine candidates, and updated treatment recommendations.

Summary

While leishmaniasis is a complex disease, learning the prominent clinical manifestations and major parasite species can guide the recommendations for diagnosis and treatment.

Molecular Identification of Parasites Causing Cutaneous Leishmaniasis in Panama

Isolates from 475 cutaneous leishmaniasis (CL) patients from three endemic regions were studied by three typing techniques. The molecular analysis from lesion scrapings based on hsp70 PCR-RFLP showed that 78.1% (371/475) restriction patterns corresponded to Leishmania (Viannia) panamensis, 19% (90/475) to Leishmania (Viannia) guyanensis, and 3.0% (14/475) to Leishmania (Viannia) braziliensis. Promastigotes isolated by culture from lesions of 228 patients (48.0%, 228/475) were identified by multi-locus enzyme electrophoresis. Of them, 95.2% (217/228) were typified as L. (V.) panamensis, 1.3% (3/228) as L. (V.) guyanensis, 2.2% (5/228) as L. (V.) braziliensis, and 1.3% (3/228) as hybrids (L. [V.] braziliensis/L. [V.] panamensis). However, a partial sequencing analysis of the hsp70 gene from 77 selected samples showed 16.9% (13/77) typified as L. (V.) panamensis, 68.8% (53/77) as Leishmania (V.) sp., 1, 3.9% (3/77) as L. (V.) guyanensis, 1.3% (1/77) as L. (V.) braziliensis outlier, 2.6% (2/77) as Leishmania (Viannia) naiffi, 2.6% as (2/77) Leishmania (V.) sp., and 2 and 3.9% (3/77) hybrid isolates of L. (V.) braziliensis/L. (V.) guyanensis. These results confirm L. (V.) panamensis as the predominant species and cause of CL lesions in Panama and that L. (V.) guyanensis, L. (V.) braziliensis, and L. (V.) naiffi are circulating to a lower degree. Furthermore, the determination of parasite isolates belonging to atypical clusters and hybrid isolates suggests the circulation of genetic variants with important implications for the epidemiology and clinical follow-up of CL in Panama. No evidence of the existence of parasites of the Leishmania (Leishmania) mexicana complex in Panamanian territory was found in this study.

Quantitative analysis of proteins secreted by Leishmania (Viannia) braziliensis strains associated to distinct clinical manifestations of American Tegumentary Leishmaniasis

The role of Leishmania braziliensis in the development of different clinical forms of American Tegumentary Leishmaniasis (ATL) is unclear, but it has been suggested that molecules secreted/released by parasites could modulate the clinical outcome. Here, we analyzed the infection rate and cytokine profile of macrophages pretreated with the secretome of two L. braziliensis strains associated with polar clinical forms of ATL: one associated with localized self-healing cutaneous leishmaniasis (LCL) and other associated with the disseminated form (DL). Besides, we use an iTRAQ-based quantitative proteomics approach to compare the abundance of proteins secreted by those strains. In vitro infection demonstrated that pretreatment with secretome resulted in higher number of infected macrophages, as well as higher number of amastigotes per cell. Additionally, macrophages pretreated with LCL secretome exhibited a proinflammatory profile, whereas those pretreated with the DL one did not. These findings suggest that secretomes made macrophages more susceptible to infection and that molecules secreted by each strain modulate, differentially, the macrophages' cytokine profile. Indeed, proteomics analysis showed that the DL secretome is rich in molecules involved in macrophage deactivation, while is poor in proteins that activate proinflammatory pathways. Together, our results reveal new molecules that may contribute to the infection, persistence and dissemination of the parasite. SIGNIFICANCE: Leishmania braziliensis is associated to localized self-healing cutaneous lesions (LCL), disseminated leishmaniasis (DL), and mucocutaneous lesions (MCL). To understand the role of the parasite in those distinct clinical manifestations we evaluated infection rates and cytokine profiles of macrophages pre-treated with secretomes of two L. braziliensis strains associated with DL and LCL, and quantitatively compared these secretomes. The infection index of macrophages pretreated with the DL secretome was significantly higher than that exhibited by non-treated cells. Interestingly, whereas the LCL secretome stimulated a proinflammatory setting, favoring an effector cell response that would explain the proper resolution of the disease caused by this strain, the DL strain was not able to elicit such response or has mechanisms to prevent this activation. Indeed, DL secretome is rich in peptidases that may deactivate cell pathways crucial for parasite elimination, while is poor in proteins that could activate proinflammatory pathways, favoring parasite infection and persistence.

Leishmania donovani mucosal leishmaniasis in Malta

We report a case of a 76-year-old British man living in Malta who presented with a 7-month history of recurrent epistaxis and an enlarging right nasal vestibular lesion. Of note, his medical history included rheumatoid arthritis for which he was on long-term methotrexate. Blood results were unremarkable other than a mild lymphopaenia. Despite the use of various antibiotics and intranasal steroids, the lesion failed to resolve. This was eventually biopsied, and the histological picture was that of mucosal leishmaniasis. Leishmania donovani complex was detected by PCR. The patient was treated with liposomal amphotericin B on alternate days for a total of 20 doses. The lesion was found to have healed well at follow-up and the patient denied any further episodes of epistaxis.

