Treatment of mucocutaneous leishmaniasis - A systematic review.

Mucocutaneous leishmaniasis is a severe infectious disease, predominantly endemic in Central and South America and is characterized by granulomatous, destructive mucosal lesions in the oral, nasal, and pharyngeal cavities. It is caused by protozoa of the genus Leishmania spp. transmitted to humans by sandflies. Mucocutaneous leishmaniasis occurs after untreated or inadequately treated cutaneous leishmaniasis and is more common in immunocompromised patients. The aim of this systematic review is to summarize all reported treatment options for mucocutaneous leishmaniasis. This review is based on all English, German, French, Spanish and Portuguese articles published in the databases "PubMed" and "Lilacs" from 1995 to 2020. Most of the medical literature is limited to case reports, small case series, retrospective studies, and a few randomized controlled trials. Various treatment options include pentavalent antimonates such as meglumine antimonate or sodium stibogluconate, amphotericin B (liposomal, deoxycholate, lipid complex, colloidal dispersion), miltefosine, and pentamidine. Other therapeutic options include itraconazole, fluconazole, ketoconazole, aminosidine sulfate, and azithromycin. The choice of drug depends primarily on its availability in the endemic area and the patient's comorbidities.

Detection of Leishmania RNA Virus 1 in Leishmania (Viannia) panamensis Isolates, Panama.

We detected Leishmania RNA virus 1 (LRV1) in 11 isolates of Leishmania (Viannia) panamensis collected during 2014-2019 from patients from different geographic areas in Panama. The distribution suggested a spread of LRV1 in L. (V.) panamensis parasites. We found no association between LRV1 and an increase in clinical pathology.

Clinicopathological characteristics of cutaneous and mucocutaneous leishmaniasis in patients treated with TNF-α inhibitors.

BACKGROUND AND OBJECTIVES: The increasing use of biologics in the treatment of inflammatory diseases has led to more cases of leishmaniasis in patients subjected to iatrogenic immunosuppression. The main objective was to describe the characteristics of the patients with cutaneous (CL) or mucocutaneous (MCL) leishmaniasis who were receiving a biological therapy at the time of diagnosis. PATIENTS AND METHODS: A multicenter retrospective study was design based on a cohort of patients diagnosed with CL or MCL. All patients who were being treated with biologicals were included. For each case, two matched non-exposed patients were included for comparison. RESULTS: 38 patients were diagnosed with CL or MCL while being treated with tumor necrosis factor alpha (TNF-α) inhibitors. Leishmaniasis presented more frequently as a plaque (58.3%) with a larger median lesion size (2.5 cm), ulceration (92.1%), and required a greater median number of intralesional meglumine antimoniate infiltrations (3 doses) (P < 0.05) than in non-exposed patients. We found no systemic involvement in patients being treated with anti-TNF-α. We did not find differences regarding the treatment characteristics whether biologic therapy was modified or not. CONCLUSIONS: Although management should be individualized, maintenance of biologic therapy does not seem to interfere with treatment of CL or MCL.

A trespasser from a foreign land? A case report of primary mucosal leishmaniasis.

BACKGROUND: We report a clinically challenging and unusual case of L. donovani oral mucosal leishmaniasis. CASE PRESENTATION: Israeli resident with a former travel to central and North Africa, with no documented or prior cutaneous lesions presented with oral lesions of the maxillary gingiva and the upper lip. A delay in diagnosis and treatment have led to progression of the maxillary gingival lesions towards the hard palatal and the soft palate that could have potentially compromised the upper airway. CONCLUSIONS: This case highlights the importance of early diagnosis of leishmaniasis in patients with oral lesions and the laboratory workup necessary to appropriately characterize and treat the disease.

Clinical-therapeutic follow-up of patients with American cutaneous leishmaniasis caused by different Leishmania spp. in Brazil.

