Publications by authors named "Eugenia Carrillo"

48 Publications

Detection of cutaneous leishmaniasis in three communities of Oti Region, Ghana.

PLoS Negl Trop Dis 2021 May 24;15(5):e0009416. Epub 2021 May 24.

School of Public Health, University of Ghana, Accra, Ghana.

Background: Cutaneous leishmaniasis (CL) is the most common type of leishmaniasis, a neglected tropical disease caused by parasites of the genus Leishmania. In Ghana, some studies in the Volta region have detected Leishmania parasites among persons with skin ulcers.

Methodology/principal Findings: Using a cross-sectional study design, the prevalence of CL in three communities of the Oti Region of Ghana was investigated. Demographic and epidemiological data were obtained by a structured interviewer administered questionnaire. A total of 426 (12.4%) out of 3,440 participants screened had at least one skin ulcer. Of 595 skin ulcers sampled and tested by PCR for Leishmania infection, 150 (25.2%) ulcers from 136 individuals tested positive, accounting for an overall CL prevalence of 31.9% among persons with skin ulcers. Individual community CL prevalence of 23.2%, 29.8%, and 36.8% was observed in Ashiabre, Keri, and Sibi Hilltop respectively among persons with skin ulcers.

Conclusions/significance: Confirmation of CL in the study area suggests an active cycle of transmission of Leishmania infection. The observation of skin ulcers which tested negative to Leishmania infection suggests a need to test for additional causes of skin ulcers such as Treponema pallidum pertenue and Mycobacterium ulcerans in the study area.
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http://dx.doi.org/10.1371/journal.pntd.0009416DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8177633PMC
May 2021

Loop-Mediated Isothermal Amplification Allows Rapid, Simple and Accurate Molecular Diagnosis of Human Cutaneous and Visceral Leishmaniasis Caused by When Compared to PCR.

Microorganisms 2021 Mar 16;9(3). Epub 2021 Mar 16.

WHO Collaborating Centre for Leishmaniasis, National Center for Microbiology, Instituto de Salud Carlos III, 28220 Majadahonda, Spain.

Loop-mediated isothermal amplification allows the rapid, sensitive and specific amplification of DNA without complex and expensive equipment. We compared the diagnostic performance of Loopamp™ Detection Kit (Eiken Chemical Co., Ltd., Tokyo, Japan) with conventional and real-time polymerase chain reaction (PCR) for human cutaneous and visceral leishmaniasis caused by . A total of 230 DNA samples from cutaneous (CL) and visceral (VL) leishmaniasis cases and controls from Spain, characterized by nested PCR (LnPCR) were tested by: (i) the Loopamp™ Detection Kit (Loopamp), run on Genie III real-time fluorimeter (OptiGene, UK); and (ii) real-time quantitative PCR (qPCR). The Loopamp test returned 98.8% (95% confidence interval-CI: 96.0-100.00) sensitivity and specificity of 97.7% (95% CI: 92.2-100) on VL samples, and 100% (95% CI: 99.1-100) sensitivity and 100.0% (95% CI: 98.8-100.0) specificity on CL samples. The Loopamp time-to-positivity () obtained by real-time fluorimetry showed excellent concordance (C = 97.91%) and strong correlation (r = 0.799) with qPCR's cycle threshold (). The performance of Loopamp is comparable to that of LnPCR and qPCR in the diagnosis of cutaneous and visceral leishmaniasis due to . The excellent correlation between the and should be further investigated to determine the accuracy of Loopamp to quantify parasite load in tissues.
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http://dx.doi.org/10.3390/microorganisms9030610DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7999953PMC
March 2021

Effect of immunosuppressants on the parasite load developed in, and immune response to, visceral leishmaniasis: A comparative study in a mouse model.

PLoS Negl Trop Dis 2021 02 1;15(2):e0009126. Epub 2021 Feb 1.

WHO Collaborating Centre for Leishmaniasis, National Center for Microbiology, Instituto de Salud Carlos III, Majadahonda (Madrid), Spain.

The increasing use of immunosuppressants in areas where visceral leishmaniasis (VL) is endemic has increased the number of people susceptible to developing more severe forms of the disease. Few studies have examined the quality of the immune response in immunosuppressed patients or experimental animals with VL. The present work characterises the parasite load developed in, and immune response to, Leishmania infantum-induced VL in C57BL/6 mice that, prior to and during infection, received immunosuppressant treatment with methylprednisolone (MPDN), anti-tumour necrosis factor (anti-TNF) antibodies, or methotrexate (MTX). The latter two treatments induced a significant reduction in the number of CD4+ T lymphocytes over the infection period. The anti-TNF treatment was also associated with a higher parasite load in the liver and a lower parasite load in the spleen. This, plus a possibly treatment-induced reduction in the number of cytokine-producing Th1 cells in the spleen, indicates the development of more severe VL. Interestingly, the MPDN and (especially) MTX treatments provoked a greater presence of soluble Leishmania antigen-specific multi-cytokine-producing T cells in the spleen and a lower liver parasite load than in control animals. These results highlight the need to better understand how immunosuppressant treatments might influence the severity of VL in human patients.
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http://dx.doi.org/10.1371/journal.pntd.0009126DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7877784PMC
February 2021

Whole Blood Stimulation Assay as a Treatment Outcome Monitoring Tool for VL Patients in Ethiopia: A Pilot Evaluation.

J Immunol Res 2020 23;2020:8385672. Epub 2020 Jan 23.

Unit of Neglected Tropical Diseases, Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium.

Visceral leishmaniasis (VL) is a lethal disease if left untreated. Current treatments produce variable rates of treatment failure and toxicity without sterile cure, rendering treatment efficacy monitoring essential. To avoid repeated invasive tissue aspirates as well as empirical treatment, there is a need for new tools that allow a less-invasive and early assessment of treatment efficacy in the field. Cross-sectional studies have suggested levels of cytokines/chemokines after whole blood stimulation as good markers of cure, but longitudinal studies are lacking. In this study, we followed 13 active VL cases in an endemic area in Ethiopia by measuring the production of IFN-, TNF-, IP-10, IL-2, IL-10, MCP-1, and MIG before, during, and at the end of treatment. After 24 hours of stimulation of whole blood with soluble antigen, we observed an early, robust, and incremental increase of IFN-, TNF-, and IP-10 levels in all patients during treatment. Moreover, based on the IFN- levels that showed an average 13-fold increase from the time of diagnosis until the end of treatment, we could almost perfectly discriminate active from cured status. Similar concentrations and patterns were found in stimulation assays with the two main species. The levels of IFN-, IP-10, or TNF- also seemed to be inversely associated with the parasite load at baseline. Despite a 1/10 drop in concentrations, similar patterns were observed in IFN- and IP-10 levels when dried plasma spots were stored at 4°C for an average of 225 days. All the above evidence suggests a detectable restoration of cell-mediated immunity in VL and its association with parasite clearance. With a potential application in rural settings by means of dried plasma spots, we recommend to further explore the early diagnostic value of such assays for treatment efficacy monitoring in large cohort studies including treatment failure cases.
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http://dx.doi.org/10.1155/2020/8385672DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7193677PMC
February 2021

Role of asymptomatic and symptomatic humans as reservoirs of visceral leishmaniasis in a Mediterranean context.

