Transcriptomics analysis highlights potential ways in human pathogenesis in Leishmania braziliensis infected with the viral endosymbiont LRV1.

The parasite Leishmania (Viannia) braziliensis is widely distributed in Brazil and is one of the main species associated with human cases of different forms of tegumentary leishmaniasis (TL) such as cutaneous leishmaniasis (CL) and mucosal leishmaniasis (ML). The mechanisms underlying the pathogenesis of TL are still not fully understood, but it is known that factors related to the host and the parasite act in a synergistic and relevant way to direct the response to the infection. In the host, macrophages have a central connection with the parasite and play a fundamental role in the defense of the organism due to their ability to destroy intracellular parasites and present antigens. In the parasite, some intrinsic factors related to the species or even the strain analyzed are fundamental for the outcome of the disease. One of them is the presence of Leishmania RNA Virus 1 (LRV1), an endosymbiont virus that parasitizes some species of Leishmania that triggers a cascade of signals leading to a more severe TL phenotype, such as ML. One of the strategies for understanding factors associated with the immune response generated after Leishmania/host interaction is through the analysis of molecular patterns after infection. Thus, the gene expression profile in human monocyte-derived macrophages obtained from healthy donors infected in vitro with L. braziliensis positive (LbLRV1+) and negative (LbLRV1-) for LRV1 was evaluated. For this, the microarray assay was used and 162 differentially expressed genes were identified in the comparison LbLRV1+ vs. LbLRV1-, 126 upregulated genes for the type I and II interferons (IFN) signaling pathway, oligoadenylate synthase OAS/RNAse L, non-genomic actions of vitamin D3 and RIG-I type receptors, and 36 down-regulated. The top 10 downregulated genes along with the top 10 upregulated genes were considered for analysis. Type I interferon (IFNI)- and OAS-related pathways results were validated by RT-qPCR and Th1/Th2/Th17 cytokines were analyzed by Cytometric Bead Array (CBA) and enzyme-linked immunosorbent assay (ELISA). The microarray results validated by RT-qPCR showed differential expression of genes related to IFNI-mediated pathways with overexpression of different genes in cells infected with LbLRV1+ compared to LbLRV1- and to the control. No significant differences were found in cytokine levels between LbLRV1+ vs. LbLRV1- and control. The data suggest the activation of gene signaling pathways associated with the presence of LRV1 has not yet been reported so far. This study demonstrates, for the first time, the activation of the OAS/RNase L signaling pathway and the non-genomic actions of vitamin D3 when comparing infections with LbLRV1+ versus LbLRV1- and the control. This finding emphasizes the role of LRV1 in directing the host's immune response after infection, underlining the importance of identifying LRV1 in patients with TL to assess disease progression.

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.

Characterization of Differentially Abundant Proteins Among Leishmania (Viannia) braziliensis Strains Isolated From Atypical or Typical Lesions.

Leishmania (Viannia) braziliensis is the main etiological agent of cutaneous and mucocutaneous leishmaniasis in Latin America. Non-ulcerated atypical tegumentary leishmaniasis cases caused by L. braziliensis have been reported in several regions of the American continent, including the Xacriabá indigenous reserve in São João das Missões/Minas Gerais, Brazil. Parasites isolated from these atypical clinical lesions are resistant to antimony-based therapeutics. In the present study, proteins displaying differential abundance in two strains of L. braziliensis isolated from patients with atypical lesions compared with four strains isolated from patients with typical lesions were identified using a quantitative proteomics approach based on tandem mass tag labeling (TMT) and mass spectrometry. A total of 532 (P<0.05) differentially abundant proteins were identified (298 upregulated and 234 downregulated) in strains from atypical lesions compared to strains from typical lesions. Prominent positively regulated proteins in atypical strains included those that may confer greater survival inside macrophages, proteins related to antimony resistance, and proteins associated with higher peroxidase activity. Additionally, we identified proteins showing potential as new drug and vaccine targets. Our findings contribute to the characterization of these intriguing L. braziliensis strains and provide a novel perspective on Atypical Cutaneous Leishmaniasis (ACL) cases that have been associated with therapeutic failures.