American cutaneous leishmaniasis (ACL) may present different clinical manifestations, immune and therapeutic responses, depending on the Leishmania species, as well as inoculum size and factors inherent to the affected individual. Thus, the aim of this study was to carry out clinical-therapeutic follow-up of Brazilian patients with ACL caused by different Leishmania species. Between 2015 and 2018, patients with ACL from Amazonas and Pernambuco states (Brazil) were submitted to blood collection before and after treatment. The qPCR technique was used to quantify the parasite load. To identify the Leishmania species, one of the following techniques was employed: a conventional PCR performed from biopsy or blood DNA, followed by sequencing; or Multilocus Enzyme Electrophoresis from Leishmania isolated from biopsy/aspirated lesion. A total of 10.8% (23/213) of the patients included in positive cases were followed-up. All 23 patients were clinically and epidemiologically compatible with ACL and were also positive in parasitological tests (86.96%), molecular tests (73.91%) or both (60.87%). Seventeen samples collected before treatment and 11 collected after treatment were positive in the qPCR assay, with a mean parasite load (MPL) of 38.33 fg/µL and 11.81 fg/µL, respectively. Eight samples were positive in both collections. Thirteen patients (56.52%) were clinically cured (wound healing). Ten patients (43.47%) were not clinically cured at the time of return with the attending physician. Identification of Leishmania species was carried out in samples from nine patients, and six were identified as L. (Viannia) braziliensis, 2 as L (Viannia) guyanensis and 1 as L (Leishmania) amazonensis. One patient infected with L. guyanensis and other with L. braziliensis were not clinically cured and increased the mean parasite load after treatment. The data obtained from the followed-up patients and the relationship between clinical evolution and the infecting species demonstrate the need to understand its etiology to define the effective therapeutic protocol.

A Potential New Source of Therapeutic Agents for the Treatment of Mucocutaneous Leishmaniasis: The Essential Oil of Rhaphiodon echinus.

Weeds are an important source of natural products; with promising biological activity. This study investigated the anti-kinetoplastida potential (in vitro) to evaluate the cytotoxicity (in vitro) and antioxidant capacity of the essential oil of Rhaphiodon echinus (EORe), which is an infesting plant species. The essential oil was analyzed by GC/MS. The antioxidant capacity was evaluated by reduction of the DPPH radical and Fe3+ ion. The clone Trypanosoma cruzi CL-B5 was used to search for anti-epimastigote activity. Antileishmanial activity was determined using promastigotes of Leishmania braziliensis (MHOM/CW/88/UA301). NCTC 929 fibroblasts were used for the cytotoxicity test. The results showed that the main constituent of the essential oil was γ-elemene. No relevant effect was observed concerning the ability to reduce the DPPH radical; only at the concentration of 480 µg/mL did the essential oil demonstrate a high reduction of Fe3+ power. The oil was active against L. brasiliensis promastigotes; but not against the epimastigote form of T. cruzi. Cytotoxicity for mammalian cells was low at the active concentration capable of killing more than 70% of promastigote forms. The results revealed that the essential oil of R. echinus showed activity against L. brasiliensis; positioning itself as a promising agent for antileishmanial therapies.

Immunoproteomics characterization of Leishmania panamensis proteins for potential clinical diagnosis of mucosal Leishmaniasis.

Diagnosis of leishmaniasis based on antibodies detection represents a challenge due to cross-reaction of sera with other infectious agents, which co-exist in endemic areas of Leishmania sp, especially patients with Trypanosoma cruzi. This work is aimed at searching for immunogenic proteins in sera from patients with cutaneous and mucosal leishmaniasis that may be potential candidates for the development of diagnostic tests and/or vaccines that help control the infection. Total protein extracts of L. panamensis promastigotes were put in contact with sera from patients with cutaneous and mucosal leishmaniasis (immunoblots). Immunoreactive proteins were identified by mass spectrometry and bioinformatics tools. 81 proteins were identified. One of these was uniquely recognized by the sera from patients with ML but not from sera from either CL or Chagas disease patients. MS analysis of this band pointed to the putative leishmanial 3-oxoacyl-(Acylcarrierprotein) reductase.

In situ study of cellular immune response in human cutaneous lesions caused by Leishmania (Viannia) panamensis in Panama.

