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de Aquino SR, Diniz LFB, Nunes SLP, Silva RLDO, Gouveia GV, Gouveia JJS, Sales KGDS, Dantas-Torres F, do Carmo RF. Blood parasite load by qPCR as therapeutic monitoring in visceral leishmaniasis patients in Brazil: a case series study. Rev Soc Bras Med Trop 2023; 56:S0037-86822023000100605. [PMID: 36995785 PMCID: PMC10042474 DOI: 10.1590/0037-8682-0456-2022] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Accepted: 02/01/2023] [Indexed: 03/29/2023] Open
Abstract
Background: This study aimed to describe the kinetics of Leishmania parasite load determined using kinetoplast DNA (kDNA)-based quantitative polymerase chain reaction (qPCR) in visceral leishmaniasis (VL) patients. Methods: Parasite load in blood was assessed by qPCR at five time points, up to 12 months post-diagnosis. Sixteen patients were followed up. Results: A significant reduction in the parasite load was observed after treatment (P < 0.0001). One patient had an increased parasite load 3 months post-treatment and relapsed clinically at month six. Conclusions: We have described the use of kDNA-based qPCR in the post-treatment follow-up of VL cases.
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Affiliation(s)
- Samuel Ricarte de Aquino
- Universidade Federal do Vale do São Francisco, Programa de Pós-Graduação em Ciências da Saúde e Biológicas, Petrolina, PE, Brasil
- Universidade Federal do Vale do São Francisco, Hospital Universitário, Petrolina, PE, Brasil
| | - Lucyo Flávio Bezerra Diniz
- Universidade Federal do Vale do São Francisco, Programa de Pós-Graduação em Ciências da Saúde e Biológicas, Petrolina, PE, Brasil
- Universidade Federal do Vale do São Francisco, Hospital Universitário, Petrolina, PE, Brasil
| | - Sávio Luiz Pereira Nunes
- Universidade de Pernambuco, Programa de Pós-Graduação em Biologia Celular e Molecular Aplicada, Recife, PE, Brasil
| | | | - Gisele Veneroni Gouveia
- Universidade Federal do Vale do São Francisco, Colegiado de Zootecnia, Petrolina, PE, Brasil
| | | | | | | | - Rodrigo Feliciano do Carmo
- Universidade Federal do Vale do São Francisco, Programa de Pós-Graduação em Ciências da Saúde e Biológicas, Petrolina, PE, Brasil
- Universidade de Pernambuco, Programa de Pós-Graduação em Biologia Celular e Molecular Aplicada, Recife, PE, Brasil
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Siala E, Bouratbine A, Aoun K. Mediterranean visceral leishmaniasis : update on biological diagnosis. Tunis Med 2022; 100:13-26. [PMID: 35822327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/29/2022]
Abstract
Visceral leishmaniasis (VL) is a severe life threatening parasitosis requiring early management of cases. It is an emerging disease in the Mediterranean region with a spread of endemic areas and an increase in case incidence. The patient profile has also evolved with more affected adults, presenting generally non-specific symptoms. Hence the interest of a systematic biological confirmation. The microscopic detection of Leishmania amastigotes in bone marrow aspirates (BMA) smears is the gold standard diagnostic technique. However, it requires invasive sampling. Serological tests searching for specific antibodies remain highly contributory, but their interpretation must always take into account the epidemiological context and the patient's clinical and biological features. Currently, the Western-Blot represents the most specific serological technique for diagnostic confirmation. VL diagnosis has greatly improved by the introduction of both rapid diagnostic tests (RDTs) and molecular biological techniques. RDTs using recombinant rk39 antigen are easy to perform and deliver results in less than 30 minutes. Real-time PCR (Polymerase Chain Reaction) is currently retained as the best technique for VL diagnosis. It is efficient on simple blood samples, allowing to avoid invasive BMA needed for microscopy. In addition, real time PCR estimates parasite load which is helpful for the post-treatment follow-up. In any case, the choice of techniques to be used should be strategic and adapted to the local epidemiology as well as to the means available.