PLoS Negl Trop Dis 2020 04 23;14(4):e0008253. Epub 2020 Apr 23.

Drugs for Neglected Diseases Initiative, Geneva, Switzerland.

Background: In the Mediterranean basin, Leishmania infantum is the causative agent of visceral leishmaniasis (VL), a zoonosis in which the dog is the primary domestic reservoir, although wildlife may have a leading role in the sylvatic cycle of the disease in some areas. Infections without disease are very frequent. There is limited information regarding the role that VL patients and asymptomatic infected individuals could be playing in the transmission of L. infantum. Xenodiagnosis of leishmaniasis has been used in this descriptive study to explore the role of symptomatic and asymptomatic infected individuals as reservoirs in a recent focus of leishmaniasis in southwestern Madrid, Spain.

Methodology And Main Findings: Asymptomatic blood donors (n = 24), immunocompetent patients who were untreated (n = 12) or treated (n = 11) for visceral leishmaniasis (VL), and immunocompromised patients with VL (n = 3) were enrolled in the study. Their infectivity to Phlebotomus perniciosus was studied by indirect xenodiagnosis on peripheral blood samples. Quantitative polymerase chain reaction of blood samples from immunocompetent patients untreated for VL and immunocompromised untreated, treated and under secondary prophylaxis for VL was performed. Antibodies against Leishmania were studied by indirect fluorescent antibody and rK39-immunochromatographic tests. A lymphoproliferative assay with a soluble Leishmania antigen was used to screen for leishmaniasis infection in the healthy population. Sixty-two xenodiagnostic tests were carried out and 5,080 sand flies were dissected. Positive xenodiagnosis was recorded in four patients, with different sand fly infection rates: 1 immunosuppressed HIV / L. infantum coinfected asymptomatic patient, 1 immunosuppressed patient with multiple myeloma and symptomatic active VL, and 2 immunocompetent patients with untreated active VL. All blood donors were negative for both xenodiagnosis and conventional PCR.

Conclusions / Significance: There is no consensus amongst authors on the definition of an 'asymptomatic case' nor on the tools for screening; we, therefore, have adopted one for the sake of clarity. Immunocompetent subjects, both infected asymptomatics and those treated for VL, are limited in number and appear to have no epidemiological relevance. The impact is limited for immunocompetent patients with untreated active VL, whilst immunosuppressed individuals undergoing immunosuppressive therapy and immunosuppressed individuals HIV / L. infantum coinfected were the most infectious towards sand flies. It is noteworthy that the HIV / L. infantum coinfected patient with asymptomatic leishmaniasis was easily infectious to sand flies for a long time, despite being under continuous prophylaxis for leishmaniasis. Accordingly, screening for latent Leishmania infection in HIV-infected patients is recommended in scenarios where transmission occurs. In addition, screening for VL in HIV-infected patients who have spent time in VL-endemic areas should also be implemented in non-endemic areas. More research is needed to better understand if some asymptomatic coinfected individuals contribute to transmission as 'super-spreaders'.
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http://dx.doi.org/10.1371/journal.pntd.0008253DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7200008PMC
April 2020

Implications of asymptomatic infection for the natural history of selected parasitic tropical diseases.

Semin Immunopathol 2020 06 18;42(3):231-246. Epub 2020 Mar 18.

Drugs for Neglected Diseases initiative, Geneva, Switzerland.

Progress has been made in the control or elimination of tropical diseases, with a significant reduction of incidence. However, there is a risk of re-emergence if the factors fueling transmission are not dealt with. Although it is essential to understand these underlying factors for each disease, asymptomatic carriers are a common element that may promote resurgence; their impact in terms of proportion in the population and role in transmission needs to be determined. In this paper, we review the current evidence on whether or not to treat asymptomatic carriers given the relevance of their role in the transmission of a specific disease, the efficacy and toxicity of existing drugs, the Public Health interest, and the benefit at an individual level, for example, in Chagas disease, to prevent irreversible organ damage. In the absence of other control tools such as vaccines, there is a need for safer drugs with good risk/benefit profiles in order to change the paradigm so that it addresses the complete infectious process beyond manifest disease to include treatment of non-symptomatic infected persons.
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http://dx.doi.org/10.1007/s00281-020-00796-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7299918PMC
June 2020

Editorial: Biomarkers in Leishmaniasis.

Front Cell Infect Microbiol 2019 12;9:388. Epub 2019 Nov 12.

WHO Collaborating Centre for Leishmaniasis, National Centre for Microbiology, Instituto de Salud Carlos III, Madrid, Spain.

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http://dx.doi.org/10.3389/fcimb.2019.00388DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6861439PMC
August 2020

New Strategies and Biomarkers for the Control of Visceral Leishmaniasis.

Trends Parasitol 2020 01 9;36(1):29-38. Epub 2019 Nov 9.

WHO Collaborating Centre for Leishmaniasis, National Centre for Microbiology, Instituto de Salud Carlos III, Majadahonda (Madrid), Spain.

Effective diagnosis and treatment of visceral leishmaniasis, together with the study of vectors and reservoirs, can lead to a better understanding of the parasite transmission dynamics and the development of more efficient control measures. Recent studies have applied new methodologies and biomarkers, and these have contributed to the early and rapid diagnosis of the disease; assessment of success of pharmacological treatments; efficient monitoring of immunosuppressed individuals; and to population screening for field trials of vaccine efficacy. This opinion article proposes an update to the diagnostic tools for visceral leishmaniasis and their rational and combined use to establish the real prevalence of infection or of exposure to Leishmania in endemic areas.
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http://dx.doi.org/10.1016/j.pt.2019.10.005DOI Listing
January 2020

The Use of Specific Serological Biomarkers to Detect CaniLeish Vaccination in Dogs.

