Determination of IgG antiglobulins in rheumatoid disease using insolubilized human IgG.

IgG antiglobulins in human sera were measured by single radial diffusion in agar after elution from ethyl chloroformate insolubilized immunosorbents of rabbit or human IgG. With both immunosorbents seronegative and seropositive rheumatoid sera contained significantly higher levels of IgG antiglobulins than did sera from healthy adults. Attempts to measure antiglobulins interacting specifically with the pFc' half of the Fc region were not successful due to an unacceptably high degree of non-antibody binding.