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Bussotti G, Benkahla A, Jeddi F, Souiaï O, Aoun K, Späth GF, Bouratbine A. Nuclear and mitochondrial genome sequencing of North-African Leishmania infantum isolates from cured and relapsed visceral leishmaniasis patients reveals variations correlating with geography and phenotype. Microb Genom 2020; 6:mgen000444. [PMID: 32975503 PMCID: PMC7660250 DOI: 10.1099/mgen.0.000444] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 09/13/2020] [Indexed: 12/19/2022] Open
Abstract
Although several studies have investigated genetic diversity of Leishmania infantum in North Africa, genome-wide analyses are lacking. Here, we conducted comparative analyses of nuclear and mitochondrial genomes of seven L. infantum isolates from Tunisia with the aim to gain insight into factors that drive genomic and phenotypic adaptation. Isolates were from cured (n=4) and recurrent (n=3) visceral leishmaniasis (VL) cases, originating from northern (n=2) and central (n=5) Tunisia, where respectively stable and emerging VL foci are observed. All isolates from relapsed patients were from Kairouan governorate (Centre); one showing resistance to the anti-leishmanial drug Meglumine antimoniate. Nuclear genome diversity of the isolates was analysed by comparison to the L. infantum JPCM5 reference genome. Kinetoplast maxi and minicircle sequences (1 and 59, respectively) were extracted from unmapped reads and identified by blast analysis against public data sets. The genome variation analysis grouped together isolates from the same geographical origins. Strains from the North were very different from the reference showing more than 34 587 specific single nucleotide variants, with one isolate representing a full genetic hybrid as judged by variant frequency. Composition of minicircle classes within isolates corroborated this geographical population structure. Read depth analysis revealed several significant gene copy number variations correlating with either geographical origin (amastin and Hsp33 genes) or relapse (CLN3 gene). However, no specific gene copy number variation was found in the drug-resistant isolate. In contrast, resistance was associated with a specific minicircle pattern suggesting Leishmania mitochondrial DNA as a potential novel source for biomarker discovery.
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Affiliation(s)
- Giovanni Bussotti
- Institut Pasteur, Hub Bioinformatique et biostatistique, 28 Rue du Dr Roux, 75015 Paris, France
- Institut Pasteur, INSERM U1201, Unité de Parasitologie moléculaire et Signalisation, Département des Parasites et Insectes vecteurs, 25 Rue du Dr Roux, 75015 Paris, France
| | - Alia Benkahla
- Laboratoire de recherche, LR 16IPT09, Bioinformatique, Biomathématiques et Biostatistiques, Institut Pasteur de Tunis, Université Tunis El-Manar, 13 Place Pasteur, Tunis, Tunisie
| | - Fakhri Jeddi
- Laboratoire de Parasitologie, Hôpital de la Timone, Marseille, France
- Laboratoire de Parasitologie et Mycologie Médicale, CHU de Nantes, Nantes, France
| | - Oussama Souiaï
- Laboratoire de recherche, LR 16IPT09, Bioinformatique, Biomathématiques et Biostatistiques, Institut Pasteur de Tunis, Université Tunis El-Manar, 13 Place Pasteur, Tunis, Tunisie
| | - Karim Aoun
- Laboratoire de recherche, LR 16IPT06, Parasitoses médicales, Biotechnologies et Biomolécules, Institut Pasteur de Tunis, Université Tunis El-Manar, 13 Place Pasteur, Tunis, Tunisie
| | - Gerald F. Späth
- Institut Pasteur, INSERM U1201, Unité de Parasitologie moléculaire et Signalisation, Département des Parasites et Insectes vecteurs, 25 Rue du Dr Roux, 75015 Paris, France
| | - Aïda Bouratbine
- Laboratoire de recherche, LR 16IPT06, Parasitoses médicales, Biotechnologies et Biomolécules, Institut Pasteur de Tunis, Université Tunis El-Manar, 13 Place Pasteur, Tunis, Tunisie