AIMS: Leishmaniasis is considered a disease with multiple clinical/immunopathological characteristics, depending on the immunity of the host and the species of the parasite. In Panama, the most prevalent species that causes localized cutaneous leishmaniasis (LCL) is Leishmania (Viannia) panamensis, and its immune response is poorly studied. Therefore, we evaluated by immunohistochemistry, the in situ immune response during this infection. METHODS AND RESULTS: Biopsies from Panamanian patients with LCL were collected and processed by histological techniques. Infection by L. (V.) panamensis was demonstrated by isolation in culture and molecular characterization by Hsp70-RFLP. The in situ immune response was assessed by immunohistochemistry. The immune response was characterized by predominance of T cells, mainly CD8 cells that showed positive correlation with IFN-γ and Granzyme B. CD4 cells presented positive correlation with both IFN-γ and IL-13, pointed by mixed cellular immune response. Regulatory response was characterized by FoxP3 cells, which showed positive correlation to IL-10 but not with TGF-ß. CONCLUSIONS: L. (V.) panamensis infection triggers a mixed cellular immune response, characterized by the presence of pro-inflammatory, anti-inflammatory and regulatory elements in the skin lesion of Panamanian patients. These data contribute to a better understanding of the immunopathogenesis of Leishmania Viannia infection in Panama.

B-cell profile, B-cell activating factor concentration and IgG levels in human cutaneous and mucosal leishmaniasis.

AIMS: The aim of this study was to evaluate characteristics of B cells in human tegumentary leismaniasis (TL) analysing cutaneous leishmaniasis (CL), most prevalent form and mucosal leishmaniasis (ML), aggressive form characterized by the destruction of the oral-nasal-pharyngeal cavities. METHODS AND RESULTS: By flow cytometry analysis, we found decreased percentages of non-class-switched memory B cells in TL with the degree of the loss related to clinical severity. Using commercial ELISA, we reported high levels of B-cell activating factor (BAFF) and IgG preferentially in aggressive CL and markedly in ML together with decreased BAFF receptors in the latter. We also found lower levels of BAFF after clinical recovery suggesting a relation between BAFF and disease activity. Mucosal leishmaniasis history of therapeutic failure presented high levels of BAFF accompanied by detectable concentrations of IFN-γ and IL-6 (assayed by commercial ELISA and cytometric bead arrays respectively), cytokines involved in exaggerated inflammatory responses and tissue damage in TL. CONCLUSION: We demonstrate B-cell disturbances in TL with the degree of the alterations related to clinical severity. We suggest a relation between excess of BAFF and disease activity and point towards a possible implication of BAFF in the inflammatory phenomenon of ML.

Interventions for American cutaneous and mucocutaneous leishmaniasis.

