CO-N reaction--a new serological activity index--on Wegener's granulomatosis.

Cordyceps ophioglossoides is one of the Japanese old 'Kanpoh' drugs used for metrorrhagia as a decoction. We found that CO-N, a galactosaminoglycan from Cordyceps ophioglossoides, reacted with sera from patients with some collagen diseases. By using CO-N, we made a new serological activity index (CO-N reaction). In the present study, we investigated CO-N reaction on patients with Wegener's granulomatosis (WG). The aggregation titres of CO-N (CO-N numbers) displayed a possible correlation with their clinical activity. CO-N reaction might also serve an important role in supporting the diagnosis of active WG and in helping to assess the degree of disease activity. The purpose of this report is to introduce this new serological activity index for Wegener's granulomatosis.