Comparative Assessment of ELISAs Using Recombinant Saposin-Like Protein 2 and recombinant Cathepsin L-1 from Fasciola hepatica for the Serodiagnosis of Human Fasciolosis

Two recombinant fasciola hepatica antigens,saposin-like protein-2 (recsap2) and cathepsin l-1 (reccl1),were assessed individually and in combination in enzyme-linked immunosorbent assays (elisa) for the specific serodiagnosis of human fasciolosis in areas of low endemicity as encountered in central europe. antibody detection was conducted using proteina/proteing (pag) conjugated to alkaline phosphatase. test characteristics as well as agreement with results from an elisa using excretory-secretory products (fhes) from adult stage liver flukes was assessed by receiver operator characteristic (roc) analysis,specificity,sensitivity,youdens j and overall accuracy. cross-reactivity was assessed using three different groups of serum samples from healthy individuals (n = 20),patients with other parasitic infections (n = 87) and patients with malignancies (n = 121). the best combined diagnostic results for recombinant antigens were obtained using the recsap2-elisa (87% sensitivity,99% specificity and 97% overall accuracy) employing the threshold (cut-off) to discriminate between positive and negative reactions that maximized youdens j. the findings showed that recsap2-elisa can be used for the routine serodiagnosis of chronic fasciolosis in clinical laboratories; the use of the pag-conjugate offers the opportunity to employ,for example,rabbit hyperimmune serum for the standardization of positive controls. © 2014 gottstein et al.