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Mukhtar M, Ali SS, Boshara SA, Albertini A, Monnerat S, Bessell P, Mori Y, Kubota Y, Ndung’u JM, Cruz I. Sensitive and less invasive confirmatory diagnosis of visceral leishmaniasis in Sudan using loop-mediated isothermal amplification (LAMP). PLoS Negl Trop Dis 2018; 12:e0006264. [PMID: 29444079 PMCID: PMC5828521 DOI: 10.1371/journal.pntd.0006264] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 02/27/2018] [Accepted: 01/24/2018] [Indexed: 12/01/2022] Open
Abstract
Background Confirmatory diagnosis of visceral leishmaniasis (VL), as well as diagnosis of relapses and test of cure, usually requires examination by microscopy of samples collected by invasive means, such as splenic, bone marrow or lymph node aspirates. This causes discomfort to patients, with risks of bleeding and iatrogenic infections, and requires technical expertise. Molecular tests have great potential for diagnosis of VL using peripheral blood, but require well-equipped facilities and trained personnel. More user-friendly, and field-amenable options are therefore needed. One method that could meet these requirements is loop-mediated isothermal amplification (LAMP) using the Loopamp Leishmania Detection Kit, which comes as dried down reagents that can be stored at room temperature, and allows simple visualization of results. Methodology/Principal findings The Loopamp Leishmania Detection Kit (Eiken Chemical Co., Japan), was evaluated in the diagnosis of VL in Sudan. A total of 198 VL suspects were tested by microscopy of lymph node aspirates (the reference test), direct agglutination test-DAT (in house production) and rK28 antigen-based rapid diagnostic test (OnSite Leishmania rK39-Plus, CTK Biotech, USA). LAMP was performed on peripheral blood (whole blood and buffy coat) previously processed by: i) a direct boil and spin method, and ii) the QIAamp DNA Mini Kit (QIAgen). Ninety seven of the VL suspects were confirmed as cases by microscopy of lymph node aspirates. The sensitivity and specificity for each of the tests were: rK28 RDT 98.81% and 100%; DAT 88.10% and 78.22%; LAMP-boil and spin 97.65% and 99.01%; LAMP-QIAgen 100% and 99.01%. Conclusions/Significance Due to its simplicity and high sensitivity, rK28 RDT can be used first in the diagnostic algorithm for primary VL diagnosis, the excellent performance of LAMP using peripheral blood indicates that it can be also included in the algorithm for diagnosis of VL as a simple test when parasitological confirmatory diagnosis is required in settings that are lower than the reference laboratory, avoiding the need for invasive lymph node aspiration. Tissue aspiration, either from spleen, bone marrow or lymph node, remains the Gold Standard for parasitological confirmation in patients suspected of visceral leishmaniasis (VL), and is often used for detection of relapses, and as a test of cure. The procedure is invasive, with risks of severe complications, requires skilled personnel to perform, and appropriate facilities to manage severe adverse events, if they occur. These drawbacks can be solved by using sensitive diagnostic test based on peripheral blood. Nucleic acid amplification tests (NAAT) are sensitive for the detection of Leishmania parasites in blood; however, in VL-endemic settings, most NAAT are restricted to well-equipped laboratories. A robust NAAT, Loopamp Leishmania Detection Kit has recently been developed in a collaboration between FIND, Eiken Chemical Co. Ltd., Japan and other partners. We have evaluated this kit in Sudan and obtained a sensitivity of 97.6% and specificity of 99.1%, using DNA obtained from peripheral blood through a simple boil and spin method. Its simplicity and excellent diagnostic performance make this kit ideal for parasitological confirmation of VL in less equipped laboratories.
