Increased nitric oxide production in patients with Behcet's disease: Is it a new activity marker?

Background. The origin of Behcet's disease (BD) is unclear. One of the prominent features of BD is vasculitis and thrombosis as a result of endothelial dysfunction. Because nitric oxide (NO) is synthesized by endothelium, we considered it as an interesting target of investigation in BD. Objective: Our purpose was to define the level of NO in the serum of patients with BD and its relation with disease activity. Methods: As an indicator for NO, serum total nitrite levels (end product of NO) were measured by Griess reaction in 52 consecutive patients with BD and compared with 32 age- and sex-matched healthy staff volunteers. Serum NO levels of active and inactive patients were compared. Results: The overall serum nitrite levels in patients with BD (40.25 +/- 10.51 mumol/L) were significantly higher (P < .001) than those in healthy volunteers (25.09 +/- 5.33 mumol/L). The difference in serum total nitrite levels among patients with active BD (46.74 +/- 10.62 mumol/L) and inactive BD (33.24 +/- 3.73 mumol/L) was significant (P < .001). Significant differences were observed in serum nitrite between patients in the inactive period of BD and the control group (P < .001). Conclusion: Increased NO production might be responsible for the inflammatory process of BD, NO seems to be related to disease activity.