Case Report: Unusual Presentation of Pharyngeal Mucosal Leishmaniasis due to Leishmania (Viannia) braziliensis

Mucosal leishmaniasis (ML) affects predominantly the nose and occurs usually weeks or months after the cure of the primary cutaneous lesion. The pathology of ML is characterized by an exaggerated inflammatory reaction with infiltration of lymphocytes, macrophages, and plasma cells. There is also a paucity of parasites and a strong delayed-type hypersensitivity reaction. Herein, we report a case of a young man who had a large ulcer in his left leg and complained of dysphagia. In nasofibrolaryngoscopy, there were nodular lesions in the oropharynx and rhinopharynx. The skin lesion biopsy showed a chronic inflammation with amastigotes inside macrophages, and DNA of Leishmania braziliensis confirmed the diagnosis of ML in tissue biopsied from the pharynx. The leishmaniasis skin test was negative. Cytokine evaluation showed lack of production of interferon (IFN)-γ, interleukin (IL)-1β, and IL-17 with enhancement of these cytokine levels after cure.

One Health Approach to Leishmaniases: Understanding the Disease Dynamics through Diagnostic Tools

Leishmaniases are zoonotic vector-borne diseases caused by protozoan parasites of the genus Leishmania that affect millions of people around the globe. There are various clinical manifestations, ranging from self-healing cutaneous lesions to potentially fatal visceral leishmaniasis, all of which are associated with different Leishmania species. Transmission of these parasites is complex due to the varying ecological relationships between human and/or animal reservoir hosts, parasites, and sand fly vectors. Moreover, vector-borne diseases like leishmaniases are intricately linked to environmental changes and socioeconomic risk factors, advocating the importance of the One Health approach to control these diseases. The development of an accurate, fast, and cost-effective diagnostic tool for leishmaniases is a priority, and the implementation of various control measures such as animal sentinel surveillance systems is needed to better detect, prevent, and respond to the (re-)emergence of leishmaniases.

Application of CRISPR/Cas9-Based Reverse Genetics in Leishmania braziliensis: Conserved Roles for HSP100 and HSP23

The protozoan parasite Leishmania (Viannia) braziliensis (L. braziliensis) is the main cause of human tegumentary leishmaniasis in the New World, a disease affecting the skin and/or mucosal tissues. Despite its importance, the study of the unique biology of L. braziliensis through reverse genetics analyses has so far lagged behind in comparison with Old World Leishmania spp. In this study, we successfully applied a cloning-free, PCR-based CRISPR–Cas9 technology in L. braziliensis that was previously developed for Old World Leishmania major and New World L. mexicana species. As proof of principle, we demonstrate the targeted replacement of a transgene (eGFP) and two L. braziliensis single-copy genes (HSP23 and HSP100). We obtained homozygous Cas9-free HSP23- and HSP100-null mutants in L. braziliensis that matched the phenotypes reported previously for the respective L. donovani null mutants. The function of HSP23 is indeed conserved throughout the Trypanosomatida as L. majorHSP23 null mutants could be complemented phenotypically with transgenes from a range of trypanosomatids. In summary, the feasibility of genetic manipulation of L. braziliensis by CRISPR–Cas9-mediated gene editing sets the stage for testing the role of specific genes in that parasite’s biology, including functional studies of virulence factors in relevant animal models to reveal novel therapeutic targets to combat American tegumentary leishmaniasis.

Epidemiology, clinical pattern and impact of species-specific molecular diagnosis on management of leishmaniasis in Belgium, 2010-2018: A retrospective study

BACKGROUND

Species-directed therapy of leishmaniasis has been recommended for travelers since 2014, but little is known about species distribution and treatment practices in non-endemic countries. We aimed to describe leishmaniasis cases in Belgium since species typing became available and evaluate its impact on patient management.

METHOD

Retrospective analysis of all patients diagnosed by PCR at our national reference laboratory from 2010 to 2018. Species were typed by Hsp-70 sequencing.

RESULTS

We identified 18 visceral leishmaniasis (VL) and 147 (muco)cutaneous leishmaniasis ((M)CL) cases. VL was exclusively due to L. infantum and consistently treated with liposomal amphotericin B, with four observed failures. (M)CL was caused by ten different species. Of 62 cases diagnosed and species typed after 2014 with timing information, 28 (45.2%) were treated before the species result was available. Therapy was not species-directed in 10/32(28.1%) of those treated after species identification. Patients treated according to the guidelines tended to have a favorable outcome more often than those who were not (36/44, 81.8% versus 8/19, 57.9%; p = 0.045).

CONCLUSIONS

In contrast to VL, various species caused (M)CL in our setting and species result was often not considered for treatment. Outcome tended to be better however when therapy was species-directed.

