CONVENTIONAL IMMUNOASSAYS UNDERESTIMATE ANTI-GST ANTIBODY TITER

This paper highlights problems associated with the quantitation of ser um antibody levels to recombinant glutathione S-transferase (GST). Mea surement of anti-GST antibodies in conventional immunoassays, where GS T is bound directly to the ELISA plate, was found to substantially und erestimate the amount of GST-specific antibody levels in test sera. Th is insensitivity in immunoassay of anti-GST antibodies can be overcome by using any one of several recombinant GST fusion proteins as the co ating antigen in ELISA rather than simply GST. Comparison of anti-GST antibody titres assessed by the two procedures indicated that use of u nfused GST underestimated the anti-GST antibody titre by more than ten -fold.