Front Vet Sci 2019 24;6:373. Epub 2019 Oct 24.

i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.

Canine leishmaniosis (CanL) prevention in the Mediterranean basin is considered essential to stop human zoonotic visceral leishmaniasis. In this context, vaccination of dogs is expected to have a significant impact in disease control. CaniLeish® (Virbac Animal Health) is one of a few CanL vaccines that are at this moment licensed in Europe. This vaccine contains purified excreted-secreted proteins of having several antigens/immunogens with potential to influence serological response. Therefore, it is important to know if CaniLeish vaccination increased the diagnostic challenges associated with conventional serology, limiting the value of some antigens. To address this 20 dogs from a cohort of 35 healthy dogs that were vaccinated, maintained indoor for 1 month and then returned to their natural domiciles for 2 years. After this period, they were re-called to evaluate their clinical/parasitological condition and assess the evolution of seroreactivity against different antigens: soluble promastigote antigens (SPLA), recombinant protein cytosolic peroxiredoxin, recombinant protein K39 (rK39), recombinant protein K28 and recombinant kinesin degenerated derived repeat using ELISA. Two years after vaccination all vaccinated non-infected animals were seropositive for SPLA. For the other antigens the serological profile was indistinguishable from non-infected animals. Moreover, vaccinated animals presented a characteristic relative serological profile, with higher normalized serological response to SPLA than rK39. This fact enabled to distinguish with sensitivity 92.3% and specificity 95.4%, vaccinated non-infected dogs from infected and non-infected dogs. Ultimately, relative serological profile enabled the detection of healthy vaccinated animals enabling more accurate serological surveys.
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http://dx.doi.org/10.3389/fvets.2019.00373DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6821643PMC
October 2019

Clinical aspects of visceral leishmaniasis caused by L. infantum in adults. Ten years of experience of the largest outbreak in Europe: what have we learned?

Parasit Vectors 2019 Jul 24;12(1):359. Epub 2019 Jul 24.

Área de Infecciosas, Servicio de Medicina Interna, Hospital Universitario de Fuenlabrada, Camino del Molino 2, 28942, Fuenlabrada, Madrid, Spain.

Background: An outbreak of leishmaniasis caused by Leishmania infantum was declared in the southwest of the Madrid region (Spain) in June 2009. This provided a unique opportunity to compare the management of visceral leishmaniasis (VL) in immunocompetent adults (IC-VL), patients with HIV (HIV-VL) and patients receiving immunosuppressants (IS-VL).

Methods: A cohort of adults with VL, all admitted to the Hospital Universitario de Fuenlabrada between June 2009 and June 2018, were monitored in this observational study, recording their personal, epidemiological, analytical, diagnostic, treatment and outcome variables.

Results: The study population was made up of 111 patients with VL (10% HIV-VL, 14% IS-VL, 76% IC-VL). Seventy-one percent of the patients were male; the mean age was 45 years (55 years for the IS-VL patients, P = 0.017). Fifty-four percent of the IC-VL patients were of sub-Saharan origin (P = 0.001). Fever was experienced by 98% of the IC-VL patients vs 73% of the LV-HIV patients (P = 0.003). Plasma ferritin was > 1000 ng/ml in 77% of the IC-VL patients vs 17% of the LV-HIV patients (P = 0.007). Forty-two percent of patients fulfilled the criteria for haemophagocytic lymphohistiocytosis. RDT (rK39-ICT) serological analysis returned sensitivity and specificity values of 45% and 99%, respectively, and ELISA/iIFAT returned 96% and 89%, respectively, with no differences in this respect between patient groups. Fourteen (13.0%) patients with VL experienced treatment failure, eight of whom were in the IC-VL group. Treatment with < 21 mg/kg (total) liposomal amphotericin B (LAB) was associated with treatment failure in the IC-VL patients [P = 0.002 (OR: 14.7; 95% CI: 2.6-83.3)].

Conclusions: IS-VL was more common than HIV-VL; the lack of experience in dealing with IS-VL is a challenge that needs to be met. The clinical features of the patients in all groups were similar, although the HIV-VL patients experienced less fever and had lower plasma ferritin concentrations. RDT (rK39-ICT) analysis returned a good specificity value but a much poorer sensitivity value than reported in other scenarios. The patients with HIV-VL, IS-VL and IC-VL returned similar serological results. Current guidelines for treatment seem appropriate, but the doses of LAB required to treat patients with HIV-VL and IS-VL are poorly defined.
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http://dx.doi.org/10.1186/s13071-019-3628-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6657057PMC
July 2019

A multicentric evaluation of dipstick test for serodiagnosis of visceral leishmaniasis in India, Nepal, Sri Lanka, Brazil, Ethiopia and Spain.

Sci Rep 2019 07 9;9(1):9932. Epub 2019 Jul 9.

CSIR-Indian Institute of Chemical Biology, Kolkata, India.

Visceral leishmaniasis (VL) is one of the leading infectious diseases affecting developing countries. Colloidal gold-based diagnostic tests are rapid tools to detect blood/serum antibodies for VL diagnosis. Lack of uniformity in the performance of these tests in different endemic regions is a hurdle in early disease diagnosis. This study is designed to validate a serum-based dipstick test in eight centres of six countries, India, Nepal, Sri Lanka, Brazil, Ethiopia and Spain with archived and fresh sera from 1003 subjects. The dipstick detects antibodies against Leishmania donovani membrane antigens (LAg). The overall sensitivity and specificity of the test with 95% confidence intervals were found to be 97.10% and 93.44%, respectively. The test showed good sensitivity and specificity in the Indian subcontinent (>95%). In Brazil, Ethiopia, and Spain the sensitivity and specificity of the dipstick test (83.78-100% and 79.06-100%) were better as compared to the earlier reports of the performance of rK39 rapid test in these regions. Interestingly, less cross-reactivity was found with the cutaneous form of the disease in Spain, Brazil, and Sri Lanka demonstrating 91.58% specificity. This dipstick test can therefore be a useful tool for diagnosing VL from other symptomatically similar diseases and against cutaneous form of leishmaniasis.
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http://dx.doi.org/10.1038/s41598-019-46283-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6616445PMC
July 2019

Prevalence of asymptomatic infection and associated risk factors, after an outbreak in the south-western Madrid region, Spain, 2015.