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Affiliation(s)
- Maowia Mukhtar
- Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan
| | - Sababil S. Ali
- Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan
| | - Salah A. Boshara
- Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan
| | - Audrey Albertini
- Foundation for Innovative New Diagnostics—FIND, Geneva, Switzerland
| | | | - Paul Bessell
- Foundation for Innovative New Diagnostics—FIND, Geneva, Switzerland
| | | | | | | | - Israel Cruz
- Foundation for Innovative New Diagnostics—FIND, Geneva, Switzerland
- * E-mail:
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Abstract
The leishmaniases comprise a complex of diseases characterized by clinical outcomes that range from self-limiting to chronic, and disfiguring and stigmatizing to life threatening. Diagnostic methods, treatments, and vector and reservoir control options exist, but deciding the most effective interventions requires a quantitative understanding of the population level infection and disease dynamics. The effectiveness of any set of interventions has to be determined within the context of operational conditions, including economic and political commitment. Mathematical models are the best available tools for studying quantitative systems crossing disciplinary spheres (biology, medicine, economics) within environmental and societal constraints. In 2005, the World Health Assembly and government health ministers of India, Nepal, and Bangladesh signed a Memorandum of Understanding to eliminate the life threatening form of leishmaniasis, visceral leishmaniasis (VL), on the Indian subcontinent by 2015 through a combination of early case detection, improved treatments, and vector control. The elimination target is <1 case/10,000 population at the district or subdistrict level compared to the current 20/10,000 in the regions of highest transmission. Towards this goal, this chapter focuses on mathematical models of VL, and the biology driving those models, to enable realistic predictions of the best combination of interventions. Several key issues will be discussed which have affected previous modelling of VL and the direction future modelling may take. Current understanding of the natural history of disease, immunity (and loss of immunity), and stages of infection and their durations are considered particularly for humans, and also for dogs. Asymptomatic and clinical infection are discussed in the context of their relative roles in Leishmania transmission, as well as key components of the parasite-sandfly-vector interaction and intervention strategies including diagnosis, treatment and vector control. Gaps in current biological knowledge and potential avenues to improve model structures and mathematical predictions are identified. Underpinning the marriage between biology and mathematical modelling, the content of this chapter represents the first step towards developing the next generation of models for VL.
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Affiliation(s)
- K S Rock
- University of Warwick, Coventry, United Kingdom
| | | | - G F Medley
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - O Courtenay
- University of Warwick, Coventry, United Kingdom
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Aissi W, Ben Hellel K, Habboul Z, Ben Sghaier I, Harrat Z, Bouratbine A, Aoun K. Profils épidémiologique, clinique et biologique de la leishmaniose viscérale infantile à l’hôpital de Kairouan (Tunisie) : à propos de 240 cas. ACTA ACUST UNITED AC 2015; 108:265-71. [DOI: 10.1007/s13149-015-0438-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 06/02/2015] [Indexed: 11/25/2022]
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Mansueto P, Seidita A, Vitale G, Cascio A. Transfusion transmitted leishmaniasis. What to do with blood donors from endemic areas? Travel Med Infect Dis 2014; 12:617-27. [DOI: 10.1016/j.tmaid.2014.10.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Revised: 10/11/2014] [Accepted: 10/13/2014] [Indexed: 10/24/2022]
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Jeddi F, Mary C, Aoun K, Harrat Z, Bouratbine A, Faraut F, Benikhlef R, Pomares C, Pratlong F, Marty P, Piarroux R. Heterogeneity of molecular resistance patterns in antimony-resistant field isolates of Leishmania species from the western Mediterranean area. Antimicrob Agents Chemother 2014; 58:4866-74. [PMID: 24913173 DOI: 10.1128/AAC.02521-13] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Antimonials remain the first-line treatment for the various manifestations of leishmaniasis in most areas where the disease is endemic, and increasing cases of therapeutic failure associated with parasite resistance have been reported. In this study, we assessed the molecular status of 47 clinical isolates of Leishmania causing visceral and cutaneous leishmaniasis from Algeria, Tunisia, and southern France. In total, we examined 14 genes that have been shown to exhibit significant variations in DNA amplification, mRNA levels, or protein expression with respect to resistance to antimonials. The gene status of each clinical isolate was assessed via qPCR and qRT-PCR. We then compared the molecular pattern against the phenotype determined via an in vitro sensitivity test of the clinical isolates against meglumine antimoniate, which is considered the reference technique. Our results demonstrate significant DNA amplification and/or RNA overexpression in 56% of the clinical isolates with the resistant phenotype. All clinical isolates that exhibited significant overexpression of at least 2 genes displayed a resistant phenotype. Among the 14 genes investigated, 10 genes displayed either significant amplification or overexpression in at least 1 clinical isolate; these genes are involved in several metabolic pathways. Moreover, various gene associations were observed depending on the clinical isolates, supporting the multifactorial nature of Leishmania resistance. Molecular resistance features were found in the 3 Leishmania species investigated (Leishmania infantum, Leishmania major, and Leishmania killicki). To our knowledge, this is the first report of the involvement of molecular resistance genes in field isolates of Leishmania major and Leishmania killicki with the resistance phenotype.
