Effect of infliximab in progressive neuro-Behçet's syndrome

Recent studies have shown the beneficial effect of infliximab in ocular manifestation of Behçet's disease. The current studies examined the efficacy of infliximab in progressive neuro-Behçet's syndrome (NB) refractory to methotrexate (MTX). Five male patients with progressive NB with sustained elevation of cerebrospinal fluid (CSF) IL-6 (over 20 pg/ml) despite administration of MTX and steroid, were given intravenous infusion of 5 mg/kg infliximab at weeks 0, 2, 6, and 14 with MTX (10-17.5 mg/week) and prednisolone (<10 mg/day) at the same doses. The clinical responses were judged by neuropsychiatric findings, revised Wechsler adult intelligence scale (WAIS-R), and brain magnetic resonance imaging (MRI) scans at 24 weeks. In all the 5 patients, CSF IL-6 were markedly decreased by 1/2-1/37 on the next day of the first infusion and remained below 20 pg/ml before the last infusion at 14 weeks, whereas CSF TNF-alpha were not significantly changed at any time point. At 24 weeks from the initial infusion, none of the 5 patients showed exacerbation (3 patients significantly improved). Nor did the atrophy in midbrain, pons and medulla on brain MRI scans show significant progression. These results suggest that infliximab might have a beneficial effect in the treatment of progressive NB by reducing CSF IL-6 levels but not TNF-alpha. Since infliximab has been shown to have cytotoxic effects on monocytes/macrophages, the rapid fall of CSF IL-6 after the infusion suggest that infliximab might directly act on such inflammatory cells producing IL-6.