Euro Surveill 2019 May;24(22)

WHO Collaborating Centre for Leishmaniasis, National Center for Microbiology, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain.

BackgroundA large outbreak of leishmaniasis with 758 cutaneous and visceral leishmaniasis cases occurred in 2009 in Fuenlabrada, in the south-west of the Madrid region of Spain.AimWe aimed to determine the prevalence of asymptomatic infection after this outbreak, and its associated risk factors.MethodsA cross-sectional study of 804 healthy individuals living in Fuenlabrada who had no history of leishmaniasis, was conducted between January and July 2015. Asymptomatic infections were sought by either a combination of PCR, immunofluorescent antibody titre, and direct agglutination tests, or by whole blood stimulation assay (WBA) with interleukin-2 (IL-2) quantification.ResultsUsing the first approach, prevalence of asymptomatic individuals was 1.1% (9/804), while the second returned a value of 20.7% (143/804). Older age, being male, proximity to the park where the focus of infection was identified, and living in a detached house, were all strongly associated with the prevalence of asymptomatic infection.ConclusionsThe true number of infected individuals may be underestimated if only serological methods are used. The combination of WBA with IL-2 quantification may allow to better determine the prevalence of asymptomatic infection, which would be useful in establishing control measures and in quantifying their impact. In our study, the use of WBA with IL-2 quantification also helped establish the risk factors that influence exposure to and infection by .
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http://dx.doi.org/10.2807/1560-7917.ES.2019.24.22.1800379DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6549460PMC
May 2019

Asymptomatic immune responders to Leishmania among HIV positive patients.

PLoS Negl Trop Dis 2019 06 3;13(6):e0007461. Epub 2019 Jun 3.

WHO Collaborating Centre for Leishmaniasis, National Centre for Microbiology, Instituto de Salud Carlos III, Majadahonda (Madrid), Spain.

Concomitant infection with human immunodeficiency virus (HIV) and the Leishmania parasite is a growing public health problem, the result of the former spreading to areas where the latter is endemic. Leishmania infection is usually asymptomatic in immunocompetent individuals, but the proportion of HIV+ individuals in contact with the parasite who remain asymptomatic is not known. The aim of the present work was to examine the use of cytokine release assays in the detection of asymptomatic immune responders to Leishmania among HIV+ patients with no previous leishmaniasis or current symptomatology. Eighty two HIV+ patients (all from Fuenlabrada, Madrid, Spain, where a leishmaniasis outbreak occurred in 2009) were examined for Leishmania infantum infection using molecular and humoral response-based methods. None returned a positive molecular or serological result for the parasite. Thirteen subjects showed a positive lymphoproliferative response to soluble Leishmania antigen (SLA), although the mean CD4+ T lymphocyte counts of these patients was below the normal range. Stimulation of peripheral blood mononuclear cells (PBMC) or whole blood with SLA (the lymphoproliferative assay and whole blood assay respectively), led to the production of specific cytokines and chemokines. Thus, despite being immunocompromised, HIV+ patients can maintain a Th1-type cellular response to Leishmania. In addition, cytokine release assays would appear to be useful tools for detecting these individuals via the identification of IFN-γ in the supernatants of SLA-stimulated PBMC, and of IFN-γ, MIG and IL-2 in SLA-stimulated whole blood. These biomarkers appear to be 100% reliable for detecting asymptomatic immune responders to Leishmania among HIV+ patients.
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http://dx.doi.org/10.1371/journal.pntd.0007461DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6564048PMC
June 2019

Cellular Markers of Active Disease and Cure in Different Forms of -Induced Disease.

Front Cell Infect Microbiol 2018 13;8:381. Epub 2018 Nov 13.

WHO Collaborating Centre for Leishmaniasis, National Centre for Microbiology, Instituto de Salud Carlos III, Madrid, Spain.

Increased numbers of peripheral blood mononucleocytes (PBMC) and increased IFN-γ secretion following challenge of blood samples with soluble antigen (SLA), have been proposed as biomarkers of specific cell-mediated immunity, indicating that treatment of visceral leishmaniasis (VL) has been successful. However, infection may manifest as cutaneous leishmaniasis (CL), and less commonly as localized leishmanial lymphadenopathy (LLL) or mucosal leishmaniasis (ML). The present work examines the value of these biomarkers as indicators of cured leishmaniasis presenting in these different forms. Blood samples were collected before and after treatment from patients living in Fuenlabrada (Madrid, Spain), an endemic area recently the center of a leishmaniasis outbreak. All samples were subjected to -specific PCR, serological tests (IFAT and rK39-ICT), and the SLA-cell proliferation assay (SLA-CPA), recording PBMC proliferation and the associated changes in IFN-γ production. Differences in the results recorded for the active and cured conditions were only significant for VL. PCR returned positive results in 67% of patients with active VL and in 3% of those with cured leishmaniasis. Similarly, rK39-ICT returned a positive result in 77% of active VL samples . 52% in cured VL samples, and IFAT in 90% . 56%; in the SLA-CPA, PBMC proliferation was seen in 16% . 90%, and an associated increase in IFN-γ production of 14 and 84%, respectively. The present findings reinforce the idea that PBMC proliferation and increased IFN-γ production in SLA-stimulated PBMC provide biomarkers of clinical cure in VL. Other tests are urgently needed to distinguish between the cured and active forms of the other types of clinical leishmaniasis caused by .
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http://dx.doi.org/10.3389/fcimb.2018.00381DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6243388PMC
September 2019

Potentiation of the leishmanicidal activity of nelfinavir in combination with miltefosine or amphotericin B.

Int J Antimicrob Agents 2018 Nov 30;52(5):682-687. Epub 2018 Jun 30.

Centro Colaborador de la OMS para la Leishmaniasis, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Spain.