BACKGROUND: On the American continent, cutaneous and mucocutaneous leishmaniasis (CL and MCL) are diseases associated with infection by several species of Leishmania parasites. Pentavalent antimonials remain the first-choice treatment. There are alternative interventions, but reviewing their effectiveness and safety is important as availability is limited. This is an update of a Cochrane Review first published in 2009. OBJECTIVES: To assess the effects of interventions for all immuno-competent people who have American cutaneous and mucocutaneous leishmaniasis (ACML). SEARCH METHODS: We updated our database searches of the Cochrane Skin Group Specialised Register, CENTRAL, MEDLINE, Embase, LILACS and CINAHL to August 2019. We searched five trials registers. SELECTION CRITERIA: Randomised controlled trials (RCTs) assessing either single or combination treatments for ACML in immuno-competent people, diagnosed by clinical presentation and Leishmania infection confirmed by smear, culture, histology, or polymerase chain reaction on a biopsy specimen. The comparators were either no treatment, placebo only, or another active compound. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. Our key outcomes were the percentage of participants 'cured' at least three months after the end of treatment, adverse effects, and recurrence. We used GRADE to assess evidence certainty for each outcome. MAIN RESULTS: We included 75 studies (37 were new), totalling 6533 randomised participants with ATL. The studies were mainly conducted in Central and South America at regional hospitals, local healthcare clinics, and research centres. More male participants were included (mean age: roughly 28.9 years (SD: 7.0)). The most common confirmed species were L. braziliensis, L. panamensis, and L. mexicana. The most assessed interventions and comparators were non-antimonial systemics (particularly oral miltefosine) and antimonials (particularly meglumine antimoniate (MA), which was also a common intervention), respectively. Three studies included moderate-to-severe cases of mucosal leishmaniasis but none included cases with diffuse cutaneous or disseminated CL, considered the severe cutaneous form. Lesions were mainly ulcerative and located in the extremities and limbs. The follow-up (FU) period ranged from 28 days to 7 years. All studies had high or unclear risk of bias in at least one domain (especially performance bias). None of the studies reported the degree of functional or aesthetic impairment, scarring, or quality of life. Compared to placebo, at one-year FU, intramuscular (IM) MA given for 20 days to treat L. braziliensis and L. panamensis infections in ACML may increase the likelihood of complete cure (risk ratio (RR) 4.23, 95% confidence interval (CI) 0.84 to 21.38; 2 RCTs, 157 participants; moderate-certainty evidence), but may also make little to no difference, since the 95% CI includes the possibility of both increased and reduced healing (cure rates), and IMMA probably increases severe adverse effects such as myalgias and arthralgias (RR 1.51, 95% CI 1.17 to 1.96; 1 RCT, 134 participants; moderate-certainty evidence). IMMA may make little to no difference to the recurrence risk, but the 95% CI includes the possibility of both increased and reduced risk (RR 1.79, 95% CI 0.17 to 19.26; 1 RCT, 127 participants; low-certainty evidence). Compared to placebo, at six-month FU, oral miltefosine given for 28 days to treat L. mexicana, L. panamensis and L. braziliensis infections in American cutaneous leishmaniasis (ACL) probably improves the likelihood of complete cure (RR 2.25, 95% CI 1.42 to 3.38), and probably increases nausea rates (RR 3.96, 95% CI 1.49 to 10.48) and vomiting (RR 6.92, 95% CI 2.68 to 17.86) (moderate-certainty evidence). Oral miltefosine may make little to no difference to the recurrence risk (RR 2.97, 95% CI 0.37 to 23.89; low-certainty evidence), but the 95% CI includes the possibility of both increased and reduced risk (all based on 1 RCT, 133 participants). Compared to IMMA, at 6 to 12 months FU, oral miltefosine given for 28 days to treat L. braziliensis, L. panamensis, L. guyanensis and L. amazonensis infections in ACML may make little to no difference to the likelihood of complete cure (RR 1.05, 95% CI 0.90 to 1.23; 7 RCTs, 676 participants; low-certainty evidence). Based on moderate-certainty evidence (3 RCTs, 464 participants), miltefosine probably increases nausea rates (RR 2.45, 95% CI 1.72 to 3.49) and vomiting (RR 4.76, 95% CI 1.82 to 12.46) compared to IMMA. Recurrence risk was not reported. For the rest of the key comparisons, recurrence risk was not reported, and risk of adverse events could not be estimated. Compared to IMMA, at 6 to 12 months FU, oral azithromycin given for 20 to 28 days to treat L. braziliensis infections in ACML probably reduces the likelihood of complete cure (RR 0.51, 95% CI 0.34 to 0.76; 2 RCTs, 93 participants; moderate-certainty evidence). Compared to intravenous MA (IVMA) and placebo, at 12 month FU, adding topical imiquimod to IVMA, given for 20 days to treat L. braziliensis, L. guyanensis and L. peruviana infections in ACL probably makes little to no difference to the likelihood of complete cure (RR 1.30, 95% CI 0.95 to 1.80; 1 RCT, 80 participants; moderate-certainty evidence). Compared to MA, at 6 months FU, one session of local thermotherapy to treat L. panamensis and L. braziliensis infections in ACL reduces the likelihood of complete cure (RR 0.80, 95% CI 0.68 to 0.95; 1 RCT, 292 participants; high-certainty evidence). Compared to IMMA and placebo, at 26 weeks FU, adding oral pentoxifylline to IMMA to treat CL (species not stated) probably makes little to no difference to the likelihood of complete cure (RR 0.86, 95% CI 0.63 to 1.18; 1 RCT, 70 participants; moderate-certainty evidence). AUTHORS' CONCLUSIONS: Evidence certainty was mostly moderate or low, due to methodological shortcomings, which precluded conclusive results. Overall, both IMMA and oral miltefosine probably result in an increase in cure rates, and nausea and vomiting are probably more common with miltefosine than with IMMA. Future trials should investigate interventions for mucosal leishmaniasis and evaluate recurrence rates of cutaneous leishmaniasis and its progression to mucosal disease.

