Interleukin-6 (IL-6) in patients with Behçet's disease.

We have examined the levels of interleukin-6 (IL-6) in plasma and supernatants of peripheral blood mononuclear cells (PBMC) from patients with Behçet's disease and healthy controls using a sensitive enzyme-linked immunosorbent assay (ELISA). Plasma IL-6 level was not detected in any subjects. The IL-6 concentrations in culture supernatants of patients with active Behçet's disease were significantly high compared with patients with inactive disease and healthy controls. Moreover, we investigated IL-6 gene expression in cultured PBMC from patients with Behçet's disease. IL-6 gene expression was enhanced in active patients compared with inactive patients. These results show that IL-6 may play a role in the pathogenesis of Behçet's disease.