Glutathione-binding proteins of Setaria digitata: antibody responses in human infected with Wuchereria bancrofti.

Glutathione-s-transferase activity was determined in filarial parasites. The activity was detected in adult stages of cattle parasite Setaria digitata. It was absent in other stages of Setaria and also in infective larval stages of Wuchereria bancrofti and Brugia malayi. The activity was enhanced about twenty five fold following purification of adult setaria extracts on glutathione agarose column. Antibody (IgG and IgM) levels to the affinity purified proteins (SdGBP) were detected predominantly (90%) in Wuchereria bancrofti infected individuals compared with normal residents of endemic regions. IgA and IgE responses could not be detected. Filarial sera in contrast to non-filarial caused reduction in the enzymatic activities of Sd GBP. Microfilaraemic sera after diethylcarbamazine treatment resulted in enhanced reduction of enzymatic activity.