The present work assesses the effect in vitro of combining the antiretroviral drug nelfinavir (NFV), a drug used against HIV but also a strong in vitro inhibitor of the growth of Leishmania promastigotes and amastigotes, with amphotericin B or miltefosine on different strains of Leishmania infantum. The isobolograms revealed a synergistic effect for both combinations, with a fractional inhibitory concentration index (∑FIC) <0.5. The ∑FIC values obtained with reference strain MCAN/ES/98/LLM-724 were 0.25 ± 0.1 (95% CI: 0.178-0.322) for the combination NFV+AMB and 0.48 ± 0.2 (95% CI: 0.377-0.573) for the combination NFV+MTF. The effect of NFV on visceral leishmaniasis induced by L. infantum in BALB/c mice was also examined, and the results confirmed a leishmanicidal effect when administered alone, with approximately 60% (P<0.05) reductions in the liver and spleen parasite burdens. This is the first time this has been reported in an in vivo model. A significant reduction in the liver (77%; P<0.01) and spleen (76%; P<0.01) parasite burdens was also observed for NFV+MTF compared with those obtained when these drugs were used alone. This indicates that such combinations may be useful treatment options in patients with visceral leishmaniasis who are also infected with HIV.
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http://dx.doi.org/10.1016/j.ijantimicag.2018.06.016DOI Listing
November 2018

Antigenicity of -Activated C-Kinase Antigen (LACK) in Human Peripheral Blood Mononuclear Cells, and Protective Effect of Prime-Boost Vaccination With pCI-neo-LACK Plus Attenuated LACK-Expressing Vaccinia Viruses in Hamsters.

Front Immunol 2018 23;9:843. Epub 2018 Apr 23.

WHO Collaborating Center for Leishmaniasis, National Center of Microbiology, Instituto de Salud Carlos III, Madrid, Spain.

-activated C-kinase antigen (LACK) is a highly conserved protein among species and is considered a viable vaccine candidate for human leishmaniasis. In animal models, prime-boost vaccination with LACK-expressing plasmids plus attenuated vaccinia viruses (modified vaccinia Ankara [MVA] and mutant M65) expressing LACK, has been shown to protect against cutaneous leishmaniasis (CL). Further, LACK demonstrated to induce the production of protective cytokines in patients with active CL or cured visceral leishmaniasis, as well as in asymptomatic individuals from endemic areas. However, whether LACK is capable to trigger cytokine release by peripheral blood mononuclear cells from patients cured of CL due to () or induce protection in -infected hamsters [visceral leishmaniasis (VL) model], has not yet been analyzed. The present work examines the immunogenicity of LACK in cured VL and CL patients, and asymptomatic subjects from an area. It also evaluates the vaccine potential of LACK against infection in hamsters, in a protocol of priming with plasmid pCI-neo-LACK (DNA-LACK) followed by a booster with the poxvirus vectors MVA-LACK or M65-LACK. LACK-stimulated PBMC from both asymptomatic and cured subjects responded by producing IFN-γ, TNF-α, and granzyme B (Th1-type response). Further, 78% of PBMC samples that responded to soluble antigen showed IFN-γ secretion following stimulation with LACK. In hamsters, the protocol of DNA-LACK prime/MVA-LACK or M65-LACK virus boost vaccination significantly reduced the amount of DNA in the liver and bone marrow, with no differences recorded between the use of MVA or M65 virus vector options. In summary, the Th1-type and cytotoxic responses elicited by LACK in PBMC from human subjects infected with , and the parasite protective effect of prime/boost vaccination in hamsters with DNA-LACK/MVA-LACK and DNA-LACK/M65-LACK, revealed the significance of LACK in activating human and hamster immune responses and support LACK to be a valuable candidate for inclusion in a vaccine against human VL.
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http://dx.doi.org/10.3389/fimmu.2018.00843DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5924775PMC
June 2019

Evaluation of fluorimetry and direct visualization to interpret results of a loop-mediated isothermal amplification kit to detect Leishmania DNA.

Parasit Vectors 2018 04 17;11(1):250. Epub 2018 Apr 17.

WHO Collaborating Centre for Leishmaniasis, National Centre for Microbiology, Instituto de Salud Carlos III, Madrid, Spain.

Background: Nucleic acid amplification tests (NAATs) have proven to be advantageous in the diagnosis of leishmaniases, allowing sensitive diagnosis of: (i) cutaneous leishmaniasis in long duration lesions and (ii) visceral leishmaniasis using a less-invasive sample like peripheral blood, in opposition to tissue aspiration required for parasite demonstration by microscopy. Despite their benefits, the implementation of NAATs for leishmaniasis diagnosis at the point-of-care has not been achieved yet, mostly due to the complexity and logistical issues associated with PCR-based methods.

Methods: In this work, we have evaluated the performance of a ready-to-use loop-mediated isothermal amplification (LAMP) kit using two real time fluorimeters to amplify leishmanial DNA obtained by silica column-based and Boil & Spin protocols.

Results: The different approaches used to run and interpret the LAMP reactions showed a performance equivalent to PCR and real-time PCR, using spiked and clinical samples. The time to positivity obtained with real-time fluorimetry showed an excellent correlation with both Ct values and parasite load from real-time quantitative PCR.

Conclusions: The results obtained open the possibility of using a highly stable, ready-to-use LAMP kit for the accurate diagnosis of leishmaniasis at the point-of-care. Furthermore, the feasibility of relating time to positivity, determined with a portable real-time fluorimeter, with the parasite burden could have a wider application in the management of leishmaniasis, such as in treatment efficacy monitoring or as a pharmacodynamics tool in clinical trials.
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http://dx.doi.org/10.1186/s13071-018-2836-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5905109PMC
April 2018

Can artificial tears prevent Acanthamoeba keratitis? An in vitro approach.

Parasit Vectors 2018 01 22;11(1):50. Epub 2018 Jan 22.

Facultad de Farmacia, Universidad San Pablo CEU, CEU Universities, Madrid, Spain.

Background: The use of contact lenses has increased in recent years as has the incidence of Dry Eye Syndrome, partly due to their use. Artificial tears are the most common treatment option. Since these changes can facilitate Acanthamoeba infection, the present study has been designed to evaluate the effect of three artificial tears treatments in the viability of Acanthamoeba genotype T4 trophozoites. Optava Fusion™, Oculotect®, and Artelac® Splash were selected due to their formulation.

Methods: Viability was assessed using two staining methods, Trypan Blue stain and CTC stain at different time intervals (2, 4, 6, 8 and 24 h). Trypan Blue viability was obtained by manual count with light microscopy while the CTC stain was determined using flow cytometry.

Results: Trypan Blue staining results demonstrated a decrease in viability for Optava Fusion™ and Artelac® Splash during the first 4 h of incubation. After, this effect seems to lose strength. In the case of Oculotect®, complete cell death was observed after 2 h. Using flow cytometry analysis, Optava Fusion™ and Oculotect® exhibited the same effect observed with Trypan Blue staining. However, Artelac® Splash revealed decreasing cell respiratory activity after four hours, with no damage to the cell membrane.

