Expression of costimulatory molecules and cytokines in CSF and peripheral blood mononuclear cells from multiple sclerosis patients.

We amplified the mRNA for cytokines in peripheral blood mononuclear cells (PBMC) and cerebrospinal fluid (CSF) cells from 18 multiple sclerosis (MS) patients and 21 other neurological patients, using the reverse transcription polymerase chain reaction (RT-PCR). Radioactive hybridization of the amplified DNA allowed quantitation of mRNA levels. Expression of tumor necrosis factor (TNF)-alpha, interferon (IFN)-gamma and interleukin (IL)-10 mRNA was elevated in CSF cells from MS patients. IFN-gamma and IL-10 mRNA levels were higher in MS patients than in other inflammatory neurological diseases. mRNA coding for transforming growth factor (TGF)-beta was detectable in the majority of cases, with higher expression in CSF cells of MS and other inflammatory neurological diseases than in noninflammatory controls, and higher expression in PBMC of MS patients than in all other cases. In many MS patients both proinflammatory and immunoregulatory cytokine messages were detected in the CSF compartment without correlation with the clinical activity of the disease. In contrast, mRNA for the costimulatory molecule B7.1 was only detected in the CSF cells of some MS patients, who showed clinical signs of acute relapse at the time of the spinal tap.