Cutaneous leishmaniasis in male schoolchildren in the upper and lower Dir districts of Khyber Pakhtunkhwa, and a review of previous record in Pakistan

Documented reports are limited, showing cutaneous leishmaniasis (CL) as a severe threat to schoolchildren in Pakistan. The present study aimed to investigate the clinico-epidemiology and associated risk factors of CL in local and Afghan male schoolchildren between 6 and 16 years of age. The experimental strategy involved a questionnaire for the collection of information and clinical diagnosis (microscopy and semi-nested PCR) of 113 CL symptomatic schoolchildren out of 8,833 schoolchildren (7,175 local and 1,658 Afghan refugees) studying in nineteen schools of the Upper and Lower Dir Districts, Khyber Pakhtunkhwa, Pakistan. Previous records of CL in Pakistan was studied, and spatial analysis was performed on elevation and agro-ecological maps using Arc-GIS v10.3.1. Active lesions were found predominant (n=113, 1.2%: cutaneous lesions, 97, 86%, and lesions with mucosal involvement, 16, 14%) than scars (20, 0.25%). Active lesions of both local (100, 88%) and Afghan refugees (13, 12%), and infected age groups were found significantly different. Majority of the lesions were dry crusted (98, 86.7%), single (83, 73%), and frequently infecting facial region (59, 52%). Avoiding bed nets, living in mud houses and animal shelters were highly associated with CL infection. Temergara (30, 26.5%) and Rabath (14, 12.3%) were hyperendemic CL foci. Microscopically, 71 (63%) cases were positive, while the PCR assay revealed Leishmania tropica in 110 (97.3%) cases. Previous record revealed that L. tropica is dominant throughout Pakistan, and dry mountains and plateaus of northwestern and southwestern regions are spatially at high-risk. Measures should be taken to reduce CL infection by eliminating the associated risk factors, promoting PCR-based diagnosis and basic medical facilities.

In-depth quantitative proteomics uncovers specie-specific metabolic programs in Leishmania (Viannia) species

Leishmania species are responsible for a broad spectrum of diseases, denominated Leishmaniasis, affecting over 12 million people worldwide. During the last decade, there have been impressive efforts for sequencing the genome of most of the pathogenic Leishmania spp. as well as hundreds of strains, but large-scale proteomics analyses did not follow these achievements and the Leishmania proteome remained mostly uncharacterized. Here, we report a comprehensive comparative study of the proteomes of strains representing L. braziliensis, L. panamensis and L. guyanensis species. Proteins extracted by SDS-mediated lysis were processed following the multi-enzyme digestion-filter aided sample preparation (FASP) procedure and analysed by high accuracy mass spectrometry. "Total Protein Approach" and "Proteomic Ruler" were applied for absolute quantification of proteins. Principal component analysis demonstrated very high reproducibility among biological replicates and a very clear differentiation of the three species. Our dataset comprises near 7000 proteins, representing the most complete Leishmania proteome yet known, and provides a comprehensive quantitative picture of the proteomes of the three species in terms of protein concentration and copy numbers. Analysis of the abundance of proteins from the major energy metabolic processes allow us to highlight remarkably differences among the species and suggest that these parasites depend on distinct energy substrates to obtain ATP. Whereas L. braziliensis relies the more on glycolysis, L. panamensis and L. guyanensis seem to depend mainly on mitochondrial respiration. These results were confirmed by biochemical assays showing opposite profiles for glucose uptake and O2 consumption in these species. In addition, we provide quantitative data about different membrane proteins, transporters, and lipids, all of which contribute for significant species-specific differences and provide rich substrate for explore new molecules for diagnosing purposes. Data are available via ProteomeXchange with identifier PXD017696.

Case Report: Successful Treatment with Miltefosine of Severe New World Mucosal Leishmaniasis Caused by Leishmania guyanensis

An 88-year-old man with mutilating mucosal leishmaniasis (ML) involving septal perforation, with granulomas in the pharynx and larynx, was treated with oral miltefosine, 50 mg three times/day for 28 days. Miltefosine, an antineoplastic agent, is considered an alternative option for the treatment of ML, showing efficacies of 75-92% in Bolivia, Brazil, and Argentina. The patient denied having previous cutaneous (CL) leishmaniasis, and no CL lesions were recognized by physical examination. Parasites obtained from mucosal lesions were identified by cytochrome b gene sequencing as Leishmania guyanensis. Clinical cure was observed 2 months posttreatment, and no evidence of reactivation was observed in the 3-year follow-up. Adverse effects such as nausea, loss of appetite, and epigastric pain were experienced during treatment with miltefosine. There is a need for improved access to miltefosine in leishmaniasis-endemic areas of Latin America and a greater awareness of ML and its treatment among physicians working in endemic countries.

Cutaneous leishmaniasis in north-central Ethiopia: trend, clinical forms, geographic distribution, and determinants

Background

Cutaneous leishmaniasis (CL), being among the neglected tropical diseases, catches little attention despite its considerable influence. This study aimed at estimating the prevalence and associated factors of CL in Boru Meda Hospital, Dessie town, north-central Ethiopia.

