Abstract:Abstract. The analysis of promastigote excreted-secreted antigen (ESA) reactivity with 53 visceral leishmaniasis (VL) cases showed that each sample reacted regardless of the antigen or the Leishmania species used in enzyme-linked immunosorbent assay (ELISA) displayed 100% positivity with the L. (L.) chagasi ESA-blot recognizing bands of molecular weight ranging from 26.5 to 31.5 kDa. The analysis of 160 non-visceral cases showed that 5% of the samples crossreacted with the L. (L.) chagasi ESA-ELISA and 9.4% re… Show more
“…The test was then marketed (LEISHMANIA WB IgG, LDBIO Diagnostics, France), and is currently used as a VL confirmation technique in France (Haute Autorité de Santé, 2017). Other studies in patients with VL due to L. infantum also highlighted the excellent results of this test that targets different antigenic fractions (Tebourski et al, 1994;Marty et al, 1995;Santos-Gomes et al, 2000;Pinedo-Cancino et al, 2013;Seyyedtabaei et al, 2017;Heidari et al, 2019). In the immunocompetent patients included in these studies, sensitivity (90-100%) and specificity (98-100%) were excellent.…”
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.
“…The test was then marketed (LEISHMANIA WB IgG, LDBIO Diagnostics, France), and is currently used as a VL confirmation technique in France (Haute Autorité de Santé, 2017). Other studies in patients with VL due to L. infantum also highlighted the excellent results of this test that targets different antigenic fractions (Tebourski et al, 1994;Marty et al, 1995;Santos-Gomes et al, 2000;Pinedo-Cancino et al, 2013;Seyyedtabaei et al, 2017;Heidari et al, 2019). In the immunocompetent patients included in these studies, sensitivity (90-100%) and specificity (98-100%) were excellent.…”
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.
“…Several studies demonstrate that promastigote antigens of Leishmania cross-react with sera showing positive reactions against antigens of malaria and Chagas disease ( Romero et al, 2009 , Pinedo-Cancino et al, 2013 , Toledo-Machado et al, 2015 ). In this study, sera positive for malaria and Chagas disease showed considerable cross reactivity in the p-ELISA while the rK39 ICT and IFAT did not.…”
BackgroundDefinitive diagnosis of visceral leishmaniasis (VL) by demonstrating parasites in tissue smears or by culture involves invasive procedures, technical expertise and adequate laboratory facilities. Endemic countries rely mainly on serological tests to diagnose VL. Currently, the immunochromatographic test incorporating the recombinant K39 antigen (rK39 ICT) is the reference test for rapid diagnosis of VL in the Indian subcontinent. The performance of serological tests using rK39 and other promastigote antigens can vary due to differences in antigen expression, the various hosts and environmental factors. To achieve elimination of VL, diagnostic accuracy will be necessary for active case detection especially in those who carry asymptomatic infections. We evaluated the performance of rK39 ICT, enzyme linked immunosorbent assay using mixed Leishmania promastigotes from different Leishmania species (p-ELISA) and indirect fluorescent antibody test (IFAT) utilizing whole promastigotes from the Leishmania donovani complex for sero-diagnosis of VL in Bangladesh.MethodsThe sensitivity of each serological test was evaluated on 155 patients who were diagnosed to have VL by microscopy and/or by culture methods. Test specificities were calculated on 706 healthy blood donors, 91 diagnostic sera from patients with a febrile illness and sera from patients positive for malaria (n = 91) and Chagas disease (n = 91). All statistical calculations were at 95% confidence intervals.ResultsThe sensitivities of rK39 ICT, p-ELISA and IFAT were 100%, 86.5% and 92.3%, respectively. All three serological methods had a pooled sensitivity of 82.6%. The specificities of rK39 ICT, p-ELISA and IFAT from combined control groups were 100%, 93.1% and 99.9%, respectively. The respective positive and negative predictive values of the tests were both 100% for rK39 ICT, 66.3% and 97.8% for p-ELISA and 99.3% and 98.8% for IFAT. The p-ELISA showed cross reactivity with 36.3% of sera positive for malaria and 28.6% of sera positive for Chagas disease while rK39 ICT and IFAT showed no cross reactivity.ConclusionThis study confirms the efficiency of rK39 ICT for rapid diagnosis of VL. The p-ELISA using mixed promastigote antigens did not perform well as a serological test for VL in Bangladesh. Due to high sensitivity and specificity of whole promastigote antigen of L. donovani complex utilized in IFAT, this test can be considered in combination with rK39 ICT to confirm VL diagnosis when clinical diagnosis cannot distinguish between other diseases.
“…Exoantigens from L. seymouri (TCC011E) and C.
fasciculata (TCC039) were obtained as previously described for
excreted-secreted antigens (ESA) of L. (L.) infantum chagasi
20
(MHOM/BR/1972/LD). Briefly, exoantigens from L. seymouri and
C. fasciculata were recovered from RPMI-1640 medium containing 1-5 x
10 8 cultured parasites/mL after incubation for 24 h at 26 °C without
agitation, and stored in small aliquots at -40 °C.…”
Section: Short Communicationmentioning
confidence: 99%
“…and anti- T. cruzi antibodies has been overlooked. In contrast, exoantigens of T. cruzi 15 , and Leishmania spp 16 have been studied, have performed well in the diagnosis of CD 17 , 18 , and have also been promising for the diagnosis of VL 19 - 21 and ATL 20 - 23 .…”
Section: Short Communicationmentioning
confidence: 99%
“…Trypomastigote excreted-secreted antigens (TESA) of T. cruzi (Y strain) were obtained as described elsewhere 17 . Alkaline extracts (AEs) from L. seymouri, C. fasciculata and L. (L.) infantum chagasi promastigotas and T. cruzi epimastigotes were prepared as previously described 6 , 18 , 20 . Briefly, the parasite pellets were solubilized in 0.3 N NaOH for 18 h at 4 °C, neutralized with 0.3 N HCl to pH 7-8, and centrifuged at 12,000 g for 1 min.…”
Exoantigens (exo) from Leptomonas seymouri and Crithidia
fasciculata were used in an enzyme linked immunosorbent assay (ELISA),
showing 100% reactivity with sera from visceral leishmaniasis (VL) cases, and no
reactivity with American tegumentary leishmaniasis (ATL) ones. Our results have
indicated that these exoantigens can be applied in the discrimination of VL and ATL
cases.
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