Changes in biomarkers focused on differences in disease course or treatment in patients with neuro-Behçet's disease

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).

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.

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).

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.