DETECTION OF MICROFILARIAL ANTIGEN IN CIRCULATING IMMUNE-COMPLEX FROMSERA OF WUCHERERIA BANCROFTI-INFECTED INDIVIDUALS

Polyethylene glycol-precipitated circulating immune complexes (CICs) f rom the sera of patients with Bancroftian filariasis were examined for parasite antigen content by an ELISA. Of the 227 patients, 214 were a symptomatic microfilariae carriers with microfilaremias ranging betwee n six and 14,000/ml blood, and 13 were symptomatic patients with chron ic filariasis without microfilaremia. In addition, the sera of 10 of t he patients treated with diethyl carbamazine were also examined. These assays were devised using mouse monoclonal antibody raised against mi crofilariae of Wuchereria bancrofti. Using an acid-phase covalent-boun d plate for the ELISA makes it possible to assay the antigen contents simply. Microfilarial antigens were detected from 92 (43.0%) of microf ilaria (mf)-positive individuals. Furthermore, the level of antigen in CIC was correlated with mf counts from night blood Nuclepore filtrati on results. Antigen was not detected in CIC from patients with a varie ty of nonfilarial helminth infections. These findings indicate that mi crofilariae play an important role of CIC formation in lymphatic filar iasis.