Methods

Medical records of patients who attended the Dermatology Department of the Hospital in 2012-May 2018 were assessed. In addition, dermatological patients who were visiting the hospital during the data collection period (November 2017-May 2018) were interviewed to capture socio-demographic, environmental variables, and related factors. The source population was individuals who visited the hospital for skin problems in the stated years and CL positives were the targets. The association between CL and its determinants was tested by logistic regression.

Results

CL prevalence was 1.5% showing increasing trend with the year of examination. Localized, diffused, and mucosal CL was evident across the years. Dessie town had the highest prevalence, 291 (32.8%) patients out of 888 cases. The number of examined (29,701) and positives (543, 1.8%) for males was comparable with females, 28,459 and 345 (1.2%), respectively, increasing with age but without significant difference. Dessie town residence (adjusted odds ratio (AOR) 12.2, 95% confidence interval (CI) 2.2-18.6, p = 0.01), no bed net (AOR 9.9, 95% CI 2.7-16.7, p < 0.01), nearby irrigation (AOR 8.1, 95% CI 1.9-12.4, p < 0.01), and travel to CL endemic areas (AOR 13.9, 95% CI 4.4-14.3, p < 0.01) were significantly associated with CL.

Conclusion

CL is a growing health problem in Dessie and its surroundings. Known risk factors prevail. Comprehensive parasitological, entomological, and social studies are warranted to better manage the disease.

Immune Profile of the Nasal Mucosa in Patients with Cutaneous Leishmaniasis

Localized skin lesions are characteristic of cutaneous leishmaniasis (CL); however, Leishmania (Viannia) species, which are responsible for most CL cases in the Americas, can spread systemically, sometimes resulting in mucosal disease. Detection of Leishmania has been documented in healthy mucosal tissues (conjunctiva, tonsils, and nasal mucosa) and healthy skin of CL patients and in individuals with asymptomatic infection in areas of endemicity of L (V) panamensis and L (V) braziliensis transmission. However, the conditions and mechanisms that favor parasite persistence in healthy mucosal tissues are unknown. In this descriptive study, we compared the cell populations of the nasal mucosa (NM) of healthy donors and patients with active CL and explored the immune gene expression signatures related to molecular detection of Leishmania in this tissue in the absence of clinical signs or symptoms of mucosal disease. The cellular composition and gene expression profiles of NM samples from active CL patients were similar to those of healthy volunteers, with a predominance of epithelial over immune cells, and within the CD45⁺ cell population, a higher frequency of CD66b⁺ followed by CD14⁺ and CD3⁺ cells. In CL patients with molecular evidence of Leishmania persistence in the NM, genes characteristic of an anti-inflammatory and tissue repair responses (IL4R, IL5RA, POSTN, and SATB1) were overexpressed relative to NM samples from CL patients in which Leishmania was not detected. Here, we report the first immunological description of subclinically infected NM tissues of CL patients and provide evidence of a local anti-inflammatory environment favoring parasite persistence in the NM.

Isolated Laryngeal Leishmaniasis: A Diagnostic Dilemma

Isolated laryngeal Leishmaniasis is a rare entity in the Indian subcontinent. We describe a case of a 45 year old male with hoarseness and noisy breathing. Patient's initial histological and serological workup was inconclusive. Final biopsy findings (suggestive of Leishmania donovani), positive rK-39 serology and his native place being Bihar (endemic for Leishmaniasis) led us to the diagnosis. He was treated with high dose liposomal Amphotericin B to which he responded well. This case report highlights the importance of remaining aware of rare infectious causes of laryngitis. Timely diagnosis and intervention are crucial.

Cost-effectiveness analysis of Mucosal Leishmaniasis diagnosis with PCR-based vs parasitological tests in Colombia

To estimate the cost-effectiveness of available diagnosis alternatives for Mucosal Leishmaniasis (ML) in Colombian suspected patients. A simulation model of the disease's natural history was built with a decision tree and Markov models. The model´s parameters were identified by systematic review and validated by expert consensus. A bottom-up cost analysis to estimate the costs of diagnostic strategies and treatment per case was performed by reviewing 48 clinical records of patients diagnosed with ML. The diagnostic strategies compared were as follows: 1) no diagnosis; 2) parasite culture, biopsy, indirect immunofluorescence assay (IFA), and Montenegro skin test (MST) combined ; 3) parasite culture, biopsy, and IFA combined; 4) PCR-miniexon; and 5) PCR-kDNA. Three scenarios were modeled in patients with ML clinical suspicion, according to ML prevalence scenarios: high, medium and low. Adjusted sensitivity and specificity parameters of a combination of diagnostic tests were estimated with a discrete event simulation (DES) model. For each alternative, the costs and health outcomes were estimated. The time horizon was life expectancy, considering the average age at diagnosis of 31 years. Incremental cost-effectiveness ratios (ICERs) were calculated per Disability Life Year (DALY) avoided, and deterministic and probabilistic sensitivity analyses were performed. A threshold of willingness to pay (WTP) of three-time gross domestic product per capita (GDPpc) (US$ 15,795) and a discount rate of 3% was considered. The analysis perspective was the third payer (Health System). All costs were reported in American dollars as of 2015. PCR- kDNA was the cost-effective alternative in clinical suspicion levels: low, medium and high with ICERs of US$ 7,909.39, US$ 5,559.33 and US$ 4,458.92 per DALY avoided, respectively. ML diagnostic tests based on PCR are cost-effective strategies, regardless of the level of clinical suspicion. PCR-kDNA was the most cost-effective strategy in the competitive scenario with the parameters included in the present model.

