Brain tumors: detection of B-cell stimulatory factor-2/interleukin-6 in the absence of oligoclonal bands of immunoglobulins.

24 patients with neoplasia of the central nervous system (CNS-N) were investigated for the presence of B-cell stimulatory factor-2/interleukin-6 (IL-6) in the cerebrospinal fluid (CSF). Whereas IL-6 was detected in 21 (88%) of these CSF samples, only 6% of CSF from non-inflammatory brain diseases and 12% of the samples from multiple sclerosis patients were positive. IL-6 was found in both primary and secondary CNS-N. The presence of IL-6, a cytokine which activates B-lymphocytes to produce high-rate immunoglobulin (Ig) synthesis, is in contrast to the ineffective intrathecal B-cell activation as suggested by the failure to detect oligoclonal bands of Igs in CNS-N.