Immunodiagnosis of fasciolosis using recombinant procathepsin L cystein proteinase

Cathepsin L1, a cystein protease secreted by the gastrodermis of juvenile a nd adult Fasciola hepatica, was expressed in Escherichia coli as a fusion p rotein containing the proregion, supplied with six histidyl residues at the N-terminal end (rproCL1). In this study we tested its potential as antigen for the serologic diagnosi s of F. hepatica infections by enzyme-linked immunosorbent assay (ELISA). T he analyzed human sera included 16 positive samples, 99 negative controls a nd 111 from individuals affected by other parasitic and non parasitic disea ses. The sensitivity and specificity of the rproCL1-ELISA were 100%. We als o assessed the ability to detect antibodies in sera from 10 experimentally infected sheep, obtaining preliminary results that shown a response since t he third week post infection in all the studied animals. Therefore, the recombinant rproCL1-based ELISA could be a standardized test for the accurate diagnosis of fasciolosis. (C) 2001 Elsevier Science Inc. All rights reserved.