Conclusions: The present study uses, for the first time, CTC stain analyzed by flow cytometry to establish Acanthamoeba viability demonstrating its usefulness and complementarity with the traditional stain, Trypan Blue. Artelac® Splash, with no preservatives, and Optava Fusion TM, with Purite®, have not shown any useful amoebicidal activity. On the contrary, promising results presented by Ocultect®, with BAK, open up a new possibility for Acanthamoeba keratitis prophylaxis and treatment although in vivo studies should be carried out.
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http://dx.doi.org/10.1186/s13071-018-2639-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5778793PMC
January 2018

Pre-clinical antigenicity studies of an innovative multivalent vaccine for human visceral leishmaniasis.

PLoS Negl Trop Dis 2017 Nov 27;11(11):e0005951. Epub 2017 Nov 27.

Parasite Disease group, Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal.

The notion that previous infection by Leishmania spp. in endemic areas leads to robust anti-Leishmania immunity, supports vaccination as a potentially effective approach to prevent disease development. Nevertheless, to date there is no vaccine available for human leishmaniasis. We optimized and assessed in vivo the safety and immunogenicity of an innovative vaccine candidate against human visceral leishmaniasis (VL), consisting of Virus-Like Particles (VLP) loaded with three different recombinant proteins (LJL143 from Lutzomyia longipalpis saliva as the vector-derived (VD) component, and KMP11 and LeishF3+, as parasite-derived (PD) antigens) and adjuvanted with GLA-SE, a TLR4 agonist. No apparent adverse reactions were observed during the experimental time-frame, which together with the normal hematological parameters detected seems to point to the safety of the formulation. Furthermore, measurements of antigen-specific cellular and humoral responses, generally higher in immunized versus control groups, confirmed the immunogenicity of the vaccine formulation. Interestingly, the immune responses against the VD protein were reproducibly more robust than those elicited against leishmanial antigens, and were apparently not caused by immunodominance of the VD antigen. Remarkably, priming with the VD protein alone and boosting with the complete vaccine candidate contributed towards an increase of the immune responses to the PD antigens, assessed in the form of increased ex vivo CD4+ and CD8+ T cell proliferation against both the PD antigens and total Leishmania antigen (TLA). Overall, our immunogenicity data indicate that this innovative vaccine formulation represents a promising anti-Leishmania vaccine whose efficacy deserves to be tested in the context of the "natural infection".
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http://dx.doi.org/10.1371/journal.pntd.0005951DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5720812PMC
November 2017

Monocyte Chemotactic Protein 1 in Plasma from Soluble Antigen-Stimulated Whole Blood as a Potential Biomarker of the Cellular Immune Response to .

Front Immunol 2017 29;8:1208. Epub 2017 Sep 29.

WHO Collaborating Centre for Leishmaniasis, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Madrid, Spain.

New biomarkers are needed to identify asymptomatic infection as well as immunity following vaccination or treatment. With the aim of finding a robust biomarker to assess an effective cellular immune response, monocyte chemotactic protein 1 (MCP-1) was examined in plasma from soluble antigen (SLA)-stimulated whole blood collected from subjects living in a -endemic area. MCP-1, expressed 110 times more strongly than IL-2, identified 87.5% of asymptomatic subjects and verified some asymptomatic subjects close to the cutoff. MCP-1 was also significantly elevated in all patients cured of visceral leishmaniasis (VL), unlike IL-2, indicating the specific memory response generated against . These results show MCP-1 to be a robust candidate biomarker of immunity that could be used as a marker of cure and to both select and follow the population in vaccine phase I-III human clinical trials with developed rapid, easy-to-use field tools.
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http://dx.doi.org/10.3389/fimmu.2017.01208DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5626820PMC
September 2017

Efficacies of prevention and control measures applied during an outbreak in Southwest Madrid, Spain.

PLoS One 2017 13;12(10):e0186372. Epub 2017 Oct 13.

Department of Mathematics of University of Florida, Gainesville, Florida, United States of America.

Leishmaniasis is a vector-borne disease of worldwide distribution, currently present in 98 countries. Since late 2010, an unusual increase of human visceral and cutaneous leishmaniasis cases has been observed in the south-western Madrid region, totaling more than 600 cases until 2015. Some hosts, such as human, domestic dog and cat, rabbit (Oryctolagus cuniculus), and hare (Lepus granatensis), were found infected by the parasite of this disease in the area. Hares were described as the most important reservoir due to their higher prevalence, capacity to infect the vector, and presence of the same strains as in humans. Various measures were adopted to prevent and control the disease, and since 2013 there was a slight decline in the human sickness. We used a mathematical model to evaluate the efficacy of each measure in reducing the number of infected hosts. We identified in the present model that culling both hares and rabbits, without immediate reposition of the animals, was the best measure adopted, decreasing the proportion of all infected hosts. Particularly, culling hares was more efficacious than culling rabbits to reduce the proportion of infected individuals of all hosts. Likewise, lowering vector contact with hares highly influenced the reduction of the proportion of infected hosts. The reduction of the vector density per host in the park decreased the leishmaniasis incidence of hosts in the park and the urban areas. On the other hand, the reduction of the vector density per host of the urban area (humans, dogs and cats) decreased only their affected population, albeit at a higher proportion. The use of insecticide-impregnated collar and vaccination in dogs affected only the infected dogs' population. The parameters related to the vector contact with dog, cat or human do not present a high impact on the other hosts infected by Leishmania. In conclusion, the efficacy of each control strategy was determined, in order to direct future actions in this and in other similar outbreaks. The present mathematical model was able to reproduce the leishmaniasis dynamics in the Madrid outbreak, providing theoretical support based on successful experiences, such as the reduction of human cases in Southwest Madrid, Spain.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0186372PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5640254PMC
October 2017

Molecular detection of Leishmania infantum and Leishmania tropica in rodent species from endemic cutaneous leishmaniasis areas in Morocco.

Parasit Vectors 2017 Oct 2;10(1):454. Epub 2017 Oct 2.

Ecology and the Environment Laboratory L2E, (URAC 32, CNRST ERACNERS 06), Faculty of Sciences Semlalia, Cadi Ayyad University, Marrakesh, Morocco.

