Parasitology

Research Article

Assessment of monoclonal antibodies to Echinococcus granulosus Antigen 5 and Antigen B for detection of human hydatid circulating antigens

D. Liua1 c1, M. D. Rickarda2 and M. W. Lightowlersa1

a1 University of Melbourne, Veterinary Clinical Centre, Princes Highway, Werribee, Victoria 3030, Australia

a2 C.S.I.R.O. Division of Animal Health, Private Bag No. 1, Parkville, Victoria 3052, Australia

Abstract

Four monoclonal antibodies (MAb) to Echinococcus granulosus Antigen 5 (Ag5) and Antigen B (AgB) were assessed in an enzyme-linked immunosorbent assay (ELISA) for detection of circulating antigens (CAg) in sera of human patients with E. granulosus infection. Around 5·5–8% of 200 sera from 42 surgically proven hydatid patients contained detectable CAg by individual MAb. The combined detection rate for CAg, using four MAb, was 19% (38/200). Although hydatid CAg was detected by MAb in at least one serum sample from 21 of 42 patients, some patients remained negative in the assay regardless of the time when serum samples were taken (pre- or post-operatively), or of the continuing presence of hydatid cysts, their location or fertility. In addition, it was observed that the binding capacity of MAb for sheep hydatid cyst fluid antigen (SHCF) was somewhat reduced in the presence of normal human serum. The CAg detection assay would only be useful for assessment of hydatid infection status in patients with detectable CAg in serum samples.

(Received February 14 1992)

(Revised May 11 1992)

(Accepted May 14 1992)

Correspondence:

c1 D. Liu, Department of Food and Agriculture, Pastoral and Veterinary Institute, Ballarat Road, Hamilton, Victoria 3300, Australia

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