The separation of proteins of normal and rheumatoid sera by continuous flow electrophoresis (paper curtain) has provided additional data concerning the characteristics of rheumatoid factor and the nature of rheumatoid serologic reactions. Two distinct inhibitors of these reactions were found, one appearing in the gamma globulin fraction and the other in the fraction containing alpha and beta globulins.Le separation del proteinas in seros normal e rheumatoide per electrophorese a 0~x 0 continue (cortina de papiro) ha fornite datos additional relative a1 characteristicas de factor rheumatoide e a1 natura de rheumatoide reactiones serologic. Esseva trovate duo distincte inhibitores de iste reactiones. Le un es in le fraction de globulina gamma, le altere in le fraction que contine globulina alpha e beta.HE SERUM of patients with rheumatoid arthritis participates in an un-T usual serologic reaction which has attracted great interest. A recent review' summarizes much of the available information about this phenomenon. Two essential substances are required, one of which is a component of gamma globulin (reactant) and the other a macroglobulin present in the serum of many patients with rheumatoid arthritis (rheumatoid factor). The presence of the latter may be demonstrated by its ability to cause agglutination of various carriers such as erythrocytes or latex particles coated with reactant, or by a precipitin reaction.Two inhibitors of the reaction are known. One of these is reactant which, if present in excess, will interfere with the demonstratian of the rheumatoid factor.2J It will be designated as Type I inhibitor in this paper. The other, to be called Type 11, is located in another fraction of This laboratory has been interested for some time in the use of carriers in the study of antigen-antibody reactions. The description by Singer and PlotzoJ of the latex fixation test in rheumatoid arthritis prompted a study of these particles in several serologic systems. Preliminary work aroused interest in the rheumatoid reaction itself, particularly with reference to the nature of the reactant. The results of the investigation of various aspects of this problem will be described.
MATERIALS AND METHODSHuman sera.-Sera were obtained aseptically from healthy medical students, persons with elevated antistreptolysin 0 titers and patients with rheumatoid arthritis, and stored