Recent Advances in the Discovery of Novel Antiprotozoal Agents

Parasitic diseases have serious health, social, and economic impacts, especially in the tropical regions of the world. Diseases caused by protozoan parasites are responsible for considerable mortality and morbidity, affecting more than 500 million people worldwide. Globally, the burden of protozoan diseases is increasing and is been exacerbated because of a lack of effective medication due to the drug resistance and toxicity of current antiprotozoal agents. These limitations have prompted many researchers to search for new drugs against protozoan parasites. In this review, we have compiled the latest information (2012-2017) on the structures and pharmacological activities of newly developed organic compounds against five major protozoan diseases, giardiasis, leishmaniasis, malaria, trichomoniasis, and trypanosomiasis, with the aim of showing recent advances in the discovery of new antiprotozoal drugs.

What makes mucosal and anergic diffuse cutaneous leishmaniases so clinically and immunopathogically different? A review in Brazil

American cutaneous leishmaniasis (ACL) is a parasitic protozoan disease caused by different Leishmania species widely distributed throughout Latin America. Fifteen Leishmania species belonging to the subgenera Viannia, Leishmania and Mundinia are known to cause ACL. Seven of these species are found in Brazil, of which Leishmania (Viannia) braziliensis and Leishmania (Leishmania) amazonensis have the highest potential to cause mucosal (ML) and anergic diffuse cutaneous leishmaniasis (DCL), respectively, the most severe forms of ACL. The clinical and immunopathological differences between these two clinical forms are reviewed here, taking into account their different physiopathogenic mechanisms of dissemination from cutaneous lesions to mucosal tissues in the case of ML and to almost all body surfaces in the case of anergic DCL. We also discuss some immunopathogenic mechanisms of species-specific Leishmania antigens (from the subgenera Viannia and Leishmania) that are most likely associated with the clinical and immunopathological differences between ML and anergic DCL. Those discussions emphasize the pivotal importance of some surface antigens of L. (V.) braziliensis and L. (L.) amazonensis, such as lipophosphoglycan, phosphatidylserine and CD200 (an immunoregulatory molecule that inhibits macrophage activation), that have been shown to exert strong influences on the clinical and immunopathological differences between ML and anergic DCL.

Mucosal leishmaniasis: A forgotten disease, description and identification of species in 50 Colombian cases

INTRODUCTION

Mucosal leishmaniasis has a progressive course and can cause deformity and even mutilation in the affected areas. It is endemic in the American continent and it is mainly caused by Leishmania (Viannia) braziliensis.

OBJECTIVE

To describe a series of mucosal leishmaniasis cases and the infectious Leishmania species.

MATERIALS AND METHODS

We included 50 patients with a clinical diagnosis of mucosal leishmaniasis and parasitological confirmation, and we described their clinical and laboratory results. We performed species typing by PCR-RFLP using the miniexon sequence and hsp70 genes; confirmation was done by sequencing.

RESULTS

The median time of disease evolution was 2.9 years (range: 1 month to 16 years). The relevant clinical findings included mucosal infiltration (94%), cutaneous leishmaniasis scar (74%), total loss of the nasal septum (24%), nasal deformity (22%), and mucosal ulceration (38%). The symptoms reported included nasal obstruction (90%), epistaxis (72%), rhinorrhea (72%), dysphonia (28%), dysphagia (18%), and nasal pruritus (34%). The histopathological study revealed a pattern compatible with leishmaniasis in 86% of the biopsies, and amastigotes were identified in 14% of them. The Montenegro skin test was positive in 86% of patients, immunofluorescence in 84%, and culture in 8%. Leishmania (V.) braziliensis was identified in 88% of the samples, L. (V) panamensis in 8%, and L. (V.) guyanensis and L. (L.) amazonensis in 2% respectively.

CONCLUSION

In this study, we found a severe nasal disease with destruction and deformity of the nasal septum in 25% of the cases, probably associated with late diagnosis. Leishmania (V.) braziliensis was the predominant species. We described a case of mucosal leishmaniasis in Colombia caused by L. (L.) amazonensis for the first time.

