Objective: Neurological manifestations of Behçet's disease (NB) are serious complications. However, their pathogenesis remains unclear. The current study examined the levels of proinflammatory cytokines, including IL-1β, IL-6, IL-8 and TNF-α, in cerebrospinal fluid (CSF).

Methods: CSF cytokines were measured using an enzyme-linked immunosorbent assay. CSF was obtained from 17 patients with acute NB, 19 patients with chronic progressive NB and 20 patients with non-inflammatory neurological diseases, including cerebrovascular disease, cervical spondylosis and degenerative diseases.

Results: CSF total cell counts and polymorph nuclear leukocyte counts were significantly lower in the patients with chronic progressive NB than in those with acute NB. The CSF levels of IL-6 and IL-8 were markedly elevated in the NB patients compared with those measured in the control patients. There were no significant differences in the CSF levels of IL-6 and IL-8 between the patients with acute NB and those with chronic progressive NB. In contrast, there were no significant differences in the CSF levels of IL-1β and TNF-α among the control, acute NB and chronic progressive NB patients. Consistently, the CSF levels of IL-6 and IL-8 were significantly decreased following successful treatment in both acute NB and chronic progressive NB patients, whereas the CSF levels of IL-1β and TNF-α were not changed significantly. Of note, the CSF levels of IL-6 were significantly correlated with the CSF levels of IL-8 in the patients with acute NB (r =0.7647, p =0.0003) but not in the patients with chronic progressive NB (r =0.1343, p =0.5835).

Conclusion: These results indicate that CSF IL-6 and IL-8 play important roles in the pathogenesis of NB. However, the data also suggest that the mechanisms underlying the elevation of CSF IL-6 and IL-8 might be different in patients with acute NB and those with chronic progressive NB.