Abstract
The concentration of [gamma] -globulin in the cerebrospinal fluid (csf) showed strong correlation with the Lange colloidal-gold reaction. In those cases where csf [gamma] -globulin concentration is increased, the concentration in the serum is normal, but it is not known whether the increased [gamma] -globulin in the csf originates from the blood, by increased selective premeability of the blood/csf barrier to [gamma] -globulin, or whether [gamma] -globulin is produced in the central nervous system. Albumin, [alpha]- and [beta]-globulins from serum and csf inhibit coagulation of the colloidal-gold sol and [gamma] -globulin coagulates the sol. Csf proteins are similar to serum proteins, except that the more rapidly sedimenting components of serum [alpha]-globulin are not detected in the csf; also, csf [alpha]-globulin inhibits coagulation of the colloidal-gold sol more than does serum a-globulin. An additional protein is found in the csf in the [beta]- and [gamma] -globulin fractions, component "S", which has a very low sedimentation constant and inhibits the colloidal-gold reaction. This component, together with the difference in the a-globulins, is responsible for the difference between the colloidal-gold reaction of normal csf and that of diluted serum. The proportion of component "S" in the csf [gamma] -globulin is greater in normal csf than in csf having a positive colloidal-gold reaction. The positive colloidal-gold reaction, given by csf from some multiple sclerosis patients, is due to the increased concentration of the [gamma] -globulin component with sedimentation constant S = 6.5, relative component "S". Component "S" is a protein and is not precipitated by 18% sodium sulfate.