Type I interferons induced by endogenous or exogenous viral infections promote metastasis and relapse of leishmaniasis.

The presence of the endogenous Leishmania RNA virus 1 (LRV1) replicating stably within some parasite species has been associated with the development of more severe forms of leishmaniasis and relapses after drug treatment in humans. Here, we show that the disease-exacerbatory role of LRV1 relies on type I IFN (type I IFNs) production by macrophages and signaling in vivo. Moreover, infecting mice with the LRV1-cured Leishmania guyanensis (LgyLRV1- ) strain of parasites followed by type I IFN treatment increased lesion size and parasite burden, quantitatively reproducing the LRV1-bearing (LgyLRV1+ ) infection phenotype. This finding suggested the possibility that exogenous viral infections could likewise increase pathogenicity, which was tested by coinfecting mice with L. guyanensis and lymphocytic choriomeningitis virus (LCMV), or the sand fly-transmitted arbovirus Toscana virus (TOSV). The type I IFN antiviral response increased the pathology of L. guyanensis infection, accompanied by down-regulation of the IFN-γ receptor normally required for antileishmanial control. Further, LCMV coinfection of IFN-γ-deficient mice promoted parasite dissemination to secondary sites, reproducing the LgyLRV1+ metastatic phenotype. Remarkably, LCMV coinfection of mice that had healed from L. guyanensis infection induced reactivation of disease pathology, overriding the protective adaptive immune response. Our findings establish that type I IFN-dependent responses, arising from endogenous viral elements (dsRNA/LRV1), or exogenous coinfection with IFN-inducing viruses, are able to synergize with New World Leishmania parasites in both primary and relapse infections. Thus, viral infections likely represent a significant risk factor along with parasite and host factors, thereby contributing to the pathological spectrum of human leishmaniasis.

Mucosal Leishmaniasis in Travelers with Leishmania braziliensis Complex Returning to Israel.

Mucosal leishmaniasis (ML) is a complication of New World cutaneous leishmaniasis (CL) caused mainly by Leishmania (Viannia) braziliensis. This retrospective study investigated all cases of ML caused by L. (V.) braziliensis in a tertiary medical center in Israel, evaluating the risk factors, clinical presentations, diagnosis, treatment, and outcome of mucosal involvement in ML caused by L. (V.) braziliensis in travelers returning to Israel. During 1993-2015, a total of 145 New World CL cases were seen in travelers returning from Bolivia; among them, 17 (11.7%) developed ML. Nasopharyngeal symptoms developed 0-3 years (median 8 months) after exposure. The only significant risk factor for developing ML was the absence of previous systemic treatment. Among untreated patients, 41% developed ML, compared with only 3% of treated patients (p = 0.005). Systemic treatment for CL seems to be a protective factor against developing ML.

A polymorphism in the IL1B gene (rs16944 T/C) is associated with cutaneous leishmaniasis caused by Leishmania guyanensis and plasma cytokine interleukin receptor antagonist.

