Introduction: The aim of the investigation was to determine pleiotropic cytokine IL-6 concentrations in serum and CSF of MS patients, with regard to clinical circumstances.
Material and methods: The study covered 27 MS patients: 23Ð51 years old; in the 2-7 clinical stage according to Kurtzke's Scale; mean 3.6±1.8; disease duration time ranged between 2-22 years. Serum and CSF interleukin-6 were determined by the use of commercial ELISA kits.
Results: Increase of Il-6 in serum of MS patients was found (12.1±1.8 pg/ml) in comparison to the control group (6.6±4.5 pg/ml) (p=0.03). Concentration of IL-6 in CSF of MS patients was 13.4±1.77 pg/ml and in the majority of patients it was higher than in the serum. The highest mean of IL-6 concentrations in serum and CSF have been found in patients at the longer disease duration time, although there were not statistically significant.We have found some degree of dependence between serum IL-6 concentration and the level of disability in Kurtzke's scale.
Conclusions: IL-6 participation in the basic MS immune processes is confirmed by its elevated concentration in serum and CSF, its relation to disease severity with the more expressed rise in cerebrospinal fluid.

Keywords: CSF, interleukin-6-serum, Multiple Sclerosis