Differences in Serological Properties of Macroglobulins from Cancer And Normal Sera. ∗

Abstract

Discussion and Summary

Studies on the alpha-2 macroglobulins isolated from the sera of patients with various types of cancer and from the sera of healthy individuals revealed definite serological differences between the two groups of fractions. These differences relate to flocculation of bentonite particles, reaction with coelomic fluid substance, and precipitin reactions with anti-alpha-2 sera.

The alpha-2 fraction from cancer sera was found to flocculate bentonite particles in 91.5% of the fraction tested, while the reaction was negative in 77.1% of the fractions from normal sera. This is in accord with previous investigation in which the addition of bentonite particles reduced the alpha-2 content of cancer, but not of normal sera. The increased affinity of macroglobulins from cancer sera to bentonite may be based on differences in total electric charge. This, however, should be investigated using ion exchangers to separate the fractions from both types of sera.

Treatment of cancer sera and normal sera of blood Groups O and B with CFS revealed that in cancer sera the α₂ agglutinins may be altered, since a large percentage of them were not inhibited by CFS, as was the case of agglutinins in normal sera. Changes of α₂ isoagglutinins present in cancer sera may be due to the effect of antigenic substances from blood and other tissues released during tissue destruction. These may not have the normal antigenic pattern and thus immunize the individual producing antibodies differently from the normal isoagglutinins. Cancer sera, unlike normal sera, may therefore have abnormal agglutinins not inhibited by CFS, but normal a2 isoagglutinins may also be present, depending on the stage of the disease.

The fact that a large percentage of alpha-2 globulins from cancer sera reacted with 3 bands of precipitate when tested against anti-alpha-2 sera, while no more than 2 bands were observed with the fractions from normal sera, suggests that the macromolecules from cancer sera are affected, and possibly split into smaller molecules.

The findings above suggest that the changes produced in alpha-2 macroglobulins by cancer processes should be further evaluated in relation to the development of a serological diagnostic test.