Leishmania RNA virus-1 is similarly detected among metastatic and non-metastatic phenotypes in a prospective cohort of American Tegumentary Leishmaniasis.

American Tegumentary Leishmaniasis (ATL) is an endemic and neglected disease of South America. Here, mucosal leishmaniasis (ML) disproportionately affects up to 20% of subjects with current or previous localised cutaneous leishmaniasis (LCL). Preclinical and clinical reports have implicated the Leishmania RNA virus-1 (LRV1) as a possible determinant of progression to ML and other severe manifestations such as extensive cutaneous and mucosal disease and treatment failure and relapse. However, these associations were not consistently found in other observational studies and are exclusively based on cross-sectional designs. In the present study, 56 subjects with confirmed ATL were assessed and followed out for 24-months post-treatment. Lesion biopsy specimens were processed for molecular detection and quantification of Leishmania parasites, species identification, and LRV1 detection. Among individuals presenting LRV1 positive lesions, 40% harboured metastatic phenotypes; comparatively 58.1% of patients with LRV1 negative lesions harboured metastatic phenotypes (p = 0.299). We found treatment failure (p = 0.575) and frequency of severe metastatic phenotypes (p = 0.667) to be similarly independent of the LRV1. Parasite loads did not differ according to the LRV1 status (p = 0.330), nor did Leishmanin skin induration size (p = 0.907) or histopathologic patterns (p = 0.780). This study did not find clinical, parasitological, or immunological evidence supporting the hypothesis that LRV1 is a significant determinant of the pathobiology of ATL.

The Paradox of a Phagosomal Lifestyle: How Innate Host Cell-Leishmania amazonensis Interactions Lead to a Progressive Chronic Disease.

Intracellular phagosomal pathogens represent a formidable challenge for innate immune cells, as, paradoxically, these phagocytic cells can act as both host cells that support pathogen replication and, when properly activated, are the critical cells that mediate pathogen elimination. Infection by parasites of the Leishmania genus provides an excellent model organism to investigate this complex host-pathogen interaction. In this review we focus on the dynamics of Leishmania amazonensis infection and the host innate immune response, including the impact of the adaptive immune response on phagocytic host cell recruitment and activation. L. amazonensis infection represents an important public health problem in South America where, distinct from other Leishmania parasites, it has been associated with all three clinical forms of leishmaniasis in humans: cutaneous, muco-cutaneous and visceral. Experimental observations demonstrate that most experimental mouse strains are susceptible to L. amazonensis infection, including the C57BL/6 mouse, which is resistant to other species such as Leishmania major, Leishmania braziliensis and Leishmania infantum. In general, the CD4+ T helper (Th)1/Th2 paradigm does not sufficiently explain the progressive chronic disease established by L. amazonensis, as strong cell-mediated Th1 immunity, or a lack of Th2 immunity, does not provide protection as would be predicted. Recent findings in which the balance between Th1/Th2 immunity was found to influence permissive host cell availability via recruitment of inflammatory monocytes has also added to the complexity of the Th1/Th2 paradigm. In this review we discuss the roles played by innate cells starting from parasite recognition through to priming of the adaptive immune response. We highlight the relative importance of neutrophils, monocytes, dendritic cells and resident macrophages for the establishment and progressive nature of disease following L. amazonensis infection.

Multiple evolutionary lineages for the main vector of Leishmania guyanensis, Lutzomyia umbratilis (Diptera: Psychodidae), in the Brazilian Amazon.

