Wb E34 monoclonal antibody: further characterization and diagnostic use in bancroftian filariasis

The Wb E34 monoclonal antibody raised against Wuchereria bancrofti microfilarial excretory secretory (mf ES) antigen was reported to be useful in detecting the filarial antigen in W. bancrofti and Brugia malayi infected sera. Further studies in this laboratory showed that this monoclonal antibody reacts with a stage-specific antigen of W. bancrofti filarial parasite. Wb E34 identified three antigenic components with molecular weights, 55, 57.5, and 63 kilodaltons (Kd) in western blot analysis. The target antigen of Wb E34 was found to be located in the cytoplasm of microfilariae by indirect immunofluorescence technique. The inhibitory antibodies to Wb E34 were detected in a higher percentage of microfilaraemic sera (81%) than in clinical filarial (33%) or tropical eosinophilia sera (35%). Thus the inhibition ELISA using W. bancrofti mf ES antigen and Wb E34-penicillinase may be useful in detecting the filarial antibody associated with the active stage of infection.