Excretory/secretory antigens of Strongyloides venezuelensis applied to IgG detection in human strongyloidosis

Diagnostic accuracy of somatic and excretory−secretory antigens from Strongyloides venezuelensis infective larvae for the immunodiagnosis of human strongyloidiasis

“…venezuelensis E/S products were 100% sensitive and 97.88% specific for the detection of IgG antibodies when its cut-off was 0.300. These values were higher than the values obtained by Cunha et al (2017) (95% sensitive and 96.7% specific) using S. venezuelensis, and higher than the values published by Rokni and Kia (2005) (88.2% sensitive and 86.2% specific) using S. stercoralis E/S antigens. Differences in the performance and diagnostic accuracy may be due to variations in the procedure for obtaining E/S products (i.e.…”

“…In this study, 48 h of in vitro maintenance at 37°C were used to obtain E/S products from 80 000 larvae/mL because preliminary experiments showed that a great percentage of larvae die after 48 h of in vitro maintenance. Our procedure differs from the procedure described by Cunha et al (2017), who maintained 30 000 larvae/mL in either RPMI 1640 medium or PBS for 72 h, and from Maeda et al (2019) who maintained about 6153 larvae/ mL in PBS for 12 h or in Dulbecco's modified Eagle's medium (DMEM) for 36 h. With regards to other Strongyloides species, Brindley et al (1988) maintained 50 000-100 000 S. stercoralis larvae/mL for 24 to 48 h in DMEM, and Soblik et al (2011) maintained 30 000 S. ratti larvae/mL for 24 h in RPMI 1640 medium. The survival time of Strongyloides larvae from different species can vary and in vitro maintenance in certain fluids (medium culture or PBS) do not create natural environmental conditions, which may affect the metabolic pattern of E/S products released by the parasite.…”

“…E/S products were obtained based in the procedures described by Soblik et al (2011) and Cunha et al (2017), but with some modifications. Briefly, approximately 400 000 living iL3 larvae were placed in sterile polypropylene tubes containing 5.0 mL of phosphate-buffered saline 0.01 M, pH 7.2 (PBS) supplemented with a mixture of antibiotics (penicillin 100 U/mL, streptomycin 100 U/mL, gentamicin 50 μg/mL and amphotericin 2.5 μg/mL) and incubated at 37°C under 5% CO 2 for 48 h to obtain E/S products.…”

“…These E/S products also provide a valuable source of antigens for the immunodiagnosis of helminth infections (Lightowlers and Rickard, 1988;Harnett, 2014). In this context, E/S products from S. venezuelensis iL3 have been little explored and applied for the immunodiagnosis (Cunha et al, 2017). Thus, the aim of this study was to assess the diagnostic accuracy of two types of somatic antigenic preparations and E/S products from S. venezuelensis iL3 for the immunodiagnosis of human strongyloidiasis using ELISA.…”

Caracterização do excretoma/secretoma de Strongyloides venezuelensis e sua aplicação no imunodiagnóstico da estrongiloidíase humana

“…Ao entrar em contato com o sistema imune do hospedeiro, os produtos de E/S também constituem uma valiosa fonte de antígenos para o imunodiagnóstico. Nesse sentido, Cunha et al (2017) verificaram que os produtos de E/S de iL3 de S.…”