Background: Leishmaniasis remains a major public health problem in African nations, including Morocco, where little is known about the vertebrate reservoirs involved in the causal parasites' transmission cycles. The present study investigates the role of rodent species as potential reservoirs of Leishmania spp. in central Morocco, where both L. tropica and L. infantum have been reported.

Methods: Rodents were caught from 22 sites in central Morocco, by using Sherman metal traps, and identified morphologically. For each specimen, genomic DNA was extracted from different tissues using the Speed Tools DNA extraction Kit. Then, samples were PCR-analyzed, targeting the SSU rRNA gene to detect Leishmania spp. DNA, followed by amplification of the internal transcribed spacer 1 (ITS1) and its sequencing to identify the species.

Results: A total of 197 rodents belonging to ten species were captured and identified: Rattus rattus (40.61%), Mus musculus (25.38%), Apodemus sylvaticus (8.63%), Mus spretus (7.11%), Meriones shawi (5.58%), Rattus norvegicus (4.57%), Meriones libycus (3.05%), Mastomys erythroleucus (2.03%), Gerbillus campestris (2.03%) and Lemniscomys barbarus (1.01%). Molecular analysis revealed the presence of Leishmania species in 18 specimens: six R. rattus (out of 80 captured; 7.5%), 11 M. musculus (out of 50 captured; 22%), and one R. norvegicus (out of 9 captured; 11.11%).

Conclusions: To the best of our knowledge, L. infantum and L. tropica were identified in rodent species for the first time in Morocco. These findings suggest that rodent species may be involved in L. infantum and L. tropica transmission cycles in this country but that further studies are needed to confirm their role as reservoirs of Leishmania species in Morocco.
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http://dx.doi.org/10.1186/s13071-017-2398-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5625640PMC
October 2017

F1 Domain of the Nucleoside Hydrolase Promotes a Th1 Response in Cured Patients and in Asymptomatic Individuals Living in an Endemic Area of Leishmaniasis.

Front Immunol 2017 12;8:750. Epub 2017 Jul 12.

Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.

The nucleoside hydrolase NH36 is the main antigen of the Leishmune vaccine and one of the promising candidates for vaccination against visceral leishmaniasis. The antigenicity of the N-terminal (F1), the central (F2), or the C-terminal recombinant domain (F3) of NH36 was evaluated using peripheral blood mononuclear cells (PBMC) from individuals infected with from an endemic area of visceral leishmaniasis of Spain. Both NH36 and F1 domains significantly increased the PBMC proliferation stimulation index of cured patients and infected asymptomatic individuals compared to healthy controls. Moreover, F1 induced a 19% higher proliferative response than NH36 in asymptomatic exposed subjects. In addition, in patients cured from visceral leishmaniasis, proliferation in response to NH36 and F1 was accompanied by a significant increase of IFN-γ and TNF-α secretion, which was 42-43% higher, in response to F1 than to NH36. The interleukin 17 (IL-17) secretion was stronger in asymptomatic subjects, in response to F1, as well as in cured cutaneous leishmaniasis after NH36 stimulation. While no IL-10 secretion was determined by F1, a granzyme B increase was detected in supernatants from cured patients after stimulation with either NH36 or F1. These data demonstrate that F1 is the domain of NH36 that induces a recall cellular response in individuals with acquired resistance to the infection by . In addition, F1 and NH36 discriminated the IgG3 humoral response in patients with active visceral leishmaniasis due to (Ethiopia) and (Spain) from that of endemic and non-endemic area controls. NH36 showed higher reactivity with sera from -infected individuals, indicating species specificity. We conclude that the F1 domain, previously characterized as an inducer of the Th1 and Th17 responses in cured/exposed patients infected with , may also be involved in the generation of a protective response against and represents a potential vaccine candidate for the control of human leishmaniasis alone, or in combination with other HLA epitopes/antigens.
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http://dx.doi.org/10.3389/fimmu.2017.00750DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5506215PMC
July 2017

Environmental Factors as Key Determinants for Visceral Leishmaniasis in Solid Organ Transplant Recipients, Madrid, Spain.

Emerg Infect Dis 2017 07;23(7):1155-1159

During a visceral leishmaniasis outbreak in an area of Madrid, Spain, the incidence of disease among solid organ transplant recipients was 10.3% (7/68). Being a black person from sub-Saharan Africa, undergoing transplantation during the outbreak, and residing <1,000 m from the epidemic focus were risk factors for posttransplant visceral leishmaniasis.
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http://dx.doi.org/10.3201/eid2307.151251DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5512489PMC
July 2017

IFN-γ, IL-2, IP-10, and MIG as Biomarkers of Exposure to spp., and of Cure in Human Visceral Leishmaniasis.

Front Cell Infect Microbiol 2017 31;7:200. Epub 2017 May 31.

WHO Collaborating Centre for Leishmaniasis, Centro Nacional de Microbiologia, Instituto de Salud CarlosMadrid, Spain.

New biomarkers are needed for monitoring the effectiveness of treatment for visceral leishmaniasis (VL). They might also improve the detection of the asymptomatic population in endemic areas. This paper examines the IL-2, IFN-γ, IFN-γ-induced protein 10 (IP-10), and monokine-induced-by-IFN-γ (MIG) levels in whole blood-stimulated with soluble antigen (SLA)-taken from asymptomatic individuals and patients treated for VL living in a post-outbreak () area in Spain, and in an endemic () area of Bangladesh. IP-10 was found to be an accurate global marker of asymptomatic subjects with positive cellular/humoral tests, while MIG was found to be a better marker of contact with than IL-2 but no for those with . Determining IP-10, MIG, and IFN-γ levels proved useful in monitoring the cellular immune response following treatment for active disease caused by .
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http://dx.doi.org/10.3389/fcimb.2017.00200DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5449718PMC
February 2018

Infectivity of Post-Kala-azar Dermal Leishmaniasis Patients to Sand Flies: Revisiting a Proof of Concept in the Context of the Kala-azar Elimination Program in the Indian Subcontinent.

Clin Infect Dis 2017 Jul;65(1):150-153

Drugs for Neglected Diseases Initiative, Geneva, Switzerland.

We compared xenodiagnosis with quantitative polymerase chain reaction in skin biopsies from 3 patients with maculopapular or nodular post-kala-azar dermal leishmaniasis (PKDL). All patients infected sand flies. Parasite loads in skin varied from 1428 to 63 058 parasites per microgram. PKDL detection and treatment are important missing components of the kala-azar elimination program.
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http://dx.doi.org/10.1093/cid/cix245DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5848257PMC
July 2017

Nucleoside Hydrolase (NH36) Domains Induce T-Cell Cytokine Responses in Human Visceral Leishmaniasis.

