Neopterin is released from monocytes/macrophages specifically by stimulation with interferon-γ. Therefore the increase refers to the activation of T lymphocytes.

Our objective was to examine the potential role of neopterin in the cell mediated immune response to Behçet's disease.

We studied 67 patients of Behçet's disease classified by Shimizu and a control group of 30 normal healthy people. Serum neopterin was detected by radioimmunoassay technique.

The serum neopterin concentration of the group with Behçet's disease was significantly elevated, compared with the control group (6.36 nmol/ml vs 3.63 nmol/ml). The increase of neopterin concentration was well correlated to the clinical severity of the diseases in increasing order.

Our data suggest that the T lymphocyte derived IFN-γ which stimulates the production of neopterin has some role in the pathogenesis and clinical severity of Behçet's disease.