Flocculation of Unsensitized Bentonite Particles by Cancer Serum. ∗

Abstract

Discussion and summary

The high degree of flocculation of unsensitized particles of bentonite by cancer sera and not by normal or by sera from other disease conditions, may be of help in developing a test for cancer diagnosis. Heating of the sera at 50°C for 30 minutes is required to establish the difference in reactivity between cancer and other sera. The factors affected by such heat treatment are not yet clear.

Although the flocculation reaction occurs in cancer sera in a gradient and at high titers, no other indication could be found to show that this may be an antigen-antibody reaction, as could have been expected if the bentonite particles became coated with either excess antigen or antibody present in the sera. Also, addition of guinea pig complement did not restore the reaction in sera heated to 56OC for 30 minutes. Since in vivo antigen-antibody interaction has been considered to take place in some acute or chronic diseases such as systemic lupus erythematosus and glomerulonephritis, this theory should not be discarded.

Absorption of the α₂ globulin by the bentonite suggests an ionic type of reaction with some component of this fraction. Immunoelectrophoretic studies using antian globulin sera and bentonite may clarify this point. The low percentage of reactivity of normal and other sera as compared with cancer sera suggests the possibility of a test based on the effect of bentonite on specific components of the α₂ globulin.