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Mourão MVA, Toledo A, Gomes LI, Freire VV, Rabello A. Parasite load and risk factors for poor outcome among children with visceral leishmaniasis. A cohort study in Belo Horizonte, Brazil, 2010-2011. Mem Inst Oswaldo Cruz 2014; 109:147-53. [PMID: 24676657 PMCID: PMC4015258 DOI: 10.1590/0074-0276140257] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Accepted: 12/05/2013] [Indexed: 01/08/2023] Open
Abstract
Clinical and laboratory risk factors for death from visceral leishmaniasis (VL) are
relatively known, but quantitative real-time polymerase chain reaction (qPCR) might
assess the role of parasite load in determining clinical outcome. The aim of this
study was to identify risk factors, including parasite load in peripheral blood, for
VL poor outcome among children. This prospective cohort study evaluated children aged
≤ 12 years old with VL diagnosis at three times: pre-treatment (T0), during treatment
(T1) and post-treatment (T2). Forty-eight patients were included and 16 (33.3%) met
the criteria for poor outcome. Age ≤ 12 months [relative risk (RR) 3.51; 95%
confidence interval (CI) 1.89-6.52], tachydyspnoea (RR 3.46; 95% CI 2.19-5.47),
bacterial infection (RR 3.08; 95% CI 1.27-7.48), liver enlargement (RR 3.00; 95% CI
1.44-6.23) and low serum albumin (RR 7.00; 95% CI 1.80-27.24) were identified as risk
factors. qPCR was positive in all patients at T0 and the parasite DNA was
undetectable in 76.1% of them at T1 and in 90.7% at T2. There was no statistical
association between parasite load at T0 and poor outcome.