Lutzomyia umbratilis is the main vector of Leishmania guyanensis in the Brazilian Amazon and in neighboring countries. Previous biological and molecular investigations have revealed significant differences between L. umbratilis populations from the central Brazilian Amazon region. Here, a phylogeographic survey of L. umbratilis populations collected from nine localities in the Brazilian Amazon was conducted using two mitochondrial genes. Statistical analyses focused on population genetics, phylogenetic relationships and species delimitations. COI genetic diversity was very high, whereas Cytb diversity was moderate. COI genealogical haplotypes, population structure and phylogenetic analyses identified a deep genetic differentiation and three main genetic groups. Cytb showed a shallower genetic structure, two main haplogroups and poorly resolved phylogenetic trees. These findings, allied to absence of isolation by distance, support the hypothesis that the Amazon and Negro Rivers and interfluves are the main evolutionary forces driving L. umbratilis diversification. The main three genetic groups observed represent three evolutionary lineages, possibly species. The first lineage occurs north of the Amazon River and east of Negro River, where Le. guyanensis transmission is intense, implying that L. umbratilis is an important vector there. The second lineage is in the interfluve between north of Amazon River and west of Negro River, an area reported to be free of Le. guyanensis transmission. The third lineage, first recorded in this study, is in the interfluve between south of Amazonas River and west of Madeira River, and its involvement in the transmission of this parasite remains to be elucidated.

Potential antigenic targets used in immunological tests for diagnosis of tegumentary leishmaniasis: A systematic review.

Immunological tests may represent valuable tools for the diagnosis of human tegumentary leishmaniasis (TL) due to their simple execution, less invasive nature and potential use as a point-of-care test. Indeed, several antigenic targets have been used with the aim of improving the restricted scenario for TL-diagnosis. We performed a worldwide systematic review to identify antigenic targets that have been evaluated for the main clinical forms of TL, such as cutaneous (CL) and mucosal (ML) leishmaniasis. Included were original studies evaluating the sensitivity and specificity of immunological tests for human-TL, CL and/or ML diagnosis using purified or recombinant proteins, synthetic peptides or polyclonal or monoclonal antibodies to detect Leishmania-specific antibodies or antigens. The review methodology followed PRISMA guidelines and all selected studies were evaluated in accordance with QUADAS-2. Thirty-eight original studies from four databases fulfilled the selection criteria. A total of 79 antigens were evaluated for the detection of antibodies as a diagnostic for TL, CL and/or ML by ELISA. Furthermore, three antibodies were evaluated for the detection of antigen by immunochromatographic test (ICT) and immunohistochemistry (IHC) for CL-diagnosis. Several antigenic targets showed 100% of sensitivity and specificity, suggesting potential use for TL-diagnosis in its different clinical manifestations. However, a high number of proof-of-concept studies reinforce the need for further analysis aimed at verifying true diagnostic accuracy in clinical practice.

Safety and efficacy of allylamines in the treatment of cutaneous and mucocutaneous leishmaniasis: A systematic review.

Cutaneous and mucocutaneous leishmaniasis affect a million people yearly, leading to skin lesions and potentially disfiguring mucosal disease. Current treatments can have severe side effects. Allylamine drugs, like terbinafine, are safe, including during pregnancy. This review assesses efficacy and safety of allylamines for the treatment of cutaneous and mucocutaneous leishmaniasis. It followed the PRISMA statement for reporting and was preregistered in PROSPERO(CRD4201809068). MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, the Global Health Library, Web of Science, Google Scholar, and clinical trial registers were searched from their creation to May 24th, 2020. All original human, animal, and in vitro studies concerning allylamines and cutaneous or mucocutaneous leishmaniasis were eligible for inclusion. Comparators-if any-included both placebo or alternative cutaneous or mucocutaneous leishmaniasis treatments. Complete cure, growth inhibition, or adverse events served as outcomes. The search identified 312 publications, of which 22 were included in this systematic review. There were one uncontrolled and two randomised controlled trials. The only well-designed randomised controlled trial that compared the treatment efficacy of oral terbinafine versus intramuscular meglumine antimoniate in 80 Leismania tropica infected patients showed a non-significant lower cure rate for terbinafine vs meglumine antimoniate (38% vs 53%). A meta-analysis could not be performed due to the small number of studies, their heterogeneity, and low quality. This systematic review shows that there is no evidence of efficacy of allylamine monotherapy against cutaneous and mucocutaneous leishmaniasis. Further trials of allylamines should be carefully considered as the outcomes of an adequately designed trial were disappointing and in vitro studies indicate minimal effective concentrations that are not achieved in the skin during standard doses. However, the in vitro synergistic effects of allylamines combined with triazole drugs warrant further exploration.