Nod-like Receptor Protein3 (NLRP3) inflammasome in macrophages infected with Leishmania sp. enhances the secretion of IL-1ß. Excess IL-1ß production is linked to disease severity in patients with cutaneous leishmaniasis (CL) caused by L. mexicana. Blockade of the NLRP3 inflammasome in cell cultures from skin biopsies of patients with CL caused by L. braziliensis inhibited the release of IL-1ß. We hypothesized that common single nucleotide polymorphisms in the IL1B and in its receptor antagonist IL1RN genes may be predictive of CL caused by L. guyanensis. The SNPs -511T/C (rs16944) and +3954C/T (rs1143634) of the IL1B and IL1RN VNTR (rs2234663) were assessed in 881 patients with CL and 837 healthy controls by PCR-RFLP and direct PCR respectively. Plasma cytokines levels were also assayed. The plasma levels of IL-1ß were higher in patients compared to control subjects. In contrast, increased plasma levels of IL-1Ra were observed in controls. The rs16944 C/C genotype was more common among the patients (OR = 1.5 [95%CI 1.1-2.0]; P = 0.004) and the C allele suggests susceptibility to CL (OR = 1.2 [95%CI 1.1-1.4]; P = 0.003). The rs16944 C/C genotype shows a tendency to correlate with lower levels of the IL-1Ra cytokine. Low levels of IL-1Ra cytokine and rs16944 C/C genotype seem to confer susceptibility to L. guyanensis-infection in the Amazonas.

Tilting the balance between RNA interference and replication eradicates Leishmania RNA virus 1 and mitigates the inflammatory response.

Many Leishmania (Viannia) parasites harbor the double-stranded RNA virus Leishmania RNA virus 1 (LRV1), which has been associated with increased disease severity in animal models and humans and with drug treatment failures in humans. Remarkably, LRV1 survives in the presence of an active RNAi pathway, which in many organisms controls RNA viruses. We found significant levels (0.4 to 2.5%) of small RNAs derived from LRV1 in both Leishmania braziliensis and Leishmania guyanensis, mapping across both strands and with properties consistent with Dicer-mediated cleavage of the dsRNA genome. LRV1 lacks cis- or trans-acting RNAi inhibitory activities, suggesting that virus retention must be maintained by a balance between RNAi activity and LRV1 replication. To tilt this balance toward elimination, we targeted LRV1 using long-hairpin/stem-loop constructs similar to those effective against chromosomal genes. LRV1 was completely eliminated, at high efficiency, accompanied by a massive overproduction of LRV1-specific siRNAs, representing as much as 87% of the total. For both L. braziliensis and L. guyanensis, RNAi-derived LRV1-negative lines were no longer able to induce a Toll-like receptor 3-dependent hyperinflammatory cytokine response in infected macrophages. We demonstrate in vitro a role for LRV1 in virulence of L. braziliensis, the Leishmania species responsible for the vast majority of mucocutaneous leishmaniasis cases. These findings establish a targeted method for elimination of LRV1, and potentially of other Leishmania viruses, which will facilitate mechanistic dissection of the role of LRV1-mediated virulence. Moreover, our data establish a third paradigm for RNAi-viral relationships in evolution: one of balance rather than elimination.

Cutaneous, mucocutaneous and visceral leishmaniasis in Sweden from 1996-2016: a retrospective study of clinical characteristics, treatments and outcomes.

BACKGROUND: Leishmaniasis is a neglected and poorly reported parasitic infection transmitted by sand flies in tropical and subtropical regions. Knowledge about leishmaniasis has become important in non-endemic countries due to increased migration and travel. Few studies of the clinical management of cutaneous, mucocutaneous and visceral leishmaniasis in non-endemic regions have been published to date. In this study, we aimed to evaluate patient characteristics, clinical manifestations and treatments of leishmaniasis in Sweden, over a 20-year period. METHODS: A retrospective observational nationwide study was performed using medical records of patients diagnosed with leishmaniasis in Sweden from 1996 to 2016. Cases with culture and polymerase chain reaction verified leishmaniasis were identified at the Public Health Agency of Sweden. RESULTS: In total, 165 cases of leishmaniasis were diagnosed from 1996 to 2016. Medical records from 156 patients (95%) were available for review and included in the study. Cutaneous leishmaniasis was the dominant manifestation (n = 149, 96%), and in 66 patients (44%) cutaneous leishmaniasis was due to Leishmania tropica. Other manifestations were mucocutaneous (n = 4, 3%), visceral (n = 2, 1%) and post-kala-azar dermal leishmaniasis (n = 1, 1%). During this time period, the number of cases increased, especially after 2013. Most patients (n = 81, 52%) were migrants who were infected in their countries of origin (from 2013 to 2016, mainly Syria or Afghanistan). Other groups were Swedish tourists (25%) and returning workers (13%). The time from collection of the diagnostic sample to the start of treatment was less than one month in 81 (66%) patients and under three months in 124 patients (96%). Among the 149 patients with cutaneous leishmaniasis, 125 patients received antileishmanial treatment, and in 88 of these patients (70%) cure was achieved, regardless of treatment. CONCLUSIONS: The number of leishmaniasis cases diagnosed in Sweden increased between 1996 and 2016, mainly in migrants from endemic countries. Although leishmaniasis is a rare disease in Sweden, patients appear to be diagnosed early and treated according to current European guidelines, resulting in an overall high cure rate.

