IgG- and IgG4-detected antigens of Dirofilaria immitis adult worms for bancroftian filariasis by enzyme-linked immunoelectrotransfer blot

In Thailand, Wuchereria bancrofti filariasis has persisted along the border between Thailand and Myanmar, its dynamic distribution caused by the infected transmigrants between neighboring countries, and the availability of susceptible mosquito vectors. Dirofilaria immitis adult worm was used as a source of antigens, excretory-secretory (ES) and partial surface extracts, to detect human filariasis. ES products showed several stained bands with Coomassie brilliant blue ranging from 14.5-93 kDa and mostly being glycoproteins as shown by concurrent reaction with Concanavalin A, except those at 18, 16 and 14.5 kDa which stained only with Coomassie brilliant blue. Surface proteins of 33.5-91.5 kDa were stained with Coomassie brilliant blue and showed smear bands with Concanavalin A. By enzyme-linked immunoelectrotransfer blot, Bancroftian filariasis sera gave specific reactions with glycoprotein ES antigens at MW 20.5 kDa against anti-human IgG. A prominent band of 18 kDa appeared consistently with the IgG4-ES antigen system. Surface extracts reacting with IgG and IgG4 were considered to be unsuitable as antibodies from all cases of filariasis could not detect any bands.