Sustained monocyte activation in clinical remission of systemic vasculitis.

Monocytes have been shown to be activated in ANCA-positive systemic vasculitis, but their state of activation in clinical remission is unknown.Fifteen patients with a new diagnosis of systemic vasculitis were included in the study. Blood samples were analysed at diagnosis and at clinical remission after three to six months. The expression of adhesion molecules (CD62L and CD11b) on monocytes and the serum concentration of the endothelium activation factor VEGF and the chemokine MIP-1alpha were determined.We demonstrate an increased expression of CD11b on monocytes from patients with acute vasculitis that is sustained in clinical remission. The increased state of activation in clinical remission was accompanied by a decrease in VEGF and MIP-1alpha levels. This generates the intriguing question whether a treatment targeted to normalize monocyte activation in clinical remission would have an impact on relapse rate and outcome in this group of patients with high risk of systemic and renal complications.