Antigenemia in Patients with Mediterranean Visceral Leishmaniasis

Ferruà, Bernard; Rol, Nicolas; Michel, Grégory; Marty, Pierre

doi:10.1128/jcm.00649-09

Cited by 6 publications

(6 citation statements)

References 11 publications

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“…This could result in loss of signal, consistent with our observation (Fig. 3a ) at lysates from one million L. donovani promastigotes containing about 4 μg protein which could compete with target antigen binding [ 18 ].…”

Section: Resultssupporting

confidence: 89%

“…It is noteworthy that a Leishmania sandwich ELISA developed by Ferrua et al could detect circular Leishmania antigen in sera of L. infantum infected visceral leishmaniasis patients with sensitivity like that shown in Fig. 3 [ 18 ]. Since the maximum binding capacity of a 96-well ELISA plate well is about 1 μg protein, it is necessary to dilute the Leishmania lysate to a concentration of 20 μg/ ml (1 μg/50 μl/ well) in coating buffer.…”

Section: Resultsmentioning

confidence: 99%

“…Definitive diagnosis of VL still requires microscopic identification of the parasite in internal organs such as in spleen, liver or bone marrow aspirates, an invasive and dangerous process with varied sensitivity (53–99%) [ 8 – 10 ]. Therefore, development of an assay that can sensitively detect Leishmania antigen from blood or urine samples would be helpful for rapid and definitive VL diagnosis, test of cure and relapse [ 18 – 24 ].…”

Section: Introductionmentioning

confidence: 99%

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Development of a sandwich ELISA to detect Leishmania 40S ribosomal protein S12 antigen from blood samples of visceral leishmaniasis patients

et al. 2018

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BackgroundVisceral leishmaniasis (VL), caused by Leishmania donovani complex parasites, is a neglected parasitic disease that is generally fatal if untreated. Despite decades of research to develop a sensitive VL diagnostic test, definitive diagnosis of VL still mainly relies on the visualization of the parasite in aspirates from the spleen, liver or bone marrow, an invasive and dangerous process with variable sensitivity. A sensitive assay that can detect Leishmania antigen from blood samples will help confirm cause, cure or recurrence of VL.MethodsIn this study, rabbit polyclonal antibodies were raised against eight recombinant Leishmania proteins that are highly abundant in Leishmania. The antibodies were purified and labeled with biotin for developing a prototype sandwich enzyme-linked immunosorbent assay (ELISA).ResultsThe ELISA for the Leishmania 40S ribosomal protein S12 detected target antigen with the highest sensitivity and specificity and could detect 1 pg of purified protein or as few as 60 L. donovani parasites. The 40S ribosomal protein S12 sandwich ELISA could detect the target antigen from Peripheral Blood Mononuclear Cell (PBMC) samples in 68% of VL patients and post-kala-azar dermal leishmaniasis (PKDL) patients, providing an estimation of parasitemia ranging from 15 to 80 amastigotes per ml of blood.ConclusionThese results indicate that the 40S ribosomal protein S12 sandwich ELISA warrants further tests with more clinical samples of VL patients and other parasitic diseases. It is hopeful that this ELISA could become a useful tool for confirming VL diagnosis, monitoring treatment progress, disease recurrence and possibly detecting asymptomatic Leishmania infections with a high parasite load.

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Section: Resultssupporting

confidence: 89%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Development of a sandwich ELISA to detect Leishmania 40S ribosomal protein S12 antigen from blood samples of visceral leishmaniasis patients

et al. 2018

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“…Similarly, ICT can give positive results in asymptomatic patients, and this makes the diagnosis of relapse or re-infection challenging, especially in endemic areas (Brandonisio et al, 2002;Carvalho et al, 2003;Maia et al, 2012;Elmahallawy et al, 2014). Quantitative serological assays (ELISA, IFAT, and DAT) also are not recommended for patient followup because of the slow decrease of the antibody titer after VL treatment (De Almeida Silva et al, 2006;Ferrua et al, 2009). It should be noted that the slow antibody reduction is not a sign of bad prognosis or poor therapeutic response (De Almeida Silva et al, 2006).…”

Section: Follow-up Of Treated Patientsmentioning

confidence: 99%

Place of Serology in the Diagnosis of Zoonotic Leishmaniases With a Focus on Visceral Leishmaniasis Due to Leishmania infantum

Lévêque

Lachaud

Simon

et al. 2020

Front. Cell. Infect. Microbiol.

