Correlation of Extent of Tuberculosis with Amount of Polysaccharide in the Serum. ∗

Abstract

An intensive study has been made in recent years of tuberculous sera, with the objective of detecting the presence of antigen, antibody or any substance which may be characteristic of the disease. The primary approach has been based upon observation of the electrophoretic diagrams of sera by means of the Tiselius technic.

It was shown 1 that during the development of tuberculosis in the rabbit the beta globulin fraction increased in proportion to the extent of the disease. In the human being, on the other hand, the consistent change 1 was a progressive increase in the gamma globulin. Increases in alpha and beta globulin fractions also frequently occurred but not with the same degree of regularity as was the case with the gamma globulin.

An explanation of the cause of the rise in any of these components would be of value in the understanding of the disease. The possibility of the presence of antibodies immediately presents itself in connection with the rise in the gamma globulin, especially in view of the fact that antibodies to the tuberculin protein have been to be present in this fraction in sensitized rabbits. However, there could not be shown to be sufficient antibody to account for the total rise in the gamma globulin.

In seeking for other explanations of the rise, one is impressed with the idea that if tuberculin polysaccharide were found free in the serum, it would migrate in electrophoresis with approximately the same mobility as the gamma globulin.³ Analyses were, therefore, made of the polyssacharide content of the albumin and the gamma globulin fractions isolated from several sera by means of electrophoresis.

The polysaccharide was determined directly on the protein solutions, without preliminary hydrolysis, by means of the carbazole reaction,⁴ as outlined previously, 6 using the Evelyn colorimeter.