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Affiliation(s)
| | - Antonio Toledo
- Serviço Multiprofissional de Infectologia, Universidade José do Rosário Vellano-UNIFENAS, Belo Horizonte, MG, Brasil
| | - Luciana Inácia Gomes
- Laboratório de Pesquisas Clínicas, Centro de Pesquisas René Rachou-Fiocruz, Belo Horizonte, MG, Brasil
| | - Verônica Vieira Freire
- Laboratório de Pesquisas Clínicas, Centro de Pesquisas René Rachou-Fiocruz, Belo Horizonte, MG, Brasil
| | - Ana Rabello
- Laboratório de Pesquisas Clínicas, Centro de Pesquisas René Rachou-Fiocruz, Belo Horizonte, MG, Brasil
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Verma S, Avishek K, Sharma V, Negi NS, Ramesh V, Salotra P. Application of loop-mediated isothermal amplification assay for the sensitive and rapid diagnosis of visceral leishmaniasis and post-kala-azar dermal leishmaniasis. Diagn Microbiol Infect Dis 2013; 75:390-5. [PMID: 23433714 DOI: 10.1016/j.diagmicrobio.2013.01.011] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Revised: 01/09/2013] [Accepted: 01/16/2013] [Indexed: 11/30/2022]
Abstract
Loop-mediated isothermal amplification (LAMP) is at the forefront in the search for innovative diagnostics for rapid and specific amplification of target DNA under isothermal conditions. We have applied LAMP assay using SYBR Green for clear-cut naked eye detection of Leishmania (Leishmania) donovani in 200 clinical samples of visceral leishmaniasis (VL) and post-kala-azar dermal leishmaniasis (PKDL). The assay was positive in 53/55 VL blood samples (sensitivity, 96.4%; 95% confidence interval [CI], 87.7-99%), 15/15 VL bone marrow aspirate samples (sensitivity, 100%; 95% CI, 79.6-100%), 60/62 PKDL tissue biopsy samples (sensitivity, 96.8%; 95% CI, 88.9-99.1%), and 1/68 control samples (specificity, 98.5%; 95% CI, 92.1-99.7%). The assay was specific for L. (L.) donovani, the causative species for VL and negative for L. (L.) infantum, L. (L.) tropica, and L. (L.) major. This is the first comprehensive clinical study demonstrating the applicability of the LAMP assay for a rapid and reliable molecular diagnosis of VL and PKDL.
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Affiliation(s)
- Sandeep Verma
- National Institute of Pathology (ICMR), Safdarjung Hospital Campus, New Delhi 110029, India
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Pourabbas B, Ghadimi Moghadam A, Pouladfar G, Rezaee Z, Alborzi A. Quantification of Leishmania infantum kinetoplast DNA for monitoring the response to meglumine antimoniate therapy in visceral leishmaniasis. Am J Trop Med Hyg 2013; 88:868-71. [PMID: 23400573 DOI: 10.4269/ajtmh.12-0440] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Meglumine antimoniate (Glucantime) remains the therapeutic cornerstone of visceral leishmaniasis (VL). Twenty-one VL patients were treated with Glucantime, extending for 1 week after defervescence. For monitoring the response, Leishmania infantum kinetoplast DNA loads were evaluated using real-time polymerase chain reaction (PCR) assay in the blood. The maximum duration of treatment was 14 days. The loads before treatment ranged from 8 to 1,300,000 parasites/mL (mean = 73,095 parasites/mL), and the mean values on days 3, 7, 14, 28, and 90 were 4,902, 506, 6.33, 0.26, and 0.14, respectively. The loads decline to < 1 parasite/mL for 16 (76%) and 20 (95%) patients on days 14 and 28, respectively, and they decline for all patients by day 90. Results showed a dramatic decrease of the parasite loads, although complete clearance was not accomplished at the end of treatment. Only one relapse (4.5%) was observed. The parasite load can also serve as a dependable index for monitoring the response to Glucantime.
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Affiliation(s)
- Bahman Pourabbas
- Professor Alborzi Clinical Microbiology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.
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Verma S, Bhandari V, Avishek K, Ramesh V, Salotra P. Reliable diagnosis of post-kala-azar dermal leishmaniasis (PKDL) using slit aspirate specimen to avoid invasive sampling procedures. Trop Med Int Health 2012; 18:268-75. [PMID: 23279800 DOI: 10.1111/tmi.12047] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
OBJECTIVE Confirmatory diagnosis of post-kala-azar dermal leishmaniasis (PKDL) is primarily based on invasive skin biopsy procedure. We evaluated the utility of minimally invasive slit aspirate specimen for serological and molecular diagnosis of PKDL. We compared the PKDL diagnosis using slit aspirate and skin biopsy specimens from the same patients. METHODS Serological diagnosis using rK39 strip test was performed with serum and slit aspirate sample; molecular diagnosis for parasite detection and quantification was carried out by quantitative real-time PCR (Q-PCR) with skin biopsy and slit aspirate sample. RESULTS The rK39 serological strip test was positive in all PKDL cases with both slit aspirate and serum samples (n = 50) and negative in all control cases (n = 24), giving a sensitivity of 100% (95% CI: 92.9-100%) and a specificity of 100% (95% CI: 86.2-100%). Quantitative-PCR detected parasite in all PKDL slit aspirates (n = 50, sensitivity = 100%, 95% CI: 92.9-100%) and tissue biopsies (n = 46, sensitivity = 100%, 95% CI: 92.3-100; it was negative in all controls including dermal tissues (n = 24) and slit aspirates (n = 24), giving specificity of 100% (95% CI: 86.2-100%). The parasite load in tissue and slit aspirate samples was significantly (P < 0.0001) correlated (r = 0.82). CONCLUSIONS Slit aspirates are a simpler and minimally invasive sampling technique for initial screening by serology followed by confirmatory diagnosis of PKDL with microscopy and/or Q-PCR. The simplified procedure has the potential for epidemiological studies and assessment of cure in PKDL.
