Identification of gamma-E-antibodies as a carrier of reaginic activity.

Summary The immunoglobulin having reaginic activity was purified from sera of ragweed sensitive patients by salt precipitation, diethylaminoethyl (DEAE)-cellulose column chromatography, gel filtration and DEAE-Sephadex column chromatography. The γG- and γA-globulins remaining in the purified samples were absorbed with rabbit anti-γG- and anti-γA-antibodies which had been precipitated with goat antibody against rabbit γ-globulin. On a weight basis, reaginic activity of the final preparation was about 1000 times more active than the original sera and the most active fraction gave positive P-K reactions at a dilution of 1:80,000. Human serum proteins detected in the preparation were γE- and γD-globulins. The antibody against antigen E was detected in γE-globulin but not in other immunoglobulins. It was also found that the reaginic activity and γE-antibody in the preparations were precipitated by anti-γE-antibody. The results indicate that reaginic activity is associated with γE-globulin. Evidence was presented that reaginic antibody against antigen E in the serum of one individual was γE-globulin of mostly κ chain type.