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-restriction fragment length polymorphism (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.

Case Report: A Single-Center Case Series on Skin Manifestations of Leishmaniasis from a Non-Endemic State in Southern India.

Leishmaniasis is endemic in the Indian subcontinent with predominance of visceral leishmaniasis (VL) due to Leishmania donovani. Cutaneous leishmaniasis (CL) is uncommon, and mucocutaneous leishmaniasis (MCL) is rarely reported in this region. Recent reports reveal a changing epidemiology and atypical manifestations. A retrospective study of 52 suspected cases with cutaneous and mucosal involvement seen from January 2008 to December 2018 in a tertiary care setting in a non-endemic state in southern India is reported. Twelve patients were confirmed to have leishmaniasis; seven had MCL, two had CL, and three had post-kala-azar dermal leishmaniasis (PKDL). All cases were male, with a median age of 41.5 years (interquartile range, 30-55.5 years), and the median duration of the disease was 6 years (interquartile range, 1-9.5 years). Patients with MCL had mucosal involvement including destructive ulcero-proliferative lesions due to delayed diagnosis; none had a history of travel to countries endemic for MCL and all were attributable to L. donovani species. On the other hand, Leishmania major which was the causative species in both CL patients was associated with travel to the Middle East. Patients with PKDL presented with multiple plaques and hypopigmented patches; one had concomitant VL and all were from endemic areas. Hitherto uncommon MCL, caused by potentially atypical variants of L. donovani, has emerged as a new manifestation of leishmaniasis in this region. A high index of suspicion based on lesions seen and history of travel combined with PCR-based diagnostics are required to confirm diagnosis for the various skin manifestations of leishmaniasis.

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.

Mucocutaneous leishmaniasis: case report and literature review of a rare endonasal infection.

Leishmaniasis is a protozoal infection transmitted by a sandfly vector. In Germany, leishmaniasis of the mucous membranes is a rare condition and usually due to extension of local skin disease into the mucosal tissue via direct extension, bloodstream or lymphatics. We report a case of endonasal leishmaniasis in a female German resident who presented in a university hospital with nasal obstruction. Histology of the left nasal septum biopsy was suggestive of leishmaniasis. The molecular detection of DNA was positive for leishmania infantum. The patient was successfully treated as a case of mucocutaneous leishmaniasis receiving liposomal amphotericin follow up visits showed significant improvement with no recurrence.

Refractory mucocutaneous leishmaniasis resolved with combination treatment based on intravenous pentamidine, oral azole, aerosolized liposomal amphotericin B, and intralesional meglumine antimoniate.

