Differential B- and T-cell activation in Wegener's granulomatosis

Background: Autoimmune mechanisms are postulated to play a role in the development and progression of Wegener's granulomatosis (WG), a form of systemic, idiopathic necrotizing vasculitis, Objective: We investigated the relation between lymphocyte activation and disease activity in patients with WG, Methods: B- and T-lymphocyte activation was studied by cytometric assessment of the expression of the activation markers CD38 on B cells and CD25 and HLA-DR on CD4(+) and CD8(+) T-cell subsets, respectively. Activation at the cellular level was related to serum levels of antineutrophil cytoplasmic antibodies and soluble IL-2 receptor, which can be regarded as soluble activation markers of B and T cells. Results: Percentages of CD38(bright) activated B cells were higher in patients with active WG than in patients experiencing disease remission (P < .05) or in healthy control subjects (P < .05), Percentages of activated CD4(+) and CD8(+) T cells were higher in patients with active WG (CD4 subset, P < .0001; CD8 subset, P < .005) than in healthy individuals, An increased percentage of activated T cells of both subsets was also seen in patients whose condition was in remission, as compared with healthy control subjects (CD4 subset, P < .0005; CD8 subset, P < .001). Lymphocyte activation at the cellular level did not correlate with plasma levels of antineutrophil cytoplasmic antibodies or soluble IL-2 receptor. Conclusion: In WG, B-cell activation is related to active disease, whereas T-cell activation persists during remission of the disease, which points to an intrinsic disordered immune system in this disease.