Cutaneous leishmaniasis in non-endemic countries: An emerging yet neglected problem

Cutaneous leishmaniasis (CL) is the most common leishmaniasis syndrome, yet a neglected disease in industrialized non-endemic countries, where it has become an emergent problem. The lack of clinical experience, evidence-based literature and availability of some treatments complicates its management. We report a CL case in a 30 year-old man returned from Brazil, with a cutaneous ulcerated lesion, where it was possible to isolate Leishmania braziliensis/guyanensis complex (subgenus Viannia). An initial course of treatment with miltefosine was attempted, but considering the lack of response, liposomal amphotericin B was used, with very good results. Our report highlights the obstacles faced in the diagnosis and treatment of New World CL in non-endemic countries and the need for more funding and research.

A randomized, open-label clinical trial comparing the long-term effects of miltefosine and meglumine antimoniate for mucosal leishmaniasis

INTRODUCTION

The treatment of mucosal leishmaniasis (ML) is difficult due to the toxicity and route of administration of standard drugs. Miltefosine is an oral agent used for leishmaniasis treatment; however, no data exist regarding its use for ML in Brazil. In this study, we aimed to evaluate the efficacy of miltefosine for ML treatment compared to that of pentavalent antimonial in a pilot study.

METHODS

We performed a randomized clinical trial with two parallel groups. The tested intervention consisted of miltefosine 1.3-2 mg/kg/day (two capsules) for 28 days or intravenous 20 mg SbV/kg/day of meglumine antimoniate (N-MA) for 30 days. The final endpoint was defined as complete healing of the lesion four years after treatment. We also analyzed an early endpoint at 90 days after treatment.

RESULTS

Forty patients were included in this study: each experimental group comprised 20 patients. Applying a multivariate model in an intention-to-treat analysis, we observed that patients treated with miltefosine had a cure probability 2.08 times greater (95% confidence interval [CI] = 1.03-4.18) than those treated with N-MA at 90 days after treatment. At the final endpoint, we observed no differences in cure probability between miltefosine and N-MA (relative risk = 0.66; 95% CI = 0.33-1.32). With respect to adverse reactions, significant differences between groups were related to gastrointestinal effects, which were more frequent in the miltefosine group.

CONCLUSIONS

Miltefosine may be an interesting alternative for treating ML because of its oral administration and cure rate after long-term follow-up.

Melatonin and Leishmania amazonensis Infection Altered miR-294, miR-30e, and miR-302d Impacting on Tnf, Mcp-1, and Nos2 Expression

Leishmaniases are neglected diseases that cause a large spectrum of clinical manifestations, from cutaneous to visceral lesions. The initial steps of the inflammatory response involve the phagocytosis of Leishmania and the parasite replication inside the macrophage phagolysosome. Melatonin, the darkness-signaling hormone, is involved in modulation of macrophage activation during infectious diseases, controlling the inflammatory response against parasites. In this work, we showed that exogenous melatonin treatment of BALB/c macrophages reduced Leishmania amazonensis infection and modulated host microRNA (miRNA) expression profile, as well as cytokine production such as IL-6, MCP-1/CCL2, and, RANTES/CCL9. The role of one of the regulated miRNA (miR-294-3p) in L. amazonensis BALB/c infection was confirmed with miRNA inhibition assays, which led to increased expression levels of Tnf and Mcp-1/Ccl2 and diminished infectivity. Additionally, melatonin treatment or miR-30e-5p and miR-302d-3p inhibition increased nitric oxide synthase 2 (Nos2) mRNA expression levels and nitric oxide (NO) production, altering the macrophage activation state and reducing infection. Altogether, these data demonstrated the impact of melatonin treatment on the miRNA profile of BALB/c macrophage infected with L. amazonensis defining the infection outcome.

[Cutaneous leishmaniasis]

Cutaneous leishmaniasis is a parasitic infection caused by a flagellated parasite belonging to the genus Leishmania. In most cases, it is a zoonotic disease transmitted via a bite by bloodsucking sand-flies of the genus Phlebotomus. The disease reservoirs consist of wild or semi-domesticated animals, generally rodents or dogs. The disease itself is distributed extensively worldwide in the Americas, Asia, Europe and Africa. Epidemiology is affected by environmental, migratory and climatic factors. Identification of the different types of leishmaniasis is based chiefly on the biochemical characteristics (isoenzymes) on which their classification is based. The offending parasites are dimorphic intracellular organisms within the phagosome of the host's immune cells, and a single-cell flagellated protozoan with a kinetoplast contained in the gut of the vector and in culture. Three major clinical forms are seen: cutaneous leishmaniasis, mucosal leishmaniasis and visceral leishmaniasis. The clinical presentation depends on factors associated with the virulence of the parasite, with individual immune response and with the site of lesions. Although each type of leishmaniasis may have its own specific cutaneous signs and endemic regions, the most common presentations are crusted, ulcerated nodules and plaques. The natural history of leishmaniasis must also be considered when formulating therapeutic strategies. Cutaneous leishmaniasis resolves spontaneously within between one month and six years. While numerous therapeutic options have been considered in recent decades, very few have shown proven efficacy and safety. Antimony compounds administered either directly to the lesion or parenterally remain the standard treatment and their toxicity calls for vigilance and monitoring of therapy.