INTRODUCTION: Mucocutaneous leishmaniasis (MCL) is a complication of tegumentary leishmaniasis, causing potentially life-threatening lesions in the ear, nose, and throat (ENT) region, and most commonly due to Leishmania (Viannia) braziliensis. We report a case of relapsing MCL in an Italian traveler returning from Argentina. CASE DESCRIPTION: A 65-year-old Italian male patient with chronic kidney disease, arterial hypertension, prostatic hypertrophy, and type-2 diabetes mellitus was referred for severe relapsing MCL acquired in Argentina. ENT examination showed severe diffuse pharyngolaryngeal edema and erythema, partially obstructing the airways. A nasopharyngeal biopsy revealed a lymphoplasmacytic inflammation and presence of Leishmania amastigotes, subsequently identified as L. (V.) braziliensis by hsp70 PCR-RFLP analysis and sequencing. Despite receiving four courses of liposomal amphotericine B (L-AmB) and two courses of miltefosine over a 2-year period, the patient presented recurrence of symptoms a few months after the end of each course. After the patient was referred to us, a combined treatment was started with intravenous pentamidine 4 mg/kg on alternate days for 10 doses, followed by one dose per week for an additional seven doses, intralesional meglumine antimoniate on the nasal lesion once per week for six doses, oral azoles for three months, and aerosolized L-AmB on alternate days for three months. The treatment led to regression of mucosal lesions and respiratory symptoms. Renal function temporarily worsened, and the addition of insulin was required to maintain glycemic compensation after pentamidine discontinuation. CONCLUSIONS: This case highlights the difficulties in managing a life-threatening refractory case of MCL in an Italian traveler with multiple comorbidities. Even though parenteral antimonial derivatives are traditionally considered the treatment of choice for MCL, they are relatively contraindicated in cases of chronic kidney disease.The required dose adjustment in cases of impaired renal function is unknown, therefore the use of alternative drugs is recommended. This case was resolved with combination treatment, including aerosolized L-AmB, which had never been used before for MCL.

High performance of an enzyme linked immunosorbent assay for American tegumentary leishmaniasis diagnosis with Leishmania (Viannia) braziliensis amastigotes membrane crude antigens.

The diagnosis of American tegumentary leishmaniasis (ATL) still requires the design of more effective tools. Leishmania (Viannia) braziliensis is the causal agent of the 90% of Argentinean ATL cases. Considering the current knowledge, an ELISA based crude antigen (CA) for the diagnosis was designed. Ninety-nine subjects diagnosed as ATL, 27 as no-ATL, and 84 donors from non-ATL-endemic areas were included in this study. The current ATL diagnosis was based four techniques, dermal smear microscopic examination (parasitological test), PCR, Leishmanin skin test, and clinical records. We obtained CA extracts from promastigotes and amastigotes from macrophage cultures of different zymodemes of endemic Leishmania species circulating in the study area. Crude antigens from the 'local' main zymodeme of L. (V.) braziliensis showed the highest reactivity against anti-Leishmania antibodies compared to the other included species. The CA of amastigotes of this zymodeme was 3.4 fold more reactive than promastigotes one. Moreover, amastigote-membrane CA (MCA) were 3.6 fold more reactive than the soluble antigens. The MCA-ELISA reached a sensitivity and specificity of 98% (CI = 94.7%-100%) and 63.6% (53.9-73.1), respectively. When anti-Trypanosoma cruzi reactive sera were excluded, the specificity reached 98.4% (94.4-100), while the sensitivity was similar, with a positive predictive value (PV) of 98.6% (94.6-100) and negative PV of 96.3% (91.6-100). The performance of the MCA-ELISA results strongly contribute to the final diagnostic decision, since a non-reactive serological result almost discards the suspected ATL, because of its high negative PV. The developed MCA-ELISA showed a high diagnostic performance, which makes it a good candidate for ATL diagnosis, for seroprevalence studies, or for monitoring treatments efficacy.

Surveillance of cutaneous leishmaniasis in clinical samples: distribution of Leishmania guyanensis in the state of Amapá, Brazil, 2018. / Vigilância da leishmaniose cutânea em amostras clínicas: distribuição da Leishmania guyanensis no estado do Amapá, 2018.