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Leishmaniases are a group of parasitic diseases transmitted through the bite of female phlebotomine sandflies. Depending on the Leishmania species, the reservoirs can be humans (anthroponosis) or different animals (zoonosis). Zoonotic leishmaniasis present several clinical forms in function of the species involved: visceral leishmaniasis (VL), cutaneous leishmaniasis (CL), and muco-cutaneous leishmaniasis (MCL). The biological diagnosis is of utmost importance because the clinical features are not specific. In addition to parasitological and molecular biology (polymerase chain reaction, PCR) assays, serology is routinely used for the diagnosis of leishmaniasis. Indeed, although PCR is more sensitive than serological assays, its implementation is limited to referral laboratories and research centers. Therefore, serology is still a key element for their diagnosis. Here, we discuss the different serological assays available for the diagnosis of zoonotic leishmaniasis. We will review the enzyme-linked immunosorbent assay, immunofluorescence antibody test, immunochromatography test (ICT), direct agglutination test, and western blot as well as the different diagnostic strategies in function of the clinical form (VL, CL, and MCL). We will also discuss the place of serology for detecting asymptomatic carriers and for the follow-up of VL. Depending on the laboratory, different assays can be used, from ICT, which is appropriate for field testing, to a combination of serological tests to improve the sensitivity.

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“…A detecção de antígenos pode fornecer melhores resultados laboratoriais, pois os níveis de antígenos podem ser relacionados a carga parasitária de um indivíduo com LV (Kaur, Kaur, 2013). Entretanto a detecção de antígenos por ELISA é pouco usada devido a sua baixa sensibilidade e a interferência causada por imunocomplexos circulantes, podendo ocasionar resultados falsos negativos (Ferrua et al, 2009). O estudo e desenvolvimento de testes para antígenos circulantes na LV, mostra-se como ferramenta útil para o diagnóstico laboratorial, principalmente em casos específicos onde à sorologia convencional apresenta resultados conflitantes.…”

Section: Introductionunclassified

Detecção de antígenos circulantes como abordagem diagnóstica em leishmaniose visceral.

Carvalho¹

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Carvalho CA. Detection of circulating antigens as a diagnostic approach in visceral leishmaniasis [PhD thesis (Parasitology)]. São Paulo: Instituto de Ciências Biomédicas da Universidade de São Paulo; 2017. Visceral leishmaniasis is a parasitic disease characterized by high levels of IgG antibodies, important for the diagnosis of the infection, but without discriminating active disease. Without effective role during the immune response, these antibodies participate in the formation of circulating immune complexes, indicating the presence of circulating antigens. Despite the high diagnostic specificity, the detection of antigens in serum is poorly explored in visceral leishmaniasis. The detection of antigens and immunocomplexes depend on both the specificity of antibodies and the characteristics of the antigens, which may be from large proteins or small polysaccharides. In this study, we evaluated the detection of free circulating antigens or immunocomplexes, the characteristics and antigenic specificity of IgG antibodies to proteins or carbohydrates of L. (l) infantum in experimental visceral leishmaniasis. Hamster samples with experimental infection by L. (L.) infantum chagasi was evaluated at 15, 30, 45, 60 and 90 days of infection. High concentrations of specific IgG antibodies were detected in samples with experimental and natural visceral leishmaniasis, always with high avidity, even in initial periods of infection. Immunoaffinity purification of low avidity IgG also confirmed this high concentration. Proteins and carbohydrates were isolated from the total antigenic extract of promastigotes by molecular exclusion chromatography or ethanol precipitation and labeled with biotin for amines or sugars. For use in ELISA, carbohydrates were conjugated to BSA, which allowed the detection of high levels of carbohydrate-specific IgG antibodies. The presence of antigenic carbohydrates was also demonstrated by the detection of IgG increase in samples with experimental infection, which confirmed the presence of circulating immunocomplexes specific to carbohydrates. Our data suggest that the involvement of the humoral immune response in visceral leishmaniasis should have the involvement of carbohydrates of the parasite. The development of new diagnostic tools for the detection of antigenic carbohydrates may allow the identification of immunocomplexes and circulating antigens in visceral leishmaniasis.

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Antigenemia in Patients with Mediterranean Visceral Leishmaniasis

Cited by 6 publications

References 11 publications

Development of a sandwich ELISA to detect Leishmania 40S ribosomal protein S12 antigen from blood samples of visceral leishmaniasis patients

Development of a sandwich ELISA to detect Leishmania 40S ribosomal protein S12 antigen from blood samples of visceral leishmaniasis patients

Place of Serology in the Diagnosis of Zoonotic Leishmaniases With a Focus on Visceral Leishmaniasis Due to Leishmania infantum

Detecção de antígenos circulantes como abordagem diagnóstica em leishmaniose visceral.

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