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Affiliation(s)
- Sandeep Verma
- National Institute of Pathology (Indian Council of Medical Research), New Delhi, India
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Lakhal S, Mekki S, Ben-Abda I, Mousli M, Amri F, Aoun K, Bouratbine A. Evaluation of an enzyme-linked immunosorbent assay based on crude Leishmania histone proteins for serodiagnosis of human infantile visceral leishmaniasis. Clin Vaccine Immunol 2012; 19:1487-91. [PMID: 22815147 DOI: 10.1128/CVI.00257-12] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Human visceral leishmaniasis (VL) is routinely diagnosed by detecting IgG that specifically binds to Leishmania antigens. The enzyme-linked immunosorbent assay (ELISA) remains a widely used method. However, the biggest challenge remains the choice of antigen with the highest specificity and sensitivity. This study is aimed at assessing the diagnostic performances of crude Leishmania histone (CLH) protein-based ELISAs in Mediterranean VL patients. The CLH proteins were biochemically purified from promastigote nuclear extracts. Their reactivities were analyzed by Western blotting (WB) using rabbit polyclonal antibodies against Leishmania recombinant histones and sera from VL patients, respectively. Then, the diagnostic potential of CLH proteins was validated by the CLH-based ELISA using 42 infantile VL patients' sera and 70 control subjects. The CLH-based ELISA performance was compared to that of the soluble Leishmania antigen (SLA)- and the recombinant K39 (rK39)-based ELISAs. Analysis of the WB profile with the use of polyclonal antibodies confirmed the histone origin of low molecular mass proteins (12 to 16 kDa). All VL samples tested presented antibodies reacting against different antigen fractions; however, recognition patterns were different depending on the reactivity of each serum. CLH-based ELISA showed an excellent ability to discriminate between VL cases and healthy controls (97.6% sensitivity and 100% specificity). It had a diagnostic performance similar to that of rK39-based ELISA (97.6% sensitivity and 97.1% specificity, P = 0.5) and a better serodiagnosis accuracy than the SLA-based ELISA (85.7% sensitivity and 90% specificity, P < 0.05). Therefore, crude Leishmania histone extract could be a valuable antigen for clinical use.
