The Efficacy of L. (L.) chagasi Excreted-Secreted Antigens (ESAs) for Visceral Leishmaniasis Diagnosis Is Due To Low Levels of Cross-Reactivity

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% reacted with the ESA isolated from L. (L.) amazonensis and L. (V.) braziliensis, whereas a high cross-reaction ranging from 24.4% to 25% was observed with total crude promastigote antigens (PRO-ELISA). The ESA-blot of L. (L.) chagasi tested with non-visceral sera samples showed a cross-reaction with 8.8% of cases; most of these cases represented tegumentary leishmaniasis and only one acute chagasic case. These data lead us to recommend the use of ESA as an alternative antigen in VL diagnosis.

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

“…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.…”

Evaluation of recombinant K39 antigen and various promastigote antigens in sero-diagnosis of visceral leishmaniasis in Bangladesh

“…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.…”

Leptomonas seymouri and Crithidia fasciculata exoantigens can discriminate human cases of visceral leishmaniasis from American tegumentary leishmaniasis ones

“…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.…”

“…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 .…”

“…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.…”