Serum neopterin concentrations in Wegener's granulomatosis correlate with vasculitis activity.

Raised serum neopterin concentrations were found in 13 of 27 patients (47%) with Wegener's granulomatosis. The neopterin concentrations significantly correlated with the Birmingham Vasculitis Activity Score as well as with the erythrocyte sedimentation rate and C-reactive protein. High serum neopterin levels were also associated with infectious complications. The finding of increased neopterin concentrations in patients with Wegener's granulomatosis supports the role of cell-mediated immunity and particularly of activated macrophages in the pathogenesis of the disease.