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Galaï Y, Chabchoub N, Ben-Abid M, Ben-Abda I, Ben-Alaya-Bouafif N, Amri F, Aoun K, Bouratbine A. Diagnosis of mediterranean visceral leishmaniasis by detection of leishmania antibodies and leishmania DNA in oral fluid samples collected using an Oracol device. J Clin Microbiol 2011; 49:3150-3. [PMID: 21715587 PMCID: PMC3165591 DOI: 10.1128/jcm.00267-11] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Accepted: 06/20/2011] [Indexed: 11/20/2022] Open
Abstract
Current methods for diagnosis of visceral leishmaniasis (VL) require invasive sampling procedures such as visceral aspiration and/or blood drawing. The use of diagnostic tests using oral fluid, which is easier to collect, would be more simple and practical for VL diagnosis, especially under field conditions. Oral fluids from 37 VL patients and 40 healthy controls were collected using Oracol devices. Blood samples and oral fluid specimens from both groups were analyzed by recombinant protein K39 (rK39) enzyme-linked immunosorbent assay and quantitative real-time PCR. Detection of antibodies in the oral fluid had a sensitivity of 100% and a specificity of 97.5%. Antibody levels measured in serum and oral fluid showed a significant positive correlation (ρ = 0.655 and P = 0.01). Detection of Leishmania DNA in oral fluid had a sensitivity of 94.6% and a specificity of 90%. The median parasite load estimated in blood was 133 parasites/ml (interquartile range [IR], 10 to 1,048), whereas that in oral fluid specimens was 3 parasites/ml (IR, 0.41 to 92). However, there was no significant linear relationship between parasite loads assessed in the two biological samples (ρ = 0.31 and P = 0.06). VL diagnosis based on specific antibody detection and Leishmania DNA identification using oral fluid samples was equivalent in accuracy to that using blood and therefore is promising for clinical use.
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Affiliation(s)
- Yousr Galaï
- LR 05SP03, Department of Parasitology, Pasteur Institute of Tunis, Tunis, Tunisia
| | - Najla Chabchoub
- LR 05SP03, Department of Parasitology, Pasteur Institute of Tunis, Tunis, Tunisia
| | - Meriem Ben-Abid
- LR 05SP03, Department of Parasitology, Pasteur Institute of Tunis, Tunis, Tunisia
| | - Imène Ben-Abda
- LR 05SP03, Department of Parasitology, Pasteur Institute of Tunis, Tunis, Tunisia
| | | | - Fethi Amri
- Paediatrics Department, Kairouan Regional Hospital, Kairouan, Tunisia
| | - Karim Aoun
- LR 05SP03, Department of Parasitology, Pasteur Institute of Tunis, Tunis, Tunisia
| | - Aïda Bouratbine
- LR 05SP03, Department of Parasitology, Pasteur Institute of Tunis, Tunis, Tunisia
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Sudarshan M, Weirather JL, Wilson ME, Sundar S. Study of parasite kinetics with antileishmanial drugs using real-time quantitative PCR in Indian visceral leishmaniasis. J Antimicrob Chemother 2011; 66:1751-5. [PMID: 21609983 DOI: 10.1093/jac/dkr185] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES This study describes parasite kinetics in the blood of visceral leishmaniasis patients treated with liposomal amphotericin B (L-AmB) or a preformed fat emulsion of amphotericin B (ApL) using real-time quantitative PCR (qPCR). METHODS Forty-six patients were treated with a single dose (15 mg/kg of body weight) of either L-AmB (n = 13) or ApL (n = 33). qPCR was used to estimate parasite kinetics by detection of Leishmania donovani DNA using kinetoplast DNA-specific primers in peripheral blood samples using an absolute quantification method. RESULTS The mean parasite load decreased from baseline (day 0) values of 894.07 and 980.48 to 71.72 and 211.52 parasite genomes/mL at day 7 in L-AmB and ApL groups, respectively, and at day 30 these further declined to 8.30 and 133.98 parasite genomes/mL, respectively. At day 30 post-treatment evaluation, the decline in parasite load was significantly greater (P = 0.024) with L-AmB compared with ApL. Four of 33 patients in the ApL group failed treatment (1 primary failure and 3 relapses) with the presence of parasites, whereas all patients in the L-AmB group were cured at 6 month follow-up. CONCLUSIONS qPCR can be a tool to measure parasite dynamics accurately and provide a marker to measure the efficacy of various drugs. It can be used as a test of cure, allowing us to do away with invasive and risky methods such as splenic or bone marrow aspiration.
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Affiliation(s)
- Medhavi Sudarshan
- Department of Medicine, Institute of Medical Sciences, Banaras Hindu University, Varanasi-221005, UP, India
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