ANTIGENIC COMPONENTS OF EXCRETORY-SECRETORY PRODUCTS OF ADULT FASCIOLA-HEPATICA RECOGNIZED IN HUMAN INFECTIONS

The antigenic components of excretory-secretory products (ESP) of adul t worms of Fasciola hepatica were revealed by sodium dodecyl sulfate-p olyacrylamide gel electrophoresis and Western blot analysis using sera from 20 patients infected with F. hepatica. Sera from 184 other paras itic infections and 20 healthy volunteers were also analyzed. It was f ound that the ESP were composed of more than 11 polypeptides; five com ponents detected in fascioliasis sera had molecular weights of 12.4, 1 6.4, 19.4, 25, and 27 kilodaltons (kD). Only the 25- and 27-kD compone nts were recognized by all 20 fascioliasis sera. Using the ESP as anti gen, it was possible to perform an enzyme-linked immunosorbent assay w ith a sensitivity of 95% and a specificity of 97%. Sera from other par asitic infections had antibodies to antigenic components with apparent molecular weights of 37, 38.4, 52, 57, 63, 73, 87, 109, and 116 kD th at were also found in sera from fascioliasis patients. These findings suggested that the 25- and 27-kD antigenic components may be sensitive and specific for the diagnosis of human fascioliasis.