C kleine Tank2; E A Lieshout1; P Daemen2; J de Vries1; F Stelma2;
1 Leiden University Medical Centre, Netherlands; 2 Radboudumc, Netherlands
DiscussionBackground: Infection withthe
can persist for many years due to
autoinfection and may cause hyperinfection syndrome in immune compromised
patients. Screening for antibodies can be used to indicate past exposure to
this parasite, which is important in patients prior to immunosuppressive therapy. This study
evaluates the diagnostic performance of two commercial immunoassays testing for
S.stercoralis specific antibodies.
Two sample panels were used to evaluate the NovaLisa Strongyloides ELISA (NovaTec
Immundiagnostica GmbH, Dietzenbach, Germany)
and the Anti-Strongyloides IgG ELISA
(Euroimmun AG, Lubeck, Germany). The first panel (n≤44) was defined by an LUMC in-house Strongyloides ELISA which characterised the samples as being
strongly-positive (n≤11) , weakly-positive (n≤5) or negatives (n≤28). Among the negatives,
n≤17 were seroreactive to other parasitic worm infections. The second panel (n≤30) was selected from the Radboudumc serumbank
being assumedly seronegative to strongyloides
spp. of which n≤22 were selected
because of seropositivity to common cross-reactive antigens (rheumatoid factor,
Epstein Barr virus, HBs antigen and Borrelia spp.) and n≤8 were selected from a
panel of Dutch infants between 1 and 2 years.
Results: The NovaTec and the
Euroimmun assay tested positive in 11 and 12 of the 16 LUMC positive samples,
respectively, both missing one of the strongly-positives. The NovaTec assay
showed false positive reactivity in two Schistosoma
reactive samples. Both commercial assays remained seronegative when testing the
LUMC confirmed Strongyloides negative
samples and the Radboudumc negative panel.
Conclusions: The Euroimmun assay seems the most suitable
commercial alternative for an in-house ELISA immunoassays testing for Strongyloides specific antibodies.