Anti-immunoglobulin analysis by diffusion patterns of inhibition and facilitation of complementary lysis in agar III. Anti-immunoglobulin diffusion-lysis patterns of normal human and rheumatoid sera

Abstract

Diffusion-lysis tests on sera from normals, cases of active and inactive rheumatoid arthritis and a ‘miscellaneous’ group of general hospital patients indicated the presence in all sera of factors behaving as anti-immunoglobulins (anti-Ig's) against configurationally changed immunoglobulin. There appeared to be two inhibiting and one facilitating anti-Ig in all sera and a fourth anti-Ig (inhibiting) in some sera. They were recognized by the appearance of rings of haemolysis of a degree either less or more than background haemolysis. The diameters of the various rings were used as parameters for comparing the groups of sera. One inhibiting anti-Ig (designated P1) is heat-stable. There is less of it in rheumatoid arthritis (RA) than in normal sera, and more of it in ‘miscellaneous’ than normal sera. A second inhibiting anti-Ig (P2) is heat-labile, and there is more of it in RA and ‘miscellaneous’ sera than in normal sera. A third anti-Ig (L/7S/F) is facilitating and heat-labile. Although the ring diameters for this anti-Ig are not significantly different in RA and normal sera, there is other evidence that suggests there is much more of it in RA than in normal sera. A fourth anti-Ig (P/7S/I/5), heat-stable and inhibiting, corresponds to classical rheumatoid factor; there is much of it in RA sera and very little in normal sera. The index P2/P1 is positively correlated with ESR, and P1 is negatively correlated with L/7S/F. The only anti-Ig which correlates with classical rheumatoid factor is P/7S/I/5. There is no significant correlation between P1 and P2. A hypothesis regarding the functional significance of these serum factors is presented.