Phonotherapeutic Intervention in Patients With Mucosal Leishmaniasis Sequelae

PURPOSE

To characterize the voice before and after speech-language intervention, with Humming nasal sound in patients with sequelae Mucosal Leishmaniasis (ML) and Cutaneous Leishmaniasis (CL).

METHODS

Collection of phonation /a:/ from 44 patients with ML and CL for perceptual voice analysis and computed acoustic. The Wilcoxon nonparametric test and Fisher's exact test were used, with significance level of 5%.

RESULTS

It was observed, prespeech therapy, that 27.7% of participants with ML presented asthenic vocal quality, and for the acoustics characteristics there was a statistically significant result for measures of frequency, frequency disturbance, noise, and subharmonic measurements, indicating phonatory instability, weakness, and noise emission giving the emission a feeling of vocal weakness. After therapy, the subharmonic segment measurements for the group with ML, showing reduction noise emission. Patients with CL had more grade 1 instability (36.4%), indicating tremor in vocal tract structures. After speech therapy, this group presented a reduction in the degree of roughness and reduction of the frequency disturbance measures, indicating a decrease in tension in the larynx and pharynx.

CONCLUSION

Even after completing treatment for LM, patients may experience vocal changes due to the sequelae of the disease, like vocal alterations due to nasal lesions or in other locations that interfere in the correct vocal emission. As for participants with CL, no vocal changes would be expected, since these patients present thorax, leg and arm lesions that would not cause problems for the voice. Nevertheless, the two groups of participants presented vocal changes to different degrees before vocal therapy. However, it was observed that patients with ML present vocal alterations with more severe degrees. After the speech-language intervention, the participants of both groups showed vocal improvement, but the group with CL presented more vocal benefits, possibly due to the previous vocal alterations not being so severe.

Leishmaniasis

Leishmaniasis is a poverty-related disease with two main clinical forms: visceral leishmaniasis and cutaneous leishmaniasis. An estimated 0·7-1 million new cases of leishmaniasis per year are reported from nearly 100 endemic countries. The number of reported visceral leishmaniasis cases has decreased substantially in the past decade as a result of better access to diagnosis and treatment and more intense vector control within an elimination initiative in Asia, although natural cycles in transmission intensity might play a role. In east Africa however, the case numbers of this fatal disease continue to be sustained. Increased conflict in endemic areas of cutaneous leishmaniasis and forced displacement has resulted in a surge in these endemic areas as well as clinics across the world. WHO lists leishmaniasis as one of the neglected tropical diseases for which the development of new treatments is a priority. Major evidence gaps remain, and new tools are needed before leishmaniasis can be definitively controlled.

Leishmaniasis: current challenges and prospects for elimination with special focus on the South Asian region

Leishmania donovani, the most virulent species of Leishmania, is found in the South Asian region that harbours the majority of visceral leishmaniasis (VL) cases in the world. The traditionally accepted relationships between the causative species of Leishmania and the resultant disease phenotype have been challenged during recent years and have underscored the importance of revisiting the previously established taxonomy with revisions to its classification. The weak voice of the afflicted with decades of neglect by scientists and policy makers have led to the miserably inadequate and slow advancements in product development in the fields of diagnostics, chemotherapeutics and vector control that continue to hinder the effective management and control of this infection. Limitations notwithstanding, the regional drive for the elimination of VL initiated over a decade ago that focused on India, Nepal and Bangladesh, the three main afflicted countries in the Indian subcontinent is therefore, commendable, with the subsequent status reviews and restructuring of strategies possibly even more so. However, the renewed efforts would need to be combined with plans to combat new challenges in the South-Asian region that includes the emergence of atypical parasite variants, in order to realistically achieve the set goal of regional elimination of VL.

The Elderly Respond to Antimony Therapy for Cutaneous Leishmaniasis Similarly to Young Patients but Have Severe Adverse Reactions

There is evidence that elderly patients with cutaneous leishmaniasis (CL) have more mucosal and disseminated diseases than young patients and their cells produce less antigen-induced interferon (IFN)-γ. Herein, we compared the roles of interleukin (IL)-10 and IL-15 as modulators of antigen-induced immune responses and the incidence of adverse reaction and response to therapy in young versus elderly patients with CL. Study participants included 35 senior (60-85 years) and 35 young (18-40 years) patients who had a diagnosis of CL documented by typical cutaneous lesions containing Leishmania braziliensis DNA. Elderly patients had less lymph node enlargement. Antigen-induced blood cell cytokine responses were studied in the absence or presence of IL-10 antibody or exogenously added recombinant IL-15. The ratio of IFN-γ/IL-10 was lower in elderly patients, and IFN-γ production was enhanced by either neutralization of IL-10 or exogenous recombinant IL-15 in blood cells from elderly but not young patients. Patients were treated three times weekly with antimony at 20 mg/kg/day for 20 doses. Although there was no difference in response to therapy between the two groups, two young patients needed rescue therapy with amphotericin B. Ventricular arrhythmias and ventricular overload were more frequent in elderly patients. We conclude that elderly patients have alterations in the immune response that may influence clinical manifestations, but we did not find that they had a higher failure rate than young subjects to antimony therapy. However, because of the high rate of electrocardiographic abnormalities during therapy, antimony should not be used in elderly patients with CL.

