Immunologic Relationships of C-Reactive Protein from Various Human Pathologic Conditions

Abstract

The immunologic relationships were studied of C-reactive proteins (C-RP) obtained and crystallized from the sera of 3 patients with various pathologic conditions. In the experiments performed by the gel diffusion method, it was observed that 3 clear-cut lines of precipitation appeared when the 3 crystallized C-RP's were allowed to diffuse against the same anti-C-RP sera. The experiments performed with precipitin reactions and serologic cross-reactions between the various crystallized C-RP's and their specific antisera indicate that no antigenic differences could be demonstrated in the different C-RP's crystallized from the various patients by the quantitative precipitin reaction. The quantitative complement fixation technique on diluted C-RP, C-RP antiserum systems yielding no visible precipitates demonstrated an apparently complete identity of the antigenic structures of the C-RP's isolated from the different patients. In these experiments, new evidence was presented of the lack of correlation between the antibody N content of an immune serum and its C′-fixing potency. The possible interpretations of these results are discussed.