The reactions between rheumatoid factor and erythrocytes sensitized by antibodies of human, rabbit and guinea pig origin were studied using absorption, elution, dispersion, inhibition and mixed aggIutination experiments. The results indicated that there are separate molecules of the rheumatoid factor combining with y-globulin of the three species.
Le reactiones inter factor rheumatoide e erythrocytos sensibilisate per anticorpore originari in humanos, conilios, e porcos de India esseva studiate con le uso de experimentos de absorption, elution, dispersion, inhibition, e mixte agglutination. Le resultatos indica que il existe separate moleculas del factor rheumatoide que se combina con le globulina gamma del tres species.
T IS WELL ESTABLISHED that the rheumatoid factor combines in ~i t r o I with r-G-globulin of various species origin.1 The question arose whether the same molecule of the rheumatoid factor could combine with r-globulin of different species origin or whether there are different molecules for each species.
Butler et aL2 presented some experimental evidence indicating that the rheumatoid factor is primarily directed against human r-globulin and that the reactions with other 7-globulin species are only cross reactions. Similarly, Alio and Simons3 stated on the basis of their experiments that the rheumatoid factor "in toto reacts with human gamma globulin, but moieties of it also react with animal gamma globulins."
Most experiments along these lines were performed in investigating the reactions with human and rabbit 7-globulin. On the basis of their experiments, Lcspalluto and Ziff4 and Heimer and Schwartz5 came to the conclusion that there exist two factors, one combining with human r-globulin and the other combining with both human and rabbit r-globulin. On the other hand, previous studies6 from this department, in which the mixed agglutination procedure was mostly used, demonstrated the existence of three factors: Factor a combining with human r-gIobulin only, factor b combining with human and rabbit r-globulin, and factor c combining with rabbit r-globulin only. Three similar factors were also identified by Williams and Kunkel? who separated rheumatoid sera by columns conjugated with human and rabbit Fraction 11. Information about the existence of separate factors combining with 7-globulin of species other than man and rabbit has not been available.
Recently, reactions of rheumatoid arthritis sera with sheep erythrocytes sensitized by their corresponding antisera produced by guinea pigs were studied.8 Most of the sera showed similar agglutination titers with sheep erythrocytes sensitized by guinea pig antiserum and with sheep erythrocytes