Safety and efficacy of miltefosine monotherapy and pentoxifylline associated with pentavalent antimony in treating mucosal leishmaniasis

INTRODUCTION

Mucosal Leishmaniasis (ML) is a difficult to treat and severe form of Leishmaniasis. In general, more than 40% of subjects with ML have therapeutic failure upon the use of pentavalent antimony (Sb^v) at 20mg/kg/day during 30 days. Additionally, Sb^v is a toxic drug that requires parenteral administration, and many patients will need several courses to be cured. In cases that cannot be treated or cured by Sb^v, the alternative is amphotericin B, another toxic and parenteral drug. As a consequence, many ML patients will be cured only after years of disease and may present several morbidities due to the aggressiveness of the disease or toxicity related to the treatment. Areas covered: We aimed to review clinical trials with Miltefosine or Sb^v associated with pentoxifylline in the treatment of ML. Expert commentary: There are few studies to define more effective and safer therapy in mucosal disease caused by Leishmania, with an urgent need to supporting and funding well designed trials. Miltefosine monotherapy, as well as pentoxifylline combined with Sb^v are promising therapeutic approaches to increase the cure rate of this neglected disease.

Arginine and Polyamines Fate in Leishmania Infection

Leishmania is a protozoan parasite that alternates its life cycle between the sand fly and the mammalian host macrophages, involving several environmental changes. The parasite responds to these changes by promoting a rapid metabolic adaptation through cellular signaling modifications that lead to transcriptional and post-transcriptional gene expression regulation and morphological modifications. Molecular approaches such as gene expression regulation, next-generation sequencing (NGS), microRNA (miRNA) expression profiling, in cell Western blot analyses and enzymatic activity profiling, have been used to characterize the infection of murine BALB/c and C57BL/6 macrophages, as well as the human monocytic cell-lineage THP-1, with Leishmania amazonensis wild type (La-WT) or arginase knockout (La-arg^-). These models are being used to elucidate physiological roles of arginine and polyamines pathways and the importance of arginase for the establishment of the infection. In this review, we will describe the main aspects of Leishmania-host interaction, focusing on the arginine and polyamines pathways and pointing to possible targets to be used for prognosis and/or in the control of the infection. The parasite enzymes, arginase and nitric oxide synthase-like, have essential roles in the parasite survival and in the maintenance of infection. On the other hand, in mammalian macrophages, defense mechanisms are activated inducing alterations in the mRNA, miRNA and enzymatic profiles that lead to the control of infection. Furthermore, the genetic background of both parasite and host are also important to define the fate of infection.

Antiprotozoal activity of medicinal plants used by Iquitos-Nauta road communities in Loreto (Peru)

ETHNOPHARMACOLOGICAL RELEVANCE

In the Peruvian Amazon, the use of medicinal plants is a common practice. However, there is few documented information about the practical aspects of their use and few scientific validation. The starting point for this work was a set of interviews of people living in rural communities from the Peruvian Amazon about their uses of plants. Protozoan diseases are a public health issue in the Amazonian communities, who partly cope with it by using traditional remedies. Validation of these traditional practices contributes to public health care efficiency and may help identify new antiprotozoal compounds.

AIMS OF STUDY

to inventory and validate the use of medicinal plants by rural people of Loreto region.

MATERIALS AND METHODS

Rural mestizos were interviewed about traditional medication of parasite infections with medicinal plants. Ethnopharmacological surveys were undertaken in two villages along Iquitos-Nauta road (Loreto region, Peru), namely 13 de Febrero and El Dorado communities. Forty-six plants were collected according to their traditional use for the treatment of parasitic diseases, 50 ethanolic extracts (different parts for some of the plants) were tested in vitro on Plasmodium falciparum (3D7 sensitive strain and W2 chloroquine resistant strain), Leishmania donovani LV9 strain and Trypanosoma brucei gambiense. Cytotoxic assessment (HUVEC cells) of the active extracts was performed. Two of the most active plants were submitted to preliminary bioguided fractionation to ascertain and explore their activities.

RESULTS

From the initial plants list, 10 were found to be active on P. falciparum, 15 on L. donovani and 2 on the three parasites. The ethanolic extract from Costus curvibracteatus (Costaceae) leaves and Grias neuberthii (Lecythidaceae) bark showed strong in vitro activity on P. falciparum (sensitive and resistant strain) and L. donovani and moderate activity on T. brucei gambiense.

CONCLUSIONS

The Amazonian forest communities in Peru represents a source of knowledge on the use of medicinal plants. In this work, several extracts with antiprotozoal activity were identified. This work contributes to validate some traditional uses and opens subsequent investigations on active compounds isolation and identification.