Idiotype-anti-idiotype interactions of VHIX-coded anti-progesterone and anti-arsonate antibodies. Comparison of passive haemagglutination and radioimmunoassays.

The reactivity and specificity of polyclonal and monoclonal anti-idiotypic antibodies raised against monoclonal anti-progesterone and anti-arsonate antibodies have been studied by solid phase radioimmunoassay (RIA) with immobilized idiotype and by passive haemagglutination with idiotype-coupled red cells. The sensitivity of the two methods was comparable, though some cross-reactions were only detected by RIA. Passive haemagglutination was found to be especially suitable in screening for monoclonal anti-idiotypes in hybridoma supernatants and ascites, and had advantages over RIA in detection of syngeneic anti-idiotypes. Demonstration of binding site-associated idiotopes was possible by haemagglutination inhibition. RIA and haemagglutination were used to investigate the idiotypic relationships between BALB/c antiprogesterone and anti-arsonate monoclonal antibodies which share heavy chains encoded by VHIX variable region genes.