In vitro activity of new N-benzyl-1H-benzimidazol-2-amine derivatives against cutaneous, mucocutaneous and visceral Leishmania species.

The identification of specific therapeutic targets and the development of new drugs against leishmaniasis are urgently needed, since chemotherapy currently available for its treatment has several problems including many adverse side effects. In an effort to develop new antileishmanial drugs, in the present study a series of 28 N-benzyl-1H-benzimidazol-2-amine derivatives was synthesized and evaluated in vitro against Leishmania mexicana promastigotes. Compounds 7 and 8 with the highest antileishmanial activity (micromolar) and lower cytotoxicity than miltefosine and amphotericin B were selected to evaluate their activity against L. braziliensis 9and L. donovani, species causative of mucocutaneous and visceral leishmaniasis, respectively. Compound 7 showed significantly higher activity against L. braziliensis promastigotes than compound 8 and slightly lower than miltefosine. Compounds 7 and 8 had IC50 values in the micromolar range against the amastigote of L. mexicana and L. braziliensis. However, both compounds did not show better activity against L. donovani than miltefosine. Compound 8 showed the highest SI against both parasite stages of L. mexicana. In addition, compound 8 inhibited 68.27% the activity of recombinant L. mexicana arginase (LmARG), a therapeutic target for the treatment of leishmaniasis. Docking studies were also performed in order to establish the possible mechanism of action by which this compound exerts its inhibitory effect. Compound 8 shows promising potential for the development of more potent antileishmanial benzimidazole derivatives.

Local Delivery of the Toll-Like Receptor 9 Ligand CpG Downregulates Host Immune and Inflammatory Responses, Ameliorating Established Leishmania (Viannia) panamensis Chronic Infection.

Infection by Leishmania (Viannia) panamensis, the predominant etiologic agent for cutaneous leishmaniasis in Colombia, is characterized by a chronic mixed inflammatory response. Current treatment options are plagued by toxicity, lengthy treatment regimens, and growing evidence of drug resistance. Immunotherapy, modulating the immune system to mount a protective response, may provide an alternate therapeutic approach. We investigated the ability of the Toll-like receptor 9 (TLR9) ligand CpG to modulate established disease in the L (V) panamensis mouse model. Treatment of established infection with a high dose (50 µg) of CpG ameliorated disease and lowered parasite burden. Interestingly, immediately after treatment there was a significant increase in transforming growth factor ß (TGF-ß) and concomitantly an increase in T regulatory cell (Treg) function. Although a general reduction in cell-mediated immune cytokine and chemokine (gamma interferon [IFN-γ], interleukin 10 [IL-10], IL-13, IL-6, granulocyte-macrophage colony-stimulating factor [GM-CSF], IL-4, and MIP-1α) responses of the treated mice was observed, certain chemokines (RANTES, monocyte chemoattractant protein 1[MCP-1], and IP-10) were increased. Further, in peripheral blood mononuclear cells (PBMCs) from patients with cutaneous leishmaniasis, CpG treatment similarly exhibited a dose-response effect on the production of IFN-γ, IL-17, IL-10, and IL-13, with reductions observed at higher doses. To further understand the underlying mechanisms and cell populations driving the CpG mediated response, we examined the ex vivo dose effects mediated by the TLR9+ cell populations (dendritic cells, macrophages, and B cells) found to accumulate labeled CpG in vivo Notably, B cells altered the production of IL-17, IL-13, and IFN-γ, supporting a role for B cells functioning as antigen-presenting cells (APCs) and/or regulatory cells during infection. Interestingly, B cells have been previously demonstrated as a primary type of APC in patients infected with L (V) panamensis and thus may be useful targets of immunotherapy. Collectively, our results show that CpG-induced immune regulation leads to a dampening of the host immune response and healing in the mouse model, and it may provide an alternate approach to treatment of cutaneous leishmaniasis caused by L (V) panamensis.