OBJECTIVE: to investigate Leishmania species in a series of autochthonous cutaneous leishmaniasis (CL) cases in Amapá State, Brazilian Amazon. METHODS: this was a descriptive ecological study carried out from January-October/2018 at a reference center for CL diagnosis in Amapá; individuals with CL receiving care from January-May/2018 were recruited; clinical data and skin biopsies were obtained; from extracted DNA (phenol-chloroform) we amplified the hsp70-234 gene region (PCR) for nucleotide sequencing (Applied Biosystems: ABI3500XL). RESULTS: 38 individuals were interviewed, examined and diagnosed; men predominated (28/38; mean age=32.5±11.3); lesions (most ulcers: 37/38) measuring 0,4-10mm (34/38) and ≥11mm (4/38) were multiple in 20/38 individuals; diagnosis of L. braziliensis (1), L. naiffi (1), L. infantum (1), L. (Viannia) sp. (1), L. amazonensis (2) and L. guyanensis (32); individuals infected with L. guyanensis (32/38) lived in 9/10 municipalities represented in the sample, and 17/32 of these had multiple lesions. CONCLUSION: presence of Leishmania guyanensis predominated and was frequently associated with multiple lesions.

Mucosal and mucocutaneous leishmaniasis in Iran from 1968 to 2018: a narrative review of clinical features, treatments, and outcomes.

Leishmaniases are worldwide zoonotic infectious diseases caused by different types of intracellular protozoan species of the genus Leishmania. Leishmaniasis as an important vector-borne parasitic disease is transmitted between mammalian hosts by female sandflies. There are three main clinical forms of disease with varied severity: visceral leishmaniasis (VL), cutaneous leishmaniasis (CL), and mucocutaneous leishmaniasis (MCL). MCL is the most uncommon form of this syndrome in the Old World. Accordingly, the reports have characterized that patients with the involvement of mucous membranes are rare even in endemic areas. It is well-known that MCL is a rare clinical manifestation in Iran, but there have been several different cases of patients with mucosal (ML) or MCL in some parts of Iran during the past 50 years. Therefore, we aimed to report and present clinical and epidemiological features of ML or MCL in different regions of the country. Also, we demonstrated specified Leishmania species causing the ML in some cases. The present narrative review indicates that ML or MCL is not unexpected in Iran. Based on the findings of the recent studies, it is concluded that diagnosis of ML should be considered by physicians in Iran.

Leishmaniasis mucocutánea con manifestacion oral: reporte de un caso / Mucocutaneous leishmaniasis with oral manifestation: case report

La Leishmaniasis es un grupo de enfermedades transmitidas por vectores y causada por la Leishmania, un parásito intracelular, que se presenta de preferencia en regiones tropicales y subtropicales. Se manifiesta mediante un amplio rango de formas clínicas como la cutánea, mucocutánea, y visceral, dependiendo de la especie y respuesta inmunológica del paciente. Se presenta el caso de un hombre de 35 años que acudió derivado a Unidad de Estomatología del Hospital Señor del Milagro, Salta, Argentina, presentando en la cavidad oral lesión, granulomatosa, ulcerada, dolorosa a la palpación, única, en paladar blando, de tres meses de evolución. Se realizaron estudios serológicos, parasitológicos y PCR. Los ELISAs lisados, PCRs y cultivos de materiales de lesiones fueron positivos, confirmando diagnóstico de leishmaniasis mucocutánea. El paciente fue derivado al Servicio de Dermatología donde recibió tratamiento con Antimoniato de Meglumina, con repuesta clínica favorable. El conocimiento de las manifestaciones orales puede llevar al diagnóstico clínico de leishmaniasis mucocutánea por parte del odontólogo, pudiendo entregar un tratamiento oportuno y a la vez ayudar al paciente, evitando complicaciones de esta enfermedad.

