Specific and cross-reactive monoclonal antibodies to the 89-kDa antigen of Opisthorchis viverrini.

We previously reported the production of monoclonal antibodies (MAbs) to somatic (Billings et aI, 1990) and excretory-secretory (Amornpunt et aI, 1991) antigens of Opisthorchis viverrini. The characteristics of the antigens to which these MAbs reacted are summarized as shown in Table I. It was not surprising to note that all MAbs to the worm metabolic products were directed against the 89-kDa component which was previously shown to be the predominant protein in the culture medium in which these adult worms were main­ tained. It was unexpected, however, to find that these MAbs reacted with different structures of the parasite (Table I). They also varied considera­ bly with regard to immunological cross-reactivity against a number of closely related flukes of man and animals. Because both Groups I and 2 anti-89 kDa MAbs were highly specific for O. viverrini (Ov), they were tested on a limited scale for their diagnostic potential (Sirisinha et aI, 1991). The limited data obtained were highly promising and therefore a larger scale field trial has been under­ taken to further evaluate its value in an epidemio­ logical study.