Field Validation of SYBR Green- and TaqMan-Based Real-Time PCR Using Biopsy and Swab Samples To Diagnose American Tegumentary Leishmaniasis in an Area Where Leishmania (Viannia) braziliensis Is Endemic.

The precise diagnosis of American tegumentary leishmaniasis (ATL) is an essential task due to the disease's associated morbidity. A noninvasive, extremely sensitive, and highly specific exam is critical, particularly for mucosal leishmaniasis (ML), in which a low parasite quantity is expected. We aimed to compare the diagnostic accuracy of swab and biopsy sample analysis using SYBR Green- and TaqMan-based real-time PCR (qPCR) assays with that of a composite reference standard consisting of the Montenegro skin test, serology, histopathology, smears, culture, and conventional PCR. In total, 55 patients with ATL (ML, 18 patients; cutaneous leishmaniasis [CL], 37 patients) and 36 patients without ATL were studied. qPCR analysis of swabs was more accurate when using SYBR Green (87.88%; 95% confidence interval [CI], 77.86 to 93.73 patients) than when using TaqMan (78.79%; 95% CI, 67.49 to 86.92%) (P = 0.031). SYBR Green (84.72%; 95% CI, 74.68 to 91.25%) was also more accurate than TaqMan (73.61%; 95% CI, 62.42 to 82.41%) for biopsy samples (P = 0.008). All qPCR methods were 100% specific. Swabs and biopsy specimens had similar sensitivity when using the same chemistry (P = 0.125 for SYBR Green and P = 0.625 for TaqMan). Moreover, qPCR achieved better performance than most existing techniques used for the diagnosis of ATL and also detected the Leishmania parasite in a greater proportion of patients than the associated histopathology, smear, culture, and conventional PCR techniques did. Swabs therefore represent a useful diagnostic tool because they not only are noninvasive but also can achieve an accuracy similar to that of biopsy samples. The high accuracy of SYBR Green-based qPCR may also reduce the requirement for associated parasitological tests for ATL diagnosis.

Cost-effectiveness of liposomal amphotericin B in hospitalised patients with mucocutaneous leishmaniasis.

OBJECTIVE: To compare the cost-effectiveness of L-AmB with that of SbV and AmB-D, for the treatment of mucocutaneous leishmaniasis in a hospital in north-east Brazil. METHODS: We developed an economic model based on retrospective data of 73 hospitalised patients in 2006-2012, from hospital and public health system perspectives. RESULTS: In the economic model, 82.2% of patients who started treatment with L-AmB had completed it after 2 months, vs. 22.0% for the SbV and 19.9% for the AmB-D groups. After 12 months of follow-up, these proportions were 100% in the L-AmB, 77.4% in the AmB-D and 72.2% in the SbV group. Markov chain analyses showed that the group that started therapy with SbV had the lowest mean total cost (US$ 3782.38), followed by AmB-D (US$ 5211.27) and L-AmB (US$ 11 337.44). The incremental cost-effectiveness ratio for L-AmB was US$ 18 816.23 against SbV and US$ 24 504.65 against AmB-D. In the sensitivity analysis, the drug acquisition cost of L-AmB significantly influenced the results. CONCLUSIONS: In the treatment of mucocutaneous leishmaniasis, L-AmB is a cost-effective alternative to SbV and AmB-D owing to its higher effectiveness, safety and shorter course.