Cytotoxic activity of cerebrospinal fluids (CSF's) against lymphocytes and phagocytes: comparison of normal and systemic lupus erythematosus CSF's.
Fifty cerebrospinal fluids (CSF), 24 normal, 26 from systemic lupus erythematosus (SLE) patients were tested for cytotoxic activity against human lymphocytes, granulocytes and monocytes. Normal and SLE CSF's frequently killed all 3 cell types. Lympho- and granulocytotoxins often reacted at both 4 degrees/24 degrees C, and at 37 degrees C. They were more active when no complement was added (p less than 0.01), whereas monocytotoxicity was complement-dependent (p less than 0.01). Normal CSF's more often contained cold-reacting lymphocytotoxins and SLE CSF's more often had warm-reacting monocytotoxins, but the differences were not significant (p = 0.03). Cytotoxins were easily absorbed to and eluted from lymphocytes and granulocytes, and when CSF's were toxic to both types of cells, the corresponding eluates usually retained this activity. Sometimes, only 1 type of cell was killed by the eluate, whereas cytotoxicity against another was retained by the corresponding supernatant. In SLE remarkable differences were noted between CSF cytotoxins and serum cytotoxins. The former were often more potent at 37 degrees C not requiring non-human complement. Preliminary characterization of CSF cytotoxins suggests they may be IgG, however, participation of non-Ig cytotoxic substances cannot be excluded.