Leishmaniasis is a group of vector-borne diseases caused by Leishmania, an intracellular parasite, which occurs preferentially in tropical and subtropical regions. It manifests itself through a wide range of clinical forms such as cutaneous, mucocutaneous, and visceral, depending on the species and the patient's immune response. We present a case of a 35-year-old man who was referred to the Stomatology Unit of the Señor del Milagro Hospital, Salta, Argentina, presenting in the oral cavity lesion, granulomatous, ulcerated, painful on palpation, unique, soft palate with three months of evolution. Serological, parasitological and PCR studies were performed. Lysed ELISAs, PCRs and cultures of lesion materials were positive, confirming diagnosis of mucocutaneous leishmaniasis. The patient was referred to the Dermatology Service where he received treatment with Meglumine Antimony, with favorable clinical response. The knowledge of the oral manifestations can lead to the clinical diagnosis of mucocutaneous leishmaniasis by the dentist, being able to provide timely treatment and at the same time help the patient, avoiding complications of this disease.

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.

Leishmania RNA virus exacerbates Leishmaniasis by subverting innate immunity via TLR3-mediated NLRP3 inflammasome inhibition.

Leishmania RNA virus (LRV) is an important virulence factor associated with the development of mucocutaneous Leishmaniasis, a severe form of the disease. LRV-mediated disease exacerbation relies on TLR3 activation, but downstream mechanisms remain largely unexplored. Here, we combine human and mouse data to demonstrate that LRV triggers TLR3 and TRIF to induce type I IFN production, which induces autophagy. This process results in ATG5-mediated degradation of NLRP3 and ASC, thereby limiting NLRP3 inflammasome activation in macrophages. Consistent with the known restricting role of NLRP3 for Leishmania replication, the signaling pathway triggered by LRV results in increased parasite survival and disease progression. In support of this data, we find that lesions in patients infected with LRV+ Leishmania are associated with reduced inflammasome activation and the development of mucocutaneous disease. Our findings reveal the mechanisms triggered by LRV that contribute to the development of the debilitating mucocutaneous form of Leishmaniasis.

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

Introducción. La leishmaniasis mucosa tiene un curso progresivo y puede causar deformidad e incluso mutilación de las zonas afectadas. Es endémica en el continente americano y es causada principalmente por Leishmania (Viannia) brasiliensis. Objetivo. Describir una serie de casos de leishmaniasis mucosa y las especies de Leishmania infecciosas. Materiales y métodos. Se estudiaron 50 pacientes con diagnóstico clínico de leishmaniasis mucosa y confirmación parasitológica. Se describieron sus características clínicas y los resultados de laboratorio. La tipificación de especies se hizo mediante reacción en cadena de la polimerasa de los polimorfismos de la longitud de los fragmentos de restricción (Restriction Fragment Length Polymorphism Polymerase Chain Reaction, PCR-RFLP) en la secuencia del miniexon y el gen hsp70 y se confirmó por secuenciación. Resultados. La evolución de la enfermedad fue de un mes a dieciséis años (mediana de 2,8 años). Los hallazgos clínicos fueron los siguientes: infiltración mucosa (94 %), cicatriz de leishmaniasis cutánea (74 %), pérdida total del tabique nasal (24 %), deformidad nasal (22 %) y ulceración (38 %). Los síntomas reportados fueron: obstrucción nasal (90 %), epistaxis (72 %), rinorrea (72 %), disfonía (28 %), disfagia (18 %) y prurito nasal (34 %). La histopatología mostró un patrón compatible con leishmaniasis en 86 % de las biopsias y se identificaron amastigotes en 14 % de ellas. La prueba de Montenegro fue positiva en 86 % de los pacientes, la inmunofluorescencia en 84 %, y el cultivo en 8 %. Leishmania (V.) brasiliensis se identificó en 88 % de las muestras, L. (V) panamensis en 8 %, y L. (V.) guyanensis y L. (L.) amazonensis en 2 %, respectivamente. Conclusión. Se encontró enfermedad nasal grave con destrucción y deformidad del tabique nasal en una cuarta parte de los casos, probablemente debido a un diagnóstico tardío. Leishmania (V.) brasiliensis fue la especie predominante. Se describe por primera vez un caso de leishmaniasis mucosa causado por L. (L.) amazonensis en Colombia.