The S-100 antigen in cerebrospinal fluid as a possible index of cell injury in the nervous system.

The presence of the nervous system-specific S-100 antigen has been tested by microcomplement fixation assay with a monospecific anti-S-100 antiserum in cerebrospinal fluid (CSF) of subjects suffering from psychiatric disorders or various neurological diseases. The antigen was detectable in the CSF of most of the patients with neurological diseases characterized by an appreciable lesion in the nervous parenchyma, whereas it was generally absent from CSF of subjects presumably free from an extensive neurological lesion in the active phase. It is possible that the presence of S-100 IN CSF might be an index of active cell injury in the nervous parenchyma.