Front Immunol 2017 7;8:227. Epub 2017 Mar 7.

Laboratório de Biologia e Bioquímica de Leishmania, Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Rio de Janeiro, Brazil; Faculdade de Medicina, Instituto de Investigação em Imunologia, Universidade de São Paulo (USP), São Paulo, Brazil.

Development of immunoprotection against visceral leishmaniasis (VL) focused on the identification of antigens capable of inducing a Th1 immune response. Alternatively, antigens targeting the CD8 and T-regulatory responses are also relevant in VL pathogenesis and worthy of being included in a preventive human vaccine. We assessed in active and cured patients and VL asymptomatic subjects the clinical signs and cytokine responses to the nucleoside hydrolase NH36 antigen and its N-(F1), central (F2) and C-terminal (F3) domains. As markers of VL resistance, the F2 induced the highest levels of IFN-γ, IL-1β, and TNF-α and, together with F1, the strongest secretion of IL-17, IL-6, and IL-10 in DTH and cured subjects. F2 also promoted the highest frequencies of CD3CD4IL-2TNF-αIFN-γ, CD3CD4IL-2TNF-αIFN-γ, CD3CD4IL-2TNF-αIFN-γ, and CD3CD4IL-2TNF-αIFN-γ T cells in cured and asymptomatic subjects. Consistent with this, the IFN-γ increase was correlated with decreased spleen ( = -0.428,  = 0.05) and liver sizes ( = -0.428,  = 0.05) and with increased hematocrit counts ( = 0.532,  = 0.015) in response to F1 domain, and with increased hematocrit ( = 0.512, 0.02) and hemoglobin counts ( = 0.434,  = 0.05) in response to F2. Additionally, IL-17 increases were associated with decreased spleen and liver sizes in response to F1 ( = -0.595,  = 0.005) and F2 ( = -0.462,  = 0.04). Conversely, F1 and F3 increased the CD3CD8IL-2TNF-αIFN-γ, CD3CD8IL-2TNF-αIFN-γ, and CD3CD8IL-2TNF-αIFN-γ T cell frequencies of VL patients correlated with increased spleen and liver sizes and decreased hemoglobin and hematocrit values. Therefore, cure and acquired resistance to VL correlate with the CD4-Th1 and Th-17 T-cell responses to F2 and F1 domains. Clinical VL outcomes, by contrast, correlate with CD8 T-cell responses against F3 and F1, potentially involved in control of the early infection. The -predicted NH36 epitopes are conserved and bind to many HL-DR and HLA and B allotypes. No human vaccine against is available thus far. In this investigation, we identified the NH36 domains and epitopes that induce CD4 and CD8 T cell responses, which could be used to potentiate a human universal T-epitope vaccine against leishmaniasis.
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http://dx.doi.org/10.3389/fimmu.2017.00227DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5338038PMC
March 2017

Interleukin-27 Early Impacts Infection in Mice and Correlates with Active Visceral Disease in Humans.

Front Immunol 2016 4;7:478. Epub 2016 Nov 4.

i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal; Faculdade de Farmácia, Departamento de Ciências Biológicas, Universidade do Porto, Porto, Portugal.

The complexity of -host interactions, one of the main leishmaniasis issues, is yet to be fully understood. We detected elevated IL-27 plasma levels in European patients with active visceral disease caused by , which returned to basal levels after successful treatment, suggesting this cytokine as a probable infection mediator. We further addressed this hypothesis recurring to two classical susceptible visceral leishmaniasis mouse models. BALB/c, but not C57BL/6 mice, showed increased IL-27 systemic levels after infection, which was associated with an upregulation of IL-27p28 expression by dendritic cells and higher parasite burdens. Neutralization of IL-27 in acutely infected BALB/c led to decreased parasite burdens and a transient increase in IFN-γ splenic T cells, while administration of IL-27 to C57BL/6 promoted a local anti-inflammatory cytokine response at the site of infection and increased parasite loads. Overall, we show that, as in humans, BALB/c IL-27 systemic levels are infection dependently upregulated and may favor parasite installation by controlling inflammation.
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http://dx.doi.org/10.3389/fimmu.2016.00478DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5095612PMC
November 2016

Lymphoproliferative response after stimulation with soluble leishmania antigen (SLA) as a predictor of visceral leishmaniasis (VL) relapse in HIV+ patients.

Acta Trop 2016 Dec 28;164:345-351. Epub 2016 Sep 28.

WHO Collaborating Centre for Leishmaniasis, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Madrid, Spain.

The introduction of HAART resulted in the decrease of Leishmania/HIV co-infection cases; nevertheless, the number of relapses remains high and secondary prophylaxis is recommended. However, secondary prophylaxis is not necessary in all patients, and presents a high risk of toxicity and an elevated cost. Our aim was to study whether specific cellular response to Leishmania infantum (measured by cell proliferation response after stimulation with soluble Leishmania antigen (SLA)), could be a useful tool to attempt a secondary prophylaxis withdrawal. In June 2009 an outbreak of leishmaniasis by Leishmania infantum was declared in the southeast of Madrid, and since January 2013, we recruited 10 HIV+ patients that had been treated for visceral leishmaniasis. 6 patients had positive SLA-cell proliferation test. The mean CD4 cell counts of those patients with positive SLA were 140 cel/mm3 and 40 cel/mm3 in those with negative SLA test. 3 patients with positive SLA-cell proliferation test (CD4 count: 336, 307, 625) were not on prophylaxis, and the other 3 patients (CD4 count: 152, 189, 359) were on secondary prophylaxis that was withdrawn after the positive SLA-cell proliferation test with no posterior relapses (mean follow up 60 weeks). From the 4 patients, which had negative SLA-cell proliferation test and continued on prophylaxis, 3 had positive PCR for Leishmania at the end of the follow-up and 2 presented clinical relapses. The performance of SLA-cell proliferation test can be a useful tool that can permit us to try withdrawal of the prophylaxis in Leishmania/HIV co-infected patients with low CD4 counts under clinical supervision, diminishing risk of toxicity and cost.
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http://dx.doi.org/10.1016/j.actatropica.2016.09.026DOI Listing
December 2016